Glaucoma filtering surgery, a retrospective study of 300 operations

Area of Science:

• Ophthalmology
• Surgical Procedures
• Glaucoma Management

Background:

• Glaucoma is a leading cause of irreversible blindness worldwide.
• Filtering procedures are a common surgical intervention for managing intraocular pressure in glaucoma.
• Evaluating the long-term success rates and complications of glaucoma filtering surgery is crucial for patient care.

Purpose of the Study:

• To report the outcomes of 300 consecutive glaucoma filtering procedures.
• To identify factors influencing the success rate of glaucoma filtering surgery.
• To analyze postoperative intraocular pressure trends and complications.

Main Methods:

• Retrospective analysis of 300 glaucoma filtering procedures performed between January 1982 and September 1985.
• Classification of surgical success using Heuer's criteria.
• Evaluation of patient demographics, surgical history, glaucoma type, and concurrent procedures.
• Assessment of postoperative intraocular pressure and visual field progression.
• Documentation of complications such as flat anterior chamber, cataract formation, and corneal dystrophy.

Main Results:

• Overall combined success rate (complete + qualified) was 66.5%.
• Poorer success rates were observed in cases with prior unsuccessful filtering surgery (50.5%), other prior surgery (47%), patients under 50 years (61%), and certain secondary glaucomas.
• Success rate in aphakia/pseudophakia was 33%, influenced by factors like intact posterior capsule and previous surgeries.
• High success rates were noted in phakic primary open angle glaucoma (85%) and phakic primary angle closure glaucoma (73%), potentially aided by combined cataract extraction and iridectomy.
• Postoperative intraocular pressure peaked higher initially (20-25 mm Hg) than at follow-up.
• 7% of patients experienced postoperative visual field defect progression.
• Flat anterior chamber was a significant complication, leading to cataract formation and corneal dystrophy.

Conclusions:

• Glaucoma filtering surgery demonstrates a moderate success rate, with significant variations based on patient-specific factors and surgical history.
• Identifying patients with a poorer surgical prognosis is essential for optimizing surgical planning and managing expectations.
• Careful patient selection and surgical technique are vital to minimize complications like flat anterior chamber and secondary cataract formation.