ABSTRACT
Background: The aim and objective of the study was to calculate intraocular lens power with IOL master in 100 eyes of 100 patients with long axial lengths between 25mm to 32mm.To analyse and compare the results of various formulae by postoperative auto refractometry and corrected distance visual acuity and to know the most accurate formula for highly myopic eyes (Axial length more than 25.00 mm). Methods: Patients coming to Sarojini Devi Eye Hospital from December 2012-September 2014 for cataract surgery were considered in this study. All patients with visually significant cataract having fundus findings within normal limits were included in this study and patients of complicated cataract due to trauma, uveitis, Glaucoma and any corneal pathology were excluded from the study. Results: The Mean AL was 27.25 ± 1.25 mm, the Mean keratometric value was 43.62 ± 1.45 D, and the Mean Absolute Error (MAE) calculated by the Haigis was 0.07 DD. Compared to the MAEs generated by the other formulae, the MAE generated by the Haigis was comparable to that by the SRK/T (0.231 D), and significantly lower than those by the Hoffer Q (0.481 D) and Holladay (0.864 D). Conclusions: The Mean post-operative refractive error (spherical equivalent) was found to be the least with Haigis formula followed by SRK/T for eyes with long axial length. The HAIGIS formula has a better predictability and accuracy. The postoperative hyperopic shift was comparable between HAIGIS and SRK-T formulae the least postoperative hyperopic shift with Haigis formula compared to other formulae.
ABSTRACT
Background: Location of incision has a significant impact on surgical outcome. It has been reported that temporal incisions induce less astigmatism than superior incisions indicating the importance of incision location. The objective of the present study was to study the effect of surgical induced astigmatism in superior versus temporal incision in small incision cataract surgery cases. Methods: 100 patients of cataract attending to Sarojini Devi eye hospital with the rule and against the rule astigmatism were included in the study. The astigmatic profile and the effect of surgical incision on astigmatism were studied. A prospective study was done in which patients were divided into two groups. MSICS was performed with superiorly located incision in group I and temporally located incision in group II. Results: Out of the total 100 patients undergoing MSICS, 59 patients had ATR, 36 patients had WTR and 5 patients had no astigmatism. Thus the pre-operative astigmatic profile shows that ATR is more common type of astigmatism in this group. Among 50 patients in superior incision group, 18 had pre-operative WTR, 29 had ATR and 3 did not have astigmatism. Postoperatively the no. of patients with WTR decreased to 10, the no. of patients with ATR increased to 35 showing that superior incision flattens vertical meridian and steepens the horizontal meridian causing ATR shift. Among 50 patients in temporal incision group, 18 had pre-operative WTR, 30 had ATR and 2 did not have astigmatism. Post operatively the no of patients with WTR increased to 25, the no of patients with ATR decreased to 20. Conclusions: Placement of incision on steep axis reduces pre-existing astigmatism. Thus in ATR astigmatism it is placed temporally and in WTR astigmatism it is placed superiorly. Thus a simple modification in incision placement can minimize surgically induced astigmatism and reduce pre-existing astigmatism.