Abstract
Purpose :
Compare subfoveal choroidal thickness (CT) of patients with oculocutaneous albinism (OCA) and patients without ocular alterations using Optical Coherence Tomography (OCT) with Eye Tracker system and correlate CT with: visual acuity, spherical equivalent (SE), iris transparency degree, retinal transparency degree and macular thickness.
Methods :
Observational, prospective and analytical study evaluating the subfoveal CT by the OCT Angiography Avanti XR with eye tracker RTVue® in 60 eyes with OCA (mean age of 33 years) and 52 eyes (mean age of 30 years) of patients without ocular alterations. Images were obtained in the Retina Map mode, which presented better image quality. Three images of each eye were done, 5 measures of CT in each scan and 10 measures in each image, with intervals of 500μm and 1.000μm of the center of the image obtained from a horizontal and vertical scan, totaling 3.360 measures. The 3 central measures of each scan were used in the analysis and compared them with the 5 central measures to verify if a larger area would cause a significant difference. The exams were performed in the morning, to avoid the circadian variation of CT, and analyzed by a single examiner. Although albinism is a systemic genetic change, it has been observed that the same individual has distinct ocular characteristics between the two eyes, so the individual assessment by eye was necessary in this study. All analyzes were performed using the software SPSS v.20.0, adopting a significance level of 5% for all analyzes.
Results :
The study group had a mean of 219,87μm with a standard error of 12,74 (p<0.001), while in the control the mean was 275,97μm with a standard error of 9,05 (p< 0.001), therefore the CT in the study group is, on average, 56,1μm lower than the controls, with a confidence intervals distinct. The variables that presented association with EC and with statistical relevance were: age (-0.257 and p<0.05), SE (0.33 and p<0.05), macular thickness (0.318 and p<0.05) and retinal transparency (-0.415 and p<0.01).
Conclusions :
This study demonstrated with statistical significance that choroidal thickness in patients with OCA is thinner than in patients without ocular alterations and a significant positive correlation was verified with SE and macular thickness and negative correlation with age and retinal transparency.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.