An older adult patient reports to the advanced practice registered nurse (APRN) that they are having difficulty driving. The patient reports being afraid to change lanes because sometimes they do not see a car in the next lane. On physical examination, the APRN notes a defect in peripheral vision and increased cup-to-disc ratio. Which diagnosis is most likely?

Progressive visual impairment in older adults can result from several age-related ocular conditions that affect different parts of the eye. Glaucoma is a chronic optic neuropathy characterized by increased intraocular pressure leading to progressive optic nerve damage. This damage initially affects peripheral vision, often unnoticed by patients until significant loss has occurred. Changes such as increased cup-to-disc ratio and visual field defects are key diagnostic indicators of glaucomatous damage. Rationale: A. Cataracts involve clouding of the eye’s lens, leading to blurred vision, glare, and difficulty seeing in low-light conditions. They primarily affect central vision rather than peripheral vision and do not cause an increased cup-to-disc ratio. The optic nerve remains unaffected in cataracts, making this diagnosis inconsistent with the findings described. B. Glaucoma is the most likely diagnosis because it is characterized by progressive optic nerve damage associated with increased intraocular pressure. It initially causes peripheral vision loss, leading to “tunnel vision,” which explains the patient’s difficulty noticing cars in adjacent lanes. The increased cup-to-disc ratio on examination is a hallmark sign of optic nerve atrophy due to chronic pressure-related damage. C. Macular degeneration primarily affects central vision due to deterioration of the macula, the part of the retina responsible for sharp, detailed vision. Patients typically report difficulty reading or recognizing faces rather than peripheral vision loss. The presence of peripheral vision defects and optic disc changes does not align with this condition. D. Presbyopia is an age-related decline in the eye’s ability to focus on near objects due to lens stiffening. It results in difficulty with reading or close work but does not affect peripheral vision or cause optic nerve changes. The physical examination findings of increased cup-to-disc ratio are not associated with presbyopia.