Is surgery medically indicated for a patient with progressive glaucoma, worsening vision, and elevated intraocular pressure, despite maximal medical therapy and presence of a cataract?

Surgery is Medically Indicated for This Patient

For a patient with progressive glaucoma and worsening vision despite maximal medical therapy, with coexisting cataract and IOP of 20 mmHg, combined cataract and glaucoma surgery (phacotrabeculectomy) is medically indicated to prevent further irreversible vision loss. 1

Rationale for Surgical Intervention

Disease Progression Despite "Normal" IOP

• An IOP of 20 mmHg, while statistically "normal," is clearly insufficient for this patient given documented progression of glaucomatous damage 2
• When optic disc and visual field damage continues to progress despite achieving IOP <21 mmHg on maximal medical therapy, surgical intervention with mitomycin trabeculectomy is the most favored therapy 2
• The Advanced Glaucoma Intervention Study demonstrated that maintaining the lowest IOP group (47% IOP reduction) protected against further visual field deterioration in advanced glaucoma patients 1

Guideline-Based Indications Met

The American Academy of Ophthalmology Preferred Practice Pattern establishes clear criteria, all of which this patient meets 1:

• Trabeculectomy is generally indicated when medications and appropriate laser therapy are insufficient to control disease (strong recommendation, good quality evidence) 1
• Progressive glaucomatous damage despite medical therapy constitutes failure of conservative management 1
• The presence of visually significant cataract provides additional surgical indication 1

Optimal Surgical Approach: Combined Surgery

Why Combined Phacotrabeculectomy

• When both glaucoma and cataract are sight-impairing, combined surgery is indicated since it allows greater IOP decrease than phacoemulsification alone 3
• Low-quality evidence suggests combined surgery may result in better IOP control compared with cataract surgery alone 1
• Performing cataract surgery after trabeculectomy increases the risk of subsequent filtration failure 4, 3

Surgical Technique Considerations

• Phacotrabeculectomy combined with mitomycin C (MMC) achieves the best IOP lowering of all combined procedures 5
• Intraoperative MMC reduces the risk of surgical failure in eyes that have undergone no previous surgery 1
• MMC provides 30% failure rate in African American patients and 20% in Caucasian American patients over 10 years 1

Critical Caveats and Risk Considerations

Antifibrotic Agent Complications

The use of MMC carries increased likelihood of complications that must be weighed against benefits 1:

• Hypotony and hypotony maculopathy 1
• Late-onset bleb leak 1
• Late-onset infection (bleb-related endophthalmitis) 1

Postoperative Management Requirements

• Postoperative examination must occur within 12-36 hours to evaluate visual acuity, IOP, and anterior segment status 6
• At least one additional follow-up within first 1-2 weeks 6
• Additional visits during 3-month period for monitoring in uncomplicated cases 6
• Topical corticosteroids must be prescribed and tapered appropriately 6
• Most patients recover preoperative visual acuity within 1-2 months, with complete stabilization at 3 months 6

Alternative Consideration: Sequential Surgery

If glaucoma is deemed more immediately sight-threatening than cataract 3:

• Trabeculectomy first, followed by delayed cataract surgery
• However, this approach has disadvantages: cataract extraction after filtering surgery may reduce bleb function 4, 3
• The cataractogenous effect of trabeculectomy itself must be considered 3

Why Cataract Surgery Alone is Insufficient

• Phacoemulsification alone is only suggested when glaucoma can be controlled by medication and visual field defect is moderate and nonprogressive 3
• This patient has progressive glaucoma despite maximal medical therapy, making cataract surgery alone inadequate 3
• While cataract extraction may produce IOP reduction in some patients, it is insufficient for progressive disease on maximal therapy 4

Prognostic Considerations

• Treatment with IOP-lowering surgery effectively reduces development and progression of visual field defects (OR 0.62,95% CI 0.47-0.81) 7
• Combined medical and/or surgical treatment reduces progression of visual field loss and optic disc damage (HR 0.56,95% CI 0.39-0.81) 7
• The natural history of glaucoma is heterogeneous, but this patient demonstrates clear progression requiring intervention 7

The combination of progressive glaucomatous damage despite maximal medical therapy plus visually significant cataract creates a compelling indication for combined surgical intervention to preserve remaining vision and prevent irreversible blindness. 1, 2, 3