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Intermittent angle closure
Patricia M. Khu, Margarita L. Luna and Manuel B. Agulto
Sentro Oftalmologico Jose Rizal, Philippine General Hospital, University of the Philippines, Manila
Introduction
Intermittent angle closure designates a condition of primary angle closure in which mild, transient elevation of intraocular pressure occurs sporadically due to pupillary block mechanism and subsides spontaneously. Because the ocular signs and symptoms are intermediate between typical acute primary angle closure and typical chronic angle closure, they vary from one patient to another. Intermittent angle closure is not a single disease entity, but a subdivision of primary angle closure and the border of this subdivision with other ones is relatively arbitrary. The management of intermittent angle closure is basically similar to other clinical types of primary angle closure because pathophysiology is identical.
The Terminology and Guidelines for Glaucoma, published by the European Glaucoma Society, describes intermittent angle-closure glaucoma as milder clinical manifestations than acute angle-closure glaucoma and that it resolves spontaneously.1
Signs and symptoms
Mild symptoms are experienced during these attacks described as dull headaches, nonspecific eye pain in and around the involved eye, occasional haloes around light, or transient and mild blurring of vision.2 The symptoms may last for a quarter hour to several hours and may occur very infrequently once in a couple of years or relatively frequently, several times a month.
The eye is often white and quiet except for the elevated intraocular pressure and a sluggish or mid-dilated pupil that returns to normal once the attack resolves spontaneously. It is believed that the reason why the condition subsides spontaneously is that an environment factor such as bright light and sleep causes miosis before angle closure becomes irreversible. Between repeated attacks, few patients complain of visual symptoms.
Address for correspondence: M.B. Agulto, MD, Sentro Oftalmologico Jose Riza, Philippine General Hospital, University of the Philippines, Taft Avenue, Manila 1000, Philippines. E-mail: mba_eyemd@yahoo.com
Angle Closure Glaucoma, pp. 133–136 edited by Chul Hong and Tetsuya Yamamoto
© 2007 Kugler Publications, Amsterdam, The Netherlands
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Risk factors
Risk factors for intermittent angle closure are identical to those for primary angle closure which include older age, female sex, Asian parentage, smaller anterior segment dimensions such as shallower limbal and axial anterior chamber depth, thicker lens, more anteriorly positioned lens, hyperopia, and a family history of angle closure.3-11 The eyeball is smaller in women, Asians, and those with angle closure, making them at risk of getting intermittent angle closure later in life. As the lens enlarges throughout life, the anterior chamber becomes shallower with time and there is a relative anterior chamber-lens disproportion, which is also more pronounced among those with moderate to high hyperopia.
Clinical course
Intermittent angle closure may progress to chronic or acute angle closure (Fig. 1). The mild attacks may be triggered by emotions, fatigue, dim light, or prolonged near reading and tend to recur under similar circumstances.12 Dilatation of the pupil under these physiologic conditions lead to a narrower anterior chamber angle with resultant elevation of intraocular pressure. The angle may be partially closed to allow moderate elevation of the intraocular pressure with mild symptoms or a
Fig. 1. Progression of angle closure.
near complete closure that spontaneously resolves with a reactive pupil. Sleep has some beneficial effect on intraocular pressure, most likely due to sleep-induced miosis and decreased aqueous secretion.13
Some doctors prefer the term subacute angle closure. The border of intermittent
Intermittent angle closure |
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and subacute angle closures is again arbitrary. Basically, subacute angle closure glaucoma with pupillary block means attacks which are more severe than intermittent angle closure but milder than acute angle closure. Symptoms of pain, blurred vision, and haloes are more marked than in intermittent angle closure. Racial differences are seen among Caucasians, blacks, and Asians with Asians having shallow anterior chamber than blacks.
Initially, the intermittent attacks occur at intervals of weeks or months that may continue uneventfully for months to years. Some patients avoid or reduce activities, for example reading, frequently associated with the attacks. Eventually, these attacks may become more frequent or lead to a peripheral anterior synechiae (PAS) formation and chronic angle closure glaucoma.14 It may progress to severe attack.
Diagnosis of this condition is often missed because the eyes appear normal between attacks except for the narrow angle. Moreover, patient’s self-diagnosis of similar symptoms such as migraine, sinusitis, or eye strain may confuse the clinical picture.
Management
Recognition of this condition, especially among Asians, is needed to prevent PAS formation and consequent chronic angle closure glaucoma. Periodic gonioscopy must be performed to determine if the angle is ‘anatomically narrow’ for which laser iridotomy is indicated. Preferably, indentation gonioscopy and ultrasound biomicroscopy should be performed.
All eyes with an established diagnosis of intermittent angle closure should be treated appropriately by releasing relative pupillary block. In most of these cases, laser iridotomy is indicated. In some cases, phacoemulsification with posterior chamber IOL or surgical peripheral iridectomy may be indicated.
References
1.European Glaucoma Society. Primary angle-closure. In: European Glaucoma Society (eds) Terminology and Guidelines for Glaucoma, 2nd ed. Savona, Italy: Editrice DOGMA, 2003, pp 13-7.
2.Ritch R, Lowe RF. Angle-closure glaucoma: clinical types. In: Ritch R, Shields MB, Krupin T (eds) The Glaucomas: Clinical Science, 2nd ed vol 2. St Louis: CV Mosby, 1996, pp 821-2.
3.Foster PJ, Baasanhu J, Alsbirk PH, et al. Glaucoma in Mongolia. A population-based survey in Hovsgol Province, Northern Mongolia. Arch Ophthalmol 1996;114:1235-41.
4.Foster PJ, Oen FT, Machin DS, et al. The prevalence of glaucoma in Chinese residents of Singapore. A cross-sectional population survey in Tanjong Pagar district. Arch Ophthalmol 2000;118:1105-11.
5.Ramakrishnan R, Nirmalan PK, Krishnads R, et al. Glaucoma in a rural population of southern India: the Aravind comprehensive eye survey. Ophthalmology 2003;110:1484-90.
6.Vijaya L, Geaorge R, Arvind H, et al. Prevalence of angle-closure disease in a rural southern Indian population. Arch Ophthalmol 2006;125:403-9.
7.Foster PJ, Devereux JG, Alsbirk PH, et al. Detection of gonioscopically occludable angles and primary angle closure glaucoma by estimation of limbal chamber depth in Asians: modified grading scheme. Br J Ophthalmol 2000;84:186-92.
8.Deverux JG, Foster PJ, Baasanhu J, et al. Anterior chamber depth measurement as a screening tool for primary angle-closure glaucoma in an East Asian population. Arch Ophthalmol 2000;188:257-63.
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9.Foster PJ, Alsbirk PH, Baasanhu J, et al. Anterior chamber depth in Mongolians. Variations with age, sex, and method of measurement. Am J Ophthalmol 1997;124:53-60.
10.Congdon NG, Qi Y, Quigley HA, et al. Biometry and primary angle-closure glaucoma among Chinese, white, and black populations. Ophthalmology 1997;104:1489-95.
11.Aung T, Nolan WP, Machin D, et al. Anterior chamber depth and the risk of primary angle closure in 2 East Asian populations. Arch Ophthalmol 2005;123:627-32.
12.LoweRF.Angle-closureglaucoma:acuteandsubacuteattacks:clinicaltypes.TransOphthalmol Soc Aust 1961;21:65-7.
13.Reiss AR, et al. Aqueous humor flow during sleep. Invest Ophthalmol Vis Sci 1984;25:776.
14.Aung T, Lim MC, Chan YH, et al. Configuration of the drainage angle, intraocular pressure, and optic disc cupping in subjects with chronic angle-closure glaucoma. Ophthalmology 2005;112:28-32.