The role of contact lenses in the management of the radial keratotomy patient.

Approximately 15% of radial keratotomy procedures result in a residual refractive error of at least 1.00 D. Contact lenses may be used in these cases to optimize visual acuity. Patients who have undergone radial keratotomy present unique physiological challenges because of the corneal incisions; wear of lenses can produce epithelial erosion, infiltrative keratitis, neovascularization, and chronic edema. The corneal topography is altered by the surgery, with the central cornea flattened and the midperiphery steepened; these changes influence contact lens design. The lens of choice is a large, thin, rigid gas-permeable lens with a fairly small optic zone. Hydrogel lenses can also be used, but complications of wear can include neovascularization and corneal edema. Toric hydrogel lenses can be used to minimize residual astigmatism.

Collagen shields as a vehicle for collecting and studying migratory cells on human corneas.

Collagen shields have been studied in the enhancement of the initial healing of epithelial defects, as an adjunct in the treatment of dry eye, and as a reservoir and delivery system for topical ocular medications. The authors used collagen shields to collect information on the numbers and types of free cells populating the normal and postoperative ocular surface. In addition, correlative microscopic techniques were used to study details of the mechanisms responsible for the dissolution of the shields when applied to the human eye. Collagen shields were applied as a bandage lens on the eyes of patients who underwent extracapsular cataract extraction (n = 10) or penetrating keratoplasty (n = 10) and on normal volunteers (n = 10). The shields were collected at the 1-day postoperative examination and fixed in aldehyde mixtures. Specimens then were processed for correlative light (LM), transmission (TEM), and scanning (SEM) microscopy. Cell accumulation was shown by SEM on both anterior and posterior shield surfaces. Cell adherence occurred primarily on the posterior shield periphery for approximately 2 mm, with the central zone relatively clean. Both LM and TEM evaluation revealed cell counts ranging from 0.066 cells/10(4) microns2 (standard deviation, +/- 0.256) in healthy eyes compared with shields placed on postoperative eyes (194.25 +/- 7.32 cells/10(4) microns2). Various correlative microscopy techniques revealed that most cells were polymorphonuclear leukocytes with a low number of other hematogenous (lymphocytes and monocytes) and exfoliated epithelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Applications of hydrophilic disposable contact lenses as therapeutic bandages.

We employed Acuvue (Johnson & Johnson) and SeeQuence (Bausch & Lomb) disposable hydrophilic contact lenses for therapeutic purposes on 39 patients with varying pathology. Concomitant medial therapy was implemented where appropriate. The disposable bandage lens was associated with improved patient symptomatology and objective findings in the majority of cases; complications were infrequent. The disposable hydrophilic lens appears to be a reasonable alternative to traditional hydrophilic bandage lenses.

The effect of a collagen bandage lens on corneal wound healing: a preliminary report.

Collagen bandage lenses were inserted in 24 eyes of white New Zealand rabbits following 8-incision radial keratotomy. Specimens were examined at eight and 24 hours by light and electron microscopy. Treated eyes demonstrated more complete epithelial healing, as evidenced by surface microvilli and differentiation into multi-layers. In the treated eyes there was reduced stromal edema at the wound site, and reactive keratocytes were limited to the wound margins. Collagen bandage lenses therefore may be useful in the treatment of a variety of ocular surface problems.