PURPOSE To study the mechanisms of pupillary block in eyes with occludable angle by ultrasound biomicroscopy. METHODS Initially, a pilot study of 13 eyes with acute primary angle-closure without medication was executed. Ultrasound biomicroscopy measurements of the angle, posterior chamber depth and iris thickness were performed in the temporal quadrant under light and dark conditions. Afterwa...

PURPOSE To propose a method to correct optical coherence tomography (OCT) images of posterior surface of the crystalline lens incorporating its gradient index (GRIN) distribution and explore its possibilities for posterior surface shape reconstruction in comparison to existing methods of correction. METHODS Two-dimensional images of nine human lenses were obtained with a time-domain OCT syste...

PURPOSE To investigate the time course of corneal thickness changes in overnight hyperopic orthokeratology (OK) lens wear for a 4-day lens-wearing period. METHODS Fourteen subjects (age range, 20-37 years) were fitted with hyperopic OK lenses in one eye only. The fellow eye acted as a non-lens wearing control. Lenses were worn overnight only for 4 nights, and changes from baseline in subjecti...

Magnetic Resonance Imaging was used to study changes in the crystalline lens and ciliary body with accommodation and aging. Monocular images were obtained in 15 young (19-29 years) and 15 older (60-70 years) emmetropes when viewing at far (6 m) and at individual near points (14.5 to 20.9 cm) in the younger group. With accommodation, lens thickness increased (mean ± 95% CI: 0.33 ± 0.06 mm) by a ...

In this study, genital tracts of 20 healthy non-pregnant buffaloes were collected from Urmia abattoir.These genital tracts were selected based on their ovaries conditions, half of them were in follicular phase and the other half were in luteal phase. The samples were taken from anterior, middle and posterior regions of the cervix and fixed in 10% buffer formalin. Then, histological sections of ...

We demonstrate two high-speed electro-optic devices: an integrated lens/scanner and a variable radius collimating lens stack fabricated on a single crystal of Z-cut LiTaO3. The lens and scanner components consist of lithographically defmed domain-inverted regions extending through the thickness of the crystal. A lens power of 0.233 cm'kV', a deflection angle of 12.68 mrad kV', and a scan rate o...

There was a partial thickness laceration of the right cornea at the junction of the middle and lower thirds extending in an irregular horizontal line from side to side. From the depth of this laceration the cornea was split to the lower limbus and in the lamellar pocket so formed were embedded multiple fragments of a shattered corneal contact lens. At no point did this lamellar laceration penet...

PURPOSE To investigate mechanical properties of the human posterior lens capsule. METHODS Twenty-five human donor eyes were obtained from an eye bank. The age of the donors ranged from 1 to 94 years. Test specimens were prepared as tissue rings from posterior lens capsules by means of excimer laser. Capsular thickness was measured microscopically as the difference in focus between microspheru...