Electroretinography detects early glaucoma signs
Lesions appear in both outer and inner retinal layers in the early onset of glaucoma, with the most pathological change in neurophysiological processes affecting the photoreceptors cells of the outer layer. Such findings could aid in early diagnosis of the disease.
Lesions appear in both outer and inner retinal layers in the early onset of glaucoma, with the most pathological change in neurophysiological processes affecting the photoreceptors cells of the outer layer, researchers say.
Such findings could aid in early diagnosis of the disease, writes L.M. Stotska of the Filatov Eye Disease and Tissue Therapy Institute in Odessa, Ukraine, and colleagues in Clinical Ophthalmology.
Although glaucoma is common, much about its pathogenisis remains poorly understood. In fact, the term glaucoma could refer to multiple distinct diseases with similar symptoms.
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Until recently, clinicians have focused on changes in the optic nerve head and visual field defects in measuring the progress of the disease.
Although researchers have identified risk factors, they have not yet succeeded in finding ways to prevent glaucoma from occurring.
Recent research has uncovered important information about the retina in patients with primary open-angle glaucoma (POAG), including the accelerated death of ganglion cells in the retina and retinal axons.
And newer methods of investigation, including scanning laser polarimetry and optical coherence tomography, have revealed structural changes at different levels in the retina and optic nerve.
These approaches allow a better understanding of the morphology and functioning of the retina and increase the possibilities of detecting patholology in pre-clinical stages.
In hope of contributing to this knowledge, Stotska and colleagues studied 298 eyes of 156 patients with POAG or suspected pre-POAG. The group consisted of 81 women and 75 men, with an average age of 56 years. They excluded patients with absolute glaucoma and high ametropia.
The researchers divided this group into four subgroups: 42 patients, 84 eyes with suspected pre-glaucoma; 48 patients, 96 eyes with initial glaucoma; 36 patients, 56 eyes with developed glaucoma; and 30 patients, 53 eyes with advanced glaucoma. The group with suspected pre-glaucoma consisted of patients who findings were not within the normal ranges by 1 or 2 indices.
The researchers compared these groups to a control group of 60 eyes in 30 patients without POAG, who were similar in age, ametropia rate, and somatic diseases.
The eyes all underwent visometry, tonometry, tomography, refractometry, biomicroscopy, direct and reverse ophthalmoscopy, optical coherence tomography, rheophthalmography, visual field assessment and electroretinography.