Posters

Normal tension glaucoma: the improtance of MRI imaging in this great enigma of eye care

Poster Details

First Author: O. Gkorou GREECE

Co Author(s):    E. Kanonidou   M. Parava                 

Abstract Details

Purpose:

Normal tension glaucoma (NTG) is among the greatest enigmas in eye care. Diagnosis of NTG, defined as glaucoma without a clearly abnormal intraocular pressure (IOP), depends on recognizing symptoms and signs associated with optic nerve vulnerability, in addition to absence of other explanations for disc abnormality and visual field loss. NTG is a diagnosis of exclusion. Our purpose is to report the importance of MRI imaging in a case of a woman being under diagnostic evaluation of NTG.

Setting:

Department of Ophthalmology, ‘’Hippokrateion’’ General Hospital of Thessaloniki, Thessaloniki, Greece

Methods:

A 57 year old woman presented to the outpatient clinic due to gradually established,painless,bilateral visual loss.Her past ocular history included cataract surgery of the LE 6 months ago.The past medical history included mitroid valve replacement,rheumatic fever and heart failure.The ophthalmological examination revealed the following:Visual acuities with correction were 6/10 in RE and 8-9//10 in LE.A progressing mild cataract in the RE was found in the slit-lamp examination of the anterior segment of the eyes.Dilated direct ophthalmoscopic examination revealed pale optic discs in both eyes with c/d ratio:0.5 in RE and 0.7 in LE.Color vision,pupillary examination,tonometry,pachymetry and gonioscopy were normal.

Results:

Further investigation was indicated.The visual field examination revealed bilateral defects. A diurnal IOP curve was obtained and confirmed that the patient was not developing IOP spikes,with IOP levels range 11-14 in RE and 11-15 in LE.Optic nerve OCT imaging was contributory to evaluate the optic nerve damage and document the status of the optic nerve at baseline and for future comparisons.Laboratory testing for infectious or inflammatory conditions that can cause optic neuropathy was performed and the results were negative.Full neurological evaluation, to rule out other neurological conditions that may be masquerading as NTG, proved to be normal. MRI imaging revealed enlargement of the ventricular system of the brain and the subarachnoid space.The patient was referred to Neurosurgeons for further evaluation.

Conclusions:

NTG remains a challenging condition to manage.It is a chronic optic neuropathy associated with migraine,peripheral vasospasm,Raynaud syndrome,generalized peripheral vascular endothelial dysfunction,ocular circulation insufficiency,increased resistance index in the central retinal artery,impaired vascular autoregulation,autoimmune disorders,systemic vascular disease,systemic nocturnal hypotension,sleep apnea.It is important to identify any underlying medical conditions,such as other types of glaucoma,disorders of the optic nerve not caused by IOP elevations(e.g. ischemic optic neuropathy,compressive lesions of the optic nerve),systemic disorders that produce optic neuropathies(e.g. multiple sclerosis)mimicking NTG,through a detailed medical history and a range of tests with neuroimaging having exceptional role,before setting the final diagnosis of NTG.

Financial Disclosure:

NONE