A Case of Multiple Visual Field Defects Secondary to Glaucoma

Multiple visual field defects can occur simultaneously, resulting in various visual fields overlapping or presenting together due to multiple insults to the visual pathways.¹ We present a case report of multiple overlapping, bilateral visual field defects secondary to glaucoma, nonarteritic anterior ischemic optic neuropathy (NAAION), and a stroke over a 5-year period.

CASE REPORT

A 77-year-old Black male presented with complaints of reduced vision after an ischemic stroke 2 weeks earlier. He reported reduced right-sided peripheral vision in his right and left eye since his stroke. His ocular history included cataract surgery OS, NAAION OS, and glaucoma OU. He was also diagnosed with chronic hypertension, diabetes, and hypercholesterolemia, which were likely contributory to his ischemic events.

The patient’s BCVA was 20/40 OD and 20/50 OS. His pupils were equal, round, and reactive to light, but with an obvious afferent pupillary defect OS. Extraocular motilities were normal. Automated perimetry confirmed severely restricted confrontational visual fields OU (Figure 1). External examination was normal OU, except for moderate cataract OD and previous cataract surgery OS. Goldman applanation tonometry was 24 mm Hg OD and 34 mm Hg OS. Gonioscopy was normal OU, without angle recession. Dilated fundus examination revealed extensive glaucomatous cupping OU (OS > OD) and severe optic nerve pallor OS (Figure 2). MRI revealed an ischemic lesion involving the anterior left optic radiations (Figure 3), thus explaining the patient’s new visual complaint secondary to stroke.

DISCUSSION

The chronologic timeline of the patient’s visual field defects was relatively complicated. The patient’s complaints initially started with mild inferior nasal visual field defects OU, consistent with his glaucoma diagnosis 5 years prior. This was followed by an acute NAAION OS, which resulted in a commonly associated inferior altitudinal defect, which overlaid the initial nasal glaucomatous visual field defect OS (Figure 4).² The patient then was lost to follow-up for approximately 5 years, allowing his untreated glaucoma to develop a dense left superior arcuate defect OS. His most recent stroke of the anterior left optic radiations resulted in complete right-sided hemianopias OU, which overlaid all the previously accrued visual field defects (Figure 5).

Inferior and superior nasal and arcuate visual field defects associated with glaucoma have been well documented.^3,4 A previous study estimated the average time from early glaucoma to advanced glaucoma to be approximately 3 years when IOP is > 30 mm Hg.⁴ This timeframe fits well with that of this patient, as his IOP was 34 mm Hg OS when we followed up with him 5 years after his original diagnosis. Visual field defects are also common in acute strokes and have been reported in approximately 45% to 92% of stroke cases.^5-7 More specifically, complete homonymous hemianopic visual field defects have been reported in approximately 29% to 54% of stroke patients, as was the case with this patient.^6,7

LET THE CLUES PROVIDE THE ANSWER

This case highlights the importance of having a good understanding of ocular and neurologic anatomy in order to understand challenging visual field presentations. When confronted with severe visual field deterioration, it is important to use a patient’s known ocular and medical history to accurately stitch together the resultant visual field defects for a clear clinical picture for the clinician.