|LETTER TO THE EDITOR
|Year : 2012 | Volume
| Issue : 6 | Page : 581-582
Full-field perimetry for evaluation of glaucomatous (presumed) cup
Govindarajan Kummararaj1, Vijayalakshmi Balaji1, Sherin Kummararaj1, Nataraja Pillai Venugopal2
1 Glaucoma Service, A. G Eye Hospital, Trichy, Tamilnadu, India
2 Neuro-Ophthalmology Clinic, A. G Eye Hospital, Trichy, Tamilnadu, India
|Date of Web Publication||26-Nov-2012|
Nataraja Pillai Venugopal
Flat No: 19, Mathuram Apartments, Officer's Colony, [Behind YMCA], Puthur, Trichy, Tamil Nadu - 620 017
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Kummararaj G, Balaji V, Kummararaj S, Venugopal NP. Full-field perimetry for evaluation of glaucomatous (presumed) cup. Indian J Ophthalmol 2012;60:581-2
|How to cite this URL:|
Kummararaj G, Balaji V, Kummararaj S, Venugopal NP. Full-field perimetry for evaluation of glaucomatous (presumed) cup. Indian J Ophthalmol [serial online] 2012 [cited 2020 Feb 19];60:581-2. Available from: http://www.ijo.in/text.asp?2012/60/6/581/99858
We read with interest the article, "Cupped disc with normal intraocular pressure:  The long road to avoid misdiagnosis" by Choudhari et al. In this regard, we would like to highlight the following points.
It is unfortunate that in day-to-day practice, excessive cupping of the optic disc is considered to be pathognomonic of chronic glaucoma. Diagnosis of normal tension glaucoma (NTG) should be by exclusion. Intraocular pressure (IOP) varies an average of 3-6 mmHg in normal individuals over the course of the day. Probably, the modified diurnal curve is practical while still providing useful information to diagnose glaucomatous optic neuropathy. Office diurnal curve generally means checking the pressure every 1 or 2 h from about 8 am to 6 pm. In most cases of NTG, the IOPs cluster at the upper end of the normal range (18 or 19 mmHg) and show wide diurnal variation. Initial IOP less than 17 mmHg and rapidly progressive course despite apparently adequate glaucoma treatment is indicative for workup to rule out systemic disease (neurological, cardiac, carotid, anemia).
In certain invasive pituitary lesions affecting the optochiasm or tract, the initial  or follow-up fields give more information beyond the 30° isopter. Five percent of pituitary tumors present with peripheral field changes and normal central fields. In craniopharyngiomas, rupture of the cyst may cause fluctuating visual field loss. Therefore, a full-field perimetry may help to differentiate neuroophthalmic field loss from glaucomatous field loss. Altered appreciation of color in one or both temporal fields and diplopia with normal  ocular movements have been documented in pituitary tumors.
Headache (new onset or increased severity), localizing neurologic symptoms other  than migraine and neurologic visual abnormalities are relative indications to perform neuroimaging evaluation in normal tension glaucoma. Craniopharyngiomas cause visual symptoms, endocrinological disturbance, headache and cognitive deficits, including personality changes, memory loss, depression and confusion. Hirsutism, frontal bossing, prominent jaws and acromegaly are endocrinological manifestations of hormone-secreting pituitary tumors.
There is a subgroup of patients with opticochiasmal pathology who appear more visually impaired than expected from their clinically recorded visual parameters. In particular, at monocular visual acuity testing, the patients only identify the symbols on the nasal side of the test chart, even though they know that there is a full line present and, despite being prompted to correct on repeated testing, a disability to locate the temporal symbols persists. Some patients also lose the ability to read the test smoothly or to appraise a single line of print.  This condition is known as monocular temporal inattention. Alzheimer's and Parkinson's disease can also cause retinal nerve fiber layer loss. Probably higher cortical function testing may help to identify coexisting neurological disorder in glaucoma patients.
We agree with the author's recommendation that a comprehensive clinical examination is necessary to rule out neurological and systemic disease causing glaucomatous (presumed) cup. We appreciate the author's effort and research work.
| References|| |
Choudhari NS, Neog A, Fudnawala V, George R. Cupped disc with normal intraocular pressure: The long road to avoid misdiagnosis. Indian J Opthalmol 2011;59:491-7.
Wirtschafter JD, Hard-Boberg AL, Coffman SM. Evaluating the usefulness in neuro-ophthalmology of visual field examinations peripheral to 30 degress. Trans Am Ophthalmol Soc 1984;82:329-57.
Elkington SG. Pituitary adenoma, preoperative symptomatology in a series of 260 patients. Br J Ophthalmol 1968;52:322-8.
Allingham RR, Damji KF, Freedman S, Moroi SE, Shafranov G, Shields MB. Shields' Textbook of Glaucoma. 5 th
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Fledelius HC. Temporal visual field defects are associated with monocular inattention in chiasmal pathology. Acta Ophthalmol 2009;87:769-75.