PURPOSE To evaluate the correlation between refractive, corneal, and residual astigmatism and higher order aberrations (HOA) in refractive surgery candidates. METHODS Three hundred and seventy-five eyes of 188 patients aged 28.2 ± 6.24 years with a predominance of females (62.7%) were enrolled in this study. Refraction, topography (Orbscan IIz, Bausch & Lomb, Rochester, NY, USA), and aberrome...

Three methods of determining the actual size of objects on the living fundus were utilized to measure the horizontal disc diameter (H) in 68 volunteers. H1 was calculated from fundus photographs based on the refractive power of the eye and according to the formula of Bengtsson and Krakau. H2 was derived from Littmann's trigonometric curves based on the anterior corneal curvature and the refract...

We report the effect of changes in the corneal hydration on the refractive index of the cornea. Using optical coherence tomography (OCT), the geometrical thickness and the group refractive index of the bovine cornea were derived simultaneously as the corneal hydration was varied. The corneal hydration was then calculated from the corneal thickness. The group refractive index of the cornea incre...

By Thomas Olsen, MD, PhD The calculation of IOL power in an eye that has undergone corneal refractive surgery is not a straightforward task. However, if you understand why the calculation may go wrong, you will have a fair chance of getting a good result using modern technology. It is important to understand that the calculation errors of post-LASIK eyes are the sum of the traditional errors pl...

PURPOSE Lenticule implantation can be used to correct vision problems. However, it is significantly restrained by the sources of autologous lenticules. The aim of the present study was to investigate the feasibility and effects of femtosecond laser-assisted corneal small incision allogenic intrastromal lenticule implantation (AILI) in monkeys. METHODS Six healthy adult monkeys were included i...

Recently, two papers "Dorronsoro et al., Experiment on PMMA models to predict the impact of corneal refractive surgery on corneal shape, Opt. Express 14, 6142 (2006)" and "JR Jiménez et al., Deviations of Lambert-Beer's law affect corneal refractive parameters after refractive surgery, Opt. Express 14, 5411 (2006)" have been published on an important question in corneal refractive surgery: to e...

PURPOSE To assess the refractive and visual outcomes following cataract surgery and implantation of the AcrySof IQ Toric SN6AT2 intraolcular lens (IOL) (Alcon Laboratories, Inc., Fort Worth, TX, USA) in patients with low corneal astigmatism. METHODS This study is a retrospective, consecutive, single surgeon series of 98 eyes of 88 patients (with low preoperative corneal astigmatism) undergoin...

AIM To construct patient-specific solid models of human cornea from ocular topographer data, to increase the accuracy of the biomechanical and optical estimate of the changes in refractive power and stress caused by photorefractive keratectomy (PRK). METHOD Corneal elevation maps of five human eyes were taken with a rotating Scheimpflug camera combined with a Placido disk before and after ref...

We studied the potential of myopic corneal refractive laser surgery to induce myopia (axial elongation) and potential interactions between aberrations (generally resulting from the procedure) and myopia development in chicks (Gallus domesticus). Ten white Leghorn chicks were monolaterally treated one day post-hatching with photorefractive keratectomy (PRK), with a nominal dioptric change of -9....