Clinical Presentation: A Young Man With Low Vision
A 28-year-old man was referred for a low-vision evaluation. His eye doctor has been providing care for him for the past 12 years. The patient is very satisfied with the eye care; however, he was told by his eye doctor that his visual concerns now need the expertise of a low-vision specialist.
The patient reports that his general health is excellent. He has no history of systemic or ocular surgery, and he takes no systemic or ocular medications.
The patient reports that he has been wearing glasses full-time for the past 10 years and that he notices a slight improvement in his vision when he wears them. He was also fitted with a pair of contact lenses 2 years earlier. However, he stopped wearing them after a few months because they required more care than glasses.
His examination findings are described below.
Refraction and best visual acuity. A bracketing technique with just noticeable difference was used when doing this refraction (see the Table). A ±1.25 cross cylinder was also used.
Table. Refraction and Best Visual Acuity
|Eye||Refraction||Acuity -- Distance
|Acuity -- Near
|OD||+4.50-4.00 × 180||10/60+ (20/120+)||.40/2M (20/100 at 40 cm)|
|OS||+6.00-5.00 × 175||10/80+ (20/160+)||.40/3.2M (20/160 at 40 cm)|
Ocular health evaluation. The external examination reveals a horizontal pendular nystagmus, with no null point, in each eye. Iris transillumination is present in each eye. There is no sign of paresis or paralysis of the extraocular muscles in all positions of gaze. The patient demonstrates 4 prism diopters of exotropia in the left eye.
The lids, lashes, conjunctiva, cornea, and lens are normal in appearance in both eyes. The anterior chamber is open and quiet in each eye.
As a result of nystagmus, a Tono-Pen® (Reichert Technologies; Depew, New York) was used to evaluate intraocular pressure. Pressures were found to be normal, at 16 mm Hg in the right eye and 17 mm Hg in the left eye.
Ophthalmoscopic examination. The dilated fundus examination reveals clear media in each eye. Retinal hypopigmentation is accompanied by prominence of the choroidal vascular network. The optic nerve heads are slightly pale, and there is no foveal reflex in either eye. The rest of internal structures are normal (Figure 1).
Figure 1. Retinal hypopigmentation, a prominent choroidal vascular network, and a pale optic nerve head.
Visual field testing. An Esterman binocular field test was performed, and it confirmed a full (normal) binocular field.
Color vision testing. A Farnsworth dichotomous (D15) test was used to evaluate color vision. A Macbeth lamp was used for illumination. Each eye was evaluated separately, and the patient demonstrates normal color vision.
Social assessment. The patient reports that he has recently married and that he and his wife are expecting their first child. His wife works full-time, and he works at various part-time positions to make ends meet. He has a college degree in computer science and is very knowledgeable in fabricating and repairing computers and other electronic equipment.
There is an opportunity for the patient to obtain a full-time position in his area of expertise at a distance of 25-30 minutes from his home. His greatest obstacle is getting to and from the job site because no public transportation is available. Therefore, his major visual concern is his ability to obtain a driver's license to allow him to commute back and forth from work, as well as the ability to see very small electronic components at a distance of 30-40 cm.
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Cite this: Driving With Low Vision - Medscape - Jan 21, 2014.