Correlating visual function and size of area opacified by retrodots based on retro-illumination photography

Abstract

Purpose: To consider the relationship between area opacified by retrodots (RD) and visual function (best corrected visual acuity (BCVA), retinal image contrast (RIC), and high-order aberration).

Methods: Subjects comprised 140 right eyes with RD (average age 69.6±7.1 yrs) excluding other types of cataract including three main types (nuclear, cortical and posterior subcapsular cataract), water clefts and lens opacities which may affect vision, and non-cataractous eye disease, among participants of Monzen Eye Study (Monzen, Wajima City, Ishikawa, Japan) from 2006 to 2012. The area opacified by RD within the 3 mm diameter area of the pupil center (under maximal mydriasis by tropicamide) was measured with anterior eye segment analysis system (EAS-100, Nidek). RIC with the 3 mm diameter pupil and total high-order aberrations (corneal, internal, ocular) with the 4 mm diameter pupil were measured by PSF analyzer (PSF-1000, Topcon) and wavefront analyzer (KR9000PW, Topcon), respectively. RIC was measure for low, middle and high frequency with optotypes 0.081logMAR, 0.423logMAR and 0.008logMAR.

Results: Size of area opacified by RD was positively correlated with BCVA (logMAR) (p<0.05). BCVA was 0logMAR and 0.2logMAR for areas of RD 10% and 25%, respectively. There was a negative correlation between size of area opacified by RD and RIC for all three optotypes (p<0.05). RIC deteriorated by 10% as RD area increased by 10%. There was no significant correlation between area of RD and corneal, internal and ocular total high-order aberrations.

Conclusions: Within the area of 3 mm diameter of the pupil center, over 10% opacification by RD reduces VA to less than 0logMAR and RIC by 10%. However, a 10% opacification does not affect high-order aberration.

Keywords: 445 cataract • 754 visual acuity • 459 clinical (human) or epidemiologic studies: biostatistics/epidemiology methodology