Possible ways to solve the issues of drug delivery to the posterior segment of the eye

PURPOSE: To identify visual functions dynamics in patients with primary open-angle glaucoma (POAG) with preserved visual functions and compensated intraocular pressure (IOP) after trophic modified laser coagulation (tMLC) and subsequent subconjunctive injection
of Retinalamin® to the laser burn sites with local vasoconstriction.

MATERIALS AND METHODS: The study included two groups: main (118 eyes) and control (40 eyes) with moderate and advanced stages of open-angle glaucoma and normalized IOP. Main group patients underwent tMLC followed by Retinalamin® injection, while control group patients’ treatment was limited solely to tMLC. All patients underwent a general examination, which consisted of the collection of symptoms, anamnesis vitae and morbi, and a comprehensive ophthalmological examination, including visometry, tonometry, biomicroophthalmoscopy and automated static perimetry using a central threshold test. The study was conducted before treatment, on the 5th day after tMLC, 1 month after tMLC and 5 months after tMLC. Trophic modified laser photocoagulation was carried out in two stages: the creation of zones of increased
permeability in the blood-ocular barrier (BOB) and the injection of Retinalamin® into this area.

RESULTS: In the study group, there was a significant improvement in visual fields parameters immediately after the treatment and long-term preservation of the effect after treatment. In the control group, visual functions improvement was achieved only immediately after treatment, and after one month the parameters practically did not differ from baseline. The trend of parameters’ return to baseline values was revealed in both groups, but in the control group this phenomenon was registered by the 1 month timepoint, while in the study group the effect lasted longer and the decrease was observed only 5 months after the treatment, indicating a long-term preservation of the positive treatment effect.

CONCLUSION: The method of subconjunctival Retinalamin® injection with local vasoconstriction at the laser burn sites (tMLC) showed an increase in local permeability of blood-ocular barrier for drug delivery, resulting in visual functions improvement. The obtained data suggest the efficacy, safety and promising use of tMLC in combination with Retinalamin® injection as a neuroretinoprotective therapy in patients
with compensated POAG and preserved visual functions.

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