Immunopathology of intraocular silicone oil: retina and epiretinal membranes

AIMS: To determine the inflammatory response in retina and epiretinal membranes after intraocular silicone oil tamponade. METHODS: 14 proliferative vitreoretinopathy (PVR) epiretinal membranes, 33 retro‐oil epiretinal membranes, 19 retinectomies, 14 retro‐oil retinectomies and 37 idiopathic epiretinal membranes (controls) underwent immunohistochemical analysis using the avidin–biotin complex technique and a panel of monoclonal and polyclonal antibodies. The number of positive cells counted in five 0.5 mm diameter fields of immunohistochemical sections was graded on a score of 1–4. RESULTS: Macrophage cell counts were significantly greater in membranes with a history of exposure to silicone oil (p<0.001). An inflammatory response could be observed within 1 month of silicone oil exchange, and the intensity seemed to be unrelated to the duration of exposure. Macrophages were confined to epiretinal membranes on the surface of retinectomy specimens in 10 of 14 cases and intraretinal macrophages were observed only in specimens with gliotic retina. T and B lymphocytes were rarely seen in the specimens examined. Marked glial cell up regulation was observed in 11 of 16 retinectomy specimens and in 8 of 11 retro‐oil retinectomies. Glial cell content was variable in the membranes, but there was a trend of increased presence after exposure to silicone oil. CONCLUSION: This study has shown that the use of silicone oil is accompanied by an inflammatory reaction, primarily mediated by bloodborne macrophages. This response can be observed within 1 month of silicone oil injection and continues after silicone oil removal. Retinal surgeons should be aware of the potential secondary effects of intraocular silicone oil when they are considering its use (and removal) in vitreoretinal surgery

Design and conduct of randomized clinical trials evaluating surgical innovations in ophthalmology: a systematic review

PURPOSE: Surgical innovations are necessary to improve patient care. After an initial exploratory phase novel surgical technique should be compared with alternative options or standard care in randomized clinical trials (RCTs). However surgical RCTs have unique methodological challenges. Our study sought to investigate key aspects of the design, conduct and reporting of RCTs of novel surgeries. DESIGN: Systematic Review METHODS: The protocol was prospectively registered in PROSPERO (CRD42021253297). RCTs evaluating novel surgeries for cataract, vitreoretinal, glaucoma and corneal diseases were included. Medline, EMBASE, Cochrane Library and Clinicaltrials.gov were searched. The search period was January 1, 2016, to June 16, 2021. RESULTS: Fifty-two ophthalmic surgery RCTs were identified in the fields of glaucoma (n=12), vitreoretinal surgery (n=5) cataract (n=19) and cornea (n=16). A description defining the surgeon's experience or level of expertise was reported in 30 RCTs (57%); and was presented in both, control and intervention groups, in eleven (21%). Specification of number of cases performed in the particular surgical innovation being assessed prior to the trial was reported in 10 RCTs (19%); and an evaluation of quality of the surgical intervention in seven (13%). Prospective trial registration was recorded in 12 RCTs (23%), retrospective registration in 13 (25%) and there was no registration record in the remaining 28 (53%) studies. CONCLUSION: Important aspects of the study design such as surgical learning curve, surgeon's previous experience, quality assurance, and trial registration details were often missing in novel ophthalmic surgical procedures. The IDEAL framework aims to improve the quality of study design

The association between foveal floor measurements and macular hole size.

Determining which factors influence idiopathic macular hole (MH) size is important because it is a major prognostic indicator of treatment success. Foveal pit morphology is highly symmetrical within individuals and may influence MH size. Using a series of patients with unilateral MHs, we examined the foveal floor size of the fellow eye to evaluate its relationship with MH size and post-operative outcomes. A retrospective observational study Participants 241 participants with a unilateral MH treated with surgery and a fellow eye with no ocular pathology. Spectral domain ocular coherence tomography (SD-OCT) imaged both eyes at the time of surgery. Minimum linear diameter (MLD) and base diameter (BD) defined MH size. Foveal floor width (FFW) and minimal foveal thickness (MFT) defined foveal pit morphology of the fellow eye. Baseline characteristics, SD-OCT measurements and pre-operative variables were compared to determine their relationship with MH size and post-operative visual acuity in logMAR units (Va). FFW was correlated with MLD (r = 0.36; p=<0.001) and BD (r=0.30; p=<0.001) but not post-operative Va. MLD correlated with pre-operative (r=0.49; p=<0.0001) and post-operative Va (r=0.54, p=<0.0001). A two-stage regression model was developed to predict post-operative Va (r = 0.28); pre-operative Va (beta = 0.36; p=0.002) explained 13% of variability and MLD (beta = 0.29; p=0.002) and MH duration (beta=0.23; p=0.004) explained a further 16%. FFW of the fellow eye in patients with a unilateral MH was significantly correlated with MH size and may explain some of the variability in MH size observed between individuals. However, FFW could not predict post-operative vision. [Abstract copyright: Copyright © 2020. Published by Elsevier Inc.

Factors Associated with the Clinical Course of Vitreomacular Traction

Background. To analyze the optical coherence tomography (OCT) characteristics as well as the clinical and demographic features to investigate their possible role to the course of vitreomacular traction syndrome. Methods. The inclusion criteria were vitreomacular adhesion with traction causing distortion of the retinal architecture, with or without the presence of an epiretinal membrane, regardless of the size of the adhesion; age >18 years; follow-up of at least three months; and adequate quality OCT scan. Measurements of foveal thickness, average macular thickness, macular volume, maximum vertical and horizontal vitreomacular adhesion, nasal and temporal angles of traction, hyaloid hyperreflectivity, the presence of an epiretinal membrane (ERM), and cone outer segment tips detachment were obtained. Results. 150 eyes were included in the analysis. 36 eyes (24%) developed complete resolution at the last visit, 19 eyes (12.7%) formed a full-thickness macular hole, and 95 eyes (63.3%) showed no resolution of the traction. Better BCVA at the first visit was associated with an increased likelihood of resolution of the VMT, but increasing age, CMT, and BCVA in the end of the follow-up was associated with a reduction in the likelihood of resolving. Of the other variables that were studied, no statistical significant predictors were identified. Conclusions. Better BCVA in the first visit was associated with an increased likelihood of resolution of the VMT that occurred in 24% of our cases. Other factors such as the vertical area of adhesion and the angle of adhesion were not identified as prognostic factors affecting the clinical course of the disease