What is the recommended treatment for an older adult patient with a cataract in the right eye and blindness in the left eye due to macular degeneration?

Cataract Surgery in a Functionally Monocular Patient

Proceed with cataract surgery on the right eye to restore functional vision, as this represents the only effective treatment for the visually significant cataract, but ensure comprehensive preoperative counseling about realistic visual expectations given the underlying macular degeneration in the left eye. 1, 2

Primary Indication for Surgery

• The primary indication for cataract surgery is visual impairment that no longer meets the patient's needs and for which surgery provides reasonable likelihood of improvement. 1
• Cataract surgery is the only effective treatment for cataracts—no pharmacological treatments exist to eliminate cataracts or retard their progression. 2
• Surgery for visually significant cataracts in patients with AMD can substantially improve quality of life and reduce the risk of falls. 3

Critical Considerations for the Functionally Monocular Patient

• This patient is functionally monocular due to blindness from macular degeneration in the left eye, which places them in a special high-risk category requiring enhanced preoperative counseling and surgical planning. 1
• The American Academy of Ophthalmology specifically addresses "Cataract in the Functionally Monocular Patient" as a distinct clinical scenario requiring special consideration. 1
• The risk-benefit calculation differs significantly in monocular patients because any surgical complication could result in bilateral blindness. 4

Preoperative Assessment Requirements

• Perform optical coherence tomography (OCT) preoperatively to identify the extent of macular disease in the right eye and establish baseline macular status. 3
• Document best-corrected visual acuity in the right eye to establish realistic postoperative expectations. 1
• Assess whether the right eye has any signs of AMD (drusen, geographic atrophy, or neovascular changes) that could limit visual recovery after cataract surgery. 1, 5
• Evaluate the patient's ability to cooperate and position for surgery, as well as their mental and physical status. 1

Essential Preoperative Counseling Points

• Counsel the patient extensively about expected visual outcomes, emphasizing that final visual acuity depends on both successful cataract removal AND the health of the underlying macula. 1, 3
• Explain that if the right eye has underlying AMD, visual improvement may be limited even with successful cataract surgery. 3, 6
• Discuss the slightly higher risk of complications in functionally monocular patients and the potential for bilateral blindness if complications occur. 4
• Inform the patient that cataract surgery provides short-term (six months) improvement in best-corrected visual acuity in eyes with AMD, with mean improvement of -0.15 LogMAR compared to no surgery. 6
• Address realistic expectations about quality of life improvements and functional vision restoration. 1, 3

Surgical Planning Considerations

• Select standard intraocular lens (IOL) power targeting emmetropia or slight myopia for the right eye, avoiding premium IOLs (multifocal, extended depth of focus) if AMD is present in this eye. 1
• Plan for phacoemulsification with IOL implantation as the standard of care, which offers better visual outcomes and lower complication rates. 2
• Minimize intraoperative light exposure to reduce phototoxicity risk to the retina, particularly important in patients with underlying AMD. 3
• Prepare for potential intraoperative complications, as patients with AMD may have slightly higher risk. 3

Management of Concurrent AMD

• If the right eye has neovascular (wet) AMD requiring anti-VEGF therapy, real-world data suggests completing 6 months of intravitreal anti-VEGF therapy before cataract surgery is compatible with optimum long-term visual outcomes. 3
• Consider combined cataract surgery with intravitreal bevacizumab if active subfoveal neovascularization is present, as this approach has demonstrated safety and efficacy. 7
• Plan timing of intravitreal therapy carefully—administering anti-VEGF just before cataract surgery allows greater recovery time postoperatively before resuming planned intravitreal therapy. 3

Postoperative Management

• Monitor for both cataract surgery recovery and any progression of AMD in the right eye. 2
• Counsel the patient that central vision loss from AMD is common but total blindness is extremely rare, as peripheral vision is typically preserved. 5
• Refer to vision rehabilitation services if visual function remains reduced despite successful cataract surgery. 5
• Ensure the patient understands signs of complications (endophthalmitis, retinal detachment, decreased vision) requiring immediate return. 5

Common Pitfalls to Avoid

• Do not delay cataract surgery indefinitely due to concerns about AMD progression—withholding potentially beneficial treatment raises ethical concerns. 6
• Avoid overpromising visual outcomes without accounting for underlying macular disease. 1, 3
• Do not proceed without comprehensive OCT imaging to assess macular status preoperatively. 3
• Never use premium IOLs (multifocal, accommodating) in eyes with significant AMD, as these patients cannot fully utilize the optical benefits and may experience worse outcomes. 1