Mathematical substantiation of retinal laser coagulation pattern using hexagonal pattern form in the treatment of active stages of retinopathy of prematurity

Purpose. To substantiate mathematically the tissue-preserving effect on the retinal hexagonal pattern during the laser treatment of active retinopathy of prematurity. Material and methods. At the first stage of the study, a mathematical rationale of the application of a hexagonal pattern was carried out to provide a tissue-sparing effect on the retina compared to the traditional laser coagulation pattern with matrix (rectangular) patterns.The second stage was performed as clinical studies in two groups of patients with an unfavorable course type II and III stages of active ROP. The main group consisted of 44 infants, which underwent hexagonal Fyodorov Journal of Ophthalmic Surgery. 2020;1: 40–46.laser coagulation (7 applications in one «honeycomb» pattern). The control group involved 41 infants who had a matrix laser coagulation (9 applications in one «rectangular» pattern). Results. At the first stage, it was proved that the hexagonal shape of the pattern is mathematically substantiated and ensures a uniform distribution of laser applicates on the spherical surface of the retina due to the equidistant location of the spots inside one pattern and optimal matching of neighboring patterns.As a result of the second stage of research in both groups, a regression after laser treatment was obtained in more than 97% of cases at the ROP stage 2 and in 94% of cases at the ROP stage 3. The total energy load in the main group was less than in the control group. The increase in the inter-spot distance in the hexagonal pattern by 0.25 of the coagulum diameter in comparison with the matrix pattern made it possible to maintain a high clinical efficacy and to ensure tissue-preserving effects on the retina. Conclusion. Optimization of the pattern laser coagulation method using a hexagonal-shaped pattern allows to shorten the duration of the intervention maintaining a high clinical efficacy in the treatment of active ROP.