Influence on visual function of forward light scattering associated with subsurface nanoglistenings in intraocular lenses

Abstract

To quantitatively assess the impact of subsurface nanoglistenings on forward light scattering and visual function. University of Tsukuba, Tsukuba, Japan. Case-control study. Eyes with subsurface nanoglistenings and increased intraocular lens (IOL) surface light scattering and control eyes without subsurface nanoglistenings were evaluated. Forward light scattering was assessed with a double-pass device (Optical Quality Analysis System II) using the objective scatter index (OSI) as a quantitative parameter. Backward light scattering in the IOL surface was evaluated using Scheimpflug imaging (EAS-1000). The contrast sensitivity function was assessed as the area under the log contrast sensitivity function (AULCSF) measured with the Optec 6500 device. Correlations between the OSI, visual function, age, time after surgery, IOL power, and backward light scattering were analyzed. In the study group, logMAR corrected distance visual acuity (CDVA) ranged from -0.176 to 0.045 (-0.06 ± 0.07 [SD]); no patient had a CDVA worse than 20/25. The OSI was significantly higher than in the control group (P=.0074) and correlated with CDVA (P=.0021), AULCSF photopic without glare (P=.0002) and with glare (P<.0001), and AULCSF mesopic without glare (P=.0038) and with glare (P=.0008). Multivariate analysis showed OSI was the only variable that correlated with CDVA and contrast sensitivity with glare. The OSI and age correlated with contrast sensitivity without glare (P<.05). Eyes with subsurface nanoglistenings had increased forward light scattering but no deterioration in CDVA. Increases in forward light scattering correlated with reductions in visual acuity and contrast sensitivity, although both remained within their normal range. No author has a financial or proprietary interest in any material or method mentioned.