ALPI vs Medical Therapy Effects on Optic Nerve Structure & Function (Iridoplasty)
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|ClinicalTrials.gov Identifier: NCT00485238|
Recruitment Status : Unknown
Verified May 2008 by National University Hospital, Singapore.
Recruitment status was: Recruiting
First Posted : June 12, 2007
Last Update Posted : May 15, 2008
|Condition or disease||Intervention/treatment||Phase|
|Glaucoma||Procedure: Argon laser Iridoplasty Drug: Intravenous acetazolamide||Phase 4|
Primary Angle Closure Glaucoma (PACG) continues to be a major concern in Asia. It is a major cause of visual morbidity in the region1 being the most prevalent type of glaucoma especially in Chinese and Mongoloid descent.2,3 During the acute stage of the disease, prompt institution of measures to break the attack is necessary. Two recognized approaches are utilized in practice in lowering intraocular pressure and preparing for the definitive treatment of laser peripheral iridotomy. These are conventional topical and systemic medical therapy and immediate peripheral iridoplasty using either argon or diode lasers.
In the study of Lim, Tan, Chew, Seah et al., laser iridoplasty was noted to have a useful role in the management of medically unresponsive acute angle closure, particularly in those cases where laser peripheral iridotomy (PI) could not be successfully performed4 . Randomized controlled trials of Lam, Lai, Tham et al. comparing immediate laser peripheral iridoplasty plus topical medications and topical and systemic medical treatment found no significant difference in the eventual mean IOP and requirement for glaucoma medications 5 . However, significant difference in efficacy was observed between the two treatment arms within the first two hours of treatment with argon laser peripheral iridoplasty and topical medications lowering IOP faster than conventional medications6. In all the trials cited, there was no mention of sudden IOP lowering effects of either argon laser iridoplasty or conventional medications on the optic nerve head and visual field status, as well as its effect on other ocular structures like the cornea, lens and retina . In our literature search, two papers studied the optic nerve head structure and function in angle closure glaucoma, but not in the immediate period of sudden IOP lowering. Ang, Aung, Chua, Yip and Chew made a comparative assessment of the visual field loss between symptomatic and asymptomatic PACG, with 50% of asymptomatic PACG subjects presenting with end stage visual field loss in contrast to just 7% of symptomatic PACG.7 Lai, Tham, Lam et al. compared the retinal nerve fiber layer measurements of attack eyes and their fellow eyes after a single unilateral attack of acute primary angle closure (APAC) using scanning laser polarimetry six months after the acute attack8. Retinal nerve fiber layer damage was documented in eyes where the duration of the APAC attack lasted more than 48 hours8. Decompression retinopathy following laser peripheral iridoplasty for acute primary angle closure was reported in two cases reported by Lai, Lee, Leung and Chung.9 In order to compare the efficiency of laser peripheral iridoplasty and medical treatment, as well as to identify any morbidity that may come from sudden decompression of the eye, we undertake this randomized controlled trial.
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||60 participants|
|Intervention Model:||Parallel Assignment|
|Masking:||None (Open Label)|
|Official Title:||EFFECTS OF IMMEDIATE ARGON LASER PERIPHERAL IRIDOPLASTY Versus CONVENTIONAL SYSTEMIC MEDICAL THERAPY ON OPTIC NERVE HEAD STRUCTURE AND FUNCTION OF ACUTE PRIMARY ANGLE CLOSURE EYES|
|Study Start Date :||February 2007|
|Estimated Study Completion Date :||December 2008|
- optic nerve head stereometric analysis HRT3 and Stratus OCT,optic nerve head and RNFL & macula thickness average. AGIS scores of HVF is the measure of functional status. [ Time Frame: 1 year ]
- amount and rate of IOP-lowering,gonioscopy and ASOCT changes, change in LOCS grading for cataract, corneal decompensation & edema,macular,retinal edema by Stratus OCT. [ Time Frame: 1 year ]
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00485238
|Contact: Paul TK Chew, A/Profemail@example.com|
|Contact: Maria Cecilia D. Aquino, M.D.||firstname.lastname@example.org|
|National University Hospital||Recruiting|
|5 Lower Kent Ridge Road, Singapore, Singapore, 119074|
|Principal Investigator: Paul TK Chew, A/Prof|
|Principal Investigator:||Paul TK Chew, A/Prof||National University Hospital, Singapore|