Laboratory Studies
Culturing the flora of the cornea during active inflammation may be helpful in future research, but it is not necessary for the diagnosis, treatment, or management of Thygeson superficial punctate keratitis (TSPK), since it is not an infectious disease.
Imaging Studies
Slit lamp photography may be used to document active inflammation and periods of inactivity, but it is not necessary to successfully diagnose or manage the disease.
Histologic Findings
Intracellular and intercellular edema at the epithelial level are common histological features of TSPK. [15, 16, 17]
Other abnormalities have been observed in the subepithelial nerve plexus, the Bowman membrane, and the anterior stroma. These changes are most severe in eyes with a longer duration of disease and can possibly be reversed with topical steroid therapy. [16]
Staging
TSPK is in either the active stage or the inactive stage of the disease.
As mentioned above, the classic corneal lesion in active TSPK is a conglomerate of coarse, oval shaped, slightly raised, whitish gray dots that stain minimally with fluorescein. The lesions tend to accumulate centrally in the cornea, and 1-50 lesions may be present (averaging about 20 lesions per flare-up). [8]
During the inactive stages of the disease, the lesions can disappear, or they can appear as flat gray, stellate shaped, subepithelial opacities that do not stain with fluorescein. [7, 8] Also, some patients develop subepithelial opacities that occasionally become permanent even in the absence of overlying epithelial disease. [6]
Attacks may last up to several months and go into remission for up to 3 years. [2, 8] The disease may continue for an average period of 3.5-7.5 years, although reports of more than 24, 30, and 41 years have been reported, particularly with steroid use. [2, 18]
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The cornea of a 33-year-old African American man with active Thygeson superficial punctate keratitis (TSPK).
