Association of retinitis pigmentosa and advanced keratoconus in siblings

Objective. The aim of the article was to present the rare association of retinitis pigmentosa and bilateral keratoconus in two brothers, one of whom developed corneal hydrops bilaterally, within a short period of time. Methods. A 29-year-old man presented to our service with corneal hydrops in the right eye, complaining of ocular pain and photophobia. He had a history of retinitis pigmentosa, having been diagnosed as an infant. He also had a younger brother carrying the same diagnosis. Slit lamp examination revealed bilateral keratoconus with corneal hydrops in the right eye, posterior subcapsular cataract, macular atrophy and the characteristic retinal signs of retinitis pigmentosa. The patient's brother was also examined, with the same findings being noted, apart from the corneal hydrops. We documented the changes using a slit lamp biomicroscope, a fundus camera, a corneal topography, Anterior Segment Optical Coherence Tomography and visual field testing. Right hydrops regressed in one month after hyperosmolar 5% sodium chloride treatment. However, 4 weeks later, the patient presented with the same corneal findings in the left eye. The same treatment was prescribed for the left eye. Results. Corneal hydrops regressed in both eyes with remaining paracentral corneal scars. However, no other treatment for keratoconus was suitable in the case of this patient. Discussion: Retinitis pigmentosa is currently not amenable to any form of treatment, from vitamin supplementation, medical therapy, gene transfer-based therapy, stem cell-based therapy to retinal implantation. However, molecular genetics may someday provide new therapeutic prospects, that could modify the course of RP. Conclusions. The association of retinitis pigmentosa with keratoconus is a fairly rare finding, worth taking into consideration. Also, presentation with keratoconus in such an advanced state is uncommon and, in our case, it was presumably due to the patient's reduced visual function since childhood, secondary to retinitis pigmentosa, that has prevented him from perceiving any visual modifications caused by keratoconus.