An observational study on the outcome of corneal cross-linking for Keratoconus at Greys tertiary hospital, Pietermaritzburg.

Abstract

The purpose of this observational study was to evaluate the efficacy of corneal cross-linking for keratoconus, beginning when the procedure was performed up to a year after the procedure in patients at Greys Hospital in Pietermaritzburg, South Africa between January 2010 and December 2015. Keratoconus is a progressive, non-inflammatory ectatic corneal disorder characterised by a progressive corneal thinning that causes irregular astigmatism and decreasing visual acuity. It is often associated with allergic conjunctivitis and seems to also have a degree of familial inheritance. Onset is during the first decade and is progressive until the third decade of life when it often seems to stabilise. Amongst the corneal ectatic diseases it remains the most common cause of debilitating progressive visual impairment during childhood and adulthood. Individuals with keratoconus form a significant proportion of patients for a practitioner specialising in corneal diseases, yet it is a disease in which the pathogenesis is poorly understood and until recently there has been no treatment (apart from corneal transplantation) that could be offered that was curative or capable of slowing the progression of the disease. Collagen cross-linking treatment using riboflavin and UV light was developed in an attempt to address this need and the initial results were promising. Charts from a sample of 54 eyes from 49 patients aged between 13 and 35 years with keratoconus treated once with corneal cross-linking, were reviewed from the time of the procedure until 1 year after the procedure or for three consecutive follow-up visits after the procedure. Although less successful than similar studies on Caucasian patients, there was significant stability in the keratometric and pachymetry measurements. The results show that the cross-linking procedure for keratoconus is a useful conservative treatment modality to stop the progression of keratoconus. This also means that the need for corneal graft procedures is significantly reduced. The fairly minimal costs involved in this procedure compared to corneal graft procedures are also an important point to consider. More study is required to elicit whether corneal cross-linking is less successful in African patients than in Caucasians.