Patient Diagnosis and Management of Thygeson’s Superficial Punctate Keratitis
Thygeson’s Superficial Punctate Keratitis (TSPK) is a chronic eye disease that has remissions and exacerbations for a few years to decades. Patients typically present with whitish-grey, intraepithelial corneal lesions with no or limited conjunctival involvement. While the etiology of the disease remains controversial, it does have a genetic association with HLA-DR3, which is an antigen with immunogenic responses. Treatment does vary depending on how severe the case and consists of artificial tears to lubricate the cornea, corticosteroids, topical cyclosporine (where available), or soft contact lenses. Classic symptoms include photophobia, blurred vision, tearing, redness, ocular irritation, pain, and foreign body sensation.
Duscak (2007) examined a male, 33 year old, African-American who had a sensation of a foreign body in both of his eyes. The patient smoked and drank moderately, and had a family history of glaucoma (mother), with slight issues with his blood pressure that he was medicated for, and had no known allergies.
The patient had distance visual acuity of 20/20 (6/6) in each eye. Healthy optic nerve, vessels, macula, vitreous, and retina in each eye.
The differential diagnoses included herpes simplex keratitis which presents as a superficial punctate keratitis that stain with rose bengal or fluorescein; sterile corneal infiltrates as a complication of wearing contact lenses or as immune response to Staphylococcus aureus (although the overlying corneal epithelium usually remains intact); dry eye syndrome, keratitis sicca, epithelial basement membrane dystrophy, viral conjunctivitis, or recurrent corneal erosion.
One week after his consultation, the patient’s symptoms remained unchanged after steroids were contraindicuated, and nonpreserved artificial tears were given every 30 minutes after his first visit. Active TSPK was diagnosed and the patient began Fluorometholone 0.1% (FML 0.1%) every four hours, plus a continuation of artificial tears. One week after, the patient’s symptoms had improved and the burning, photophobia and foreign body sensation had gone. Lesions still showed up but there was no staining by fluoroscein. No anterior chamber reaction nor conjunctival involvement were noted. As Thygeson’s SPK was resolving, the FML 0.1% solution treatment was tapered off: 4 per day for 2 weeks, then 3 per day for 2 weeks, yet the artificial tears continued at least 4 per day. Two weeks later, symptoms were resolved.
Active Thygeson’s disease is a conglomerate of coarse, oval-shaped, white or grey dots that appear slightly raised and stain minimally with fluorescein and may or may not stain with rose bengal. Up to fifty lesions may occur across the corneal surface with about half of these present when the disease flares up centrally in the cornea. When the disease is not active, the lesions may appear flat or disappear and will not stain with fluorescein. Some patients develop subepithelial opacities that may become permanent, even when there is no overlying epithelial disease.
There can be some intracellular and intercellular edema at the epithelial level. Other abnormalities can be found in the subepithelial nerve plexus, anterier stroma, and Bowman’s membrane where the disease has been present londer or may have been reversed by the application of topical steroid therapy.
The disease may continue for a period averaging 3.5 to 7.5 years, and some reports of greater than 40 years exist, especially with steroid use. Patients as young as 2.5 years and as old as 70 years have been found with TSPK, the mean age is 29 years. The prevalence of TSPK is currently unknown.
Suggested Link: Duscak, R.S. (2007) Diagnosis and management of Thygeson’s superficial punctate keratitis, Jounral of the American Optometric Association, Vol 78, Issue 7, pp333-338. http://dx.doi.org/10.1016/j.optm.2006.12.014