What may be gained from standard photocoagulation during early worsening of diabetic retinopathy? An observational study in type-1 diabetic patients after tightening of glycaemic control.
OBJECTIVE
To assess the outcome of laser photocoagulation treatment for rapidly progressing diabetic retinopathy, socalled early worsening, subsequent to a rapid improvement of glycemic control. For the purpose of this study, early worsening was defined as any incidence or progression of retinopathy that followed a reduction in HbA1c by > 2% within 6 months.


METHODS
Retrospective observational study in type-1 diabetic patients in a university diabetes center.


METHODS
23 patients with early worsening were identfied during a 16-year period, with a mean age of 25 years, duration of diabetes of 12 years, and glycated hemoglobin HbA1c of 12.4%; retinopathy was absent or mild nonproliferative at baseline. Focal, and/or panretinal laser coagulation was performed according to standard ETDRS criteria. Retinal pathology and visual acuity was followed-up for 12-120 months.


RESULTS
Improving metabolic control induced mild non-proliferative retinopathy without macular edema in 4 patients, which regressed without treatment. In 19 patients, symptomatic diabetic maculopathy developed with macular edema, resolving by focal coagulation in 3 patients. Of the remaining 16 patients, 14 developed proliferative retinopathy (7 of whom despite focal, grid or scatter coagulation pretreatment), and were treated by full panretinal coagulation. In 7 of the 14 patients with proliferative retinopathy, vitreous hemorrhages occurred requiring pars plana vitrectomy. Proteinuria, polyneuropathy, and impaired vision prior to laser treatment were indicative of poor prognosis. Visual acuity > 0.3 in at least one eye was preserved in 22 of the 23 patients.


CONCLUSIONS
In patients with type-1 diabetes mellitus and early worsening of diabetic retinopathy, the benefit of standard laser photocoagulation was limited, and particularly in the presence of symptomatic macular edema.
Chantelau
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Diabetes outpatient clinic, Department of Metabolic Diseases and Nutrition, Heinrich-Heine-University of Düsseldorf.
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001786:Blood Glucose / Q000032:analysis; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000453:epidemiology / Q000503:physiopathology; D003930:Diabetic Retinopathy / Q000503:physiopathology* / Q000601:surgery*; D018450:Disease Progression; D005500:Follow-Up Studies; D005858:Germany; D006442:Glycated Hemoglobin / Q000032:analysis; D006785:Hospitals, University; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D008028:Light Coagulation; D015995:Prevalence; D011507:Proteinuria / Q000453:epidemiology; D012189:Retrospective Studies; D013997:Time Factors; D014792:Visual Acuity; D014821:Vitrectomy
D001786:Blood Glucose; D006442:Glycated Hemoglobin