Open Access Original Research Article
Background and Aim: Despite considerable progress made in the treatment of Retinopathy of prematurity (ROP), it is still a common cause of reduced vision in children in developed countries, and its prevalence is increasing. This is a preventable disease and responds to treatments appropriately if diagnosed at early stages, but in case of delayed diagnosis and treatment, it may lead to blindness. The aim of the present study is to describe the incidence, severity, and risk factors of ROP in a tertiary healthcare center.
Material and Methods: This was a prospective, observational, nonrandomized study conducted in a tertiary-level neonatal intensive care unit (NICU) of a teaching hospital in Gujarat. A total of 130 preterm neonates admitted in the NICU during the study period were screened for ROP as per the guidelines of NNF of India. Screening was done under topical anesthesia, and findings were documented according to the International Classification for Retinopathy of Prematurity recommendations. The data were analyzed for gestational age, birth weight, and systemic factors predisposing to ROP.
Results: Of the 130 neonates, 37 neonates were found to have ROP, with the incidence of ROP being 28.4%. The mean birth weight (1388 ± 312 g) and the mean gestational age (32.21 ± 2.50 wk) Out of the 37 neonates with ROP, 14 had a gestational age of > 32 weeks and/or birth weight of > 1500 g. ROP was classified into type 1 and type 2 as per the ETROP study, 14 (39.39%) neonates had type 1 or treatable ROP; there were no cases of APROP in our study; ROP regressed without any intervention in 13 neonates; 7 neonates were defaulters; and 11 neonates were treated with laser.
Conclusion: ROP is strongly associated with smaller, more immature, and sicker neonates. However, in our study, about 40% of neonates who developed ROP were of higher gestation (> 32 wk) and birth weight (> 1500 g). The analysis of risk factors for ROP development will help to understand and predict it in severe preterm infants.
Open Access Original Research Article
Purpose: To consider new possibilities of refractive modeling of the cornea by the radiation of an argon-fluorine excimer laser in ablative and subablative modes after saturation of the stroma with riboflavin.
Materials and Methods: Experimental (20 pork, 90 rabbit eyes) and clinical studies on photorefractive and phototherapeutic operations with saturation of the corneal stroma with riboflavin (610 operations) were analyzed. To activate riboflavin, secondary radiation induced by exposure to ablative and subablative energy densities was used. A quick transition to energy densities below the ablation threshold without additional calibrations was carried out using a “Microscan Visum-500” excimer laser (Optosystems, Russia). An objective assessment of the refractive keratomodelling effect and visual results was carried out according to the data of complex optometric studies.
Results: Experimental and clinical studies have shown the advantages of refractive keratomodeling by theradiation of an argon-fluorine excimer laser in ablative and subablative modes after saturation of the stroma with riboflavin. Isotonic 0.25% riboflavin solution did not affect the accuracy of refractive ablation and blocked the negative effect of induced secondary radiation on keratocytes and corneal nerves. This reduced the aseptic inflammatory response and the risk of developing an irreversible form of fibroplasia. Ablation with riboflavin initiated a damped crosslinking effect, which increased the photoprotective and strength properties of the thinned cornea. A refractive keratomodelling effect was found when energy densities were applied below the stromal ablation threshold. The magnitude of this refractive effect depended on the total radiation dose and the topography of the affected area. This approach made it possible to implement laser-induced refractive keratomodeling without ablation of the corneal stroma.
Conclusion: Refractive modeling of the cornea by the radiation of an argon-fluorine excimer laser in ablative and subablative modes after saturation of the stroma with riboflavin opens up new possibilities in laser correction of ametropia.