ABSTRACT
Background: The refractive outcome of glaucoma operations principally their influence on astigmatism, aren't completely explained.
Objective: to evaluate corneal topographic changes following sub-scleral trabeculectomy (SST) versus non penetrating deep sclerectomy (NPDS) in cases with primary open-angle glaucoma (POAG).
Patients and Methods: 30 eyes of 30 cases were allocated into 2 similar groups: (Group A) comprised cases who had SST with adjuvant intra-operative usage of 0.2 mg/ml Mito-mycin C (MMC) for 2-min, and (Group B) comprised cases who had NPDS with adjuvant intra-operative usage of 0.2 mg/ml MMC for 2 mins. Complete ophthalmic examination and computerized topography were performed preoperatively, then 3-mths post-operatively .The pre-operative and post-operative data were subtracted and statistically analyzed. Data included K1, K2, average keratometry (avgK), corneal astigmatism (value & axis) and apical keratometry front (AKf).This prospective comparative study was done at Ophthalmology Dep. of Al Azhar university hospitals throughout the interval from March 2021 to Sept 2021.
Results: .Highly statistical significant (p-value < 0.001) increased Δ K1(0.47 ± 0.09) , Δ K2(0.86 ± 0.18) and Δ astigmatism (1.32 ± 0.13) in group A when compared with Δ K1 (0.22 ± 0.09), Δ K2 (0.46 ± 0.08), Δ astigmatism (0.69 ± 0.1) in group B. Non significant change was found among groups A & B regarding Δ (Avg K and AKF).
Conclusion: Induced astigmatism can responsible for a decrease in unaided visual acuity in the earlier post-operative times post glaucoma operations. SST persuade further astigmatism than NPDS.