What are the appropriate steps to take if experiencing a scotoma?

Management of Scotoma

If you are experiencing a scotoma, seek immediate ophthalmologic evaluation to determine the underlying cause, as the appropriate management depends entirely on whether this represents an acute vision-threatening condition (requiring urgent intervention) versus a chronic stable defect (requiring rehabilitation strategies). 1

Immediate Assessment Priority

The first critical step is determining acuity and timing:

• Acute onset scotomas (hours to days) require urgent evaluation to rule out retinal detachment, vascular occlusion, optic neuropathy, or compressive lesions 1
• Chronic or stable scotomas shift focus to rehabilitation and adaptation strategies 2
• Document whether the scotoma is central, paracentral, or peripheral, as this localizes pathology 1

Diagnostic Evaluation

Essential Testing for Scotoma Characterization

Central scotomas require specialized assessment:

• Fundus-related macular microperimetry is the gold standard for accurate scotoma detection and fixation assessment, using eye-tracking technology to ensure stimuli are presented to correct retinal positions 2
• Traditional Amsler grid testing detects only approximately 50% of central scotomas due to perceptual completion, making it inadequate as a sole screening tool 2, 1
• Optical coherence tomography (OCT) provides objective anatomic assessment and is more specific than visual field testing for detecting retinal pathology 2

Peripheral scotomas require:

• Goldmann or automated perimetry to map the full extent of visual field loss 1
• Consider neuroimaging if pattern suggests chiasmal or retrochiasmal pathology 3, 4

Critical Diagnostic Pitfall

Scotomas appearing paracentral on traditional automated field testing may actually be central scotomas displaced by eccentric fixation 2, 1. This occurs because patients with macular disease develop unstable or nonfoveal fixation, causing the scotoma location to be mapped incorrectly. Microperimetry circumvents this problem through real-time eye tracking 2.

Condition-Specific Considerations

Drug-Induced Scotomas (Hydroxychloroquine)

For patients on hydroxychloroquine:

• Baseline retinal examination should occur within the first few months of use 2
• Annual screening with OCT and automated visual fields (10-2 protocol for central assessment) starting after 5 years of use, or earlier if risk factors present 2
• Ring scotomas on visual field testing require confirmation with repeat testing before discontinuing medication, as fields are subjective and variable 2
• East Asian patients require broader OCT scans (30° line scans) and wider field testing (24-2 or 30-2 protocols) 2

Compressive Lesions

Junctional scotomas (unilateral temporal field defect with contralateral optic neuropathy) indicate pathology at the optic nerve-chiasm junction:

• The classic junctional scotoma (upper temporal hemifield loss) often indicates ventral compression 3
• The atypical junctional scotoma (lower temporal hemifield loss) suggests dorsal compression or non-compressive pathology 3
• Paracentral temporal scotomas in one eye are rare (1-2% of pituitary adenomas) but require recognition to avoid misdiagnosis as optic neuritis 4

Rehabilitation for Persistent Scotomas

When scotomas are stable and non-progressive, rehabilitation becomes the priority:

Visual Function Optimization

• Improve lighting and reduce glare to maximize remaining visual function 1
• Increase contrast in the environment and reading materials 2, 1
• Utilize magnification tools appropriate to the degree of vision loss 2, 1

Eccentric Viewing Training for Central Scotomas

Patients with central scotomas naturally develop a preferred retinal locus (PRL) for fixation, though this is a dynamic process that changes with task, print size, and illumination 2:

• Training in eccentric viewing techniques helps patients consciously utilize their PRL 1
• Biofeedback training with microperimetry devices can develop a trained retinal locus (TRL), though evidence for efficacy remains limited due to lack of appropriate control groups 2, 1
• Fixation can be assessed as foveal versus eccentric, and stable versus unstable 2

Technological Aids

• Electronic magnification devices (video magnifiers) 1
• Illuminated magnifiers for patients with severe contrast sensitivity loss 2
• Smartphone applications for text-to-speech and object identification 1
• Computers and electronic tablets with contrast enhancement 2, 1

Important Clinical Considerations

Testing Limitations

• Binocular testing with nonautomated methods (face observation, clock face, California Central Visual Field test with laser pointer) provides useful information about fixation relative to scotoma during binocular viewing, which monocular microperimetry cannot assess 2
• Contrast sensitivity testing (Pelli-Robson, VISTECH, or computer-based tests) identifies patients requiring illumination or contrast enhancement devices 2

Patient Counseling

• Patients with vision loss may experience Charles Bonnet syndrome (visual hallucinations), which should be recognized and explained as a benign phenomenon 1
• Scotomas from conditions like acute macular neuroretinopathy or paracentral acute middle maculopathy may persist despite resolution of visible retinal lesions 5
• No ocular treatment exists for certain conditions; observation and education regarding persistent scotomas are necessary 5

Follow-Up Monitoring

• Regular monitoring of visual fields and retinal structure in progressive conditions 1
• Reassessment of visual function and adaptation to rehabilitation devices 1
• Psychological support and counseling for adjustment to persistent visual impairment 1