A practical approach to and long-term results of fitting silicone contact lenses in aphakic children after congenital cataract.

PURPOSE: This prospective study investigated characteristics of fit and performance of silicone contact lenses under conditions of permanent wear in cases of aphakia after congenital cataract.

METHODS

Seventeen aphakic children (8 eyes unilateral, 18 eyes bilateral) were fitted with silicone contact lenses on an empirical basis without the use of keratometry. The lenses were worn on a permanent basis, with a routine replacement every 3 months. The follow up was 6 years, with evaluation lens parameters, fitting characteristics, lens condition, replacement rate, wearing time, complications, and visual acuity.

RESULTS

The back optical zone radius (BOZR) remained stable at 7.50 mm, up to the age of 1.5 years old. At the age of 4 years, almost all eyes needed a BOZR of 7.90 mm. Mean +/- SD contact lens power was +25.47 diopter (D) +/- 4.0 (range +32.00 D - +20.00 D) at 3 months of age, and +17.94 D +/- 3.8 (range +29.00 D - +15.00 D) at 3 years of age. This represents an average decrease of 0.23 D per month. The power decrease in unilateral cases was significantly lower (P < 0.01) than in bilateral aphakia. Snellen visual acuity at 4 years of age was 0.1 to 0.3 (20/200-20/60) in 15 eyes, 0.3 to 0.5 (20/60-20/40) in 10 eyes and greater than 0.5 (>20/40) in 1 eye. Lens usage over a total period of 90 wearing years was 5.6 lenses/eye/year, including the regular exchange every 3 months. No serious complications occurred. A positive correlation (r = 0.89) was found between age and deposit buildup. With the need for permanent wear reduced, therefore, 73% of the eyes were refitted with high-water content soft lenses or high gas-permeable (HGP) lenses, when the patients ranged in age from 4 to 6 years old.

CONCLUSIONS

The procedure for fitting silicone lenses in aphakic children is feasible in an easy and logical way without keratometry. Permanent wear with a low complication rate is possible up to the age of 3. with a lens usage (including a 3-month regular exchange) of 5.6 lenses/eye/year. From the age of 3, deposit formation is the determining factor for refitting with high-water content soft or HGP lenses.