INTRA-STROMAL RINGS FOR LOW MYOPIC CORREC TION

Objectives of the study Intra-stromal rings (ICR) represent a new meth od for low myopic correction. An indirect central flattening is induce d by a peripheral steepening related to the segments. This surgery was recently approved in Europe, but is still under evaluation in the mul ticenter study controled by the FDA (Food and Drug Administration). We took part in that protocol and report our results at one year follow- up. Material and method Twenty-five patients were included in the stud y with 47 operated eyes and a follow-up between 3 to 18 months. Data r elative to refractive results, quality of the vision and anatomic chan ges induced by intra stromal segments will be collected at the issue o f a rigourous survey. Results At one year, non-corrected visual acuity was 20/40 or better in 100% and 20/20 in 60%. We noted no loss in bes t visual acuity and an improvement of one or two lines in 20% of opera ted eyes. No significative changes were observed concerning : intraocu lar pressure, corneal sensitivity, central pachymetry or corneal endot helium. Three eyes had to be explanted and recovered the preoperative refraction. No severe complications were observed. Discussion Analysis of results is in favor of the efficacy, predictibility and reproducti bility of the surgery, which might be better with rings of a diameter under 0.40 mm. Occurrence of postoperative astigmatism appears to cons titue the main limit suggesting discussion on etiologic factors and mo dalities of treatment. Conclusion This concept of intra-corneal rings appears particularely, promising for correction of low myopia and mayb e in the near future for correction of others ametropia, requiring des ign of new specific segments. Essential interest of this surgery is th e respect of rite central area and its potential reversibility.