Abstract
Purpose: :
To analyze the most common neurophthalmological conditions that may mimic glaucomatous optic neuropathy and to determine the discrimination ability of glaucoma specialists to distinguish between glaucomatous and nonglaucomatous optic neuropathy.
Methods: :
We reviewed the charts of consecutive patients with optic neuropathies caused by neurophthalmological conditions evaluated in a single Eye Clinic between August 2009 and November 2011. Eyes whose fundoscopic appearance could resemble glaucoma were selected based in pre-defined criteria (vertical cup-to-disc ratio > 0.5, asymmetry of the cup-to-disc ratio ≥ 0.2 between eyes, presence of localized retinal nerve fiber layer defects and/or neuroretinal rim defects and/or disc haemorrhages). Color fundus photographs and standard achromatic perimetry tests (Humphrey Visual Field, HVF) of these eyes were mixed with tests from 21 consecutive glaucomatous patients (42 eyes). The cases were mixed randomly and reviewed by a glaucoma specialist in a masked fashion.
Results: :
Among the 101 eyes (68 patients) enrolled with neurophthalmological diseases, 16 (15.8%) were considered as conditions that could mimic glaucoma. The most common diagnoses were ischemic optic neuropathy (25%), compressive optic neuropathy (18,7%) and hereditary optic neuropathy (18,7%). Based on fundus photographs and HVF tests, 25% of these were misdiagnosed as glaucoma (2 ischemic optic neuropathies and 2 congenital optic disc anomalies), while 11.9% of the glaucomatous neuropathies were misdiagnosed as neurophthalmological disorders. Overall, the glaucoma specialist has correctly diagnosed 84.5% of the eyes.
Conclusions: :
Some neurophthalmological disorders can resemble glaucoma at presentation. Ischemic and compressive optic neuropathies seem to be the most common conditions. As judged by a glaucoma specialist, approximately one quarter of these eyes may be misdiagnosed as glaucoma, what could lead to inappropriate management of the diseases and influence their prognosis.
Keywords: optic disc • neuro-ophthalmology: diagnosis • intraocular pressure