Changes in ocular biometry and anterior chamber parameters after pharmacologic mydriasis and peripheral iridotomy in primary angle closure suspects

Abstract

PurposeThe aim of this study was to evaluate the effects of pharmacologic mydriasis and Peripheral Iridotomy (PI) on ocular biometry and anterior chamber parameters in primary angle closure suspects.MethodsIn this prospective interventional case series, 21 primary angle closure suspects were enrolled. Intraocular pressure, refraction, ocular biometry (Lenstar, LS900), and anterior chamber parameters (Pentacam HR) were measured at four occasions: before PI (before and after mydriasis with phenylephrine) and two weeks after PI (before and after mydriasis). The study was conducted on both eyes and only one eye per patient, in random, was included in the analysis.ResultsThe mean age of the participants was 60 ± 7 years and 17 (81%) were female. There were no significant differences in intraocular pressure, refraction, keratometry, biometric and anterior chamber parameters between groups, except for anterior chamber volume, which showed increments with PI and mydriasis. The corresponding values for anterior chamber volume were as follows: 88.2 ± 13.7 mm3 before PI, undilated; 106.3 ± 18.8 before PI, dilated; 99.0 ± 14.6 after PI, undilated, and 107.4 ± 16.5 after PI, dilated (P < 0.001).ConclusionsThis study showed no change in the ocular biometric and anterior chamber parameters including iridocorneal angle after PI and/or pharmacologic mydriasis except for increments in anterior chamber volume. This factor has the potential to be used as a numerical proxy for iris position in evaluating and monitoring patients with primary angle closure suspects after PI.

Water-drinking Test and Pharmacologic Mydriasis as Provocative Tests in Primary Angle Closure Suspects

“…[8] The lack of any changes in the ocular biometric parameters in our patients of both groups is in line with other studies on the angle closure patients. [24,25,26,27] In a group of fellow eyes of 21 patients with acute primary angle closure and in 17 patients with PACG, the ACD did not change following WDT. [26] The study by Poon et al on PACG and primary open-angle glaucoma revealed no association between WDT-IOP changes and anterior chamber depth and axial length.…”

“…[27] In a study on PACS patients, no changes in ocular biometric or anterior chamber parameters including iridocorneal angle after peripheral iridotomy and/or pharmacologic mydriasis except for increments in anterior chamber volume were observed. [24]…”

Evaluation of the Anterior Chamber Angle in Angle-Closure Suspect Patients by Anterior Segment Optical Coherence Tomography (AS-OCT) and Pentacam

“…Also, another study was done by Razeghinejad et al (29) showed that the mydriatic test didn't cause a signi cant difference in intraocular pressure or parameters of anterior chamber except the anterior chamber volume, which increased after the mydriatic test. Our study differs from this one in many aspects, rstly, in ours, there was a signi cant increase in IOP measurements after mydriasis, secondly, this study revealed a signi cant increase in ACV post mydriatic while ours showed a non-signi cant decrease in ACV post mydriatic…”