Mark J. Mannis

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The refractive error of 240 phakic dogs of various breeds was measured using streak retinoscopy and averaged (-0.27 +/- 1.41 D relative to infinity). Analysis by breed showed that the German Shepherd, Rottweiler, and Miniature Schnauzer breeds had an increased prevalence of myopia with an average refractive error of -0.86 +/- 1.31 D, -1.77 +/- 1.84 D, and(More)
OBJECTIVE To determine whether endothelial cell loss 5 years after successful corneal transplantation is related to the age of the donor. DESIGN Multicenter, prospective, double-masked clinical trial. PARTICIPANTS Three hundred forty-seven subjects participating in the Cornea Donor Study who had not experienced graft failure 5 years after corneal(More)
BACKGROUND Endogenous electric fields and currents occur naturally at wounds and are a strong signal guiding cell migration into the wound to promote healing. Many cells involved in wound healing respond to small physiological electric fields in vitro. It has long been assumed that wound electric fields are produced by passive ion leakage from damaged(More)
Epithelia of the cornea, lens and retina contain a vast array of ion channels and pumps. Together they produce a polarized flow of ions in and out of cells, as well as across the epithelia. These naturally occurring ion fluxes are essential to the hydration and metabolism of the ocular tissues, especially for the avascular cornea and lens. The directional(More)
Complaints of visual distortion often precede a decrement in visual acuity in keratoconus. We studied seven patients with keratoconus who had undergone keratoplasty in one eye and whose Snellen visual acuity measurements were equal in the grafted and nongrafted eyes. Subjects were examined clinically; we then measured contrast thresholds for seven spatial(More)
PURPOSE The PI3K/Akt pathway is required for cell polarization and migration, whereas the phosphatase and tensin homologue deleted on chromosome 10 (PTEN) has inhibitory effects on the PI3K/Akt pathway. The authors therefore hypothesized that wounding would downregulate PTEN and that this downregulation would enhance wound healing. METHODS In human(More)
PURPOSE Beta-adrenergic receptor (AR) antagonists are frequently prescribed ophthalmic drugs, yet previous investigations into how catecholamines affect corneal wound healing have yielded conflicting RESULTS With the use of an integrated pharmacologic and genetic approach, the authors investigated how the beta-AR impacts corneal epithelial healing. (More)
PURPOSE To report the intereye asymmetry with regard to pachymetry and corneal elevation variables in subjects with normal corneas and in those with keratoconus. METHODS This is a prospective study that included 151 patients who had Pentacam imaging in both eyes: 53 subjects with bilateral normal corneas and 98 with bilateral keratoconus. Central corneal(More)
OBJECTIVE To determine whether graft survival over a 5-year follow-up period using corneal tissue from donors older than 65 is similar to graft survival using corneas from younger donors. DESIGN Multicenter prospective, double-masked, controlled clinical trial. PARTICIPANTS One thousand ninety subjects undergoing corneal transplantation for a(More)