Intraocular pressure variations after diode laser photocoagulation for threshold retinopathy of prematurity

Purpose: To investigate the intraocular pressure (IOP) variations occurring after indirect diode laser photocoagulation for threshold retinopathy of prematurity. Design: Prospective, nonrandomized, comparative study. Participants: A study group-21 consecutive premature babies (42 eyes) undergoing diode laser photocoagulation for retinopathy of prematurity-and control groups-32 premature babies (64 eyes) undergoing retinal examination with or without scleral indentation. Intervention: Intraocular pressure was measured with a portable electronic tonometer before, immediately after, and 1, 2, and 3 days after diode laser photocoagulation in the study group; before retinal examination in control group 1; and before and after retinal examination with scleral indentation in control group 2. Main Outcome Measure: Intraocular pressure after diode laser photocoagulation for threshold retinopathy of prematurity. Results: Mean IOP in the study group rose from 15 mmHg (standard deviation [SD] = 4.1) before coagulation to 33.2 mmHg (SD = 7.8; range, 20-50) immediately after, and then dropped to 22.2 (SD = 5.2), 16.5 (SD = 3), and 14.5 mmHg (SD = 2.1) 1, 2, and 3 days later, respectively. All the changes were statistically significant at P<0.0001, except for the difference between days 2 and 3 (P = 0.096). Mean baseline IOPs were 16.3 mmHg (SD = 3.7) in control group 1 and 15.7 mmHg (SD = 2.3) in control group 2 (P = 0.84 between control group 1 and study group, and P = 0.32 between control group 2 and the study group). At termination of the retinal examination with scleral indentation (control group 2), IOP measured 15.1 mmHg (SD = 2.2) (P = 0.49 compared with baseline). Conclusions: Intraocular pressure may be significantly elevated after diode laser photocoagulation for retinopathy of prematurity. The mechanism and long-term clinical implications of this observation should be investigated. (C) 2004 by the American Academy of Ophthalmology.