Tear fluid vascular endothelial growth factor level as a marker of effectiveness of proliferative diabetic retinopathy combined treatment

Aim. To assess the tear fluid level of vascular endothelial growth factor in patients with proliferative diabetic retinopathy in case of panretinal photocoagulation and intravitreal ranibizumab treatment. Methods. Panretinal photocoagulation was performed in 20 patients (40 eyes) with proliferative diabetic retinopathy (first group). In the second group, which included 20 patients (40 eyes) with the same stage of diabetic retinopathy, panretinal photocoagulation was combined with intravitreal ranibizumab treatment. 20 healthy subjects (40 eyes) were examined as a contol group. There were no adverse events registered during the treatment. At the follow-up, 4 patients from the first group were diagnosed with partial intraocular hemorrhage; a posterior vitrectomy was required in 1 eye, in 3 eyes intraocular hemorrhage has resolved spontaneously. A complex of clinical and laboratory examinations included visual acuity testing, biomicroscopy, indirect ophthalmoscopy using Mainster wide field lens, fluorescein angiography, optical coherence tomography, tear fluid ELISA. Results. There was a complete regression of retinal neovascularization (no blood flow in newly grown blood vessels) in 14 (35%) eyes of patients from the first group after the first procedure. In the second group a complete regression of retinal neovascularization was observed in 100% of cases after the first procedure. The tear fluid level of vascular endothelial growth factor increased from 398.6±112.2 to 668.2±102.2 pg/ml (p <0.05) in 40 (100%) eyes of patients from the first group, in the second group the level of vascular endothelial growth factor decreased after the angiogenesis inhibitor injections in 40 eyes (100%) from 332.1±98.2 до 314.6±44.4 pg/ml (p <0.05). 1 month after treatment the visual acuity in the first group the visual acuity improved in 40% of cases (16 eyes), was stable in 45% (18 eyes), decreased in 15% (6 eyes) with the mean value changed from 0.22±0.12 to 0.24±0.08 (p <0.05); in the second group the visual acuity improved in 40% of cases (16 eyes), was stable in 45% (18 eyes), decreased in 15% (6 eyes) with the mean value changed from 0.22±0.12 to 0.24±0.08 (p <0.05). Conclusion. The use of panretinal photocoagulation combined with intravitreal ranibizumab treatment in patients with proliferative diabetic retinopathy decreases the tear fluid vascular endothelial growth factor level, improves the visual acuity and thickness of the retina. There was a marked and prolonged effect after the combined treatment, that allows to recommend this treatment method to all patients with proliferative diabetic retinopathy.

VEGF, diabetic retinopathy, panretinal photocoagulation, vascular endothelial growth factor, ranibizumab