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The aim of this study is to report on didanosine-associated retinal toxicity (DART) in four adult patients with human immunodeficiency virus (HIV) identified incidentally during routine diabetic eye screening and review all reported cases to date. This study is a retrospective, observational, case series from two health institutions with a review of published literature. DART is often asymptomatic, and patients have good vision (mean visual acuity 6/9), but in advanced cases, severe visual field defects can occur. Fundal changes range from mild granular pigmentary mottling to patches of mid-peripheral chorioretinal atrophy. Continuous expansion of chorioretinal degenerative changes posteriorly may lead to significant macular involvement as demonstrated in two of our cases. Despite cessation of therapy, DART was progressive in approximately 25% of reported cases. Our cases were incidentally discovered during routine diabetic eye screening and did not report any ocular symptoms prior to referral. Given the initial asymptomatic nature of DART, we believe that the true prevalence of the disease may be higher than previously thought. It may be prudent to screen and follow-up patients with a history of DDI use. We demonstrate the utility of multimodal imaging, optical coherence tomography, electrodiagnostic testing and visual fields in evaluating the effects of DART.

Background: Diabetic macular oedema (DMO) is effectively treated with ranibizumab but multiple injections are required. Where there is also peripheral ischaemia, it has been promoted that targeted panretinal photocoagulation (PRP) may reduce the number of injections. Method: Patients with optical coherence tomography confirmed DMO and Ultra-widefield Fundus Fluorescein Angiography confirmed peripheral retinal ischaemia were randomised to PRP plus ranibizumab or ranibizumab monotherapy. After three injections, repeat injections were given until the visual acuity was stable and the macula was dry. Re-treatment was given if there was a drop of visual acuity and/or a recurrence of intra-retinal fluid. The primary outcome was the number of repeat injections required after the first 6 months up until 1 year. Results: There were 49 patients, 25 in the ranibizumab only group and 24 in the ranibizumab + PRP group recruited at seven UK sites. The average number of injections in the ranibizumab-only arm was 6.84 over 1 year and 2.52 between months 6 and 12. The average number of injections in the combined arm was 6.67, with the number of injections in the second 6 months 1.92. For the primary outcome, comparing the number of 6- to 12-month injections, the result was not statistically significant (p = 0.33). Conclusion: The addition of targeted PRP to areas of non-perfusion in a patient with DMO does not reduce the number of injections required in the first year. It seems most likely that local VEGF at the macula is the main cause of DMO.

Background: The single optical cylinders used in the osteo-odonto-keratoprosthesis (OOKP) are known to produce very small visual fields. Values of 40° are typically quoted. The purpose of this paper is to present designs for new optical cylinders that significantly increase the field of view and therefore improve the visual rehabilitation of patients having an OOKP. Methods: Computer ray-tracing techniques were used to design and analyse improved one- and two-piece optical cylinders made from polymethyl methacrylate. All designs were required to have a potential visual acuity of 6/6 before consideration was given to the visual field and optimising off-axis image quality. Aspheric surfaces were used where this significantly improved off-axis image quality. Results: Single optical cylinders, with increased posterior cylinder (intraocular) diameters, gave an increase in the theoretical visual field of 18% (from 76° to 90°) over current designs. Two-piece designs based on an inverted telephoto principle gave theoretical field angles over 120°. Aspheric surfaces were shown to improve the off-axis image quality while maintaining a potential visual acuity of at least 6/6. This may well increase the measu-red visual field by improving the retinal illuminance off-axis. Conclusions: Results demonstrate that it is possible to significantly increase the theoretical maximum visual field through OOKP optical cylinders. Such designs will improve the visual rehabilitation of patients undergoing this procedure.