Efficiency of vitreal cavity tamponade in prevention of postoperative  hemophthalmos in patients with an advanced stage of proliferative diabetic  retinopathy

Purpose. To compare the effectiveness of tamponade of the vitreal cavity with a gas-air mixture and silicone oil (SO) in the prevention of postoperative hemophthalmos in patients with an advanced stage of proliferative diabetic retinopathy (PDR). Material and methods. Of the 80 patients (80 eyes) with advanced stage of PDR (classification by Kroll P., 1987), 37 were operated by vitrectomy with tamponade of the vitreous cavity with gas-air mixture (group 1), and 43 – with SO (group 2), followed by its removal after 3 months. When postoperative hemophthalmos were detected, conservative therapy was prescribed first for 1 month, in cases without effectiveness, additional vitreoretinal intervention (VRI) with SO tamponade was performed. Control examinations were performed after 1, 3 and 6 months. The observation period was 6 months. Statistical data processing was performed using the IBM SPSS statistic program; differences were considered significant at p<0.05. Results. The best-corrected visual acuity (BCVA) before VRI in group 1 averaged 0.08±0.03, in group 2 – 0.1±0.02 (p1–2>0.05). After 1 month, BCVA corresponded to 0.2±0.02 in group 1 and 0.18±0.04 in group 2, respectively (p1–2>0.05, p1,2<0.05 to pre-treatment data). 1 month after VRI, in 1st group, postoperative hemophthalmos was diagnosed in 35.1% of cases, in 21.6% cases additional VRI with SO tamponade was required. The effectiveness of primary VRI against the background of gas-air mixture was 78.4% of cases. In the 2nd group, postoperative hemophthalmos was diagnosed in 2.3% of cases at the same time, in 1 patient out of 43 (p1–2<0.05). Primary VRI against the background of SO was effective in all cases (43/43) (p1–2<0.05). After 3 months, BCVA in patients of 1st group averaged 0.2±0.05, in 2nd group (after SO removal) – 0.3±0.02 (p1–2<0.05, p1>0.05 to data 1 month after primary VRI, p2<0.05 to data 1 month after primary VRI). In 1st group, after 3 months, primary postoperative hemophthalmos were diagnosed in 11 (new) cases (+29.7%) (p1–2<0.05, p1,2<0.05 to data 1 month after primary VRI), in 2nd group underwent additional (second) VRI – SO removal. At the 6-month follow-up examination, the effectiveness of primary VRI was 56.7% of cases (21/37) in the 1st group patients with gas-air mixture tamponade, and 86% of cases (37/43) in the 2nd group with SO tamponade, respectively. Long-term SO tamponade was observed in 43.2% of cases (16/37) in the 1st group, and in 14% of cases (6/43) in the 2nd, respectively) (p1–2<0.05). The average BCVA in group 1 was 0.22±0.03, in group 2 – 0.35±0.015 (p1–2<0.05, p1>0.05 to data 1 and 3 months after primary VRI, p2<0.05 to data 1 month after primary VRI, p2>0.05 to data 3 months after primary VRI). Conclusion. The effectiveness of primary VRI to preventing postoperative hemophthalmos in patients with advanced stage of PDR against the background of tamponade of the vitreal cavity with gas-air mixture after 1 month was 78.4%, while its decrease to 56.7% within 3 months and was maintained by the end of observation period (after 6 months), whereas against the background of SO tamponade, the effectiveness of primary VRI was 100% after 1 month, with a decrease to 86% after 3 months (after SO removal), which was maintained after 6 months (p1–2<0.05). Thus, the choice of SO tamponade of the vitreal cavity is an effective method for the prevention of postoperative hemophthalmos in comparison with gas-air mixture, providing better morphofunctional results in the long term. Key words: proliferative diabetic retinopathy, vitreoretinal intervention, additional vitreoretinal interventions, vitreous cavity tamponade, gas-air mixture, silicone oil, postoperative hemophthalmos