English

Abstract

INTRODUCTION: Glaucoma is the second leading cause of blindness worldwide & is especially common & morbidity causing among women and Asians. Glaucoma afflicts 12 million people in our country. Primary open angle glaucoma is more common in general population. However angle closure glaucoma tends to be more aggressive & visually debilitating. Inspite of being treated with iridotomy, medical & surgical management, it continues to produce excessive visual morbidity. Acute angle closure glaucoma which is vision threatening is a potentially preventable condition and hence early identification and treatment with laser peripheral iridotomy in susceptible patients is of utmost importance. AIMS AND OBJECTIVES: To study the angle morphology before and after laser peripheral iridotomy in patients with primary angle closure & primary angle closure glaucoma. METHODOLOGY: Prospective observational study to study the changes in anterior chamber angle structures before and after laser peripheral iridotomy using Ultrasound biomicroscopic technique. The study was conducted in patients presenting to the glaucoma clinic of the department of ophthalmology of Govt Rajaji Hospital, Madurai for the period of 6 months. A total of 50 patients were studied. Patients presenting with shallow angles were studied & their complete history, assessment of anterior segment which includes slit lamp examination, gonioscopy by Goldman 3 mirror goniolens, IOP measurement by applanation tonometry, fundus examination using +90D lens and standard perimetry was done. The patients were categorised as Primary angle closure or as Primary angle closure glaucoma depending on the clinical findings. Then Ultrasound biomicroscopic assessment was done prior to and after 2 weeks of laser peripheral iridotomy to measure central ACD (anterior chamber depth), AOD (angle opening distance), TIA (trabecular iris angle) & other angle parameters. Results were analysed statistically. RESULTS: Among the total studied population of 50 patients, 48% were diagnosed to have primary angle closure & remaining 52% had primary angle closure glaucoma. In the PAC group: There was a significant change in all the parameters measured. ACD (mm) changed from an average from 2.199±0.04 to2.32±0.00 with a p value of ˂ 0.001. AOD 500 (Angle opening distance mm) increased from an average of 0.106 ± 0.0 to 0.209 ± 0.0 with a p value of ˂ 0.001. Sup TIA (deg) increased from an average of 8.252±0.16 to 16.081±0.23 with a p value of ˂ 0.001. Inf TIA (deg) increased from an average of 9.125±0.04 to 16.118±0.24 with a p value of ˂ 0.001. TCPD (TRABECULAR CILIARY BODY DISTANCE mm) increased from an average of 0.745 ± 0.0 to 0.82 ± 0.01 with a p value of ˂ 0.001. IT (IRIS THICKNESS mm) increased from an average of 0.459 ± 0.01 to 0.487 ± 0.00 with a p value of ˂ 0.001 ILCD (IRIS LENS CONTACT DISTANCE mm) decreased from an average of 1.217 ± 0.05 to 1.162 ± 0.02 with a p value of ˂ 0.001. ILA (IRIS LENS ANGLE deg) ) increased from an average of 25.729 ± 0.52 to 27.754 ± 0.57 with a p value of ˂ 0.001. In the Primary angle closure glaucoma group: There was no significant change in any of the measured parameters. CONCLUSION: Among the studied population, observation in the angle characteristics showed that there was statistically significant change in the UBM parameters noted in the primary angle closure group, however no such significant change was noted in the primary angle closure glaucoma group. Hence effective strategies should be adopted in order to identify angle closure at an early stage so that they can be treated prior to development of irreversible angle closure glaucoma.