Corneal Cryopreservation Using Glycerylphosphorylcholine-Enriched Medium.

PURPOSE: To determine the effects of prolonged cryopreservation at subzero-degree temperatures on corneal transparency and histology after treatment with preservation medium containing the phosphodiester glycerylphosphorylcholine (GPC). METHODS: Rabbit corneas (n = 30) were immersed for 3 hours in K-Sol preservation medium containing 30 mM GPC. Three groups with 6 corneas each were refrigerated at -8°C for 2 weeks and liquid nitrogen temperature for 2 and 6 weeks, respectively. Two groups with 6 corneas each immersed in K-Sol preservation medium only were refrigerated at -8°C for 2 weeks and liquid nitrogen temperature for 6 weeks, respectively. Postthawing corneal transparency was measured on a grading scale after which corneas were prepared for and analyzed by light and transmission electron microscopy. RESULTS: All 3 groups of corneas preserved with GPC maintained a greater degree of corneal transparency compared with corneas preserved without GPC. The number of corneas retaining epithelial and endothelial layers increased in all groups where corneas were preserved in medium containing GPC, in contrast to corneas preserved in medium without GPC. Cytoplasmic vacuolization or nuclear damage was greater in corneas preserved without GPC. Similar findings were found in corneas stored at -8°C and liquid nitrogen temperatures. CONCLUSIONS: This study demonstrates a cryoprotective effect of corneas preserved in K-Sol containing the phosphodiester GPC at subzero-degree temperatures. In corneas immersed in preservation medium containing GPC, a higher degree of transparency is maintained and a lesser degree of histopathologic changes is observed with storage at both -8°C and in liquid nitrogen.

Increase in tear film lipid layer thickness following treatment with warm compresses in patients with meibomian gland dysfunction.

PURPOSE: Warm-compress therapy applied to the skin of the closed eyelids has been recommended as a treatment for meibomian gland dysfunction (MGD). Previous studies have evaluated the effects of warm-compress therapy on tear-film fluorescein break-up time and tear evaporation rate. The purpose of this study was to determine if tear-film lipid layer thickness (TFLLT) was altered following 5, 15, and 30 minutes of warm, moist compress therapy. METHODS: Twenty patients with a diagnosis of dry eye associated with MGD and a baseline TFLLT of

Lid-wiper epitheliopathy and dry-eye symptoms in contact lens wearers.

PURPOSE: To evaluate whether dry-eye symptoms are associated with epitheliopathy of that portion of the upper eyelid marginal conjunctiva-the lid wiper-that wipes the ocular, or contact lens surface, during blinking. METHODS: Subjects were divided into two groups based on the presence or absence of dry-eye symptoms. The lid wiper of asymptomatic (n=75) and symptomatic (n=30) soft contact lens wearers was examined, following the instillation of fluorescein and rose bengal dyes. Lid-wiper staining was graded zero to 3. RESULTS: Eighty percent of the symptomatic subjects displayed lid-wiper staining compared to 13% of the asymptomatic subjects. The difference in staining between the two groups was significant (P<0.0001). Of the symptomatic subjects, 20% showed no staining; 26.6%, grade 1 staining; 36.6%, grade 2; and 16.6% showed grade 3 staining. Of the asymptomatic subjects, 87% exhibited no staining; 9%, grade 1 staining; 3%, grade 2; and 1% showed grade 3 staining. CONCLUSIONS: This study describes a new clinical condition, lid-wiper epitheliopathy, an alteration of the epithelium of that portion of the marginal conjunctiva of the upper eyelid that wipes the ocular surface, diagnosed by staining with fluorescein and rose bengal dyes.