EVALUATION OF DIFFERENCE IN THE ANTERIOR CHAMBER ANGLE FOLLOWING CATARACT SURGERY IN SENILE CATARACT

Abstract

Need for the study: As per World Health Organization, cataract is the prime cause of blindness all over the world, held responsible for 47.8% of blindness and accounting for 17.7 million blind people. In India, 80% of the blindness is due to cataract. Glaucoma is the second most common cause of blindness and a principal reason for permanent blindness globally. Asians embody 47% of cases of glaucoma and 87% of cases with Angle Closure Glaucoma (ACG). Worldwide, primary angle closure glaucoma (PACG) forms nearly half the glaucoma cases. Many studies have indicated that cataract removal can cause anterior chamber deepening, iridocorneal angle widening, and intraocular pressure decrease in glaucomatous and nonglaucomatous eyes. Studies have also exposed that cataract removal can help in restoring vision and in relieving a narrow angle in eyes. Still, the anatomic predictors of angle widening subsequent to cataract surgery have not been completely understood. The purpose of this thesis is to assess if patients with senile cataract having narrow angle undergoing cataract surgery and intraocular lens (IOL) implantation are also incidentally getting treated for predisposition to angle closure. This study also correlates the biometric factors related to changes in the angle recess, like changes in Axial length (AL), Anterior xiii chamber depth (ACD), Lens thickness (LT), and ACA and scrutinizes for any noticeable associations between these parameters. Objectives:  To evaluate the difference in anterior chamber angle (ACA) following cataract surgery and in the bag posterior chamber intraocular lens (PCIOL) implantation in senile cataract.  To correlate axial length (AL), anterior chamber depth (ACD), vitreous chamber depth (VCD) and lens thickness (LT) with angle of anterior chamber. Methods: This was an observational study, where patients diagnosed with senile cataract and posted for small incisional cataract surgery with PCIOL implantation underwent thorough ocular examination. Anterior chamber angle was evaluated with gonioscopy and Van Herick‘grading while AL, ACD, LT and VCD were measured through biometry before and after cataract surgery, and difference was estimated. Results: Out of 48 participants, males consisted of (47.92%) (n= 23) and females consisted (52.08%) (n=25) of the study population. The 19 (100%) participants with Shaffer‘s grade 4, 17 participants with grade 3 (100%), 8 (72.73%) with grade 2 and 1 (100%) patient with grade 1 angle preoperatively on gonioscopy became grade 4 post cataract surgery and IOL implantation. A good association was found between cataract extraction and deepening of angle. The mean ACD difference was 0.53mm and mean VCD difference was 1.15mm for before and after cataract surgery values which was statistically significant (p<0.001). Conclusion: This study proves that ACA and ACD change significantly following cataract surgery with PCIOL implantation in patients with senile cataract. All patients demonstrated xiv an increase in angle of anterior chamber as well as ACD and VCD post cataract surgery. The study shows that the patients with narrow angle or susceptibility to angle closure in future, on undergoing cataract surgery, also benefit by preventing future development of PAC/PACG or by treatment of a preexisting case.