Objective vs subjective vault measurement after myopic implantable collamer lens implantation

Abstract

PURPOSE: To evaluate the relationship between subjective measurements of vault and objective values measured with Visante optical coherence tomography (OCT) in eyes receiving an implantable contact lens (ICL) for myopia correction. DESIGN: Observational cross-sectional study. METHODS: SETTING: Fernández-Vega Ophthalmological Institute, Oviedo, Spain. PATIENTS: Four hundred and fifty-two eyes from 246 patients were elected to be implanted with a Visian ICL V4 (STAAR Surgical Inc, Monrovia, California, USA). OBSERVATION PROCEDURES: Subjective and objective measurements of vault after implantation of ICL. MAIN OUTCOME MEASURES: Subjective vault classified in 5 levels assessed using an optical section during slit-lamp examination. Objective vault was measured with Visante OCT (Carl Zeiss Meditec Inc, Dublin, California, USA). RESULTS: Average values of objective and subjective vault were 414 +/- 228 microm and 2.1 +/- 1.0, respectively and both parameters were highly correlated (r = 0.82; P < .001). Differences in average objective vault were statistically significant among the 5 groups of subjective vault (P < .001). Subjective vault 0 corresponded to a mean OCT value of 62 +/- 49 microm with 99% confidence interval (CI) [38; 86] microm; eyes with vault 1 to 203 +/- 93 microm with 99% CI [176; 230] microm; eyes with vault 2 to 402 +/- 131 microm with 99% CI [378; 425] microm; eyes with vault 3 to 594 +/- 146 microm, 99% CI [554; 633] microm; and vault 4 to 794 +/- 182 microm with 99% CI [713; 875] microm. CONCLUSIONS: Subjective and objective values of vault are highly correlated. In 99% of cases within the CI, objective values for eyes subjectively classified within a certain level vary within a narrow interval (+/-25 to 80 microm) around the mean value, and this interval is characteristic of each subjective level.THIS STUDY WAS SUPPORTED IN PART BY A UNIVERSITAT DE VALENCIA RESEARCH GRANT NO. UV-AE-20070225#, (DR Montes-Mico) and Fundacao para a Ciencia e Tecnologia of Portugal Grant no. FCT-SFRH-BD-34303-2007= (Dr Fernandes). The authors indicate no financial conflict of interest. Involved in design and conduct Of Study (J.F.A., C.L., A.P., P.F., J.GAM., R.M.-M.); collection, management, analysis, and interpretation of the data (J.F.A., C.L., A.P., P.F., J.G.-M., R.M.-M.); and preparation, review, or approval of the manuscript (J.F.A., C.L., P.F., J.G.-M., R.M.-M.). The study was approved by the Fernandez-Vega Ophthalmological Institutional Review Board. The study protocol was approved by and all study procedures adhered to the recommendations of the Declaration of Helsinki