Comparison of Phacotrabeculectomy and Trabeculectomy in the Treatment of Primary Angle-closure Glaucoma (PACG)
Primary angle closure glaucoma (PACG) is caused by contact between the iris and trabecular meshwork, which in turn obstructs outflow of the aqueous humor from the eye. This contact between iris and trabecular meshwork (TM) may gradually damage the function of the meshwork until it fails to keep pace with aqueous production, and the pressure rises, and at last the optic nerve is damaged, the vision may be lost in some severe cases. Therefore, ocular pressure reduction is the key to treat the disease and prevent blindness. Trabeculectomy is the most common conventional surgery performed for glaucoma. This allows fluid to flow out of the eye through this opening, resulting in lowered intraocular pressure(IOP) and the formation of a bleb or fluid bubble on the surface of the eye.
Cataract surgery is common in the elderly. Cataract surgery is the removal of the natural lens of the eye (also called "crystalline lens") that has developed an opacification, which is referred to as a cataract. Cataract extraction includes intracapsular cataract extraction, extra capsular cataract extraction & phacoemulsification, and phacoemulsification is the preferred method. It has been reported that IOP reduction could occur in cataract patients with PACG after the cataract surgery. For some cases with PACG, such IOP reduction may be insufficient for neuronal protection, and many patients still require glaucoma medication and incisional surgery such as trabeculectomy to control IOP. In such cases, a combined cataract-glaucoma procedure (phacotrabeculectomy) is a reasonable option. In keeping with this concept, previous studies have shown that phacotrabeculectomy could effectively and simultaneously reduce IOP and improve vision in patients with a coexistence of PACG and vision-threatening cataract. However, phacotrabeculectomy may heighten inflammatory response, result in a higher frequency of postoperative complications such as hyphema and fibrin in the anterior chamber, endophthalmitis, and increased scarring of the filtering bleb. Thus, it is unclear whether phacotrabeculectomy is as effective and safe as trabeculectomy in lowering IOP for PACG patients.
In the present study, the investigators compared the efficacy and safety of phacotrabeculectomy and trabeculectomy in patients with coexisting PACG and cataract.
Procedure: combined phacotrabeculectomy
|Study Design:||Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Comparison of Combined Phacotrabeculectomy and Trabeculectomy Only in the Treatment of Primary Angle-closure Glaucoma|
- reduction of intraocular pressure [ Time Frame: within 18 months after surgery ]the difference of intraocular pressure between preoperation and postopration at the last followup
- Number of Glaucoma medications [ Time Frame: within 18 months after surgery ]to compare the number of pre- and post-operative intraocular pressure lowering drugs
- Morphology of filtering blebs [ Time Frame: within 18 months after surgery ]The filtering bleb morphology was assessed using simplified the Indiana bleb assessment grading system with a slit-lamp.Then to analyze the number of eyes with different type of blebs
- Visual outcomes [ Time Frame: within 18 months after surgery ]best corrected visual acuity was measured on Snellen decimal charts and subsequently converted to the logarithm of the minimal angle of resolution (logMAR) for analysis.
- number of eyes with complications during and after surgery [ Time Frame: within 18 months after surgery ]number of eyes with different complications such as shallow anterior chamber, malignant glaucoma,hyphema, Exudation in the anterior chamber,Corneal edema,Choroidal detachment,intraocular pressure spike on postoperative day 1
|Study Start Date:||January 2005|
|Study Completion Date:||May 2007|
|Primary Completion Date:||January 2007 (Final data collection date for primary outcome measure)|
|Active Comparator: trab||Procedure: trabeculectomy|
|Active Comparator: phacotrab||
Procedure: combined phacotrabeculectomy
trabeculectomy plus phacoemulsification with intraocular lens implantation
Please refer to this study by its ClinicalTrials.gov identifier: NCT01298635
|Principal Investigator:||Jian Ge, MD, PhD||Zhongshan Ophthalmic Center, Sun Yat-sen University|