Thickness of the crystalline lens does not depend on cataract formation

Abstract

Aims/Purpose: To assess the influence of cataract formation on the lens thickness (LT), anterior (ACS) and posterior (PCS) cortex space and nuclear thickness (NT).Methods: A prospective cross‐sectional study including patients seeking for cataract surgery was performed. The standardized Lens Opacification Classification System (LOCS)‐III was used to classify lens opacities. A control group composed of non‐cataractous patients was also created. In addition, cataract patients were also classified according to the cataract location (presence or absence of cortical, nuclear or posterior subcapsular cataract). Optical biometry was performed to measure LT, ACS, NT and PCS. Propensity score was used to match cataract and non‐cataract patients one‐to‐one for sex, age and axial length. Groups were compared using the Student's t‐test or Yuen's test.Results: A sample of 603 volunteers (403 females, 200 males) aged 59.1 ± 18.8 years was recruited. Before matching, the lens cataract and the non‐cataract group was composed of 361 cataractous and 242 non‐cataractous volunteers. Also, all participants were classified into cortical and non‐cortical cataract groups (226 vs. 377), nuclear and non‐nuclear cataract groups (313 vs. 209) and into subcapsular and non‐subcapsular cataract groups (242 vs. 361). Before matching, cataract groups showed significant (p ≤ 0.003) higher LT (4.52 ± 0.39 vs. 3.94 ± 0.46 mm), ACS (0.75 ± 0.20 vs. 0.58 ± 0.23 mm), NT (3.34 ± 0.23 vs. 3.18 ± 0.25 mm) and PCS (0.42 ± 0.19 vs. 0.37 ± 0.19 mm). After matching, the lens, cortical, nuclear and subcapsular cataract samples were composed of 146, 258, 182 and 226 participants, respectively. Then, no significant (p ≥ 0.08) differences were found for LT, ACS, NT and PCS.Conclusions: Thickness of the lens and/or its main components is not changed due to cataract formation. The progressive lens growth associated to aging might be the main confounding factor misleading the outcomes of previous studies that reported differences in LT between cataractous and non‐cataractous patients.