The first preclinical, angiospastic phase of retinopathy of prematurity

    Purpose. To evaluate the role of the first preclinical phase in the pathogenesis of retinopathy of prematurity (ROP).

    Material and methods. 642 premature babies were examined. The gestational age at the time of birth was up to 30 weeks and the weight was up to 1500 g. Ophthalmological monitoring was carried out from 28–30 weeks of postconceptional gestational age. Indirect ophthalmoscopy, digital calibration of retinal vessels, and studies on a wide-field retinal pediatric camera were performed. Dopplerography data of the blood flow in the brain vessels and in the ocular artery were analyzed in 28 children (56 eyes). The partial pressure of oxygen (pO₂) and carbon dioxide (pCO₂) in capillary blood was studied using Radiometer ABL800 FLEX gas analyzer (normal levels of pO₂ are 40–60 mmHg, pCO₂ is 35–45 mmHg).

    Results. It was revealed that the lower the degree of maturity of the child’s body was, the more often retinal arteriospasm was detected. In children with a postconceptional age of 25–27 weeks, arteriospasm was detected in 82% of cases, at 28 – 29 weeks – in 67%, 30 – 32 weeks – in 54% of cases. The degree of angiospasm correlates with a high index of blood flow resistance in the brain vessels and the ocular artery. The predominance of a high index of blood flow resistance in more premature infants with low body weight was revealed.The index of resistance of brain vessels 0.8 and higher, according to dopplerography, is a critical indicator of the threat of ROP development in a premature baby.

    Conclusion. During retinopathy of prematurity, it is important to detect the first preclinical, antispasmodic phase of ROP development, which lasts about one month and until now practically does not attract the attention of ophthalmologists. In this phase, the pathogenesis of pathological angiogenesis is formed. Further study of the preclinical phase will radically revise the strategy and tactics of diagnosis and treatment of RP.

    Key words: retinopathy of prematurity, first preclinical angiospastic ROP phase, active ROP phase, scarring ROP phase, autoregulation of retinal vessels, hypoxic and hypercapnic drives.