We consider zero-sum stochastic games with finite state and action spaces, perfect information, mean payoff criteria, without any irreducibility assumption on the Markov chains associated to strategies (multichain games). The value of such a game can be characterized by a system of nonlinear equations, involving the mean payoff vector and an auxiliary vector (relative value or bias). We develop...

PURPOSE The aim of this study was to map the sensitivity of the marginal and other conjunctival regions and to investigate changes in the sensitivity of these regions when determined in the morning and evening. METHODS Thirty-five healthy, noncontact lens wearers (20 female, 15 male; age 27.7 ± 7.3 years) were enrolled. Mechanical sensitivity was measured at 8 locations on the ocular surface ...

ACCURATE measurement of corneal sensitivity was first attempted by von Frey (1894), using as a criterion the length and bend of a horse hair through which pressure was applied and increased until the threshold of sensation was reached. The basic principle laid down by von Frey was generally accepted. Modifications were made by using different materials and adjustable plastic thread, which permi...

AIMS In a quantitative prospective study the corneal sensation in patients with leprosy was compared with age matched controls. METHODS The patients with leprosy were classified as paucibacillary and multibacillary and were divided in three groups: (1) patients without clinically detectable eye pathology; (2) patients with lagophthalmos, (3) patients with signs of iridocyclitis. The corneal s...

PURPOSE To evaluate changes in corneal sensitivity following corneal cross-linking (CXL) in patients with progressive earlier stage keratoconus. METHODS Thirty-eight eyes of 19 patients (11 women, 8 men) were included in a prospective, nonrandomized clinical study. The mean patient age was 22 years (range, 18-26 years). Inclusion criteria were early stage bilateral progressive keratoconus, a ...

A novel ophthalmic drug delivery system (NODS) has been developed to give precise and controlled delivery of a drug to the eye. The drug is incorporated into a polyvinyl alcohol flag attached to a carrier. When applied to the eye the flag detaches and gradually dissolves, releasing the drug. We investigated corneal anaesthesia produced by different concentrations of proxymetacaine NODS, and con...

BACKGROUND Peripheral nerve damage of the cornea is a complication following surgery or infection which may lead to decreased visual function. We examined the efficacy of the semaphorin 3A inhibitor, SM-345431, in promoting regeneration of peripheral nerves in a mouse corneal transplantation model. METHODOLOGY/PRINCIPAL FINDINGS P0-Cre/Floxed-EGFP mice which express EGFP in peripheral nerves ...

PURPOSE To describe corneal sensitivity changes caused by different incision methods-manual small-incision cataract surgery (manual SICS) and phacoemulsification-and their influence on tear film quantity and quality. METHODS This was a prospective observational study conducted in 30 subjects undergoing manual SICS or phacoemulsification. Corneal sensitivity was assessed before and 1, 7, and 1...

PURPOSE To determine whether cyclosporine (0.05%) can safely and effectively accelerate corneal nerve regeneration after LASIK, thereby facilitating faster recovery of corneal sensitivity. METHODS This prospective, randomized, single-center clinical study comprised 44 eyes of 22 patients scheduled to undergo bilateral LASIK. One eye was randomly assigned to receive cyclosporine drops twice da...

PURPOSE Amino-amide or amino-ester local anesthetics, which are currently used for topical ocular anesthesia, are short acting and may delay corneal healing with long-term use. In contrast, site 1 sodium channel blockers (S1SCBs) are potent local anesthetics with minimal adverse tissue reaction. In this study, we examined topical local anesthesia with two S1SCBs, tetrodotoxin (TTX) or saxitoxin...