Evaluation of changes in anterior chamber parameters before and after Nd:YAG laser peripheral iridotomy in primary angle closure suspects using pentacam

• Author Details:   
• Vidyadevi Mahadevappa
• Drishya Sudev ^*
• Anuradha Appaji
• Nandini Haugeppa
• Sai Dheera Mulasthanam
• Hima Bhatt

---

Background: Primary angle closure glaucoma is characterized by elevated intraocular pressure as a result of mechanical obstruction of the trabecular meshwork by either apposition of the peripheral iris to the trabecular meshwork or by a synechial closed angle. It carries a heavier risk of ocular morbidity compared to open angle glaucoma. With the development of imaging devices for the anterior segment of the eye, like Pentacam a better understanding of the pathogenesis and of angle closure has been reached.

Objectives: To determine anterior chamber parameter changes (ACV-anterior chamber volume, ACD-anterior chamber depth, ACA-anterior chamber angle, CCT-central corneal thickness) before and after Nd:YAG laser peripheral iridotomy (LPI) in primary angle closure suspect (PACS) patients using Pentacam.

Materials and Methods: Hospital based prospective observational study conducted on patients attending our tertiary care hospital. A total of 45 patients (60 eyes), fulfilling inclusion criteria were included in the study conducted over a period of 18 months from February 2021 to September 2022.

Results: Total 60 eyes of 45 patients were included in the study. Following Nd:YAG LPI, there was significant widening of ACA according to Shaffer’s grading. The change in ACV from baseline to first week (65.35 ± 16.44 mm³ to 74.93 ± 16.93 mm³) and first month (65.35 ± 16.44 mm³ to 83.98 ± 18.66 mm³) were statistically significant. The mean ACA increased from baseline to first week (23.18 ± 4.53 degree to 25.12 ± 5.40 degree) and first month (23.18 ± 4.53 degree to 26.09 ± 4.92 degree) and was statistically significant. The increase in mean ACD from baseline to first week (2.06 ± 0.35 mm to 2.25 ± 0.38 mm) and first month (2.06 ± 0.35 mm to 2.42 ± 0.33 mm) was also statistically significant. The shift in the values of CCT from baseline wasn’t statistically significant.

Conclusion: Our study confirms previous reports of increased ACV, ACA, ACD after LPI in PACS. Pentacam is an extremely useful tool in quantifying these changes.

Keywords: Laser peripheral iridotomy, Oculus pentacam, Primary angle closure suspect.