Types of cataract and change of crystalline lens power and refractive power: Reykjavik Eye Study

Poster Details

First Author: H.Sasaki JAPAN

Co Author(s):    N. Hatsusaka   E. Shibuya   H. Osada   E. Kubo   K. Sasaki   F. Jonasson

Abstract Details

Purpose:

We followed-up Icelanders for 12 years and investigated change of crystalline lens power and refractive power by types of cataract.

Setting:

University of Iceland, Reykjavik, Iceland

Methods:

Among 1045 subjects who joined the Reykjavik Eye Study (RES) in 1996, 573 subjects participated in 2008. From those 398 right eyes that had transparent lens and no evidence of WC (age 58.1±6.1 yrs) in 1996 were selected as subjects in this study. They were grouped as transparent or with only one of the 3 main types of cataract (302, transparent ;, 56, cortical; 33, nuclear, and 7, PSC). Eyes with transparent lens and cortical opacity were further classified by presence of WC (within 3-mm central optical zone (Central: C) and outside (Peripheral: P)). Lens power (LP) was calculated from refractive power, corneal refractive power, and axial length by Olsen's method.

Results:

Spherical equivalent (SE) increased by 0.6D (0.6±1.8D to 1.2±1.8D) and 0.6D (1.0±2.5D to 1.6±2.5D) over 12 yrs in transparent group and cortical group, respectively. LP significantly decreased by 1.04D (22.5±2.2D to 21.5±2.2D, p<0.05) in trasparent group and by 1.03D (21.8±2.0D to 20.8±2.3D, p<0.05) in cortical group, with no significant difference between these groups. LP increased by 0.29D (21.1±2.1D to 21.4±2.4D) and SE decreased by 0.2D in nuclear group. Hyperopia in eyes with WC (C) in transparent and cortical groups worsened by 1.48±0.78D, as LP decreased by 2.39±1.26D which was significant compared with eyes without WC (p<0.05). WC (P) had no influence on LP.

Conclusions:

Eyes aged >50 yrs with transparent lens, and those with cortical opacity, develop hyperopia at the rate of 0.5D a decade with decreasing refractive power, whereas those with nuclear opacity became slightly myopic. Water cleft located within the 3-mm central optical zone is an important factor of hyperopia due to decreased lens refractive power. FINANCIAL DISCLOSURE?: No