Definition: SLK is a bilateral chronic recurrent inflammatory lesion located in the superior bulbar and tarsal conjunctiva.
Etiology: SLK is often associated with thyroid dysfunction. One theory is that lid retraction results in rubbing of the tarsus and bulbar conjunctiva producing inflammation.
Epidemiology: Most common in adult women 20-70 years old.
Clinical: A bilateral and localized process confined to the superior limbal area and tarsus from the 10-2 o'clock position. Thickening of the conjunctiva accompanies dilated blood vessels and erythema of the conjunctiva. Both Rose Bengal and fluorescein stain in this region. Clinically these cases are often associated with dysthyroid eye disease that features lid retraction. In general thyroid function tests are recommended in patients that present with these findings.
Histopathology: Click to enlarge photo.
Superior limbic keratoconjunctivitis has been described as having keratinization of the epithelium (see the keratohyaline granules and anucleate squamous cells here) , acanthosis (notice the thickening to the far right), and cellular infiltration with lymphocytes, plasma cells and ballooning degeneration (see central cystic space with degeneration of epithelial cells and exocytosis of lymphocytes). In addition in this photo there is a chronic perivascular inflammatory infiltrate.
Treatment: SLK often spontaneously resolves but may recur for 10 years. Some treatments that have been used include bandage contact lenses, punctal occlusion, topical cyclosporin A (0.5%), topical application of autologous serum, thermo and chemical cauterization of the area affected , and resection of the conjunctiva.
