Introduction In proliferative diabetic retinopathy (PDR), vascular endothelial growth factor (VEGF) and connective tissue growth factor (CTGF) may cause blindness by neovascularisation followed by fibrosis of the retina. It has previously been shown that a shift in the balance between levels of CTGF and VEGF in the eye is associated with this angiofibrotic switch. This study investigated whether anti-VEGF agents induce accelerated fibrosis in patients with PDR, as predicted by this model. Methods CTGF and VEGF levels were measured by ELISA in 52 vitreous samples of PDR patients, of which 24 patients had received intravitreal bevacizumab 1 week to 3 months before vitrectomy, and were correlated with the degree of vitreoretinal fibrosis as determined clinically and intra-operatively. Results CTGF correlated positively, and VEGF correlated negatively with the degree of fibrosis. The CTGF/VEGF ratio was the strongest predictor of fibrosis. Clinically, increased fibrosis was observed after intravitreal bevacizumab. Conclusions These results confirm that the CTGF/VEGF ratio is a strong predictor of vitreoretinal fibrosis in PDR, and show that intravitreal anti-VEGF treatment causes increased fibrosis in PDR patients. These findings provide strong support for the model that the balance of CTGF and VEGF determines the angiofibrotic switch, and identify CTGF as a possible therapeutic target in the clinical management of PDR.

Objective To compare the outcome of air tamponade with gas tamponade in primary vitrectomy for the treatment of rhegmatogenous retinal detachment (RRD). Methods We examined the records of 524 cases of 523 patients that underwent primary vitrectomy for RRD with air or sulphur hexafluoride 20% gas tamponade and a follow-up of at least 3 months, excluding cases with inferior retinal breaks. Results 318 cases were treated with gas and 128 cases with air. Overall, vitrectomy led to an attached retina after a single operation in 85.1% of cases. Eyes treated with air had an 81.0% chance of primary success and those treated with gas had an 86.9% success rate (p=0.083, NS, χ² test). Involvement of lower retinal quadrants in the retinal detachment was revealed as a significant confounding factor. After correction for this confounder using a multivariate logistic regression model, air versus gas tamponade became a statistically significant determinant for success rate (OR 1.97; p=0.012). In a sub-analysis, eyes with a retinal detachment that involved the inferior quadrants had significantly lower primary success rates when using air tamponade (69.6%), compared to gas tamponade (84.7%; p=0.009, χ² test). Conclusions Gas tamponade is superior to air tamponade in retinal detachment cases with involvement of the lower quadrants. These results suggest that air tamponade should only be used in retinal detachments that are restricted to the superior quadrants. Further prospective study is needed to confirm these findings, and to address functional outcome.

Purpose: To describe fundus autofluorescence and optical coherence tomography (OCT) features of the macula after pars plana vitrectomy for rhegmatogenous retinal detachment. Methods: Thirty-three eyes of 33 consecutive patients with repaired rhegmatogenous retinal detachment with or without the involvement of the macula were prospectively investigated with simultaneous fundus autofluorescence and OCT imaging using the Spectralis HRA+OCT (Heidelberg Engineering, Heidelberg, Germany) within a few weeks after the operation. Results: Fundus autofluorescence imaging of the macula showed lines of increased and decreased autofluorescence in 19 cases (57.6%). On OCT, these lines corresponded to the following abnormalities: outer retinal folds, inner retinal folds, and skip reflectivity abnormalities of the photoreceptor inner segment/outer segment band. Other OCT findings, not related to abnormal lines on fundus autofluorescence, consisted of disruption of photoreceptor inner segment/outer segment band and collection of intraretinal or subretinal fluid. The presence of outer retinal folds significantly related to metamorphopsia but did not relate to poor postoperative visual acuity. Conclusion: Partial-thickness retinal folds occur commonly after vitrectomy for rhegmatogenous retinal detachment repair and may represent an important anatomical substrate for postoperative metamorphopsia. Fundus autofluorescence and OCT are both sensitive techniques for the detection of these abnormalities.