An Introduction to Scleral Contact Lenses3:47 PM
|A typical RGP (gas permeable lens above, compared to the larger scleral |
lens below via
The first time most people see a scleral contact lens, the immediate response, is "wow, that's big." The size of a scleral contact lens can be intimidating, but there are so many reasons for patients (and their doctors) to learn to love these larger contact lenses. They offer unparalleled vision and comfort for many patients with irregular corneas, dry eye, or high astigmatism. If your doctor has recommended scleral contact lenses for you, here's what you need to know:
|A scleral contact lens fully covers the cornea and sits on the white of the eye (the sclera) via|
- Scleral Contact Lenses typically range from 14 to over 18 mm in diameter, fitting completely over the cornea so that no part of the edge of the lens touches the cornea. As such, the lens is much more initially comfortable than a smaller rigid gas permeable lens that moves around on the cornea with blink. A scleral lens basically creates a shell covering the cornea, masking any corneal irregularities like keratoconus, scarring from refractive surgeries like RK and LASIK that have resulted in vision issues, and high amounts of astigmatism.
- Scleral lenses create a little pool of moisture under the lens that stays between the contact lens and the cornea all day. Due to this property, scleral lenses have even been used for dry eye treatment. Before you put your lenses in, you must fill the contact lens with the proper saline (or bath water if you will) to keep your cornea from getting irritated under the contact lens. Most commonly recommended filling solutions are:
- Preservative Free Saline (like Unisol)
- Preservative Free Artificial Tears
- 0.9% NaCl inhalation vials (off label use but these are preservative and buffer free, making them ideal for the sensitive cornea)
- These lenses are difficult for some to learn how to insert and remove. Since you are filling your contact lens up with a pool of solution, you have to put the lens in without dumping all of your solution out. Your doctor will train you on the proper technique, but the Scleral Lens Education Society has a great instruction video if you need more help at home:
- Why do I fit scleral contact lenses? They definitely aren't a quick-fit type of contact lens, but once you have the proper lens, your patient should see better and with better comfort than they have in years. With that being said, I typically plan for between 3-5 visits for first time scleral wearers to get the proper lens fit. If you are a patient in the process of the fit and are feeling frustrated, keep in mind that these lenses are all made to order, and the parameters to change are very involved. Most companies have a remake period of 2-3 months since it takes 1-2 weeks to make a new lens, and then more time to ship out and schedule a time that works for the patient's schedule.
- Wouldn't it be nice if scleral contact lenses are the end all-be all lens that works for everyone? Unfortunately, that is not the case. I have found that people with small diameter corneas and small eyes/tight eyelids are very difficult to fit with this lens. I use Essilor Jupiter lenses, and their company representative discouraged fitting lenses on people with smaller than 12 mm corneas (especially with limbus to limbus astigmatism) due to the problematic issues they have encountered. These lenses are gaining more and more popularity, but doctors are still debating the best fitting techniques and trouble shooting skills, so we may not be able to get the perfect lens for every patient yet. With more doctors fitting sclerals, and more companies offering better parameter options, the industry may grow to accommodate more and more patient types. If you are an optometrist or student, I plan on posting tips on scleral lens fitting in a future post, so stay tuned for what I have learned so far!