Friday, August 26, 2016

Prescribing Glasses for Kids

Common misconception: a glasses prescription isn't a finite, objective number.  We don't use a machine to measure your eye and spit a number that's immutable and definite -- if we did it wouldn't look that great to you, the wearer.  The visual system is so complex, involving not just the eye itself but the muscles in and around the eye and the visual cortex of the brain, that a measurement of the eye is just one component to a successful glasses prescription.  When prescribing for children, doctors are at a distinct disadvantage because the subjective responses of the patient can be unreliable or just plain unusable.  Some kids are shy; some are scared; some really, really, really want glasses. The latter are one of the most challenging because as a concerned parent you might worry something must be horribly wrong; your child can't even see the big E!  And then of course the doctor tells you "nope all fine, no glasses here" to the wail of your child's disappointment.   Today we're talking the art of prescribing for kids -- when to prescribe, what to prescribe, and how to get kids that need glasses wearing them!

via
Don't Under Minus
Parents often worry that their child's prescription is changing too fast, and some may even ask the doctor to cut back their child's Rx so it's not "too strong."  But a prescription that is under minused in school aged children (made weaker on purpose) is much worse for the developing eye than one that corrects vision clearly.  A 2002 study proved that undercorrecting near sighted children by +0.75D caused their eyes to worsen faster than if they were prescribed their full strength prescription. Scientists theorize that the presence of any blurred vision causes children's eyes to change at a faster speed.  Prescribing the full amount to achieve 20/20 vision in near sighted (myopic) school-aged children is the best approach. Remind parents that if their child complains of changing vision in 6 months, go ahead and schedule a follow-up appointment to get things rechecked.  It's better to adjust their glasses mid year to achieve clarity than to let them go another 6 months with blurry vision with that risk of accelerated rate of myopic progression.  For more on myopia control check this post.

Don't Over Plus
It's normal for especially young children to be farsighted (hyperopic).  Studies show the average newborn has just over 2.00D of hyperopia and the average 2 year old has just over 1.00D.  The range of acceptable variability where a child would still be expected to have normal visual function is wide. When to prescribe?
For 1- 4 year old patients prescribe if Rx > +3.50 D; Cut Rx by 1.00D
For 4-5 year old patients prescribe if Rx > +2.50 D; Cut Rx for 1.00D
For 6 and up prescribe if Rx > +1.50 D or if pt is symptomatic; no cut in Rx necessary

It's important to cut back the prescription in young hyperopic patients to encourage the chance that the patient's eyes will normalize to zero as they continue to grow (called emmetropization).  By age 6 research suggests emmetropization is pretty much over, which is why you no longer have to cut the Rx down.  As a general rule, a school aged child with great visual acuity, normal binocular and accommodative function and no complaints is likely doing great without glasses, even if they have a low hyperopic prescription.

Correcting Astigmatism
There are few things in vision more normal than astigmatism. In fact, 69% of infants are born with over 1.00D of astigmatism.  Most kids born with astigmatism undergo rapid improvement by the time they are four years of age, so prescribing for astigmatism in young children is not usually necessary. If astigmatism is still present by school age years, however, it can begin to have a big impact on classroom performance.  A 2016 study showed that correcting the prescription of kids with high amounts of astigmatism (3.00D or more) immediately improved their reading fluency by an average of one grade level. 
For patients under 2 prescribe if astigmatism > 2.50 D; Cut cylinder Rx by 50%
For 2-4 year old patients prescribe if astigmatism  > 2.00 D; Cut cylinder Rx by 50%
For 5 and up prescribe if astigmatism > 1.50 D or if pt is symptomatic with lower astigmatism; no cut in Rx necessary

Astigmatism can make it difficult to distinguish letters or numbers, especially in higher grade levels where the font size gets smaller. via
Exception to these rules: when the eyes have big differences in their prescription (called anisometropia) and amblyopia (lazy eye) or strabismus (eye turn) is developing, then prescribing the full amount of prescription even in very young children becomes important to achieving the best possible outcome. 

Check for Accommodative Dysfunction
It's easy to think a child that has no prescription but won't read the chart is malingering (the polite doctor term for faking it).  Glasses these days are the cool thing to have, and sometimes when a child's friend gets glasses it becomes mission number one for your child to have glasses too.  But sometimes a child might have no real distance vision issue but won't be able to read the chart for a true medical reason.  I always do a quick and easy accommodative test (NRA/PRA is a go to for responsive kids - MEM Retinoscopy on younger) to rule out accommodative dysfunction.   If a child has accommodative dysfunction, they won't be able to see clearly in the distance because their focusing system is "locked up" at near.  Their eyes won't be able to adjust back and forth between distance and up close, so distance looks blurry.  Referral for vision therapy is a great solution for kids suffering from this issue, and sometimes progressive glasses can help the eyes adjust more easily from near to far.  

When to prescribe progressives for myopes? For a few years it was a commonly discussed theory that prescribing progressive glasses for near sighted children could help reduce how quickly their vision worsened year to year.  The COMET study proved that prescribing progressive or bifocal glasses for controlling nearsightedness had no benefit in children with normal focusing systems -- prescribing progressive glasses in a normal nearsighted child did NOT slow down the worsening of their myopia. But in myopic children that have accommodative dysfunction, progressive glasses do help. Prescribing for the right patient can make a difference.

Don't Forget Safety and Sun Protection
Did you know that kids are the most at risk for ocular sun damage?  In fact 25% of the sun damage that occurs in a person's lifetime happens before age 18.  Sun damage in the eye is responsible for potentially fatal conditions like ocular melanoma, but also diseases of the eye we associate with aging like cataracts and macular degeneration.  Those conditions don't develop due to the sun damage we get when we're 80; they're a result of the sun damage we started getting as children.  That's why prescribing sun protection in children's glasses is so important.  Transitions lenses allow kid's glasses to be 100% UVA and UVB protective without kids having to keep track of multiple pairs -- a win for kids and parents both.


A huge trend in kids eyewear the last few years is wearing rec specs for full time glasses wear.  The sporty appearance make kids feel more confident than the traditional round metal frames many kids get fit in with dread.  photo via
Another major risk for children's eyesight is injury, especially if they play sports.  90% of all blinding sports-related eye injuries in America could be prevented if the child had been wearing protective eyewear. Shatter resistant lens materials like polycarbonate and trivex are essential for kid's glasses both on and off the field to protect the eye from potential injury. 

And don't underestimate the way that a child's self esteem can be tied to their perceived appearance. I always encourage parents to let their child lead the selection process for their glasses when they enter school age years.  Their glasses need to be a part of their identity that they like; not only will the chance that they actually wear their glasses go way up, but higher self esteem is associated with higher academic performance as well!

Monday, August 15, 2016

Rethinking Refractive Tech

A few weeks ago we got the not so surprising news that Opternative, the online refraction technology that's seen significant legal battles over the past few months, is now partnering with 1-800 Contacts to offer online contact lens prescription services.  Not a surprise that a partnership would blossom between these two companies since they seemingly share a desire to avoid patients entering a doctor's office at all, but still, I have to admit when I read the news I took it with a morbid sense of pseudo-shock.  Despite legislation making Opternative illegal in 3 states (Georgia, Indiana, and South Carolina), in today's world, tech business deals can move much quicker than our own legal system. And if you feel like you've been bombarded by new technologies attempting to replace traditional refractions, you're correct.  This past year has seen not just Opternative, but portable refraction technology from Eyenetra, and  SVONE PRO by Smart Vision Labs also enter the "subjective autorefraction" marketplace.  Five years ago when I was wrapping up my optometric medical education at the Southern College of Optometry, if you would have told me that in just a few more years patients would be offered prescriptions right from their home computer, I wouldn't have believed you.  It seems so reckless, so impractical, so insane.  But that's just an eye doctor talking; to the general public, it's obviously not so dangerous sounding.  And that's where the problem lies.

Head here to download or subscribe to our podcast and listen to this week's episode!

This week Dr. Darryl Glover and I got a chance to sit down with Vitor Pamplona, the designer and founder of Eyenetra for our new optometry podcast, Defocus. I was expecting to talk to someone who would be casually dismissal of ocular health exams, who didn't understand that refractions and vision correction often had nothing to do with the actual health of a patient's eye.  What I found was a man who not only had an far-reaching command of the physics of our eye's optical system, but an impressive understanding of the healthcare issues facing the introduction of new tech like his.  Vitor is clear he has designed software that is not a replacement for a doctor, and that the NETRA is marketed as nothing but a portable auto-refractor.

"How many prescriptions has Eyenetra written in the United States and worldwide?" Dr. Glover asked him during our interview.  

"None" Vitor replied.  

His tech doesn't write prescriptions; doctors write prescriptions.  He paints a picture of a doctors using the Eyenetra smartphone-powered autorefractor just like any other work up test currently used in office, with the doctor choosing to additionally perform a phoropter based refraction to verify results.  His pitch is if you can speed up refraction with his system, you can see more patients or spend more time on what really matters, the ocular health assessment and discussion.  He talks about using this system remotely for mobile clinics, concierge care, or in areas or countries where the access to healthcare is limited.  He talks about a future where patients with conditions like diabetes might even have an Eyenetra device at home; not to get their own prescriptions, but to check themselves regularly for Rx changes that could mean they need a trip to the doctor sooner for better blood sugar control than their yearly comprehensive.  His vision is one that doctors would struggle to find fault with, but I had to remind myself during our interview that this is the same company that I saw illustrations circling on the internet for auto-refractor stations in a prominent online glasses retailer where patients could sit on couches sipping a latte during their refraction.  No doctor; no exam room.  It's a future that is easy to envision too; insanely lucrative for both the tech companies behind these inventions and the online and big box optical retailers that could offer in office Rxes without having to employ a doctor on site to do so.

Could you refract yourself and order a drink at the bar at the same time? Oh wait, that bar is really an optical display.
Vitor understands that replacing ocular healthcare with only refractive care is not in the best interest of the patient, but he points out that it's optometry that has failed patients if there is a concern that patients would chose to skip a health exam. I'm sure not many ODs are going to take his idea of spinning off a new name for ocular healthcare providers, separate from the title of optometry, in order to rebrand our profession's image in the minds of patients, but the truth is, maybe we need a disruptive outside voice saying that optometry has a problem that we aren't successfully fixing.  Our problem isn't new technology entering the marketplace; our problem is what patients think about what we do (glasses prescriptions, right?) and why they should care (they can see fine, so of course their eyes are healthy, right?).  As a profession, we have been able to dilate our patients and assess and treat ocular health since the 1970s, but due to a complex history of propaganda from outside groups and in a not-so distant past even our MD colleagues, our public image has never expanded fully to that of comprehensive ocular healthcare providers, despite the fact that's what we've been doing since PCO first handed out the Doctorate of Optometry title in 1923.

Vitor Pamplona with the NETRA auto-refractor device
I entered this interview thinking I was going to skewer Vitor for creating a product that is a public health risk (very nicely, politely, and enthusiastically based on the sound of my voice on playback apparently). Instead, I realized that the problem isn't his product; it's me, it's all doctors -- optometrists and ophthalmologists.  We are the ones that write the prescriptions, and in the US, prescriptive medical devices like glasses and contact lenses require our signature.
  • Ethically, is it in our patient's best interest to perform a refraction (either in person or remotely) without assessing ocular health?  
  • Ethically, is it in our patient's best interest to give them a contact lens prescription without actually assessing if that contact lens fits properly on the eye or if the patient has corneal health issues putting them at risk for significant vision loss with the wrong type of contact lens (I'm looking at you Opternative!!)? 
As a doctor, we're educated that we should never, ever give a prescription for anything without assessing my patients' ocular health (or getting records proving they've had that done within the last year), and I'm wondering, what doctor would? Who are these doctors who would sign an Rx for any medical device without assessing ocular health themselves or verifying that health had been assessed by another doctor within a year's time?  We're all worried about refractive tech confusing our patients into thinking their eyes are healthy when they haven't even been checked, but it's doctors that would be to blame if a medical condition was missed. It's that doctor who compromised and offered refractive care without ocular healthcare who is at fault when a condition goes undiagnosed, maybe even blinds or kills someone -- no, I'm not being extremist.  So as doctors, I ask you to think about what you do and why you do it.  A prescription is more than just a print out from an autorefractor; it's your signature that you have evaluated this patient and given them your care. Stand for something bigger than your paycheck; stand up for those millions of Americans with undetected glaucoma, early retinopathy or retinal diseases, or even ocular tumors -- conditions that in early, treatable stages aren't going to present with any vision issues on a refraction.  You won't find these conditions if you don't look for them. And looking for them, that's our job. We have to claim this new autorefracting technology and all new tech innovations for what their true place is in the role of our exam.  The tech is not more than us; it isn't an exam but just a tool, and it can't operate to give anyone a prescription without us.  None of this new tech bypasses a doctor or bypasses an ocular health exam; only a doctor can chose to bypass an ocular health exam.  So I ask you, use this tech like it was designed.  It's a refractive tool to aid in your exam.  It's not an exam.  It doesn't even pretend to be an exam. The only person in the room that can make it replace an exam is you.

I encourage all of us to think about our part in the future of our profession, and act now as a group to legislate ourselves about what is required of a doctor to give a prescription for glasses or contact lenses.  We should all have personal ethics keeping the best interest of our patients in mind, and we should legislate and define those ethics in our own professions. Optometrists and ophthalmologists can legislate what's required for a prescription so no loopholes exist for a doctor that might be willing to compromise their personal ethics for a paycheck.  The technology doesn't control our profession, our pens, or our patients.  We are the caregivers, and the prescription is our care.  What does your prescription stand for?

Wednesday, August 10, 2016

Upgrading to Multifocal and Toric IOLs

In today's world, cataract surgery is typically met with excitement moreso than dread. Why? Many patients have been waiting for years to be more independent from glasses and contact lenses, and the intraocular lenses (IOLs) used after cataract removal can greatly reduce their need for glasses after surgery. If you or a loved one is undergoing cataract surgery, the choices for IOL designs can be overwhelming. Do you want multifocal implants, to help you see with a range of vision both near and far? Do you need toric implants to reduce your astigmatism and limit the chance you'll need glasses for clear driving vision? These options exist, but they are options you have to choose to pursue out of your own pocket. Insurance only covers standard implants--they won't correct your reading vision, and they won't correct moderate to high amounts of astigmatism; you will need glasses after cataract surgery for a majority of your visual needs with a standard implant. How do you know if pursuing premium IOLs is worth your investment? Your cataract surgeon and your personal optometrist that is comanaging your care can walk you through the best choices for your individual needs. Today we're bringing you the basics courtesy Dr. Dawn Williams, an optometrist at See Clearly Vision who routinely provides pre- and post-operative cataract care, and Irina Price, their surgery coordinator.



What can a patient expect with a successful multifocal IOL after surgery? Success, from my perspective, is defined as increased functionality and decreased dependence on spectacles and/or contact lenses. I would suspect we are about 95% successful. Patients have to know that they will still need to use glasses sometimes; reading small print, reading in dim lighting, perhaps even for crystal clear driving vision. Success is highly dependent on setting realistic expectations prior to surgery. Preparing a patient for real expectations is a combined effort of every staff member who meets with the patient. From the surgeon, to optometrist to surgical counselors. This is where surgical counselors can play a big part in helping patients understand their expectations in comparison to their goal or surgical outcome. It is important for each patient to understand that the goal is to reduce dependency -- not eliminate the need for glasses. When a patient selects a multifocal they expect to be glasses free, however, when they’re sitting down at the sewing machine or trying to remove a splinter from a grandchild’s hand, they need to be educated that they may need assistance with reading glasses for these high visual demand situations.

Multifocal IOLs have rings of distance and near vision to achieve a range of vision near to far. via

Are there any side effects with multifocal IOLs?
The possibility of halos at night are a negative side effect of multifocal IOLs due to their multiple ring design. Halos and glare aren't a big issue with the other type of near focusing implant, accommodating IOLs, but these implants tend to have more trouble with unclear near/reading vision. The implant has to move within the eye, and if the patient's ocular tissue doesn't adequately support this movement then reading vision will be limited. This is something that doctors can't really screen for, which is why there is such variability in the success rate of accommodating IOLs. This is where every doctor and eyecare provider who comes in contact with the patient needs to be educating the real expectations for what each implant can and can't do. Here's an example of our dialogue:
“Mrs. Smith, a multifocal is going to give you a range of vision, however, the goal is to reduce your dependency on glasses. That being said, you still may need reading glasses for doing fine hand work or to correct residual astigmatism at distance”.

Accommodating IOLs have to flex within the eye to focus your vision between near and far.  The range of vision achieved post-operatively depends on the anatomy of the patient's eye and how much flexure is accomplished. via


Can someone with high astigmatism or high prescription have multifocal IOLs?  Or are there certain Rxes that are just not possible for this type of lens?
High amounts of cylinder (astigmatism) or highly ametropic (high prescription) patients are not excluded from having premium lenses unless they have corneal scarring, retinal pathology, or amblyopia. As long as the necessary IOL is within the range of available lenses, even in cases where the IOL would leave some residual refractive error, if it will reduce the patient's dependency and increase functionality it may be a good option. Patients with a high risk of residual prescription need to understand though that for their best vision they will still need glasses; these implants will reduce their need, but they won't give them crystal clear vision.

What conditions would prevent a patient from being a good candidate for multifocal IOLs?
Corneal scarring, retinal pathology like diabetic retinopathy or macular degeneration, and amblyopia (lazy eye) are a few things that would preclude a person from a premium IOL. Both eyes have to have a high level of function to be successful in these implants. The ring design of a multifocal IOL can greatly increase your risk for glare or halos at night or in dim lighting, so if the retina or cornea has a condition that causes visual distortion, the chance that the patient will be visually successful in this implant is very low. In the process of assisting patients in selecting their IOLs, physicians are able to guide patients towards certain lenses based on their overall ocular health. During the pre-op surgical evaluation, the doctor carefully examines the retina with dilated views and OCT imaging, and performs corneal topography for prospective multifocal patients; these results will help guide a patient towards, or away from, a premium IOL.

What's hiding behind that cataract? A thorough retinal examination is needed to make sure each patient is a good candidate for premium IOLs.  
When do you recommend monovision implants (one eye set for reading, one eye set for distance) versus multifocal (both eyes see a range of distance and reading) IOL implantation?
The most successful IOL recommendations are made based on the patient's prior visual correction and their goals. If a patient has had monovision before in their contact lenses with good success, it's generally very easy to achieve success with a monovision IOL surgery. But if a patient has never worn monovision before, it is not their best choice. It's very difficult to demonstrate monovision with the presence of a cataract in one or both eyes, so the patient won't be able to try it out in contact lenses prior to surgery in most cases to know if they like it or not. If a patient has not had monovision in the past, we would like recommend presbyopic (multifocal or accommodating) IOL

When do you recommend toric (or astigmatism) IOLs?
A good candidate for a toric IOL will have a cylinder power of -1.25 to around -5.00 diopters.


When do you recommend Laser Assisted cataract surgery?
Laser-assisted cataract surgery is FDA approved for the treatment of low amounts of astigmatism, with a maximum correction of up to -1.50 diopters. It can also be beneficial in patients with very dense cataracts or corneal endothelial disorders (Fuch's Dystrophy). It’s important to remember that the goal of laser-assisted cataract surgery is to help reduce patient dependence on glasses following surgery. Patients who have worn contact lenses all their lives may be more inclined to select laser-assisted cataract surgery to reduce their dependence on eyewear as that is the goal of contact lenses in the first place -- to reduce your dependence on glasses. As a surgical counselor, I find that many contact lens patients are excited at the thought of less dependence on contacts and glasses after surgery.

What should optometrists referring their patients for cataract surgery talk to their patients about before the referral?
Discuss the possible IOL options and realistic expectations for what premium IOLs can do; as an optometrist you've been caring for your patient for years and know their personality and needs better than anyone! Many patients that are referred to our offices have been utilizing the benefits of monovision for years. It is beneficial if the referring OD is able to discuss with the patient whether or not they would like to maintain monovision following surgery as well as provide the contact lens prescription the patient has worn in the past to achieve success.

When an optometrist takes over the post-operative care for their patients after premium IOL implantation, are there any common patient issues with these types of lenses that ODs should be familiar with or know how to troubleshoot?

Reassure the patient that vision after multifocal and accommodating IOLs keeps changing and improving after surgery. For most, the best vision will be achieved about 4 weeks after surgery, so don't panic if the vision is not quite perfect at the 1 week post-op. The brain needs time to learn to use it's new vision, and there is still healing going on from the surgery itself in the first few weeks, so we don't expect perfect clarity right away. Always remind pre and post-operative patients that healing takes time, patience and rest. Having worked as a technician and surgical counselor, I’ve often been known to remind patients that if they had knee surgery they wouldn’t be up running a marathon the next day so they need to give their eye the same amount of time to heal. It helps remind patients that they need to be realistic about healing and not consider their cataract surgery to be providing them with a bionic eye.

Check out Dr. Williams, Irina Price, and the whole See Clearly Vision team at their website and on their Instagram account to learn more.

Sunday, July 24, 2016

Scleral Lens Fitting: Selecting and Evaluating Your Initial Lens

Since the mid 2000s, no other type of contact lens has seen more growth and excitement than scleral lenses.  In last year's annual contact lens trend report from Contact Lens Spectrum, doctors reported fitting scleral contact lenses more than both rigid gas permeable toric and multifocal lenses, with sclerals making up 3% of all contact lenses being fit (including soft, hybrids, and RGPs) in 2015. Why sclerals?  The larger contact lens size makes for more stable vision and improved comfort over traditional small diameter RGPs, ideal for irregular corneas, high astigmatism, and conditions like keratoconus.  Breaking into the world of fitting scleral contact lenses can have a sharp learning curve, so I strongly recommend attending courses like those offered from the Scleral Lens Education Society, Blanchard, and Vision By Design.  Once you feel ready to get started, the fitting set arrives and it's time to put lenses on your patient.  What to do? We're talking initial lens selection and evaluation in today's post!

Choosing the Right Diameter
There are a ton of scleral contact lens options out there, with common diameters ranging from as small as 14.3 mm to over 18 mm.  The truth is, lens diameter selection depends on your patient. Smaller lenses are typically easier to fit, especially on corneas with lower amounts of irregularity. Advantages of smaller diameter lenses include:

  • better oxygen permeability (smaller lenses can be fit with less central vault, meaning better oxygen exchange through the tear film)
  • easier patient handling
  • easier removal (smaller lenses will fit flatter in general so will have less suction with removal)
  • avoiding scleral toricity  --- The white of the eye (sclera) tends to have more of it's own innate astigmatism as you venture more peripherally from the limbus.  The larger the scleral lens you are fitting, the more likely you'll have to use  toric peripheral curves to achieve a good fit.
  • minimize fogging -- larger lenses tend to have more issues with lens fogging, theoretically because they are interacting more with the conjunctival goblet cells that produce mucin
Proper lens diameter should clear the limbus by 2-3mm on either side.  The lens above shows inferior fenestration which isn't used by many doctors these days -- at one point fenestrations were popular to improve oxygen transmission.  These days, doctors change their fit to improve oxygen transmission by minimizing their central and limbal vault (see below).  via
Select a lens that is about 5 mm larger than the patient's cornea.  You want about 2-3 mm of lens clearance over the limbus in every direction.  Almost 90% of the time I fit the 15.6 mm diameter Jupiter Scleral from Essilor, but there are options to size up or down as needed.

Choosing the Right Vault (Corneal Clearance)
When sclerals first began being popularized for irregular corneas in the early 2000s, we fit them a lot differently than we do now.  Back then it was large diameter and deep vault (maybe 400 microns or more).  But very quickly doctors learned that fitting with that much lens vault creates a potentially tight fit (meaning much more difficult for the patient to remove at night) and can drastically reduce the oxygen transmission through the lens. The more tear film between the lens and the cornea, the less oxygen trransmissibility you'll get.  Ideally, you want between 150 and 200 microns of central corneal clearance 30 minutes after the lens is placed on the eye.   So yes, we are at a disadvantage as clinicians because we often see patients right after they put lenses on their eyes.  Studies show scleral lenses settle down by about 80 microns through the course of the day.  Therefore if you are evaluating a lens right after insertion, you ideally want about 250-300 microns of central clearance to get that perfect fit after settling.

How do you assess central clearance?  Fill the lens with nonpreserved saline and a swirl of NaFl dye.  You can judge the central clearance of the lens by comparing the tear film thickness (green above due to the NaFl dye) to the corneal thickness on your slit beam.  Knowing the average corneal thickness is about 550 microns, you have a predictable judge of  tear clearance.  In the picture above, the tear clearance is almost as thick as the corneal clearance, so I would grade this around 450- 500 microns of clearance.  This is TOO MUCH!! Photo via
Of course, if you have an OCT you can image the exact amount of corneal clearance with an anterior segment scan. via
How do you get in the right ballpark for this perfect amount of clearance when starting with your fitting set?  Select an initial lens based on your patient's flat K.  
  • For example: your patient has a flat K of 44 diopters.  Your first lens to try on should be around a 7.67 mm base curve (select the closest thing in your fitting set).  You can find a diopter to base curve conversion chart here
  • Need more or less central clearance? As a rule of thumb, changing base curve by 0.1 mm will give you about 35 microns of vault.  Steepening the lens gives more vault; flattening the lens gives less.

Assessing Limbal Clearance
Once you are happy with the amount of central clearance you have, you still need to assess the periphery of the lens.  At the limbus, you ideally want 30-40 microns of clearance to achieve good oxygen permeability.  A great way to assess clearance is to insert NaFl dye in the lens before insertion,  You should see a faint band of dye at the limbus -- just barely there.  Bubbles here mean the lens has too much limbal clearance; touch means not enough.  

Want the perfect limbal clearance? You should just see a faint hint of NaFL dye right at the limbus with the perfect fit of 30-40 microns.  Of course, you could also use an OCT to assess this area if you have access! via
  • Need more limbal clearance? Increase the lens diameter will achieve more limbal clearance without changing your central vault
  • Too much limbal clearance?  You can decrease lens diameter, but likely if you have too much limbal clearance you have too much central clearance as well and you can solve the issue just by flattening your central base curve
Assessing Periphery
The edges of the lens are important for comfort and ease of removal.  We've all seen pictures of a tight edge causing blanching of the conjunctiva.  Assessing the lens after it's been on the eye for about 30 minutes will help you detect signs of blanching and reduce the risk of the lens binding down after the patient takes it home.  Make sure you assess the peripheral edges, central vault, and limbal clearance with the patient looking in central gaze.  When the patient looks up or extremely to the sides, you may see some changes to the clearance and especially the edges as the lens relationship with the sclera changes.  Central fit is the important characteristic to evaluate!

If the edge of the lens is too tight, you'll see blanching of the conjunctival vessels in as little as half an hour.  This will cause severe discomfort and binding of the lens when the patient attempts removal.  Before sending the lens home with a patient, make sure you check the edge carefully to ensure that the conjunctival vessels are passing underneath the edge of the lens freely, without any pinching or thinning. via
There are a few tips based on the patient's comfort that can help you troubleshoot improper edge fit:
  • "My eyes are red after a few hours"  Likely this is a tight edge lens.  Tell the lab to flatten the edge
  • "I can feel the edges"  Likely this is a flat edge, causing some fluting of the lens as it lands on the conjunctiva.  Tell the lab to steepen the edge.
Selecting Material
There are a ton of great materials that you can chose for scleral lenses, just like you have available in traditional RGPs.  My personal go-to is Tyro 97 -- high oxygen transmission and low risk of surface filming or fogging with a proper fit. 

Once you've found an initial lens you like, over refract and place your order!  Need more scleral lens advice? 



Sunday, July 17, 2016

Meet Xiidra: The Newest Dry Eye Therapy

The last time a medication was approved for the treatment of dry eye syndrome? October 2003.  That medication was the blockbuster Restasis, still commanding the dry eye marketplace 13 years later. Over those 13 years, we've learned a lot more about dry eye and the 16 million Americans that are diagnosed and treated for it every year.  They suffer from symptoms like burning, watering, redness, blurry vision, and tired eyes. For many, even the best medical care available on the market is not enough to overcome their discomfort.  That's why the world is so excited for a new medication on the market.  Shire's Xiidra was FDA approved on July 12th for the treatment of the signs and symptoms of dry eye disease (Restasis is FDA approved to treat the signs of dry eye disease only). Slated to become commercially available this fall, there's still a lot about Xiidra that patients and eyecare providers don't know. We don't know the cost, we don't know exactly how patients will respond in our offices, we don't know how Xiidra will compete with Restasis, and we don't know how insurance coverage will look.  Here's what we do know so far:

via


What It Is:
Xiidra (lifitegrast 5%) is a non-steroidal anti-inflammatory eye drop, treating dry eye by disrupting the inflammatory cascade responsible for much of the discomfort and ocular surface changes associated with dry eye disease. It specifically targets intracellular adhesion molecule 1 (ICAM-1); Xiidra binds to proteins on the surface of white blood cells (leukocytes) where ICAM-1 would typically bind, thus blocking ICAM-1 from being able to attach and signal the inflammatory cascade. When ICAM-1 molecules bind to leukocytes, they signal T-cells (the body's main inflammatory cell unit) to the area.  Xiidra prevents this binding, and thus T-cells aren't signaled to migrat to the ocular tissue.  What does blocking the inflammatory cascade mean to you? Inflammation is what makes dry eye so miserable - redness, burning, and surface cell damage (called superficial punctate keratitis -- basically dried out corneal cells sloughing off the cornea creating symptoms like sharp pain and blurry vision).

Superficial punctate keratisis: when corneal surface epithelial cells dry out, the cell wall break and they begin to slough off.  The process can cause you to feel sharp, shooting pain and chronic discomfort and visual fluctuations. via

What It Does: 
In the clinical trials that earned Xiidra FDA approval, over 1000 people with dry eye disease were treated with Xiidra over the course of 12 weeks and the results were compared to placebo treatment. Patients being treated with Xiidra showed statistically significant improvement at Week 6 and Week 12 as compared to those on placebo eye drops in both the signs and symptoms of dry eye, as measured by a subjective symptom scoring questionnaire called the Eye Dryness Score (EDS) and inferior corneal staining (see superficial punctate keratitis above).

How It's Used:
  • Like Restasis, Xiidra is dosed 1 drop in both eyes 2 times a day.  
  • Clinical trials suggest that Xiidra will begin improving both the signs and symptoms of dry eye as early as 6 weeks into treatment, much faster than Restasis whose clinical trials showed improvement in signs of dry eye (judged by Shirmer score) at 6 months versus placebo.  
  • Xiidra and Restasis both target the inflammatory cascade, but they do not target the same molecules so there is no scientific data that suggests they could not be used in combination. 
  • Xiidra is pregnancy category C (meaning it was not tested for safety)
  • Xiidra is approved for ages 17 and up
  • Xiidra is not approved for use with contact lenses; you must remove contact lenses before insertion and wait 15 minutes before reinserting them.
  • Side effects of Xiidra: 
    • 5-25% of users experienced burning with drop insertion, altered or bad taste (called dysguesia), and blurry vision after insertion
    • 1-5% of users reported adverse reactions of ocular redness, headache, watering eyes, runny nose, and ocular discharge
What We Don't Know:
Now that Xiidra is FDA approved, Shire has the task of setting the price for the medication and working with government and insurance coverage. Cash price for competitor Restasis is currently over $400 for a 30 day supply when using 2 vials a day. Analysts expect Xiidra will be priced similarly.  There is debate that Xiidra may try to come in slightly lower to directly compete with Restasis, but there are also analysts predicting Xiidra will come in slightly above Restasis in cost since they have a significantly faster method of action and Xiidra is also approved to treat the symptoms of dry eye while Restasis is not. 

Stay tuned as more information become available we will continue to report on this exciting new treatment option!

Sunday, July 10, 2016

What's Trending in Optometry? Dr. Jackie Garlich and 20/20 Glance

Does your desk have stacks of optometry magazines dating back to your graduation year that you insist you'll read -- eventually? Is your email full of unopened blasts from your favorite digital optometry subscriptions?  And (the horror!) you haven't even gotten around to reading the latest Eyedolatry post yet? We live busy lives, and between patient care and families at home, most ODs are completely spent when it comes to spending precious free time reading about optometry.  So instead of reading a full article, wouldn't it be great to get just short, to the point little blurbs about the most exam-room worthy topics of discussion from the past week? Stories curated by an OD that will impact how you practice and what you can tell your patients about new innovations?  This beautifully simple idea is from Dr. Jackie Garlich, the mastermind behind 20/20 Glance.


As an undergrad, Dr. Garlich wasn't sure what path her future would take.  "I had a degree in Agriculture but apparently I learned nothing because I still killed all my plants."  She moved to Central America for a year to figure out her next step in life, and while there, she volunteered at an eye clinic.  "I liked that you could have such an immediate effect on patients' lives with something as simple as updated glasses.  It seemed to be a rewarding profession and since I already had a thing for science, we were a good match!" She went on to graduate from the New England College of Optometry and completed her residency at the St. Louis VA Medical Center.

Why did you start 20/20 Glance? 
It's our responsibility as clinicians to keep up with relevant optometry news but, for me, it always seemed challenging to do that.  I felt guilty looking at the stack of journals I wanted to read but never got around to reading at night because I was exhausted from the day and a new episode of Scandal was calling my name. When I asked colleagues how they kept up, most said, "I don't".   But you know what I did have time to do?  Shut off my morning alarm, roll over and read a few emails before the day started.  So I drew my inspiration from theSkimm but put an optometry spin on it.  It's an email that takes less than five minutes to read and has a rundown of relevant optometry news for the past week along with article summaries of things your patients might ask you.


How do you choose the topics you feature in 20/20 Glance each week? 
The main question I ask myself when I read an eye-related article is, "is this clinically relevant"?  Can I apply this or talk about this with my patients? If not, I leave it out.  

What's your vision for the future of 20/20 Glance? 
I want 20/20 Glance to be known for providing consistent, reliable, easy to read updates in optometry.  I have grand plans on how to expand on the delivery of this clinically relevant information but because 20/20 Glance is still new, I'm taking it one step at a time!

Any advice for new grads, current optometry students, or those considering our profession? 
  • Find yourself a good mentor. Someone you can ask for help on cases (even after you graduated), negotiating work contracts when you are looking for a job etc.  If you've found a good one, their input is invaluable. 
  • Ask questions.  Ask a lot and often.  No one expects you to know everything and you learn so much by asking.  There is always someone who knows more than you, so buy that person a coffee and pick their brain.
  • Be active in leadership in school. Join a student council; volunteer with SVOSH.  Leadership takes practice and you will be expected to be a leader in the future so start developing your skills now.
  • Strongly consider residency. I absolutely recommend it. I wanted to work in an MD/OD setting and I knew that a residency would make me more valuable to a potential employer.  I really loved my VA internships and ocular disease so I knew I wanted to do a residency in the VA system.  I remember thinking I was so smart when I graduated from school but then I saw my first disc edema patient, that confidence quickly faded and was replaced by excessive perspiration as I sprinted to find help.  So yeah, residency made me a lot less sweaty with challenging cases.
Head on over to 20/20 Glance to start receiving your weekly emails, and you can follow Dr. Garlich for more optometry news on social media:

Monday, July 4, 2016

5 Biggest Mistakes You're Making When You Buy Sunglasses

With all the glories of long days, barbecues, and beach trips full upon us, sunglasses are practically a wardrobe staple for most Americans.  If they aren't, let me be the first to say you are definitely doing it wrong.  But for many, even when you are actively trying to protect your eyes from sun damage (which includes yellowing growths on the eyes and the risk of blindness as you age), you may be unwittingly putting your eyes at risk by investing in the wrong sunglasses.  Not all sunglasses are created equal, so avoid  these common mistakes to make sure you are actually wearing glasses that give you true UV protection:
  • Too Small  Sunglasses need to give your eyes and eyelid skin full protection.  That means coverage from brow to cheek.  If light can easily enter from above or the sides of your sunglasses, your delicate eye and eyelid skin is still unprotected and at risk.  Luckily oversized frames have been stylish for years, but I'm seeing smaller frames sneak back in to the market lately and they just aren't as safe.
Rihana in Miu Miu frames.  Light can easily enter over the top of her sunglasses to damage the eyes.  Likely with a larger frame or even just a better adjustment to make these frames sit higher on her bridge, they'd offer significantly better protection.  via
  • Too Dark Surprisingly often, when I bring sunglasses up in the exam room I have patients tell me they can't wear sunglasses because they just can't see through them.  They feel like their vision is too dark or dim.  Dark grey sunglasses with poor optical quality can absolutely dim and decrease vision, but if that same person were to try a brown or sports performance tinted lens with polarization, their level of vision is going to blow them away.  I often wear my brown polarized sunglasses while driving in pop-up rain showers or on slightly cloudy days because the contrast provided through this color tint gives me even better vision than if I were wearing nothing at all.  
  • Not Actually UV Blocking A dark tint doesn't mean your glasses are protective!  This is a common misconception, and patients will think that $5 drugstore glasses are the same as what they can get with an optical grade lens.  Yes, it's true you can get inexpensive sunglasses with 100% UV protection, but you have to make sure they have a sticker verifying they meet that 100% UVA and UVB coverage.  No sticker; please don't waste your money. Anything you purchase in an optical won't just be 100% UV protective, but the clarity of vision through an optical grade lens material is going to provide unparalleled clarity while you're enjoying the outdoors.
Examples of various stickers that will be on over the counter sunglasses to demonstrate safety.  If your $10 glasses don't have this sticker on them at the time of purchase; leave them at the store!! via
  • The Wrong Wrap Wrapped frames offer fantastic protection from sun and wind, and are excellent for athletes to protect their eyes from sun damage from all sides.  While wrapped frames are excellent for non-prescription eyewear, if you wear prescription sunglasses you may run into issues. High prescriptions, progressives, and especially those with astigmatism can have extreme distortion in a wrapped frame. An eyecare specialist can help find a frame that will work with your specific prescription to make sure you don't get that terrible fishbowl effect in your vision.  Not all prescriptions will work in all frames and you need an expert to help find the match for you!


Wrapped frames offer unparalleled protection, but might not be an option for your prescription (see the fish bowl effect on the lens to the left). via


  •  Mirrored Lenses There's not much trending bigger than mirrored lenses these days, but they can potentially have issues.  Think about what a mirror does: it reflects light.  As a side effect, your vision will be dimmer in a mirrored lens than in traditional sunglasses because more light is being reflected off your glasses and less will enter into your eye.  Another potential risk? As light reflects back off your mirrored lenses, light rays will rebound outwards, with some of these reflecting back onto your nose.  Make sure you wear sunscreen outdoors, especially protecting your nose area to reduce your risk of sunburns or skin cancer. 
    I love the way mirrored frames look too, but think about where that light bouncing off your glasses might reflect. Sunscreen on your nose is really important when wearing mirrored sunglasses, especially on the water where you'll be getting reflections from all angles (both above from the sun and below bouncing off the pool, lake, or ocean).  via

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