Objective vs subjective vault measurement after myopic implantable collamer lens implantation.

Abstract

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. Observational cross-sectional study. Fernández-Vega Ophthalmological Institute, Oviedo, Spain. 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). Subjective and objective measurements of vault after implantation of ICL. 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). 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. 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.