Yothin Titawattanakul, Kittisak Kulvichit, Adisai Varadisai, Apivat Mavichak Vitreo-retina Research Unit, Department of Ophthalmology, Faculty of Medicine, King Chulalongkorn Memorial Hospital, Chulalongkorn University, Bangkok, ThailandCorrespondence: Kittisak KulvichitDepartment of Ophthalmology, Faculty of Medicine, Chulalongkorn University, Bangkok, ThailandTel +66 2 2564000Email kulvichit@gmail.comIntroduction: 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.Keywords: retinopathy of prematurity, pre-early treatment for retinopathy of prematurity, outcomes, regression