Medication-induced acute angle closure attack

OBJECTIVE: To review acute angle closure attacks induced by local and systemic medications. DATA SOURCES: PubMed literature searches up to August 2011. STUDY SELECTION: The following key words were used for the search: 'drug', 'iatrogenic', 'acute angle closure glaucoma'. DATA EXTRACTION: A total of 86 articles were retrieved using the key words. Only those concerning acute angle closure attack triggered by local or systemic drug administration were included. For articles on the same or related topics, those published at later or more recent dates were selected. As a result, 44 articles were included and formed the basis of this review. DATA SYNTHESIS: An acute attack of angle closure can be triggered by dilatation of the pupil, by anatomical changes in the ciliary body and iris, or by movement of the iris-lens diaphragm. Local and systemic medications that cause these changes have the potential to precipitate an attack of acute angle closure. The risk is higher in subjects who are predisposed to the development of angle closure. Many pharmaceutical agents including ophthalmic eyedrops and systemic drugs prescribed by general practitioners and various specialists (in psychiatry, otorhinolaryngology, ophthalmology, medicine, and anaesthesia) can precipitate an acute angle closure attack. The medications include: anti-histamines, anti-epileptics, antiparkinsonian agents, antispasmolytic drugs, mydriatic agents, sympathetic agents, and botulinum toxin. CONCLUSION: Since acute angle closure attack is a potentially blinding eye disease, it is extremely important to be vigilant and aware of ophthalmic and systemic medications that can lead to such attacks in predisposed subjects and to diagnose the condition when it occurs.published_or_final_versio

Enophthalmos caused by an orbital venous malformation

Orbital vascular malformations usually present with proptosis. We report a case where a patient with an orbital venous malformation presented with enophthalmos. Since many underlying orbital pathologies, including orbital metastases, can cause enophthalmos, it is important to investigate patients properly. Computed tomographic imaging of the orbit remains the most useful tool in the management of patients with enophthalmos.published_or_final_versio

Orbital myiasis complicating squamous cell carcinoma of eyelid

Myiasis is infestation of the body by fly maggots. Immobile patients with skin wounds in exposed areas are at high risk of developing myiasis. We report a case of orbital myiasis from the species Chrysomya bezziana complicating squamous cell carcinoma of the eyelid. Magnetic resonance imaging of the orbit is useful for delineating the extent of the infestation and identifying residual maggots. In extensive orbital myiasis, exenteration is needed to prevent intracranial extension of tissue destruction.published_or_final_versio

Screening for retinopathy of prematurity and treatment outcome in a tertiary hospital in Hong Kong

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Prospective study on retinal nerve fibre layer changes after an acute episode of phacomorphic angle closure

To investigate the retinal nerve fibre layer (RNFL) changes after an acute attack of phacomorphic angle closure. This prospective study involved ten cases of phacomorphic angle closure that underwent cataract extraction and intraocular lens insertion after intraocular pressure lowering. Apart from visual acuity and intraocular pressure (IOP), RNFL thickness and vertical cup disc ratio (VCDR) were measured by optical coherence tomography (OCT) at 3-9 months post attack. Humphrey visual field assessment was performed at 9 months post attack. All cases had mean phacomorphic duration of  0.2. Patients with <5 days duration of phacomorphic angle closure are likely to have reasonable postoperative vision. An acute episode of phacomorphic angle closure can trigger an accelerated RNFL thinning despite normal IOP and open angles, most noticeable in the superior and inferior quadrants, occurring between 3 and 9 months post attack. Glaucomatous optic neuropathy in the attack eye was evident by OCT but not by visual field assessment at the same time interval. © 2012 The Author(s).published_or_final_versio

Recurrent acute angle-closure attack due to plateau iris syndrome after cataract extraction with or without argon laser peripheral iridoplasty: a case report

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Two-Year Clinical Results After Selective Laser Trabeculoplasty for Normal Tension Glaucoma

Open Access JournalThis article aims to investigate the clinical results at 2 years after selective laser trabeculoplasty (SLT) for normal tension glaucoma (NTG). This prospective cohort study recruited NTG patients taking antiglaucoma medication. Subjects were excluded if they had previous glaucoma surgery/laser or corneal pathologies. All subjects underwent a 1-month washout. A single session of SLT was performed to 360° of the trabecular meshwork. Medication was resumed at 1 month to achieve a targeted 30% intraocular pressure (IOP) reduction from the post-washout/pre-SLT IOP. IOP was measured every 3 months and medication use was recorded at 3, 6, 12, and 24 months. Subjects with a secondary SLT or cataract extraction were excluded from IOP and medication analyses. At 24 months, 34 of the initial 45 right eyes were eligible for analyses. There were significant IOP reductions at all time intervals (except at 1 week) following SLT when compared to the prestudy (without medication) or pre-SLT (post-washout) IOP (P 20% from pre-SLT, without medication) was achieved in 11.1% (5/45). Reductions in IOP and medication use were evident at 2 years following SLT for the treatment of NTG whereas 11% remained medication free. Trial Registrations: The Clinical Trials Register of the University of Hong Kong HKCTR1847. The European Clinical Trials Database 2014-003305-15 (August 11, 2014).published_or_final_versio

Argon laser peripheral iridoplasty versus systemic intraocular pressure-lowering medications as immediate management for acute phacomorphic angle closure.

Background: The purpose of this study was to compare the efficacy and safety of argon laser peripheral iridoplasty (ALPI) and systemic intraocular pressure (IOP)-lowering medications in the immediate management of acute phacomorphic angle closure. Methods: Consecutive cases of acute phacomorphic angle closure were randomized to receive ALPI and an intravenous or oral carbonic anhydrase inhibitor as initial treatment. Intravenous mannitol was administered for presenting IOP > 60 mmHg or IOP > 40 mmHg 2 hours posttreatment in both arms. Results: Of 10 consecutive cases, six received medical therapy and four received ALPI. Fifty percent in the medical group and none in the ALPI group required intravenous mannitol. The ALPI group took less time to achieve IOP < 25 mmHg (18.8 ± 7.5 minutes versus 115.0 ± 97.0 minutes, P = 0.001, F test); had a greater IOP reduction within 30 minutes (69.8% ± 7.7% versus 40.9 ± 23.9%, P = 0.03, t-test); and had a consistently smaller post-attack cup to disc ratio (0.50 ± 0.02 versus 0.60 ± 0.20, P = 0.002, F test). Conclusion: ALPI offers greater safety, consistency, and efficacy than systemic IOP-lowering medications as initial treatment for phacomorphic angle closure. © 2013 Lee et al, publisher and licensee Dove Medical Press Ltd.published_or_final_versio

Glaucoma Drainage Device Tube Retraction and Blockage in a Patient with Iridocorneal Endothelial Syndrome Treated With Nd:YAG Membranectomy

Purpose: To report on a case that demonstrates the successful treatment of tube blockage of the Ahmed Glaucoma Valve at its aqueous entry site by Nd:YAG laser membranectomy. Method: We report a case of refractory intraocular pressure elevation in a patient with iridocorneal endothelial syndrome after glaucoma drainage device due to blocked tube from the iridocorneal endothelial syndrome membrane. In July 2014, our patient presented with sudden right eye elevated intraocular pressure to 67 mmHg despite a well-controlled intraocular pressure in the range of teens with timolol alone over the last 2 years. Gonioscopy showed total synechial angle closure and increasing her medical treatment failed to control the intraocular pressure. Ahmed glaucoma valve was implanted successfully. However, recurrence of raised intraocular pressure from partial tube retraction and tube blockage at its aqueous entry site by an endothelial membrane was noted at 2 weeks after the surgery. Nd:YAG laser membranectomy was performed on 2 occasions to restore the patency of the tube shunt. After the second laser membranectomy, the patient’s intraocular pressure returned to, and remained at, normal level since. Conclusion: Tube occlusion by membrane is a well-known complication following glaucoma drainage device tube in patients with iridocorneal endothelial syndrome. Nd:YAG membranectomy is effective to restore the patency of tube lumen without subjecting patients to more invasive surgical interventions including tube extender or another glaucoma drainage device. However, more studies are required to ascertain the long term effect of laser membranectomy to a blocked tube, in comparison to other treatment modalities. To our knowledge, this is the first reported case of using laser membranectomy alone in treating Ahmed glaucoma valve tube obstruction due to a retracted tube blocked by endothelial membrane.published_or_final_versio

Intraocular Pressure Elevation in the Contralateral Untreated Eye Following Selective Laser Trabeculoplasty in Rabbit Eyes

Our study aimed at evaluating if a single session of unilateral selective laser trabeculoplasty would affect the intraocular pressure of the fellow untreated eye in rabbits. Eleven rabbits were involved. 360° selective laser trabeculoplasty with 532 nm frequency-doubled green Nd:YAG laser was performed over the right eyes. The mean intraocular pressure of both eyes at baseline, 3 hours, 24 hours, 3 days and 7 days after laser were measured. The baseline mean intraocular pressure of the right eye and the left eye were 8.07 ± 1.72 mmHg and 8.27 ± 1.56 mmHg respectively (p=0.78). The mean intraocular pressure of the treated eye was lower than the baseline from 3 hours through 3 days after laser, with a maximum mean decrease of 1.36 mmHg on Day 3. On the contrary, the mean intraocular pressures of the untreated eyes were higher than the baseline throughout the study, particularly at later course (1.91 mmHg on Day 3 and 1.85 mmHg on Day 7). This suggests the change of intraocular pressure in one eye after selective laser trabeculoplasty, leads to a change in the pressure of the fellow eye. It is thought that a neuronal and humoral response is triggered centrally after unilateral intraocular pressure change. The detailed mechanisms would require further studies to evaluate. The rising intraocular pressure trend in the contralateral untreated eye suggests that response may continue to exert its action for some time after the initial laser. This is the first reported study of intraocular pressure elevation of the untreated eye following contralateral selective laser trabeculoplasty.published_or_final_versio