AIM: To explore the possible application of quadrant classification in retinopathy of premature infants at threshold and type 1 pre-threshold stage.

METHODS: Thirty-two preterm infants with retinopathy at the threshold and type 1 threshold preterm stage in the Affiliated Eye Hospital of Nanchang University from April 2017 to January 2018 were recruited for retrospective case analysis. The main location and stage of the retinopathy in these premature infants were divided into three categories by the quadrant method: only one quadrant(above the nose, subnasal, supratemporal, and subtemporal)recorded as “1 quadrant”; distributed in two quadrants(supertemporal+infratemporal, supra-nasal+sub-nasal, supra-nasal+super-temporal, sub-nasal+sub-temporal, supra-nasal+sub-temporal, sub-nasal+super-temporal)were recorded as “2 quadrants”; distributed more than two quadrants recorded as “>2 quadrants”. The clinic characteristics of all cases and the responses to intravitreal injection of ranibizumab were observed according to the quadrant method.

RESULTS: Totally 32 cases with 62 eyes of premature infants recruited in the study. Only 2 eyes were in 1 quadrant before surgery, and the efficiency of a single injection was 100%. A total of 25 eyes were distributed in 2 quadrants, and with a single injection, the effective rate was 100%. 35 eyes with a distribution “2 quadrants” had a single injection rate of only 74% and a recurrence rate of 26%.

CONCLUSION: The main lesions in most cases are distributed in “2 quadrants”(supertemporal+subtemporal). The more of quadrants accumulated for the major lesions and the more severe of the condition; the higher recurrence rate after intravitreous anti-VEGF therapy.