Intrastromal corneal ring segments to correct low myopia in eyes with irregular or abnormal topography including forme fruste keratoconus: 4-year follow-up

PurposeTo report the 4-year outcomes after Intacs intrastromal corneal ring segment (ICRS) implantation to correct low myopia in patients with abnormal topography.SettingInstituto de Microcirugia Ocular, Barcelona, Spain.MethodsThis retrospective consecutive interventional case series included eyes with myopia lower than −4.50 diopters (D) and abnormal topography that excluded excimer laser surgery. Evaluation was performed preoperatively and at yearly intervals up to 4 years postoperatively. The 4-year outcomes measures were uncorrected (UDVA) and corrected (CDVA) distance visual acuities, predictability and stability of refractive correction, the efficacy and safety indices, and complications.ResultsAfter ICRS implantation, 82.05% of 39 eyes (21 patients) were within ±1.00 diopter (D) of emmetropia and 46.15% were within ±0.50 D. Refractive correction improved during the first 6 months and remained stable up to 4 years. The UDVA was 20/40 or better in all eyes and 20/20 or better in 38.46% of eyes. Seven eyes (17.95%) lost 1 line of CDVA, and no eye lost 2 or more lines. No intraoperative complications occurred. The ICRS were exchanged for thicker ICRS in 7 eyes (17.9%) because of undercorrection. One patient requested ICRS removal due to unsatisfactory refractive results.ConclusionsThe 4-year results indicate that ICRS implantation is effective and safe in the correction of low myopia in patients for whom excimer laser surgery is contraindicated because of abnormal topography, including forme fruste keratoconus. The achieved refractive correction remained stable throughout the follow-up.Financial DisclosureNo author has a financial or proprietary interest in any material or method mentioned.