July 13, 2015
Bernard Miller, O.D.
Low Vision Specialist
LEGALLY BLIND FROM KERATOCONUS
The Disease and its Qualification for Legal Blind Status
According to the National Keratoconus Foundation, “Keratoconus is a progressive debilitating bilateral eye disease in which degenerative thinning of the cornea results in complex irregular bulging of the normally round, spherical cornea.” Keratoconus is characterized by thinning and protrusion of the central cornea, resulting in a ghosting and glare, photophobia, halos around lights, decreased vision, and monocular diplopia. While the early stages of Keratoconus can be treated with spectacles, those with moderate to severe Keratoconus suffer from decreased vision which cannot be corrected with conventional spectacles or conventional contact lenses. Keratoconus is one of the few conditions where contact lenses are considered not just therapeutic and not cosmetic, but are medically necessary according to the 1999 American Medical Association (AMA) definition of Medical Necessity.
For many years, eye care professionals have strived to control the ill-effects of this corneal disease using specially designed prosthetic devises. One of the most telling indicators of Keratoconus is that corrective lenses, such as conventional glasses and/or conventional contact lenses do not improve one’s visual acuity. Legal determination or certification of legal blindness using visual acuity as criteria has been well established as 20/200 or worse, in one’s better eye with conventional corrective lenses. When acuity cannot be improved any better than 20/200 with conventional corrections, medically necessary contact lenses are indicated and the patient should be considered as legally blind.
The low vision community, a select group of eye care professionals that work with legally blind and partially-sighted individuals, utilize special low vision appliances to improve the visual acuity of a visually challenged person. A special, low vision telescope, in conjunction with conventional corrective lenses can, in many cases, improve acuity significantly, with improvement approaching 20/20 to 20/40. An unconventional, therapeutic Keratoconus contact lens is also a low vision appliance and should also be considered a low vision aid. Both aids are worn when improved acuity is desired; if only for ten minutes or, if able, for ten hours.
Mile Brujic, O.D., nationally renowned lecturer on Keratoconus adds, “Keratoconus is an unfortunate condition of the cornea that creates such an irregularity in the optical system, then if simply left with glasses to correct for these individuals, a number of them would be legally blind. Unlike most people who wear contact lenses for cosmetic purposes, contact lenses for these individuals are truly therapeutic in nature as they re-normalize the surface of the eye.”
Michael J. Lipson, O.D., FAAO, Assistant Professor at the University of Michigan’s Department of Ophthalmology and Visual Science adds, “Keratoconus is a severe visual handicap. In advanced cases where vision is at the level of legal blindness (20/200), traditional optical corrections often fail to improve vision while contact lenses designed for Keratoconus can improve vision significantly to a very functional level.”
Severe Keratoconus can result in certification as legally blind when conventional glasses or contact lenses do not improve visual acuity any better than 20/200. Low vision aids such as Keratoconus contact lenses are part of a treatment plan which, when the day is done, helps stave off the need for corneal transplantation. It is long overdue in accepting therapeutic Keratoconus contact lenses as low vision aids, enabling those with Keratoconus to live more fruitful lives as they stave off further vision loss from this disease.