The importance of PDGF, VEGF, PIGF and B-FGF levels in vitreous and serum of patients with wet TYPE age-related macular degeneration

Vascular endothelial growth factor (VEGF), platelet derived growth factor (PDGF), placental growth factor (PlGF) and basic fibroblast growth factor (bFGF), take a place in physiologic processes displaying their physiologic effects in both intraocular environment and systemic circulation. In our study, we aimed to investigate changes in vitreous and blood VEGF, PDGF, PlGF and bFGF levels in wet-type age-related macular degeneration (w-AMD) after anti-VEGF therapy with intravitreal ranibizumab injections. In our study, we recruited 38 eyes of 38 patients with w-AMD. Measurements of baseline best-corrected visual acuity (BCVA) and central macular thickness (CMT) were taken and repeated 1 month after treatments. All patients received consecutive monthly intravitreal injection of 0.5 mg/0.05ml ranibizumab. First blood samples were collected at the day of the first injection, second sample at the next day, and third samples at the next day after the fourth injection (at month 3). Vitreous samples were collected at the time of 1, 2 and 4. intravitreal injections. Samples were stored at -80 C. The levels of VEGF-A, PDGF, PIGF, FGF in the samples were measured by enzyme-linked immunosorbent assay kits. Mean age of 31 patients who completed the study was 70.96±7.69 years. Nineteen patients were female (61.3%) and 12 were male (38.7%). Mean age of age- and sex-matched 17 controls who undergone vitreoretinal surgery for epiretinal membran or macular hole was 71.41±7.78 years. A statistically significant improvement in BCVA and CMT was observed in all patients. Mean levels of VEGF, PDGF and PlGF were 49.27±32.28, 27.86±16.29 and 12.17±6.87 pg/mL for the first vitreous samples and 23.61±10.56, 27.31±11.16 and 11.08±6.07 pg/mL, respectively for the second vitreous samples and 20.66±7.74, 27.25±12.94 and 13.50±8.98 pg/mL, respectively for the third vitreous samples. The difference between the three measurements was statistically significant in VEGF, but not in PDGF and PlGF (p<0.001, p:0.82 and p:0.13, respectively). Blood VEGF and PDGF levels were 336.84±172.48 pg/ml and 3583.41±1492.95 pg/ml at baseline; 326.37±164.75pg/ml and 3640.96±1458.84pg/ml at month 1 and 320.34±170.99pg/ml and 3428.80±1477.90 pg/ml at month 3. Blood PlGF and bFGF levels were 17.72±4.44 pg/ml and 2.77±1.74 pg/ml at baseline; 15.44±3.61 pg/ml and 2.80±1.72 pg/ml at day 1 and 14.98±4.0 pg/ml and 2.45±1.18 pg/ml at month 3. There was no significant difference between the first, second and third measurements of serum growth factors. Baseline vitreous VEGF level was higher than the control group (p=0.037). While intravitreal ranibizumab treatment caused suppression of intraocular VEGF levels for the first 3 months, it did not cause significant changes in systemic VEGF levels the day after the 1st and 4th injections. There was no significant treatment-related change in vitreous and serum values of other factors. A positive correlation was found between blood VEGF and FGF levels. Keywords: Age-Related Macular Degeneration, PDGF, PlGF, VEGF, FGF, Vitreous, Serum