Intermittent exotropia affecting baseball performance
A 9-year-old boy is brought because his parents notice his right eye drifting outward when he is tired or watching television. He sometimes closes one eye in bright sunlight, but he denies double vision. He plays shortstop on a baseball team and his coach says his catching has worsened. On examination, uncorrected acuity is 20/20 in each eye; cycloplegic refraction is +1.00 DS in each eye. Cover testing shows an intermittent exotropia of 18 prism diopters at distance and 8 prism diopters at near. During a standardized 30-second observation at distance, the eye is deviated for about 15 seconds; at near, it is deviated for about 5 seconds. Near point of convergence is 12 cm. Stereoacuity is 100 seconds of arc at near. Extraocular movements are full, and there is no vertical deviation or A/V pattern. The parents ask whether he needs surgery before the next season.
1. How do you interpret the control score, and what else would you assess?
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Control in intermittent exotropia is dynamic, so a single measurement is only a snapshot. A 30-second observation at distance with deviation for about 15 seconds indicates poor control, roughly 50% of the observation period. The near score of about 5 seconds is better but still not perfect. I would repeat the observation at a separate visit and after fatigue or prolonged near work, because control fluctuates. I would also assess stereopsis at distance as well as near, suppression with a Worth 4-dot test, convergence, and whether the deviation is truly intermittent or becoming constant. I would ask about frequency at home, whether he closes one eye outdoors, and whether he has any diplopia. The baseball difficulty matters functionally, but it does not by itself determine surgical urgency. The decision should rest on control, stereopsis, deviation size, and progression over time.
2. What initial management would you recommend, and why?
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This child has a moderate-distance intermittent exotropia with poor control and a functional complaint, but he still has 100 seconds of arc stereopsis at near. I would not rush to surgery solely because of one season. Initial management could include correcting any significant refractive error; here +1.00 DS is modest, so full correction is not guaranteed to improve control. Over-minus lenses can stimulate accommodation and convergence, but they may cause asthenopia and are not a universal first step. Part-time patching or vision therapy is sometimes used, though evidence for therapy is limited. Because control is poor at distance and the deviation measures 18 prism diopters, I would refer to pediatric ophthalmology for consideration of surgery versus observation. I would explain that surgery can reduce the angle but does not guarantee stable control, and that overcorrection can produce diplopia. I would schedule monitoring every 3–6 months with control scores, stereopsis, and deviation measurements.
3. How would you counsel the parents about surgery versus waiting?
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I would first ask what they have heard and what outcome matters most to them. I would explain that intermittent exotropia can remain stable for years, improve, or become more constant, and that treatment aims to preserve binocular vision and control rather than to make the eye “look straight” only in photographs. I would present observation with close monitoring as a reasonable option if control and stereopsis are stable, and surgery as an option if control is deteriorating, stereopsis is being lost, or the family finds the appearance and functional symptoms unacceptable. I would describe the risks of surgery, including undercorrection, overcorrection with double vision, infection, and the possibility of further surgery. I would avoid promising that surgery will improve baseball performance. I would give them written information and a follow-up plan so the decision is shared and not rushed.