Comparative Study of Comparison of Surgically Induced Astigmatism (Sia) Between Superior Approach (Incision) and Temporal Incision in Small Incision Cataract Surgery (Sics)

Abstract

BACKGROUND Cataract extraction is the largest surgical workload in the world. Goal of the modern cataract surgery is to reduce pre-operative astigmatism after operation to improve visual acuity and quality. Regarding the choice of incision location, previous studies reports that the superior incision induces greater change in corneal astigmatism (against the rule) than temporal (with the rule). With The Rule (WTR) is preferred, because it allows better uncorrected visual acuity. With The Rule (WTR) is preferred in most cases, as it frequently allows better uncorrected visual acuity. Nowadays, phacoemulsification remains the more advanced and technically superior method of cataract surgery; it is not always either from a cost purpose and its limitations of few type of cataracts. When incision is located superiorly, both gravity and eyelid blink tend to create a drag on the incision. These forces are better neutralised with temporal incision, because it is parallel to the vector of the forces. With-the-rule astigmatism induced by a temporal incision is advantageous, because most elderly patients have preoperative against-the-rule astigmatism. When incision is located superiorly, both gravity and eyelid blink tend to create a drag on the incision. These forces are better neutralised with temporal incision, because it is parallel to the vector of the forces. With-the-rule astigmatism induced by a temporal incision is advantageous, because most elderly patients have preoperative against-the-rule astigmatism. MATERIALS AND METHODS Subjects of the study were selected from consecutive cases of patients attending the Outpatients Departments of Ophthalmology with consideration of inclusion and exclusion criteria properly, NRS Medical College and Hospital, Kolkata from Nov. 2011 to Sept. 2012. RESULTS The surgically induced astigmatism in temporal SICS (0.98 ± 0.59) is much lower than superior SICS (1.45 ± 1.24) and the difference is statistically very significant (as P value is < 0.01). In age wise distribution table, Surgically Induced Astigmatism (SIA) in temporal SICS is lower than superior SICS. It is clinically significant and statistically significant (P value < 0.05) in all age groups except in < 40 yrs. In superior SICS male vs female, difference in SIA is statistically insignificant (p value > 0.05) and in temporal SICS difference is also statistically insignificant, (p value > 0.05), hence the value is independent on gender factor. CONCLUSION The age wise distribution and comparison table between patients undergoing superior and temporal SICS found that the temporal approach SICS gives less surgically induced astigmatism in all age groups and it is statistically significant (p value) in all groups (except in the age group < 40 yrs.). But as the sample is very small compared to other age groups, so anything cannot be concluded. So overall the study found that the surgically induced astigmatism in temporal SICS is lower than superior SICS and it is statistically significant.