Claude Posala, Jeyanth Rose, Michael Goggin, Peter Cooper
To estimate the surgically induced astigma-tism using vector analysis in manual small incision cataract surgery.
This prospective study consisted of a con-secutive series of 44 eyes of 56 patients who had uncomplicated manual small incision cataract surgery performed by a single surgeon between Jan 2011 to Jun 2012. The incision size was documented in all cases & the surgical technique was standardized. Outcome measures used to calculate the vector mean of induced astigmatism included preoperative & post-operative keratometry using the Nidek hand held auto keratometer at 6–10 weeks postoperatively. The data was entered into a spreadsheet & statistical analysis was performed using Microsoft excel.
This article reports postoperative clinical outcomes at 6–10 weeks.The age spectrum was between 42 to 90 years. 68% of patients were female & 55% belonged to the native ethnic group. 84% patients had visual acuity of 6/12 or better.SIA calculated using the vector method had a mean of 1.10 diopters with a range of 0.09–4.62 diopters (SD = 0.7), Flattening effect at the surgical axis (90°) was ?0.25 (SD = 0.84). A summated vector mean of the SIA was 0.45D at 1170.
These data suggest that this method of incision construction is astigmatically active to a small degree but, in common with many incisional techniques, the axis of effect of the incision varies sug-gesting that a significant proportion of the observed effect is due to the common variations in all kerato-metric measurements.