Objective:

To describe a case of mild central retinal vein occlusion (CRVO) occurring after intense exercise and assess possible contributing factors.

Approach:

• Case: A 38-year-old woman developed brief episodes of photopsias and blurred vision during a high-intensity exercise class. Examination and imaging showed mild perfused CRVO in the left eye.
• Evaluation and follow-up: An extensive workup found no alternative cause. She received no pharmacologic treatment and was advised to increase oral hydration and temporarily avoid strenuous exercise.

Key Findings:

• Visual acuity was 20/20 in both eyes; the left eye had venous tortuosity and scattered intraretinal hemorrhage without macular edema, ischemia, or neovascularization.
• At 1 month, the retinal findings had improved; by 10 months, venous tortuosity had resolved, with no symptoms and vision still 20/20.
• The patient later resumed exercise while mindful of hydration, without symptom recurrence.

Interpretation:

The authors proposed that exercise-associated dehydration could have contributed through transient hyperviscosity, increased erythrocyte aggregability, and reduced blood flow. These mechanisms were not objectively confirmed.

Limitations:

• This is a single case and cannot establish a causal relationship between exercise, dehydration, and CRVO.
• Objective measures of dehydration or transient hyperviscosity were not reported.
• Repeat fluorescein angiography was not performed.

Conclusion:

The authors suggested that excessive exertion and dehydration, particularly during summer, may be modifiable risk factors for CRVO in young adults.