Sakari Nakamine1,2, Hiroshi Sakai3, Yoshikuni Arakaki1, Michiko Yonahara1, Tadayoshi Kaiya2. 1. Ophthalmology, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan. 2. Kaiya Eye Clinic, Hamamatsu, Shizuoka, 430-0903, Japan. 3. Ophthalmology, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan. hi-hiro@mtf.biglobe.ne.jp.
Abstract
PURPOSE: To study the effect of the internal fixation lamp on anterior chamber width measured by anterior segment optical coherence tomography. METHODS: In a prospective cross sectional observational study, consecutive 22 right eyes of 22 patients (4 men and 18 women) with suspected primary angle closure underwent swept source domain anterior segment optical coherence tomography (AS-OCT), (CASIA SS-1000, Tomey, Nagoya, Japan). Anterior chamber parameters of angle opening distance (AOD), trabecular-iris angle (TIA), angle recess area (ARA) at 500 or 750 µm from scleral spur and pupil diameter were measured by AS-OCT in a three-dimensional mode in 4 quadrants (superior, inferior, temporal and nasal) in dark room setting both with and without internal fixation lamp. RESULTS: Anterior segment parameters of AOD 500 in superior, inferior and temporal quadrants, AOD 750 at superior and nasal, TIA 500 at superior, and inferior and TIA 750 at superior and nasal, and ARA 500 or 750 at superior and inferior with internal fixation lamp were greater and the pupil diameter was significantly (all P < 0.05, paired t test) smaller than when measured without fixation lamp. CONCLUSIONS: Internal fixation lamp of the anterior segment OCT makes the pupil constrict and angle wider. When using AS-OCT with usual setting with internal fixation lamp on with eyes in which the anterior chamber angle is narrow but open, it is recommended that the internal fixation lamp be turned off to ensure a clear indication as to whether the angle is open or closed in the dark.
PURPOSE: To study the effect of the internal fixation lamp on anterior chamber width measured by anterior segment optical coherence tomography. METHODS: In a prospective cross sectional observational study, consecutive 22 right eyes of 22 patients (4 men and 18 women) with suspected primary angle closure underwent swept source domain anterior segment optical coherence tomography (AS-OCT), (CASIA SS-1000, Tomey, Nagoya, Japan). Anterior chamber parameters of angle opening distance (AOD), trabecular-iris angle (TIA), angle recess area (ARA) at 500 or 750 µm from scleral spur and pupil diameter were measured by AS-OCT in a three-dimensional mode in 4 quadrants (superior, inferior, temporal and nasal) in dark room setting both with and without internal fixation lamp. RESULTS: Anterior segment parameters of AOD 500 in superior, inferior and temporal quadrants, AOD 750 at superior and nasal, TIA 500 at superior, and inferior and TIA 750 at superior and nasal, and ARA 500 or 750 at superior and inferior with internal fixation lamp were greater and the pupil diameter was significantly (all P < 0.05, paired t test) smaller than when measured without fixation lamp. CONCLUSIONS: Internal fixation lamp of the anterior segment OCT makes the pupil constrict and angle wider. When using AS-OCT with usual setting with internal fixation lamp on with eyes in which the anterior chamber angle is narrow but open, it is recommended that the internal fixation lamp be turned off to ensure a clear indication as to whether the angle is open or closed in the dark.
Authors: Ye Zhang; Si Zhen Li; Lei Li; Ming Guang He; Ravi Thomas; Ning Li Wang Journal: Invest Ophthalmol Vis Sci Date: 2016-01-01 Impact factor: 4.799
Authors: Javier Benitez-Del-Castillo; Ali Nowrouzi; Mario Rodriguez-Calzadilla; Inmaculada Mota-Chozas; Maria Dolores Pinazo-Duran Journal: Int Ophthalmol Date: 2022-01-19 Impact factor: 2.029