PURPOSE To evaluate the impact of differente soft contact lens power in the anterior corneal curvature and regularity in subjects with keratoconus. METHODS Nineteen subjects (30 eyes) with keratoconus were included in the study. Six corneal topographies were taken with Pentacam Eye System over the naked eye and successively with soft lens (Senofilcon A) powers of -3.00, -1.50, 0.00, +1.50 and...

PURPOSE Deprivation of oxygen to the ocular surface during contact lens wear has been implicated in the alteration of sensory function. This study investigates whether increasing oxygen availability through discontinuation of contact lens wear or transfer into highly oxygen transmissible (high Dk/t) lenses leads to a change in corneal or conjunctival sensitivity. METHODS Twenty-seven long-ter...

Infant marmosets were fitted with zero-powered (plano) soft contact lenses from 4 to 8 weeks of age worn either continuously (24 h per day) (n = 4), for 12 h (n = 4), or for 8 h (n = 3) per day to determine whether limiting the daily duration of lens-wear could significantly reduce or eliminate the effects of continuous lens-wear on ocular growth and refractive state. As in macaques (Hung, L. F...

PURPOSE To assess subjective comfort during the first three months of continuous wear of hyper-transmissible soft and rigid contact lenses. METHODS One hundred subjects (50 experienced wearers and 50 neophytes) were fitted with either the Focus Night & Day lens (CIBA Vision, Duluth, GA) or the Z alpha lens (Menicon, Nagoya, Japan). Comfort was monitored at regular intervals using a vertical a...

Corneal ulcers are a major cause of blindness worldwide. A recent eye health care concern is the increasing incidence of contact lens induced corneal ulcers. Delay in the diagnosis and management of corneal ulcers can cause severe visual loss, therefore an early ophthalmologist visit and timely administration of antimicrobial agents can prevent visual loss. Factors associated with increased ris...

BACKGROUND Most corneal damage induced by contact lenses is due to interference with corneal oxygenation. OBJECTIVE To investigate the effect on the rabbit cornea of a rigid gas-permeable contact lens with a newly designed periphery. METHOD We fitted New Zealand white rabbits (n = 12) with RGP contact lenses that were identical in all respects except for the design of the periphery. In each...

Anterior segment fluorophotometry (topical) and central endothelial cell photography were performed on 40 long-term (2-23 years) contact lens wearers (four groups of ten each: hard, soft, gas permeable, and gas permeable plus prior lens usage) and 40 non-contact lens wearers of similar ages. Morphologically, the endothelial cells of contact lens wearers showed greater variability in size and sh...

BACKGROUND & OBJECTIVES With increasing use of soft contact lenses the incidence of contact lens induced infections is also increasing. This study was aimed to assess the knowledge of new and existing contact lens users about the risk of microbial contamination associated with improper use and maintenance of contact lenses, type of microbial flora involved and their potential to cause ophthalmi...