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.
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.