Homonymous visual field defect and retinal thinning after occipital stroke

Abstract

Introduction: Stroke is the most common cause of homonymous visual field defects (VFD). About half of the stroke patients recover from VFD. However, relationship between VFD and retinal changes remains elusive.

Purpose: To investigate the association between occurrence of VFD, changes of macular ganglion cell and inner plexiform layer (GCIPL) and its axon retinal nerve fiber layer (RNFL) detected with optical coherence tomography (OCT).

Patients and methods: The study consists of retrospective review of medical records and follow-up examinations. Patients with acute occipital stroke were registered. VFD was identified with confrontation and/or perimetry tests at the onset. At follow-up, the patients were examined with visual field tests and OCT measurements.

Results: Thirty-six patients met the inclusion criteria. At onset, 26 patients (72%) had VFD. At follow-up >1 year after stroke, 13 patients (36%) had remaining VFD: 5 had homonymous hemianopia, 5 had homonymous quadrantanopia, and 3 had homonymous scotomas. Average thickness of GCIPL and RNFL were significantly reduced in each eye in patients with VFD compared to non-VFD (NVFD) (p < .01 for all comparisons). Thickness of superior and inferior RNFL quadrants was significantly reduced in VFD compared to NVFD (p < .01 for both). Among these 13 patients, 4 had characteristic homonymous quadrant-GCIPL thinning, 2 had characteristic homonymous hemi-GCIPL thinning, and 7 had diffuse GCIPL thinning.

Conclusion: GCIPL and RNFL thinning were observed in the patients with VFD. GCIPL thinning appears in two forms: atypical diffuse thinning, or homonymous hemi-GCIPL thinning. Examining GCIPL and RNFL provides easy and reliable objective measures and is therefore proposed to be of predictive value on visual function.

Keywords: ganglion cell and inner plexiform layer; homonymous visual field defect; occipital stroke; optical coherence tomography; retinal nerve fiber layer.

FIGURE 1

Mean thickness of GCIPL and RNFL at follow‐up after stroke in patients with or without visual field defect (VFD or NVFD). In the VFD group, the average thickness of GCIPL and RNFL is significantly reduced in the right (A) as well as in the left eye (B) compared to the NVFD group (p < .01 for each eye). Mann–Whitney U‐test was applied for GCIPL analysis, and Student's t‐test was applied for RNFL analysis, based on normality analysis Abbreviations: GCIPL, ganglion cell and inner plexiform layer; NVFD, non‐visual field defect; RNFL, retinal nerve fiber layer; VFD, visual field defect. *p ≤ .05; **p ≤ .01.

FIGURE 2

Mean thickness of RNFL quadrants at follow‐up after stroke in patients with (VFD) or without visual field defect (NVFD). The thickness of RNFL quadrants was analyzed in each eye. Significant reduction of RNFL thickness was observed in the superior (p < .01 for each eye) and inferior (p < .01 for each eye) quadrants in the VFD group (dotted line) compared to the NVFD group (solid line). The thickness of RNFL temporal and nasal quadrants showed no significant difference between the two groups. Vertical bars represent 95% confidence intervals Abbreviations: IQL, inferior quadrant left; IQR, inferior quadrant right; NQL, nasal quadrant left; NQR, nasal quadrant right; NVFD, non‐visual field defect; RNFL, retinal nerve fiber layer; SQL, superior quadrant left; SQR, superior quadrant right; TQL, temporal quadrant left; TQR, temporal quadrant right; VFD, visual field defect. *p ≤ .05 **p ≤ .01.

FIGURE 3

(A) An 80‐year‐old male with diffuse GCIPL thinning and homonymous hemianopia. (a,b) Right side homonymous hemianopia with macular sparing detected by Humphrey visual field test; (c,d) diffuse GCIPL thinning on the OCT thickness map; (e,f) diffuse GCIPL thinning with tendency of left homonymous thinning on the OCT deviation map; (g,h) RNFL thinning on the thickness map; (i) reduced right RNFL superior, temporal and inferior quadrants (yellow coded: outside of the 95% normal limit; red coded: outside of the 99% normal limit); (j) reduced left RNFL superior quadrant (yellow coded); (k) an acute cerebral infarction with hyperintensity in the left occipital lobe as shown by diffusion MRI. (B) An 88‐year‐old female with homonymous GCIPL thinning and contralateral homonymous hemianopia. (a,b) Left side homonymous hemianopia detected by Humphrey visual field test; (c,d) right side homonymous hemi‐GCIPL thinning on the OCT thickness map; (e,f) right side homonymous hemi‐GCIPL thinning on the OCT deviation map; (g,h) relatively preserved RNFL thickness except (i) reduced thickness in the right superior RNFL quadrant (yellow coded: outside of the 95% normal limit); (j) normal left RNFL thickness in all quadrants (green coded); (k) a subacute cerebral infarction in the right occipital lobe shown by CT