Severe proliferative diabetic retinopathy treated with vitrectomy or panretinal photocoagulation: a monocenter randomized controlled clinical trial

Proliferative diabetic retinopathy without preoperative pan-retinal photocoagulation is associated with higher levels of intravitreal IL-6 and postoperative inflammation

Purpose

Intravitreal cytokine levels and differences in the severity of postoperative inflammation in patients with proliferative diabetic retinopathy (PDR) were compared between subjects treated with pan-retinal photocoagulation (PRP) prior to undergoing vitreous surgery and those treated similarly during the surgery.

Subjects and methods

We examined 130 eyes of PDR patients who underwent an initial surgical procedure at Hirosaki University Hospital. A total of 67 out of the 130 eyes were treated with PRP prior to surgery (preoperative group), while 63 underwent similar treatment during surgery (intraoperative group). Vitreous fluid was collected at the start of the vitreous surgical procedure. Following vitrectomy, intraoperative PRP was completed during the surgery in the intraoperative group. This procedure was added to the peripheral part as needed in the preoperative group. The results for the levels of 27 cytokines, including vascular endothelial growth factor (VEGF), were measured using multiplex assays and compared between the groups. For determining postoperative inflammation, eyes in which fibrin was observed for 3 days or longer in the anterior chamber or vitreous cavity were considered to have fibrin deposition. The rate of fibrin deposition was compared between these groups.

Results

Among the vitreous cytokines examined, there was no significant difference in the VEGF levels between the groups (p = 0.70). In contrast, the IL-6 level was significantly higher in the intraoperative group (2813.2 ± 6022.2 vs. 1248.5 ± 1442.2 pg/ml, p = 0.048). Furthermore, the fibrin deposition rate was significantly higher in the intraoperative (44.4%) versus the preoperative group (14.9%) (p = 0.0002).

Conclusion

Severe postoperative inflammation was frequently seen in patients who did not undergo preoperative PRP, which may have been due to the performance of the procedure during the surgery. Moreover, these results may also be associated with a higher level of intravitreal IL-6.

Surgical management of diabetic tractional retinal detachments

Tractional retinal detachment is an end-stage form of diabetic retinopathy that occurs when contractile forces in the vitreous and neovascular tissue lead to the detachment of the neurosensory retina. We review the literature related to the management of this disease. Preoperative planning includes appropriate patient selection, diagnostic and prognostic imaging, and medical optimization with reduction of systemic risk factors. Use of antivascular endothelial growth factor for preoperative treatment has had significant benefits for tractional retinal detachment repair in improving surgical efficiency and outcomes. Advances in microsurgical instrumentation are discussed, with attention to small-gauge vitrectomy with improved flow dynamics, viewing strategies, and lighting allowing bimanual surgery. Special emphasis is placed on bimanual surgical technique, choice of tamponade, and the avoidance of iatrogenic damage. Complications and special considerations are further explored. Based on our compilation of relevant literature, we propose a surgical algorithm for the management of these complex patients.

Improved outcome after primary vitrectomy in diabetic patients treated with statins

PURPOSE

To evaluate the effect of preoperative statin treatment on the outcome of primary vitrectomy in type 1 and 2 diabetic patients.

METHODS

In this open, observational institutional study, a total of 192 eyes of 171 type 1 and 2 adult diabetic patients admitted for primary vitrectomy for management of sight-threatening forms of diabetic retinopathy were divided according to the use of lipid-lowering therapy: those with statin treatment (79 eyes of 73 patients) and those taking no statin medication (113 eyes of 98 patients). One-month best-corrected visual acuity (BCVA) gain and cumulative 12-month revitrectomy frequency were analyzed.

RESULTS

In multivariate linear regression, diabetic patients with statin treatment had a better 1-month BCVA improvement than did those without statin treatment (absolute difference 0.26, 95% confidence interval [CI] 0.02-0.50, p = 0.028). Subgroup analysis revealed that diabetic patients on statin had better postoperative BCVA improvement when preoperative status included partial or panretinal laser photocoagulation (p = 0.042 and p = 0.049) and anti-vascular endothelial growth factor therapy (p = 0.011). Moreover, diabetic patients with preoperative macular edema (p = 0.009), vitreous hemorrhage (p<0.001), proliferative retinopathy (p<0.001), or tractional retinal detachment (p = 0.010) had better BCVA recovery if receiving statin. In Cox proportional hazards regression model, revitrectomies in our 12-month follow-up were less frequent in diabetic patients on statin treatment (hazard ratio 0.28, 95% CI 0.08-0.93, p = 0.037).

CONCLUSIONS

These data provide novel insight into the potential clinical benefit for patients with sight-threatening diabetic retinopathy undergoing vitrectomy treated with statin.