Anterior Chamber Angle and Volume Do Not Change after Myopic Laser-Assisted In Situ Keratomileusis in Young Patients

Abstract

Purpose We aimed to investigate whether anterior chamber angle, depth, and volume change after myopic laser-assisted in situ keratomileusis (LASIK) in young patients. Methods This retrospective study included 29 eyes of 29 patients (15 females and 14 males) between the ages of 18 and 39 years who underwent LASIK for the treatment of myopia. In addition to complete ophthalmic examination, anterior chamber angle (ACA), central anterior chamber depth (ACD), and anterior chamber volume (ACV) were measured by using a Sirius rotating Scheimpflug camera combined with Placido disc corneal topography (CSO, Florence, Italy). Preoperative and postoperative values were compared using paired t-tests. Linear regression was used to evaluate the relationship between changes in refraction and changes in ACA, ACD, and ACV as well as between attempted maximum ablation depth and changes in ACA, ACD, and ACV. Results The mean age of the study population was 25.5 ± 6.2 years. The mean preoperative and postoperative spherical equivalent values were −3.30 ± 1.92 D and −0.18 ± 0.29 D, respectively. ACV and ACA were not significantly changed after surgery; however, central ACD was significantly decreased (preoperatively = 3.366 ± 0.316 mm vs postoperatively = 3.3 ± 0.298 mm) with a mean difference of 0.066 ± 1.121 mm. There were no significant relationships between changes in refraction and anterior segment dimensions or between attempted maximum ablation depth and anterior segment dimensions. Conclusion Measurements with Sirius showed that ACA and ACV did not change; however, central ACD significantly decreased after myopic LASIK in young patients, indicating that the preoperative central ACD value should not be used interchangeably with the postoperative central ACD value.

Changes in Anterior Chamber Dimensions Following Small Incision Lenticule Extraction (SMILE)

“…Similar to our results, Yassa et al and Zhou et al reported that after LASIK, anterior chamber angle showed no difference postoperatively by using the data obtained from Sirius and Pentacam (Oculus, Wetzlar, Germany) tomography systems, respectively [7,8]. In their study comparing different techniques to assess the status of ICA, Källmark et al concluded that despite the lack of good agreement with gonioscopy, Sirius still might be a good option, since it is more comfortable for the patient, and it requires less skills to perform in an objective manner [14].…”

“…In addition, we observed a signi cant decrease at HACD (p < 0.05), but no change at ICA (p = 0.54). Yassa et al suggested that this discrepancy might be due to the accommodation of the patients while xating to the tomography device for imaging, which causes the central lens shift more anteriorly whereas the periphery remains atter [7]. However, although not statistically signi cant, in current study both temporal and nasal ACA increased postoperatively (p = 0.118, and p = 0.255, respectively).…”

“…Besides altering the cornea, corneal refractive surgery has an impact on the anterior segment structures as well. Several studies have evaluated the changes in anterior segment parameters, such as anterior chamber depth (ACD) and posterior corneal elevations after LASIK and SMILE using different tomography systems [6][7][8][9]. However, there is a paucity of published information about how the iridocorneal angle (ICA), and the other dimensions associated with it are affected following SMILE.…”

Experimental protocol designed to employ Nd:YAG laser surgery for anterior chamber glaucoma detection via UBM

“…Anterior chamber (AC) dimensions are essential for the accurate assessment of medical applications. A precise measurement of anterior chamber angle (ACA) and anterior chamber depth (ACD) is necessary to diagnose angle closure glaucoma (ACG) [1]. ACG is commonly originate in Asians $$87\%$$, and generate $$5\dot{5}$$ million persons consensual anopsia by 2020 [2, 3].…”