Afzal Qadir, Irfanullah Shah, Mahooz, Lal Mohammad, Muhammad Kashif Kamran.
Comparison of Astigmatism in two Incision Sites in Manual Small Incision Cataract Surgery.
Ophthalmol Update Jan ;12(1):43-8.

Objective: To determine the frequency of common complications after manual small incision cataract surgery. Materials and Methods: Descriptive cross sectional study was conducted at the Khyber Institute of Ophthalmic Medical Sciences (KIOMS), Hayatabad Medical Complex, Peshawar from 2nd April 2009 till 30 April 2010. All 106 patients were included in this study. Corneal astigmatism was measured by Helm Holtz keratometer (Topcon OM-4) (k-values were taken in diopter). All surgeries were performed under peribulbar anesthesia. An 8mm & Scleral incision was applied in both the groups, 1.5 mm away from the limbus; incision was made centered at 12 o?clock position in superior incision group and centered at 3 o?clock or 9 o?clock position in left and right eye respectively in temporal incision group. Corneal astigmatism was measured pre operatively then at 1st post-operative day, at 2 week then at 6 weeks in both groups using same keratometer. Using preop and 6 weeks keratometric astigmatism readings, SIA was calculated by subtraction method. Axis of astigmatism was determined by comparing K readings in diopters. K1 > K2 means with-the-rule astigmatism, K2 > K1 means against-the-rule astigmatism, while K1 = K2 means neutral astigmatism. Results: One hundred and six eyes of 106 patients above 50 years of age were included in this study, 53 patients in superior incision group and 53 pts in temporal incision group. 41.5% patients were in age range 50-55yrs and 58 (54.7%) patients entering the study were male. Keratometries were performed on all patients preoperatively at 1st post-op day, at 2 weeks and at 6 weeks. Mean SIA at 6 weeks post-op was 0.367 ± 0.669 D in superior incision group and 0.225 ± 0.529 D in temporal incision group, difference in both groups was statistically insignificant (p = 0.257). Both incision sites significantly changed the axis of astigmatism at 6 weeks in relation to preop astigmatism (p = 0.005 for superior incision group) and (p = 0.021 for temporal incision group). Mean Astigmatism in both the groups at 6 weeks was found to be similar in magnitude, 0.892 D in superior incision group vs. 0.894 D in temporal incision group. Conclusion: Both incisions resulted in same amount of mean astigmatism at 6 weeks and difference in mean SIA was found to be statistically insignificant. Temporal incision had the trend of inducing with-the-rule astigmatism.

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