To perform a pilot study of a new in-the-bag Fresnel prism intraocular lens (IOL) designed to deviate the image from diseased to healthy retina in eyes with bilateral age-related macular degeneration ...(AMD).
Anterior segment subspeciality practice, Pretoria, South Africa.
Prospective nonmasked trial.
Cataract surgery and unilateral implantation of the prismatic IOL were performed in patients with bilateral AMD and cataract. Outcomes were surgical complications, subjective and objective visual improvement, and undesirable optical effects.
Three eyes of 3 patients were evaluated. All patients reported displacement of the scotoma, and no patient reported diplopia. The only complication was posterior capsule opacification (1 eye).
Patients noted improved vision and no diplopia. This pilot was performed using a prototype IOL with single power and single angle of deviation; however, there is scope for individual patient optimization. This new technology merits further research and development because it may benefit large numbers of patients with stable end-stage AMD.
Dr. Claoué has a financial interest in the patent controlling the Fresnel prism IOL. Dr. Potgieter has no financial or proprietary interest in any material or method mentioned.
Prediction of flap response Potgieter, Frederik J; Roberts, Cynthia; Cox, Ian G ...
Journal of cataract and refractive surgery
31, Issue:
1
Journal Article
Peer reviewed
To find predictors of the induced biomechanical and optical effects of lamellar flap creation on the cornea.
Optimed Eye and Laser Clinic, Pretoria, South Africa, and the Department of Ophthalmology ...and Biomedical Engineering Center, The Ohio State University, Columbus, Ohio, and Bausch & Lomb Vision Research Laboratory, Rochester, New York, USA.
This prospective study monitored the refractive, wavefront aberration, and corneal topographic changes in 29 eyes of 15 patients for 3 months after the creation of a corneal lamellar flap. The main outcome measures for statistical analysis were refraction, total corneal thickness, residual corneal bed thickness, horizontal white-to-white corneal diameter, horizontal flap diameter, topography data, and wavefront data.
Statistically significant changes were seen in the autorefraction mode. Wavefront data showed significant change in 4 Zernike modes-90/180-degree astigmatism, vertical coma, horizontal coma, and spherical aberration. The topography data indicated the corneal biomechanical response was significantly predicted by stromal bed thickness in the early follow-up period and by total corneal pachymetry and flap diameter in a 2-parameter statistical model in the late follow-up period.
Uncomplicated lamellar flap creation is responsible for systematic changes in corneal topography and induction of higher-order optical aberrations. Predictors of this response include stromal bed thickness, flap diameter, and total corneal pachymetry.
Erythrina caffra seeds were shown to be true anaerobic germinators. They exhibit a Pasteur effect, high alcohol dehydrogenase activity and produce high levels of ethanol under anoxia, in which ...situation germination starts to be suppressed by as little as 0.1% externally applied ethanol. Toxic levels of ethanol production appear to be prevented by a decrease in the rate of ethanol accumulation. Carbon monoxide does not inhibit germination. Cyanide, SHAM, iodoacetate, pyrazole, and 4-methylpyrazole are more inhibitory to anoxic than aerobic germination whereas azide, arsenate, and fluoride inhibit both. Azide, pyrazole, 4-methylpyrazole and a low concentration of cyanide and SHAM tend to stimulate ethanol production in air. At 10 mol m−3, 4-methylpyrazole stimulates anaerobic ethanol production. At higher concentrations this compound and all other inhibitors used suppress anaerobic ethanol production initially. Inhibition of ethanol production by 10 mol m−3 cyanide is paralleled by an accumulation of acetaldehyde. Azide and cyanide appear to exert their inhibitory effect at different loci.
