Riaz H Asaria

Adjuvant 5-fluorouracil and heparin prevents proliferative vitreoretinopathy : Results from a randomized, double-blind, controlled clinical trial.

PURPOSE To assess the safety and efficacy of adjuvant combination therapy using 5-fluorouracil (5-FU) and low molecular weight heparin (LMWH) for prevention of proliferative vitreoretinopathy (PVR) after vitrectomy and retinal reattachment surgery. DESIGN Prospective randomized, double-masked, placebo controlled trial. PARTICIPANTS One hundred seventy-four high-risk patients were randomized to receive either 5-FU and LMWH therapy or placebo. Patients were selected from all patients undergoing primary vitrectomy for rhegmatogenous retinal detachment. METHOD Results of standard surgery with 5-FU and LMWH therapy or placebo were compared at the 6-month follow-up. MAIN OUTCOME MEASURES Development of postoperative PVR, retinal reattachment at 6 months after surgery, single operation reattachment rate, number of reoperations, and best-corrected visual acuity. RESULTS There were 87 patients in the 5-FU and LMWH therapy group and 87 in the placebo group. The incidence of postoperative PVR was significantly lower (P = 0.02) in the 5-FU and LMWH therapy compared with the placebo group. In 26.4% (23/87) of the placebo group and in 12.6% (11/87) of the 5-FU and LMWH group, postoperative PVR developed. In the 5-FU and LMWH group, the number of patients undergoing more than one operation was 19.5% (17/87) and the number of reoperations resulting from PVR was 52.9% (9/17). In the placebo group, the number of patients undergoing more than one operation was 25.3% (22/87) and the number of reoperations resulting from PVR was 72.7% (16/22). The difference in visual acuity was not statistically different in the two treatment groups, although those patients in whom postoperative PVR developed tended to have poorer vision (P < 0.0001). There were no differences in complication rates between the two groups. CONCLUSIONS There is a significant reduction in the incidence of postoperative PVR in patients receiving the 5-FU and LMWH therapy and in the reoperation rate resulting from PVR. This trial shows that incidence of PVR can be reduced with inexpensive and simple pharmacologic treatment with 5-FU and LMWH and should be used routinely in the treatment of patients at risk of developing PVR.

Risk factors for proliferative vitreoretinopathy after primary vitrectomy: a prospective study

AIM To assess clinical variables and vitreous protein as risk factors for the development of postoperative proliferative vitreoretinopathy (PVR). METHODS A prospective study was conducted on 140 patients with a rhegmatogenous retinal detachment in whom a primary vitrectomy was performed. 12 clinical variables were recorded and vitreous samples obtained for measurement of protein concentration. Univariate and multivariate logistic regression analysis was used to determine the risk factors for PVR. RESULTS Complete data were available for 136 of 140 patients. 40 of the 136 patients (29.4%) developed postoperative PVR. Univariate regression revealed that significant (p<0.05) risk factors included aphakia, presence of preoperative PVR, size of detachment, the use of silicone oil, and high vitreous protein level. Multivariate regression analysis revealed only aphakia (odds ratio 2.72), the presence of preoperative PVR (odds ratio 3.01), and high vitreous protein concentration (odds ratio 1.11) to be significant (p<0.05) independent, predictive risk factors for the development of PVR. CONCLUSIONS This study has shown that the significant risk factors for PVR are preoperative PVR, aphakia, and high vitreous protein levels. Two models (clinical factors only and clinical factors and vitreous protein) were constructed to predict the probability of developing postoperative PVR and may be used to identify those at risk for possible intravitreal pharmacological treatment.

How to predict proliferative vitreoretinopathy: a prospective study.

PURPOSE To determine prospectively the accuracy of a predictive risk formula for the development of postoperative proliferative vitreoretinopathy (PVR) when applied in a clinical setting. DESIGN Prospective noncomparative interventional case series. PARTICIPANTS Two hundred nineteen subjects undergoing primary vitrectomy for rhegmatogenous retinal detachment were studied. METHOD By use of a formula-based discriminant rule, subjects were classified as either high or low risk for the development of PVR. All subjects were followed prospectively. OUTCOME MEASURES Development of postoperative PVR as defined by the updated the Retina Society Classification. RESULTS Complete data were available on 212 of 219 subjects. There were 130 subjects identified as low risk and 82 subjects as high risk; 9.2% of the low-risk (12 of 130) compared with 28% (23 of 82) of the high-risk subjects had postoperative PVR develop. This difference was statistically significant (P < 0.001). CONCLUSIONS Our study has shown that using a clinical model it is possible to identify subjects at greater risk of PVR developing after primary vitrectomy.

Silicone oil concentrates fibrogenic growth factors in the retro-oil fluid

Aim: To determine whether silicone oil concentrates protein and growth factors in the retro-oil fluid. Methods: A laboratory analysis of intraocular fluid and vitreous specimens obtained from patients undergoing removal of silicone oil, revision vitrectomy, or primary vitrectomy for macular hole, proliferative vitreoretinopathy (PVR), or retinal detachment. Patients were prospectively recruited from routine vitreoretinal operating lists. Vitreous cavity fluid and vitreous samples were analysed for the presence of transforming growth factor beta (TGF-β2), basic fibroblast growth factor (bFGF), interleukin 6 (IL-6), and total protein using either commercially available enzyme linked immunosorbent assays (ELISA) or protein assay kits. Results: The median levels of bFGF, IL-6, and protein in the retro-oil fluid were raised (p<0.05) compared to all the other vitreous and vitreous cavity fluid samples. bFGF, IL-6, and protein levels were raised in PVR vitreous compared to non-PVR vitreous. TGF-β2 levels were not significantly raised in retro-oil fluid or in PVR vitreous. Conclusions: The concentration of fibrogenic (bFGF) and inflammatory (IL-6) growth factors and protein is raised in retro-silicone oil fluid. This may contribute to the process of retro-oil perisilicone proliferation and subsequent fibrocellular membrane formation.

Immunopathology of intraocular silicone oil: enucleated eyes

Aims: To characterise the distribution of silicone oil in ocular tissues in globes enucleated after complicated retinal detachment, and to document the distribution and nature of any associated inflammatory response. Method: 9 enucleated globes that had previously undergone retinal detachment surgery with silicone oil and 7 control globes that had undergone enucleation after retinal detachment surgery (n = 2) or ocular trauma (n = 5) were studied. Sections were histologically examined using light microscopy to document the distribution of silicone oil in ocular tissues. Immunohistochemical analysis was carried out using the ABC technique and a panel of monoclonal and polyclonal antibodies. Electron microscopy was undertaken to observe the penetration of silicone oil in the trabecular meshwork of the anterior chamber drainage angle. Results: Silicone oil was distributed throughout the globes—notably in the iris, ciliary body, retina, trabecular meshwork and epiretinal membranes. Focal areas of intraretinal silicone were associated with disorganised retinal architecture, retinectomy sites or subretinal oil. The distribution of macrophages was closely related to the distribution of silicone oil. T and B lymphocytes were not associated with silicone oil unless additional pathology was also present—for example, cyclitic membrane or uveitis. One of the nine eyes had silicone oil present in the optic nerve. In the control globes, the inflammatory response was mediated primarily by macrophages and T lymphocytes, and was less marked than that observed in the silicone oil globes. Conclusion: This study shows that silicone oil may be sequestered in varied ocular tissues and is associated with localised inflammation mediated by macrophages.

A Prospective Study of Binocular Visual Function before and after Successful Surgery to Remove a Unilateral Epiretinal Membrane

OBJECTIVE To examine the effect of a unilateral epiretinal membrane (uERM) on visual acuity, stereopsis, and motor fusion in patients before and after successful surgery to remove the membrane. DESIGN Cohort study. PARTICIPANTS Twenty-seven consecutive patients undergoing surgery to remove an idiopathic uERM and 30 normal control subjects. METHODS Patients underwent full orthoptic examination before and between 3 and 6 months after surgery to remove a uERM. Stereoacuities were analyzed statistically using the Wilcoxon signed-rank test, Mann-Whitney U test, and Spearman correlation. Motor fusion ranges and visual acuities were compared using paired and unpaired t tests, with correlations examined by linear regression. MAIN OUTCOME MEASURES Snellen visual acuity, TNO (stereoscopic acuity test of the Netherlands; Netherlands Organisation for Applied Scientific Research; Laméris Ootech BV, Nieuwegein, the Netherlands) and Titmus stereoacuity, motor fusion range. RESULTS Postoperative acuity and improvement in visual acuity after removal of a uERM were better in patients with a shorter duration of symptoms. Stereoacuity was substantially reduced in the presence of a uERM (TNO, P<0.001; Titmus, P<0.001; Mann-Whitney U test), as were total motor fusion ranges at near and distance (near P = 0.002; distance P = 0.015; t test). Stereoacuity was worse in patients with symptoms of longer duration (TNO, P = 0.21; Titmus, P = 0.045; Spearman rank correlation). After successful surgery, stereoscopic function improved. This improvement occurred mainly in those patients with better preoperative stereoacuity and a shorter duration of symptoms. CONCLUSIONS Improvement in visual acuity after surgery was greater in patients with visual symptoms of shorter duration. A uERM adversely affected stereoscopic function, an effect that increased with time. The best monocular and binocular visual outcomes occurred in those patients who had earlier surgery.

Same-day versus first-day review of intraocular pressure after uneventful phacoemulsification

Purpose: To compare the incidence and the spectrum of postoperative complications detected when the intraocular pressure (IOP) is reviewed 4 to 6 hours or the day after uneventful phacoemulsification cataract extraction and intraocular lens (IOL) implantation. Setting: Royal Free Hospital, London, United Kingdom. Methods: The study cohort consisted of 141 patients who had uneventful phacoemulsification and IOL implantation under regional (peribulbar/topical) or general anesthesia. Postoperative evaluation of the patients was performed by an ophthalmologist using a standard form at 4 to 6 hours or 24 hours. Results: The mean IOP at 4 to 6 hours and 24 hours was 22.85 mm Hg ± 9.56 (SD) and 19.44 ± 7.04 mm Hg, respectively. The IOP was more likely to be greater than 30 mm Hg when measured on the same day, resulting in a significantly higher intervention rate than on the first day (P = .037). The best corrected visual acuity was significantly better at 24 hours than at the same‐day review (P < .001). There was no significant difference in the extent of anterior chamber activity, patient comfort, or state of the wound between the same‐ or next‐day follow‐up. All patients attended a follow‐up appointment 3 weeks after surgery, had an IOP of 21 mm Hg or less, and were subsequently discharged. Conclusions: The results indicate that moderate IOP spikes (<40 mm Hg) can be left untreated if they are not associated with corneal edema or patient discomfort as they decline spontaneously. Before they are discharged, patients with compromised optic discs or predisposed to retinal or optic nerve pathology should be carefully evaluated the day after surgery to treat IOP elevations.

Long term outcome of secondary glaucoma following vitreoretinal surgery

Purpose: To determine the long term outcome of secondary glaucoma following retinal reattachment surgery. Method: A longitudinal retrospective study was undertaken of the medical records of patients referred to the Glaucoma Service at Moorfields Eye Hospital following retinal reattachment surgery. The main outcome measures were final intraocular pressure (IOP), progression in cup:disc ratio, and final visual acuity outcome. Results: A total of 70 eyes of 70 patients (41 males and 29 females) were identified and included in the analysis. Mean increase of IOP 2–3 weeks following the first vitreoretinal procedure was 6 (SD 3) mm Hg. After a mean follow up of approximately 4 years the mean IOP had significantly decreased from 33 (SD 10) to 16 (SD 8) mm Hg (p<0.001). The visual outcome of eyes with final IOP less than 6 or greater than 21 mm Hg was significantly worse compared with those eyes with a normal (6–21 mm Hg) range of pressure (p = 0.022 and p = 0.009 respectively). Despite the effective control of IOP in the majority of patients during the follow up period, there was mild progression of the mean vertical cup:disc ratio from 0.6 (SD 0.2) to 0.7 (SD 0.2) (p<0.001). Conclusion: Secondary glaucoma is a major complication following retinal reattachment surgery. Medical treatment is successful in lowering IOP in most patients. In persisting cases surgical treatment is very effective, however it can be associated with an increased risk of postoperative hypotony. Despite apparently adequate IOP control there may be progressive cupping of the optic disc.

Resources involved in managing retinal detachment complicated by proliferative vitreoretinopathy.

Purpose: To report the differences in cost of treatment and outcome in retinal detachment (RD) cases with and without proliferative vitreoretinopathy (PVR). Methods: Analysis of clinical trial databases of RD observed in 190 eyes of 190 patients. Eyes were classified as no PVR, developing PVR, or established PVR. For each eye, total cost of treatment undertaken on Moorfields Eye Hospital vitreoretinal unit, final retinal status, and best-corrected visual acuity were recorded. Results: Management of patients who developed PVR involved approximately double the resources of RD without PVR. Eyes with pre-exiting PVR had similar resource input to those with RD without PVR. Patients who developed PVR had a mean of 3.7 operations (including subsequent cataract surgery) compared to 1.8 and 2.1 respectively for noncomplicated RD and pre-existing PVR. Anatomic success and visual outcome was significantly worse in eyes with PVR. Conclusions: Treatment of eyes that developed PVR after initial surgery cost significantly more than eyes with no PVR or established PVR (P < 0.01). Improvements in the management of RD aimed at preventing PVR and advances in PVR treatment may have significant financial as well as clinical benefits.