The effect of an antiprostaglandin, piroxicam, in preventing surgically induced miosis is studied. Patients undergoing extracapsular cataract surgery were randomly divided into the piroxicam and placebo groups. Intra-operative measurements of the pupillary diameters were performed. The stages of procedure at which they were measured were at the beginning of operation (Stage 1), after anterior capsulotomy (Stage 2), after lens nucleus delivery (Stage 3) and at the end of irrigation and aspiration (Stage 4). It is noted in this Study that the pupillary diameters were larger at stages 2,3 and 4 in the piroxicam group. The increase in the mean pupillary areas of the piroxicam group were statistically significant for Stages 3 and 4.
One hundred and thirteen consecutive infants with a very low birthweight of less than 1500 g were followed prospectively for 6 months to determine the incidence of retinopathy of prematurity (ROP) and associated risk factors. Of this group, 36 (31.9%) infants developed ROP (13 infants had stage 1 ROP, nine had stage 2, six had stage 3, six had stage 4, and two had cicatricial stage ROP). Stepwise logistic regression analysis of various potential risk factors (birthweight, gestation, duration of oxygen therapy, duration of ventilation, highest documented PaO2 and exchange transfusion) showed that only two risk factors were significantly associated with the development of ROP. These risk factors were: the duration of oxygen therapy (p = 0.0005) and exchange transfusion during the neonatal period (odds ratio 5.754, 95% confidence interval 1.002 to 32.997, p = 0.049). The equation of the regression model is: log (odds of developing ROP) = -0.8395 + 0.1447 (OXY)- 0.8750 (ET), where OXY is the duration of oxygen therapy in days, ET = -1 when there was a history of exchange transfusion, and ET = 1 when there was no history of exchange transfusion.