Corneal grafting for keratoconus in mentally retarded patients

To compare the results of penetrating and non-penetrating corneal grafting procedures in mentally retarded keratoconus patients.

In the years 1974-2000 41 mentally retarded patients with keratoconus (33 with Down syndrome) were operated with corneal grafting. Mean age at operation was 36.7+/-10.8 years. Three different surgical procedures were used (no randomization): penetrating keratoplasty (n=16), lamellar keratoplasty (n=5) and epikeratophakia (n=20). In a retrospective study, the non-penetrating procedures (lamellar keratoplasty and epikeratophakia) were compared to the penetrating keratoplasties with regard to graft survival and frequency of serious complications. Mean follow-up time of all grafting procedures was 80+/-58 months.

All cases of serious complications (irreversible rejection, wound leakage or perforation) occurred in the penetrating keratoplasty group (p=0.0005). Older age at operation (p=0.011) adversely influenced the frequency of serious complications. Overall five-year survival was 74.9%. Graft survival was not related to surgical procedure, but rather to age at operation (poorer survival in older age, p=0.012) and degree of retardation (poorer survival in patients with more severe retardation, p=0.051).

Because of the safety and low frequency of complications, epikeratophakia is recommended as the grafting procedure of choice in the majority of mentally retarded with keratoconus. In selected cases (good cooperation, age < or =40 years, and a good peripheral corneal thickness) penetrating keratoplasty may be performed, which, if uncomplicated, often will give better functional/optical results.