Differences in Ocular Biometry Between Short-Axial and Normal-Axial Eyes in the Elderly Japanese

Takahiro Tanaka,&ast; Koichi Nishitsuka,&ast; Hiroto Obata&ast; Department of Ophthalmology, Saitama Medical Center, Saitama Medical University, Kawagoe-shi, Saitama, Japan&ast;These authors contributed equally to this workCorrespondence: Koichi Nishitsuka, Department of Ophthalmology, Saitama Medical Center, Saitama Medical University, 1981 Kamoda, Kawagoe-shi, Saitama, Japan, Tel +81-49-228-3682, Fax +81-49-225-5722, Email [email protected]: Among patients with angle-closure glaucoma, it is common to have a short-axial eye, which also makes it difficult to select an appropriate intraocular lens. Previous studies have focused on the ocular biometry of the long-axial eye, whereas only a few reports have focused on the short-axial eye. This study aimed to clarify the characteristics of the short-axial eye on ocular biometry among the elderly Japanese.Patients and Methods: This retrospective cross-sectional study included 142 patients who consulted at our hospital. The ocular axial length (AL), central corneal thickness (CCT), average anterior corneal radius of curvature (CR), white-to-white (WTW), anterior chamber depth (ACD), and lens thickness (LT) were measured using OA-2000. The short-axial and normal-axial groups (short-axial [SA] and normal-axial [NA] groups) included those with an AL less than 22.5 mm and ranging from 22.5– 26.5 mm, respectively. Comparisons between groups were analyzed using the Wilcoxon rank sum test. Spearman’s rank correlation coefficient tests and multiple regression analyses were performed for all parameters overall and per group.Results: The parameters that were significantly different between the SA and NA groups were CR, WTW, and ACD (all P < 0.0001). In the SA group (42 patients), only ACD was significantly correlated with AL (r = 0.33, P = 0.031). On multiple regression analysis for the SA group, none of the parameters had a significant effect on AL (all P > 0.05).Conclusion: In the SA group, ACD was the only factor that positively correlated with AL; it was significantly shallower than in the NA group. Thus, in the SA eye, it is clinically important to be aware of ACD.Keywords: preoperative cataract patients, swept-source optical coherence tomography, ocular axial length, ocular parameters, angle-closure glaucoma