Visual fields and electroretinography following extensive photocoagulation.
Twenty-four patients with proliferative or preproliferative diabetic retinopathy underwent extensive argon laser photocoagulation in one eye. Detailed central and peripheral visual-field examinations and electroretinography were performed before treatment, and at intervals after treatment. Visual field changes were as follows: (1) eight patients had only mild to moderate constriction of all isopters, (2) 11 had discrete scotomata in addition, (3) two had prominent nerve-fiber-bundle defects, (4) three had severe constriction of all isopters, save (in two) that to the largest peripheral test object. Electroretinographic b-wave amplitudes were reduced an average of 40% to white test flashes. Blue test flashes showed an even larger reduction of the rod response. This suggests the receptors in approximately 40% of the retinal area are destroyed by such extensive photocoagulation, covering predominantly that part of the retina that has the highest concentration of rods.
D000328:Adult; D001128:Argon; D003930:Diabetic Retinopathy / Q000503:physiopathology / Q000601:surgery*; D004596:Electroretinography; D005071:Evoked Potentials; D005260:Female; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D005654:Fundus Oculi; D006801:Humans; D053685:Laser Therapy; D007834:Lasers / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D010786:Photoreceptor Cells / Q000503:physiopathology; D012164:Retinal Diseases / Q000209:etiology* / Q000503:physiopathology; D012607:Scotoma / Q000209:etiology*; D014786:Vision Disorders / Q000209:etiology*; D014792:Visual Acuity; D014794:Visual Fields
D001128:Argon