Large-spot subthreshold infrared laser to treat diabetic macular edema.

PURPOSE: To evaluate the efficacy of a large-spot subthreshold infrared laser protocol to treat diabetic maculopathy. METHODS: In a prospective, fellow eye, controlled case series, all patients had clinically significant diabetic macular edema (DME) treated with a single application of subthreshold infrared (810 nm) laser. If bilateral disease was present, the fellow eye was treated with conventional macular laser. The study was to include 20 patients. Visual acuity and central macular thickness (CMT) measured by optical coherence tomography (OCT) were assessed in the study and fellow eyes at baseline and 6 months, and any changes were compared. RESULTS: The 11th patient developed a choroidal infarct with subsequent profound loss of vision immediately after treatment. The study was terminated prematurely at this point. For the remaining 10 patients, there was a trend toward improvement in visual acuity in the study eye compared with the fellow eye at the 6-month follow-up (median change: +1.5 letters for study eye vs -6.5 letters for fellow eye; P = 0.08). There was also significant improvement in OCT-measured CMT in the study eye (mean decrease, 117 microm) compared with deterioration in OCT-measured CMT in the fellow eye (mean increase, 24 microm; P = 0.02). CONCLUSION: This subthreshold infrared laser protocol led to improvement in OCT-measured CMT and stabilization of vision in most subjects. The current protocol is however unpredictable and should not be used in the treatment of DME without further modification.

Evaluating the use of a scanning laser-derived oedema index to grade diabetic retinopathy and maculopathy.

PURPOSE: To evaluate the Heidelburg Retina Tomograph II (HRTII) retinal module as a tool for grading severity of retinopathy in a diabetic retinal screening and treatment service. METHODS: Seventy-seven consecutive patients with type 2 diabetes underwent scanning laser tomography using the HRTII. Scan data were analysed using the proprietary macular module software and oedema indices calculated for each of nine topographic macular zones. Two consultant ophthalmologists, masked to the result of the HRTII scans, graded each subject for severity of retinopathy and presence of macular oedema. The oedema indices were analysed statistically to determine whether these correlated with severity of retinopathy and presence of macular oedema. RESULTS: There is an increased oedema index in severe non-proliferative diabetic retinopathy in the outer temporal zone compared with lesser grades of diabetic retinopathy (P = 0.001). In patients with clinically detectable macular oedema, the oedema index from the 500-microm-diameter central zone was significantly higher than those without (P = 0.03). CONCLUSION: The scanning laser-derived oedema index differentiated between moderate and severe non-proliferative diabetic retinopathy in this series and detected diabetic macular oedema. Further development of this technology may provide an important tool to supplement retinal photographic surveillance in eye clinics overwhelmed by an increasing prevalence of type 2 diabetes.

Photoscreening for diabetic retinopathy: a comparison of image quality between film photography and digital imaging.

PURPOSE: Retinal images from patients attending an urban screening centre before and after the transition from film photography to digital image acquisition were analysed for quality of image. METHODS: A total of 1946 diabetic patients, aged 12-92 years (mean 55.6 +/- 14.88 years), were included in this retrospective study of retinal screening techniques. Each imaging group was subdivided into age-matched groups. In all subjects pupils were pharmacologically dilated before photography. The images were reviewed by the same three experienced observers and graded at the time of screening from grade 1 (excellent quality) to grade 4 (unreadable). RESULTS: Of 938 patients in the film group, 31.3% had excellent images, 38.2% good, 22.7% poor and 7.8% were unreadable. Of the 1008 patients in the digital imaging group, 25.3% had excellent images, 46.3% good, 14.6% poor and 13.8% were unreadable. A significant difference was observed in patients over 65 years of age who exhibited a threefold increase in failure rate with digital imaging (33.7% v 11.3%)(P < 0.0001). CONCLUSION: In this study population a statistically significant degradation of image quality was observed in those older than 65 years following transition to digital photography. This has implications for service provision planning.

Human antitransforming growth factor beta(2) monoclonal antibody--a new modulator of wound healing in trabeculectomy: a randomized placebo controlled clinical study.

PURPOSE: The human monoclonal antibody that neutralizes the growth factor TGFbeta(2) (CAT-152) safely and effectively inhibits in vitro and in vivo models of conjunctival scarring. This phase I/IIa clinical trial was designed to assess the safety and tolerability of CAT-152 in patients undergoing trabeculectomy. DESIGN: Prospective randomized placebo-controlled clinical trial. PARTICIPANTS AND CONTROLS: Twenty-four patients who were due to undergo primary trabeculectomy at Moorfields or Western Eye Hospitals in London, England, were recruited for this study and randomly assigned to treatment with either CAT-152 (100 microg in 100 microl) (n = 16) or placebo (n = 8). METHODS: The treatment regimen was a series of four 100-microl subconjunctival injections, given immediately before and after surgery, and at 1 day and 1 week postoperatively. Assessment consisted of a full ophthalmic examination with recordings of the logarithm of the minimum angle of resolution visual acuities performed at baseline and at set intervals after surgery. Any adverse events were recorded. MAIN OUTCOME MEASURES: Logarithm of the minimum angle of resolution visual acuity, intraocular pressure, complications, and adverse events. RESULTS: The results of 12 month's follow-up on all patients are documented. There were no statistically significant differences in the incidence of complications between the two groups, and no serious adverse events related to the study drug occurred. Blebs after CAT-152 antibody treatment were diffuse, noncystic, and nonavascular, unlike blebs associated with antimetabolites. The fall in intraocular pressure was greater in the CAT-152 group at 3 and 6 months (P < 0.05) and approached statistical significance at 12 months. There was a trend toward less intervention in those patients treated with CAT-152. The small number of patients included limited the power of the study (34%) to detect a difference between groups. Sixteen patients in each arm of the study would be required to obtain a power of 90% with a 5% significance level. CONCLUSIONS: This is the first clinical study of CAT-152 in patients undergoing glaucoma filtration surgery. CAT-152 seems to be well tolerated, and based on these results further multicenter trials are underway.