Biometric indicators of Eyes with Occult Lens Subluxation inducing Secondary Acute Angle Closure

Abstract

Background: To compare the anterior biometry of eyes with secondary acute angle closure induced by occult lens subluxation (LS), misdiagnosed as acute primary angle closure (APAC) at the first visit, APAC, chronic primary angle closure glaucoma (CPACG), cataract. Methods: This retrospective case study included 17 eyes with PAC due to occult LS, who were misdiagnosed as APAC on their first visit, 56 eyes diagnosed as APAC, 54 eyes diagnosed as CPACG, and 56 eyes diagnosed as cataract. Axial length (AL), Central corneal thickness (CCT), anterior chamber depth (ACD) and lens thickness (LT) were recorded. Lens position (LP), relative lens position (RLP), corrected lens position (CLP) were calculated. Quantitative data were subject to one-way analysis of variance and correlation analysis. Categorical data were analyzed using the chi-squared test. Results: The patients in the LS group had a longer ocular axial length than those with acute angle closure and CPACG. Corneal thickness in the LS group was not significantly different from that in the APAC group, but was significantly different from those of the CPACG and cataract group. The APAC group had the smallest ACD, while the LS group had the smallest AD. The LS group exhibited significantly shallower ACD (P<0.01). The LS group had the largest lens thickness. Conclusions: This study revealed that LS secondary PAC patients had a shallower ACD, thicker CCT and lens thickness comparing to those of APAC, CPACG and cataract patients. A short depth (< 1.25 mm) and a thick lens thickness (> 5.13 mm) are crisis of lens subluxation in our data. LP and CLP can be helpful for differential diagnosis. Trial registration: NCT03752710, retrospectively registered.

Evaluation of Multimodal Biometric Parameters for Diagnosing Acute Angle Closure Secondary to Lens Subluxation

“…Lens subluxation is a multifactorial disease, with symptoms that can be variable and occult [7,8]. In the present study, we analyzed clinical characteristics and multimodal biometric parameters of patients with ASAC-LS, APAC, and cataract obtained from UBM and the IOL Epidemiological studies have shown that the prevalence of PACG is highest in East Asia [1,6].…”

“…The medical records of patients with ASAC-LS, APAC, and cataract attending the two hospitals from September 2019 to February 2022 were consecutively reviewed. We applied the following inclusion criteria of ASAC-LS [7,8]:…”

“…The routine procedure in clinical diagnosis is to observe the signs of lens subluxation, including iridodonesis, phacodonesis, visibility of the lens equator, decentration of the lens, and vitreous prolapse in the anterior chamber [7][8][9]. However, the clinical manifestations of ASAC-LS may be atypical, and these signs may be neglected due to corneal edema caused by an elevated IOP [10].…”

“…Effective methods for diagnosing lens subluxation have been explored by clinicians. Some studies have reported several indicators for the diagnosis of lens subluxation through qualitative and quantitative analysis of ultrasound biomicroscopy (UBM) imaging features or the biometric parameters from ocular biometry [7,8,[10][11][12]. Nevertheless, most of these studies involved complex measurements and complicated formulas, making them difficult to apply in clinical practice.…”

Distribution of ocular biometry in young Chinese eyes: The Anyang University Students Eye Study

“…The AL to corneal radius (AL/CR) ratio was computed with both AL and CR expressed in millimetres. Corrected lens position (LP) is defined as the sum of the AQD and half of the LT (Xing et al 2020). The calculation of the lens power (P Bennett ) was based on the formula proposed by Bennett, (Bennett 1988; Rozema et al 2011) with A and B constants extracted from the Gullstrand–Emsley eye model, where the lens refractive index was set to be n L = 1.416.…”