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Analysis of visual outcome with rigid contact lenses in keratoconic eyes
Author(s) -
KOPITO R,
WAJEMAN S,
GAUJOUX T,
TOUZEAU O,
LAROCHE L
Publication year - 2008
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2008.555.x
Subject(s) - visual acuity , keratometer , keratoconus , ophthalmology , medicine , optometry , lens (geology) , optics , cornea , physics
Purpose To analyze the variation of best corrected visual acuity (BCVA) obtained with rigid gas permeable (RGP) lenses in keratoconic eyes compared to best spectacle‐corrected visual acuity (BSCVA). Methods We prospectively recorded visual acuity data (BSCVA and BCVA with RGP), subjective refraction, keratometric readings and lens geometry in 135 eyes of 78 patients with keratoconus. Acuity data was converted into LogMAR units for statistical analysis. BSCVA was compared to BCVA with RGP lenses, and the differences were correlated with all parameters. Results The decimal BSCVA and decimal BCVA with RGP lenses was 0.36 (0.44 LogMAR, 20/56) and 0.70 (0.15 LogMAR, 20/29), respectively. The mean difference after RGP lens fitting was +2.83 lines ±2.55 (range 0‐11.6). The gain was superior to 1 line in 70%, 3 lines in 40% and 6 lines in 16%. The difference was correlated with the BSCVA (rS=0.90 p<0.001), mean keratometry (rS=0.33 p<0.001), subjective cylinder (rS=0.26; p<0.001). The difference remained unaffected by age and sex (p≥0.31). The difference was correlated with the lens radius rO (rS=0.27; p=0.002) and the lens power (rS=0.25; p=0.003). The lens diameter did not affect the variation in visual acuity (rS= ‐0.04; p=0.62). Conclusion There was a significant increase in visual acuity with RGP lenses compared to BSCVA: the lower the initial BSCVA, the better the gain with RPG lenses. The gain was independent of the patients’ age. The eccentricity of the keratoconus did not influence the visual outcome with RGP lenses.