Müller glia as an important source of cytokines and inflammatory factors present in the gliotic retina during proliferative vitreoretinopathy.

Retinal gliosis is characterized by biochemical and physiological changes that often lead to Müller glia proliferation and hypertrophy and is a feature of many neuro-degenerative and inflammatory diseases such as proliferative vitreoretinopathy (PVR). Although Müller glia are known to release inflammatory factors and cytokines, it is not clear whether cytokine production by these cells mirrors the pattern of factors present in the gliotic retina. Lysates from normal cadaveric retina and gliotic retinal specimens from patients undergoing retinectomy for treatment of PVR, the Müller cell line MIO-M1 and four human Müller glial cell preparations isolated from normal retina were examined for their expression of cytokines and inflammatory factors using semi-quantitative dot blot antibody arrays and quantitative arrays. Comparative analysis of the expression of inflammatory factors showed that in comparison with normal retina, gliotic retina exhibited greater than twofold increase in 24/102 factors examined by semiquantitative arrays, and a significant increase in 19 out of 27 factors assessed by quantitative methods (P < 0.05 to P < 0.001). It was observed that with the exception of some chemotactic factors, the majority of cytokines and inflammatory factors were produced by Müller glia in vitro and included G-CSF, MCP-1, PDGF-bb, RANTES, VEGF, and TGFß2. These results showed that a large number of inflammatory factors expressed by Müller glia in vitro are upregulated in the gliotic retina, suggesting that targeting the production of inflammatory factors by Müller glia may constitute a valid approach to prevent neural damage during retinal gliosis and this merits further investigations.

Silicone oil versus gas tamponade for giant retinal tear-associated fovea-sparing retinal detachment: a comparison of outcome.

PurposeSilicone oil is the most common choice of tamponade agent used when managing a giant retinal tear (GRT). Concern exists regarding its potential detrimental effect on vision. We herein report on visual and surgical outcomes of all patients treated at Moorfields Eye Hospital for a GRT over a five year period. We further analysed a subgroup of fovea-sparing retinal detachments (RD) treated by pars plana vitrectomy (PPV) with either silicone oil or gas tamponade.MethodsRetrospective comparative, non-randomised, cross-sectional review of patients with a new diagnosis of GRT from 1 September 2005 to 31 August 2010ResultsOne hundred twenty four eyes of 118 patients were identified with mean age of 45.5 years and median follow-up of 24 months. Subgroup analysis of fovea-sparing RDs (Silicone Oil n=49, Gas n=15) revealed visual loss (≥2 Snellen Lines of vision) in 49.0% (n=24) of patients managed with oil compared to 13.3% (n=2) of gas patients (P=0.019). In all, 73.3% (n=11) in the gas group achieved a final vision of 6/12 or better, compared to 36.7% (n=18) in the oil group (P=0.031). No difference was observed in eventual or primary anatomical success rate (100 vs 93.9%, and 66.7 vs 79.6%, gas vs oil, respectively, (P>0.1)). Postoperative complications were absent in 66.7% (n=10) of gas patients compared with 14.3% (n=7) of oil patients (P=0.002). Multiple variable linear regression determined tamponade choice as the only variable predictive of final visual acuity (P=0.046).ConclusionEyes with fovea-sparing GRT-related RDs managed with gas achieved a better visual outcome with fewer postoperative complications and no significant difference in anatomical success. A multicentre approach to investigate this further is advised.

Ethnic variation in primary idiopathic macular hole surgery.

PurposeThe purpose of the study was to investigate the role of ethnicity on idiopathic macular holes (IMH) structure and surgical outcome. This was a retrospective review.Patients and methodsConsecutive patients undergoing primary IMH surgery at two surgical sites of Moorfields Eye Hospital (London, UK) between April 2012 and June 2013. The main outcome measure was post surgical anatomical closure of IMH.ResultsTwo hundred and twenty two primary IMH surgeries were undertaken. A standard procedure including pars plana vitrectomy, internal limiting membrane peeling, and gas tamponade was undertaken for all cases. 61.3% of patients were Caucasian, 21.2% were South Asian, and 16% were Afro-Caribbean. The mean minimum linear diameter (MLD) for our cohort was 434.6 mcm. Mean MLD was 395.3 mcm in Caucasian patients, 490.0 mcm in South Asians (P=0.006), and 491.4 mcm in Afro-Caribbeans (P=0.007). Regression analysis demonstrated that MLD and Afro-Caribbean ethnicity were independent significant risk factors for surgical failure (OR: 1.01, P<0.001 and OR: 5.73, P=0.008, respectively).ConclusionSouth Asian and Afro-Caribbean patients present with larger IMH than Caucasians. In addition to IMH diameter, Afro-Caribbean ethnicity is an independent risk factor for surgical failure.

The incidence of unexplained visual loss following removal of silicone oil.

PURPOSE: To assess the incidence and clinical features of unexpected visual loss after removal of silicone oil (ROSO). PATIENTS AND METHODS: A retrospective cross-sectional observational study of 421 consecutive eyes, which underwent silicone oil removal at one institution over a 2-year period. RESULTS: Fourteen (3.3%) patients, (12 male, mean age of 53.1 years) suffered unexplained visual loss. In these eyes, the mean duration of silicone oil fill was 141 days (range 76-218). The mean loss of visual acuity was 3.7 (range 2-6) Snellen lines (SL) at 1 month, 3.5 (2-6) SL at 3 months and 2.91 (0-6) SL at 6 months. The change from preoperative visual acuity was statistically significant at all visits (P=0.02). Subgroup analysis of 20 fovea-sparing giant retinal tear (GRT) detachments, observed 10 (50%) cases of visual loss after ROSO. Electrodiagnostic testing suggested predominantly macular dysfunction, with optic nerve involvement in one case. Five of the 14 cases had variable recovery of vision. CONCLUSION: There is a 3.3% overall incidence of visual loss following ROSO with a high rate (50%) observed in maculae on GRT detachments. Although recovery of visual acuity is seen in a minority of cases, visual loss after ROSO remains a serious and unexplained concern for vitreoretinal surgeons.