Spontaneous resolution of diabetic macular oedema after discontinuation of thiazolidenediones.

AIM: To report a case of spontaneous resolution of diabetic maculopathy with cystoid macular oedema in a diabetic patient after discontinuation of rosiglitazone, documented with serial ocular computed tomography (OCT) images. METHODS: A 59-year-old male with a 6-year history of well-controlled diabetes mellitus presented with reduced visual acuity (VA) attributed to clinically significant macular oedema (CSMO). The patient had been started on rosiglitazone 8 months previously. Glitazone treatment was stopped and the patient prospectively followed up. RESULTS: The patient demonstrated CSMO on OCT at presentation. Three months after cessation of rosiglitazone, CSMO had completely resolved and VA improved. Resolution of CSMO was confirmed on OCT examination. The patient required no interventional treatment, i.e. no laser or intravitreal therapy, for his CSMO. CONCLUSIONS: To the best of our knowledge, this is the first case to document spontaneous resolution of CSMO and improvement in VA on discontinuation of a glitazone. Glitazones have a definitive role in the management of diabetic patients and ophthalmologists and physicians should both be aware that there may be an association with weight gain, peripheral oedema and CSMO. We recommend that ophthalmologists consider discontinuing glitazones in consultation with the diabetologist before embarking on interventional management such as laser or intravitreal injections.

Ambulatory photographic screening for diabetic retinopathy in nursing homes.

PURPOSE: To evaluate the feasibility and cost of screening for diabetic eye disease in homebound nursing home residents not attending a systematic screening programme. METHODS: Postal survey identification of residents with diabetes in all nursing homes in Liverpool. An ophthalmologist and nurse performed Bailey-Lovie logmar visual acuity (VA), portable slit-lamp examination, fundus photography, and subjective assessment of ability to cooperate with treatment in a sample of homes. Modified Wisconsin photographic grading was performed. Screen-positive patients were invited to a dedicated assessment clinic. Sight-threatening diabetic eye disease (STED) was defined as any of: moderate preproliferative retinopathy or worse, circinate maculopathy, or exudate within 1 disc diameter of fixation. RESULTS: A total of 54 (78%) nursing homes responded reporting 199/2427 (8.2%) residents with diabetes. Of these, 64/80 (80%) residents in 17 homes were examined: VA possible in 50 (78%); slit-lamp examination in 56 (88%); gradable photographs in at least one eye in 34 (53%); STED in 12 (35%) patients. In all, 35 (70%) patients had Snellen-equivalent VA worse than 6/12 in the better eye, of whom 13 (26%) were worse than 6/60. Of 29 screen positive patients, 12 attended the assessment clinic: one was unable to cooperate outside the home; 11 continue under ophthalmic review, four for previously undetected STED of which one listed for laser photocoagulation. Total cost pound 16,980; cost per screen event pound 60.30. CONCLUSIONS: Systematic eye screening in homebound patients with diabetes detects disease but follow-up and treatment is only feasible in a small proportion and at high cost. Alternative targeted assessment is recommended.

Incidence of sight-threatening retinopathy in Type 1 diabetes in a systematic screening programme.

AIM: To measure the cumulative incidence of any retinopathy, maculopathy and sight-threatening diabetic retinopathy (STDR), and calculate optimal screening intervals by retinopathy grade at baseline for patients with Type 1 diabetes attending an established systematic retinal screening programme. METHODS: All patients with Type 1 diabetes registered with enrolled general practitioners, excluding only those attending an ophthalmologist, were studied if retinopathy data was available at baseline and at least one further screen event. Screening utilized non-stereoscopic 3-field mydriatic photography and modified Wisconsin grading. STDR was defined as moderate pre-proliferative retinopathy or greater and/or significant maculopathy in any eye. RESULTS: Patients (n=501) underwent 2742 screen events. Cumulative incidence of STDR in patients without baseline retinopathy was 0.3% (95% CI 0.0-0.9) at 1 year, rising to 3.9% (1.4-5.4) at 5 years. Rates of progression to STDR in patients with background and mild pre-proliferative retinopathy at 1 year were 3.6% (0.5-6.6) and 13.5% (4.2-22.7), respectively. Progression to STDR was greater in patients with a higher grade of baseline retinopathy (P=0.001) or a longer disease duration (P=0.003). For a 95% likelihood of remaining free of STDR, mean screening intervals by baseline status were: no retinopathy 5.7 (95% CI 3.5-7.6) years, background 1.3 (0.4-2.0) years and mild pre-proliferative 0.4 (0-0.8) years. CONCLUSIONS: Screening at 2-3 year intervals, rather than annually, for patients without retinopathy in Type 1 diabetes is feasible because of the low risk of progression to STDR, and may result in significant cost savings for a screening programme. Patients with higher grades of retinopathy require screening at least annually or more frequent.

Current status of screening for diabetic retinopathy in the UK.

This article reviews the current status of retinopathy screening schemes in the UK. There is evidence that high-quality diabetic retinopathy screening schemes are in existence but provision is patchy. Many health authorities have ad hoc screening programmes reaching only about 60% of patients, with unacceptable or undocumented efficacy and minimal quality control. Several models of screening are currently in use with the current preferred option being camera-based screening. Digital imaging systems offer the best prospects for image acquisition, although at present evidence of adequate effectiveness only exists for 35 mm film-based systems. The final report of the National Diabetic Retinopathy Screening Programme commissioned by the UK National Screening Committee for inclusion into the national service framework for diabetes, is thus eagerly awaited and should set standards for screening programmes, in order to improve the care of all those with diabetes. Quality assurance will be the main driver in the immediate future of improvements in screening programmes. Research data will provide the evidence to refine techniques and set targets in the longer term, with the emphasis on cost-effectiveness and quality of life.

Prevalence of diabetic eye disease in patients entering a systematic primary care-based eye screening programme.

AIMS: Large-scale, baseline prevalence measurements in a population at the institution of systematic retinal screening are currently unavailable. We report the prevalence of all grades of retinopathy at entry into a systematic primary care-based diabetic eye screening programme. METHODS: Primary care-based photographic screening utilizing mydriasis and three-field non-stereoscopic photography for all patients with diabetes (except those under continuing care of an ophthalmologist) in Liverpool. Sight-threatening diabetic eye disease (STED) was defined as any of: moderate preproliferative retinopathy or worse, circinate maculopathy or exudates within one disc diameter of the centre of fovea. RESULTS: Type 1 diabetes mellitus (DM) (n = 831): baseline prevalence (95% confidence interval (CI)) of any retinopathy, proliferative diabetic retinopathy (PDR) and STED was 45.7% (42.3-49.1), 3.7% (2.4-5.0) and 16.4% (13.9-18.9), respectively. Presence of STED was associated with increased disease duration (odds ratio (OR) 1.09 per year; P < 0.0001) and higher in men (OR 2.15; P = 0.001). Type 2 DM (n = 7231): baseline prevalence (95% CI) of any retinopathy, PDR and STED was 25.3% (24.3-26.3), 0.5% (0.3-0.7) and 6.0% (5.5-6.5), respectively. Presence of STED was associated with longer time since diagnosis of DM (OR 1.03; P < 0.0001) and insulin use (OR 2.46; P < 0.0001). CONCLUSION: This study provides baseline information for health providers on prevalence of all grades of retinopathy and STED in a large population at the establishment of systematic screening. Baseline prevalence of STED was high and highest in patients with a longer disease duration in both Type 1 and Type 2 DM.

Cost effectiveness analysis of screening for sight threatening diabetic eye disease.

OBJECTIVE: To measure the cost effectiveness of systematic photographic screening for sight threatening diabetic eye disease compared with existing practice. DESIGN: Cost effectiveness analysis. SETTING: Liverpool. SUBJECTS: A target population of 5000 diabetic patients invited for screening. MAIN OUTCOME MEASURES: Cost effectiveness (cost per true positive) of systematic and opportunistic programmes; incremental cost effectiveness of replacing opportunistic with systematic screening. RESULTS: Baseline prevalence of sight threatening eye disease was 14.1%. The cost effectiveness of the systematic programme was 209 pound sterling (sensitivity 89%, specificity 86%, compliance 80%, annual cost 104996 pound sterling) and of the opportunistic programme was 289 pound sterling (combined sensitivity 63%, specificity 92%, compliance 78%, annual cost 99 981 pound sterling). The incremental cost effectiveness of completely replacing the opportunistic programme was 32 pound sterling. Absolute values of cost effectiveness were highly sensitive to varying prevalence, sensitivity and specificity, compliance, and programme size. CONCLUSION: Replacing existing programmes with systematic screening for diabetic eye disease is justified.

Prevalence of diabetic eye disease in an inner city population: the Liverpool Diabetic Eye Study.

PURPOSE: To measure the population prevalence of diabetic eye disease in an inner city setting. METHODS: As part of a systematic screening programme all adult diabetic patients in four general practices were invited to attend for slit-lamp biomicroscopy by a retinal specialist. Data on non-attenders were available from community-based photography. RESULTS: Of 395 diabetic patients identified, 326 attended biomicroscopy with photographic data available on a further 31, giving a 90% compliance rate. Point prevalence of diabetes in the target population was 12.4/ 1000. Demographic data included: mean age 60 years (range 13-92 years); type of control: type I 49, type II insulin-requiring (IR) 40, type II non-insulin-requiring (NIR) 268. Prevalences were as follows: any retinopathy: of all diabetic patients 33.6%, type I 36.7%, type II IR 45.0%, type II NIR 31.3%; proliferative/ advanced: all 1.1%, type I 2.0%, type II IR 0, type II NIR 1.1%; clinically significant macular oedema: all 6.4%, type I 2.3%, type II IR 16.2%, type II NIR 5.7%. The percentage of patients with retinopathy requiring follow-up by an opthalmologist was 4.5%, and 9.2% had macular exudates within 1 disc diameter of fixation or significant circinate maculopathy. Sight-threatening diabetic eye disease (STED) was found in 13.4%. A visual acuity of < or = 6/24 in the better eye occurred in 12 (3.4%) patients and of < or = 6/60 in the better eye in 3 (0.8%). CONCLUSIONS: Compared with previous population studies, prevalences appear to have declined in type I, but remain high in type II diabetic patients and especially in those requiring insulin.

Detection of sight-threatening diabetic eye disease.

Blindness due to diabetes mellitus is potentially preventable in the majority of patient. Early detection of sight-threatening changes is associated with a better outcome, indicating the need to screen for retinopathy. At least 50% of diabetic patients do not attend a hospital, so that diabetologists and ophthalmologists are unable to screen the diabetic population comprehensively. Although in theory all patients has access to general practitioners, these may lack training or confidence to screen for retinopathy. Hospital based or community optometrists using direct ophthalmoscopy or slit lamps and technicians performing fundus photography are alternatives which may be more effective. Further studies are required to examine the effectiveness of optometry screening. Initial studies using fundus photography raised concerns about the sensitivity of the technique, but these have been partially addressed by improvements in methodology and technology. As well as technicological effectiveness, factors affecting patient uptake of screening services still need to be addressed.

Sensitivity and specificity of photography and direct ophthalmoscopy in screening for sight threatening eye disease: the Liverpool Diabetic Eye Study.

OBJECTIVE: To evaluate different methods for community based screening for sight threatening diabetic eye disease. DESIGN: Prospective study. SETTING: Mobile screening unit visiting inner city community clinics; hospital assessment clinic (tertiary centre). SUBJECTS: 395 diabetic patients registered with four general practices in an inner city location. INTERVENTIONS: Community based photography with mydriasis and direct ophthalmoscopy through dilated pupils by an experienced ophthalmologist, both compared with reference standard of slit lamp biomicroscopy by a consultant specialist in medical retinal disease. MAIN OUTCOME MEASURES: Sensitivity and specificity of screening method and prevalence of sight threatening diabetic eye disease (moderate preproliferative retinopathy, circinate maculopathy, exudate within 1 disc diameter of fixation, other diabetes related eye disease). RESULTS: 358 subjects underwent photography, 326 attended hospital clinic for ophthalmoscopy, and six were ungradable on photographs and biomicroscopy, leaving 320 for analysis. Of these 295 (91%) attended clinic within four months of photography. Sensitivity of detection of eye disease by photography was 89% (95% confidence interval 80% to 98%), significantly better than for direct ophthalmoscopy (65% (51% to 79%)). Analysis of patients with false negative results indicated possible improvement of photographic sensitivity to 93% by addition of stereoscopic macular pair photographs. Specificity of detection of sight threatening eye disease was 86% (82% to 90%) for photography and 97% (95% to 99%) for direct ophthalmoscopy. CONCLUSIONS: Since high sensitivity is essential for an effective screening programme, a photographic method should be considered as preferred option in national, community based screening programmes. Even in the hands of an experienced ophthalmologist, direct ophthalmoscopy is limited by weaknesses inherent to the instrument.