“My child seems to hate the bright light”

Introduction

The child who appears to hate bright light is often experiencing photophobia, an unpleasant or painful sensory disturbance evoked by light, but may have other related painless sensations including dazzle, glare or delayed adaptation to light. Their behavior may be pathologic or part of the normal spectrum of light tolerance. When pathologic, their presentation is often related to readily detectable anterior segment disease but occasionally is related to less common posterior segment and neurologic conditions of visual and systemic significance, requiring more extensive investigation.

Differential Diagnosis

The causes of photophobia and similar light avoidance are summarized in Table 95.1 . They can be considered anatomically, with anterior segment disease accounting for most cases. Posterior segment, intracranial, and systemic causes are less common ( Table 95.1 )

History

For many patients with photophobia, a careful history will point to the cause. Photophobia can be characterized by the timing and nature of its onset and its subsequent progression. Associated ocular symptoms should be sought, including trauma, watering, redness, discharge, blepharospasm, itch, decreased vision, nyctalopia, nystagmus, and eye rubbing. The history should also include any systemic disease or developmental abnormality and neurologic symptoms including headache. A history of consanguinity or family history of decreased vision, nystagmus, nyctalopia or ocular disease may be relevant in hereditary retinal dystrophies.

Examination

The examination of children with photophobia is made more challenging by their aversion to light. Observation in mid-illumination conditions while taking the history from the parent may help to determine the child’s visual behavior and detect strabismus, nystagmus, and oculodigital rubbing. The examination may be facilitated by reassurance, explanation, and the use of low illumination settings on instruments. Instilling a drop of topical anesthetic to both eyes may reduce symptoms; if so it is suggestive of ocular surface disease. In some cases the child is unable to tolerate an examination that establishes the cause of their symptoms and an examination under anesthetic may be required.

The anterior segment should be examined, including the lids, conjunctiva, cornea, and anterior chamber. This should include eversion of the lids to look for subtarsal disease, fluorescein staining of the ocular surface, and high-magnification high-illumination examination of the anterior chamber for inflammatory cells and flare. The iris should be checked for structural defects, including hypoplasia, and transillumination defects. The posterior segment should be examined for any abnormality of the macula, retinal vessels or peripheries and to rule out optic disc swelling, pallor or other abnormalities suggestive of neurologic disease. Visual field examination may show scotoma associated with perichiasmal masses or other retinal and intracranial disease.