Sherry A. Fowler

Identification of Proteins in Contact Lens Surface Deposits by Immunofluorescence Microscopy

Worn soft contact lenses from five asymptomatic subjects were examined by immunofluorescence microscopy for type of protein on the lens surface. Lysozyme was the predominant protein component identified by this technique. IgA was also identified in deposits on all five lenses, but the staining was less intense than that for lysozyme. Lactoferrin was identified on the surface of four lenses, one of which stained intensely for this protein and three less intensely. IgG was identified on two contact lenses; the staining was less intense than that for lysozyme. New, never-worn soft contact lenses did not stain for any of the proteins examined in this study. We conclude that several normal tear proteins are capable of contributing to surface deposits on soft contact lenses, and all worn soft contact lenses have protein adherent to their surface as a result of normal wear.

Soft contact lenses from patients with giant papillary conjunctivitis

We used scanning electron microscopy to study the surfaces of five coated soft contact lenses from subjects with giant papillary conjunctivitis. Findings were compared to the surfaces of five coated lenses from normal, asymptomatic wearers and five new, nerver-worn lenses. Lenses were from various manufacturers. All worn contact lenses differed strikingly from new, never-worn lenses. The anterior surface of worn lenses was covered with apparently adherent deposits. In only a few areas was the surface similar to new, never-worn lenses. Thick coatings on lenses from patients with giant papillary conjunctivitis and asymptomatic wearers were similar. High magnification of the coatings revealed a trabeculated morphology. Also seen was debris that resembled mucus-like material in both strand and particulate forms. On some lenses bacterial-shaped structures were scattered randomly over the surface. Smooth structures resembling cells were also seen. The posterior lens surface of all worn lenses was smoother than the anterior lens surface. The findings support our idea that the capacity to develop giant papillary conjunctivitis is influenced by individual differences more than by differences in lens deposits.

Wound healing in the corneal epithelium in diabetic and normal rats

Abstract The rate and mode of corneal wound healing in severely diabetic rats were studied by light microscopy and scanning electron microscopy. Diabetes mellitus was induced in 52 rats by alloxan injection, and 52 nondiabetic rats were used as controls. After 3 weeks, a nonpenetrating razor-blade wound was made in the central cornea of both eyes in 48 diabetic and 48 normal rats. The incision passed through the epithelium and into the stroma. The effects of diabetes on the unwounded cornea were observed by comparison with corneas from eight unwounded rats (four diabetic and four normal). Whole corneas from wounded diabetic and normal rats were studied at 0, 1, 3, 6, 12 and 24 hr and at 2–7 days after wounding. The rate and mode of healing were not found to differ between diabetics and normals. The surfaces of corneal wounds in both groups appeared to be completely healed and indistinguishable from the surrounding unwounded epithelium after 24 hr. The epithelial cells involved in the initial healing process were derived primarily from the layer of wing cells which progressed across the wound close to the connective-tissue base. Only in the final stages of healing, after the wound had been filled by the deeper epithelial cells, did superficial epithelial cells migrate. There appeared to be more exfoliating superficial epithelial cells over the entire cornea in diabetic rats than in normals. Because the healing of central corneal incisions occurs initially and primarily by sliding of the deeper epithelial cells, and because the diabetic condition appears to be associated with increased exfoliation of surface cells, the healing of central incisions may be less affected by diabetes than the healing of defects of the whole corneal surface, where the superficial epithelial cells have been reported to be the main migratory cells in the initial healing process and where healing in diabetics is delayed.