Therapeutic outcomes of cryotherapy versus transpupillary diode laser photocoagulation for threshold retinopathy of prematurity

introduction: We undertook this study to compare the clinical outcomes in p atients treated for threshold retinopathy of prematurity (ROP) with transpu pillary diode laser photocoagulation versus transscleral cryotherapy. Metho ds: A retrospective chart review was performed of patients treated for thre shold ROP at our institution between 1988 and 1997. Cryotherapy was used to treat patients before 1992, and diode laser was used thereafter. One hundr ed fifteen eyes of 63 patients underwent cryotherapy, and 130 eyes of 70 pa tients underwent laser treatment. Because strong concordance exists between fellow eyes treated for ROP, statistical analysis was done for right eye o utcomes only. Demographics, short-term complications, and treatment paramet ers were compared on the entire cohort of patients. Structural outcomes wer e compared between a group of 79 cryotreated eyes (39 OD, 40 OS) and a grou p of 113 laser-treated eyes (56 OD, 57 OS). Mean cycloplegic refraction was compared between a group of 38 cryotreated eyes (18 OD, 20 OS) and a group of 90 laser-treated eyes (46 OD, 44 OS). Visual acuity for preverbal and n onverbal children was estimated and converted to a Snellen visual acuity eq uivalent. Geometric mean visual acuity was then compared between a group of 44 cryotreated eyes (22 OD, 22 OS) and a group of 92 laser-treated eyes (4 7 OD, 45 OS). Patients were included in each outcome analysis if adequate d ocumentation was present in the patient record. Results: Demographics and s hort-term complications were not significantly different between the 2 grou ps. In the statistical group, 22 of 39 right eyes (56.4%) in the cryotherap y group versus 49 of 56 right eyes (87.5%) in the laser group had resolutio n of ROP after treatment (P = .0008). Mean spherical equivalent cycloplegic refraction at 12 months of age and over the follow-up period was not signi ficantly different between the cryotherapy and laser groups. Estimated geom etric mean visual acuity in the cryotherapy group was 20/103 and in the las er group was 20/49 at 12 months of age (P = .0099). Conclusions: Diode lase r photocoagulation was associated with a better long-term structural outcom e and visual acuity compared with cryotherapy for the treatment of threshol d ROP. Refractive error was not significantly different between the 2 group s over an equivalent follow-up period.