Inadequate laser coagulation is an important cause of treatment failure in Type 1 retinopathy of prematurity.

PURPOSE OF THE STUDY: To examine the cause of treatment failures in Type 1 retinopathy of prematurity (ROP). PATIENTS AND METHODS: The medical charts of all infants with disease persistence after laser treatment at Uppsala University Hospital, Sweden, during a 10-year period (2009-2019) were reviewed. RetCam photography and angiography were used to document the retinal appearance before and after retreatment. RESULTS: Ten infants (18 eyes), of whom nine were referred from other hospitals, had persistence of Type 1 ROP in zone I or zone II despite previous laser treatment. Their mean gestational age was 24 weeks and their mean birth weight was 618 g. Seven eyes were diagnosed as stage 3 plus, eight eyes as stage 4A and three eyes as stage 4B. In eight infants (14 eyes), inadequate laser coagulation was suspected to be the cause for persistence of type 1 disease. Two infants (four eyes) were appreciated to have persistence of plus disease because of presence of zone I disease. For persistence of Type 1 ROP, five infants (seven eyes) were treated with vitrectomy, two infants (three eyes) with laser photocoagulation and anti-vascular endothelial growth factor (VEGF), two infants (four eyes) with anti-VEGF alone and finally two infants (four eyes) with laser photocoagulation alone. The anatomical outcome was good in 14 eyes and poor in four eyes (three infants). CONCLUSIONS: Inadequate laser coagulation is an important cause of treatment failure of ROP Type 1. Another cause is laser coagulation in zone I. To minimize remaining visual disability, some kind of centralization of the ROP treatment is suggested.