Unilateral pain, photophobia and blurry vision in a pediatric patient
Linear corneal stromal opacities were revealed during anterior segment examination.
A 5-year-old girl presented to our eye clinic with complaints of pain, photophobia and blurry vision in her right eye for 2 weeks. She was being treated with erythromycin ophthalmic ointment four times a day in the right eye. The patient had no other significant medical or ocular history.
On examination, the patient’s best corrected visual acuity was 20/20 in the right eye and 20/15 in the left eye. The pupils were 4 mm, and no afferent pupillary defect was found. Extraocular motility was full. IOP was 12 mm Hg in the right eye and 13 mm Hg in the left eye.
Anterior segment examination of the right eye revealed 1 to 2+ conjunctival injection and numerous fine, linear corneal stromal opacities less than 1 mm in size, some of which were associated with surrounding subepithelial infiltrates (Figures 1 and 2). The linear opacities were dispersed predominantly nasally but were also found superiorly and inferiorly in the paracentral and peripheral cornea. No epithelial defect or anterior chamber reaction was detected. Anterior segment examination of the left eye was unremarkable. Posterior segment examination revealed healthy optic nerve heads, and the retina appeared normal in both eyes.
Source: Bhavsar K, Strominger MB
What is your diagnosis?
Linear stromal opacities
The differential diagnosis of linear stromal opacities in a pediatric patient includes corneal foreign body, infectious keratitis and corneal dystrophies such as lattice dystrophy.
Given the acute onset of symptoms, unilateral presentation and clinical examination findings, embedded corneal foreign bodies were highly suspected in this patient. The fine, linear appearance of the opacities was thought to be possibly consistent with animal or insect hairs.
It was necessary to rule out infectious keratitis in this case, including etiologies such as epidemic keratoconjunctivitis, bacterial keratitis and fungal keratitis. Epidemic keratoconjunctivitis could account for the patient’s symptoms and exam findings of subepithelial infiltrates and conjunctival injection, but it would be unlikely to cause fine, linear opacities. This would also be atypical for both bacterial and fungal keratitis. The opacities were sharply linear without any feathery borders. This young patient also did not have any history of contact lens wear or trauma to the eye, and no epithelial defect was discovered on slit lamp examination.
Corneal dystrophies were also considered in the differential diagnosis, including type 1 lattice, type 2 granular (Avellino) and crystalline dystrophies. However, corneal dystrophy was less likely to be responsible for the presentation of this patient given the acute and unilateral presentation, as well as negative family history. Additionally, the clinical appearance of the linear opacities was not typical for any particular stromal dystrophy. Type 1 lattice characteristically presents as long, branching lines with intervening haze. Type 2 granular classically has the appearance of crumb-like opacities that fuse to form stellate or linear structures. Crystalline dystrophies tend to be diffuse and bilateral, as in Schnyder’s corneal crystalline dystrophy. Retinal involvement may occur as in Bietti’s crystalline dystrophy.
Diagnosis and management
Suspicion for embedded corneal foreign bodies was verified on further history. The patient had been playing with her cousin’s pet Chilean rose tarantula when the symptoms began. The patient was re-examined for superficial or exposed tarantula hairs, but none were discovered. The hairs were deeply embedded in the posterior stroma and were not accessible for removal. Topical therapy was initiated with Pred Forte drops (prednisolone acetate ophthalmic suspension 1%, Allergan) every 4 hours and Besivance drops (besifloxacin ophthalmic suspension 0.6%, Bausch + Lomb) three times a day in the right eye.
At 1-week follow-up, the patient’s visual acuity was stable at 20/20 in the right eye, and symptoms of tearing, pain and photophobia were resolved. On examination, the stromal infiltrates had improved, and no evidence of anterior or posterior uveitis was found. The patient completed a 10-day course of Besivance drops and started a slow Pred Forte taper. She returned for follow-up at 1 month, and examination at this time revealed fully resolved stromal infiltrates (Figure 3). Posterior migration of the tarantula hairs toward Descemet’s membrane was suspected, but no hairs were present in the anterior chamber, vitreous or retina. The patient was recommended to continue Pred Forte drops four times a day in the right eye, and close follow-up was arranged.
However, at 2-month follow-up, the patient developed significant anterior uveitis. Keratoprecipitates were discovered around hairs that had migrated and were extruding into the anterior chamber. The patient was started on Lotemax (loteprednol etabonate ophthalmic suspension, Bausch + Lomb) four times a day in the right eye and has been followed closely for persistent anterior chamber inflammation.
Ophthalmia nodosa was first described by Saemisch in 1904 and is a term that encompasses inflammatory ocular reactions to animal and vegetable hairs or hair-like structures. Cases have been reported to occur with exposure to caterpillar and tarantula hairs as well as insect stingers and wings. Ophthalmic manifestations from tarantula hairs have been widely described in the literature and include conjunctival granulomas, corneal stromal infiltrates, anterior uveitis, vitritis and retinochoroiditis.
Expulsion of dorsal hairs is a primary defense mechanism utilized by many species of tarantula. A tarantula may have close to 10,000 hairs/mm2 located on its dorsal abdomen. These “type 3” hairs are characterized as barbed and on average 0.6 mm to 1.5 mm in length. The sharp barbs facilitate penetration and intraocular migration, but no toxin has yet been identified. Nonetheless, tarantula hairs pose as a potent ocular, respiratory and dermatologic irritant.
Medical therapy is typically the first approach utilized by practitioners to treat ophthalmia nodosa and includes an initial regimen of topical steroid and antibiotic. Surprisingly, no cases of secondary infection have been reported. Surgical intervention has been rarely described and may involve slit lamp removal of superficial hairs. Surgical management of deeper intraocular hairs is little reported or performed but may be appropriate for a resistant and severe inflammatory response.
The majority of cases are successfully controlled with topical steroid therapy, but patients may require long-term therapy to control ocular inflammation. Resolution of corneal infiltrates has been described to occur within 1 to 2 months of steroid treatment. However, patients must be followed closely because intraocular hairs can persist for years and incite delayed intraocular inflammation. The patient must be warned about the potential for further ocular migration and late presentation of anterior uveitis, vitritis or retinochoroiditis.
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For more information:
- Kavita Bhavsar, MD, and Mitchell B. Strominger, MD, can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; 617-636-4219; fax: 617-636-4866; website: www.neec.com.
- Edited by Kavita Bhavsar, MD, and Michelle C. Liang, MD. They can be reached at New England Eye Center, Tufts University School of Medicine, 750 Washington St., Box 450, Boston, MA 02111; 617-636-4219; fax: 617-636-4866; website: www.neec.com.