Introduction: The earlier treat stage 3 ROP is more likely to achieve better outcomes. Primary Purpose: To study the unfavorable outcomes and regression after pre-early treatment for ROP. Secondary Purpose: To evaluate the progression and recurrence of ROP requiring retreatment after pre-early treatment for ROP. Patients and Methods: The data were retrieved retrospectively from the medical records of all infants who were screened and treated for ROP from January 2009 to January 2014 at a tertiary care facility. The outcomes measured the following: 1. unfavorable outcomes; 2. regression of ROP; 3. progression of ROP and 4. recurrence of ROP requiring retreatment. We treated all stage 3 ROP in any zone, with or without plus. The study also compared the outcomes between the pre-ETROP and the ETROP subgroups. Results: There were 91 eyes with stage 3 ROP. Of the total of 91 eyes, there were 63 eyes with the pre-ETROP group and 28 eyes of the ETROP group. The unfavorable outcomes after treatment occur 6 eyes from 28 eyes (21.43%) in the ETROP group but no unfavorable outcomes in the pre-ETROP group (P=0.001). The pre-ETROP group who were treated with laser LIO alone had 100% regression, while the ETROP group who were treated with LIO (26 eyes) had 88.46% regression. There were 2 eyes of this group who were treated with a combination of LIO and IVT Bevacizumab. Both of them did not have regression. The recurrence of ROP requiring retreatment occurred in 2 eyes (7.14%) of the ETROP group, but no recurrence in the pre-ETROP group (P=0.092). The progression after treatment occurred in 3 eyes (10.71%) in the ETROP group, but no progression in the pre-ETROP group (P=0.027). Conclusion: The pre-ETROP treatment is useful for reducing unfavorable outcomes and increasing the regression of ROP. Further, the treatment can reduce the recurrence of neovascularization and progression after treatment.

Introduction: To study the unfavorable outcomes and regression after neovascularization treatment for non-type 1 retinopathy of prematurity (ROP) in a tertiary care facility in Thailand. Methods: A retrospective study was done of all infants undergoing screening and treatment for ROP at a tertiary referral center between July 2018 and June 2021 with follow-up for 60 weeks postmenstrual ages (PMA). The outcomes measured were unfavorable outcomes, including macula involving posterior retinal folds, macula involving retinal detachment, retrolental cicatrix formation, or a mass obscuring the view of the posterior pole, and the regression of ROP after treatment. The infants received neovascularization treatment (stage 3 ROP) within 72 h of diagnosis. The study also compared the unfavorable outcomes and regression between neovascularization in type 1 ROP and non-type 1 ROP subgroups. Results: There were 58 eyes of 31 infants that received neovascularization treatment that were included in the study. Of these 58 eyes, 41 had non-type 1 ROP, and 17 had type 1 ROP. 92.68% of the eyes treated for non-type 1 ROP had stage 3 ROP in zone II with pre-plus disease and 74.47% of the eyes treated for type 1 ROP had stage 3 ROP in zone II with plus disease. The mean gestational age and birth weight of the enrolled infants were 28.48 ± 1.99 weeks and 1165.32 ± 394.57 g, respectively. Unfavorable outcomes after neovascularization treatment occurred in three eyes (17.65%) in the type 1 ROP group, but there were no unfavorable outcomes in the non-type 1 ROP group (p=0.022); these three eyes were treated with laser indirect ophthalmoscopy (LIO) combined with Intravitreal bevacizumab (IVB). The non-type 1 ROP treated with laser LIO alone group had 100% regression, whereas type 1 ROP treated with LIO or combined LIO and IVT bevacizumab group had 82.35% regression. Progression after treatment without regression occurred in five eyes (29.41%) with type 1 ROP, but no progression occurred in eyes with non-type 1 ROP (p=0.001). Conclusion: Neovascularization treatment in non-type 1 ROP is useful for preventing unfavorable outcomes and achieving the regression of neovascularization, especially for diseases less severe than type 1 ROP. Moreover, neovascularization treatment in non-type 1 ROP can reduce the progression of ROP disease.