One of the best ways of making people with keratoconus see better is by making customized scleral lenses. Keratoconus makes the cornea bulge in an irregular manner, with each irregularity distorting the image that hits the retina. This results in people experiencing halos, “ghosting”, blurred vision, or even double, triple or quadruple vision.
Scleral lenses get their name because they rest on the white part of the eye, the sclera, and create a tear-filled vault over (but not touching) the cornea. This results in smooth, rather than irregular, optical surface, and can dramatically improve vision. Scleral lenses should be comfortable to wear too: each scleral lens is custom-made to each patient’s eye, and scleral lenses are also sometimes used to treat dry eyes: the reservoir of tear fluid that bathes the eye is therapeutic and moisturises the cornea.
To give an example of just how successful scleral lenses can be for correcting vision in people with keratoconus, here is a case report of a recent patient at the ELZA Institute.
A patient with keratoconus presented to the ELZA Institute in December 2019, taking an emergency appointment, and complained of red eyes and pain. The patient had been wearing scleral lenses, each day, for the last 10 years.
We prescribed topical antibiotics and eye lubricants. Despite advice to stop wearing the scleral lenses while she was taking the prescribed medications, she refused, and continued to wear them throughout the treatment period.
While at the ELZA Institute for the appointment, we performed an OCT scan of the eye, with and without the lens. We found that the left eye’s lens was pressing against the cornea. After some investigation, we found that the patient was wearing an old right eye lens on her left eye, which is why it fitted the eye so badly. With these lenses, her left eye could only see 20/80. The Kmax value (the steepest part of the cornea) in this patient was 115 D just after the contact lens was removed, and was 144 D after 1 day of not wearing the lens. For reference, the average Kmax of a person without keratoconus in Europe is around 44 D. This patient had the steepest cornea we have measured at our institute.
Using the scans we made of the patient’s eye, we had a new custom scleral lenses made, and now the patient sees 20/30 in her left eye, rather than 20/80.