Multifocal Intraocular Lenses: An Overview

Purpose To determine the accuracy of the Holladay 2, Hoffer Q, SRK/T, and Haigis intraocular lens (IOL) power calculation formulas in high myopic and high hyperopic refractive lens exchange (RLE) with hydrophobic acrylic foldable IOLs Setting Department of Ophthalmology, Johann Wolfgang Goethe University, Frankfurt am Main, Germany Methods Preoperatively, axial length (AL) was measured by partial coherence interferometry with the IOLMaster The RLE was performed by phacoemulsification with posterior chamber IOL implantation in the capsular bag Optimization of the lens constants for each IOL type was done separately for eyes with a positive lens and eyes with a negative lens Prediction error (predicted refraction − postoperative refraction) and mean absolute error were back-calculated for the Holladay 2, Hoffer Q, SRK/T, and Haigis formulas Results Sixty-three eyes (44 myopic, AL ≥260 mm; 19 hyperopic, AL ≤220 mm) were included In myopic and hyperopic RLE, all 4 formulas had an overall good performance In myopic RLE, the Haigis formula performed better Conclusion In myopic and hyperopic RLE, optimization of lens constants improved the accuracy of IOL power calculation

Accuracy of modern intraocular lens power calculation formulas in refractive lens exchange for high myopia and high hyperopia.

Purpose To compare the astigmatic correcting effect of paired opposite clear corneal incisions (OCCIs) on the steep axis with that of single clear corneal incisions (CCIs) in cataract patients having phacoemulsification. Setting Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS, New Delhi, India. Methods This randomized prospective clinical study comprised 40 eyes of 40 patients with topographic astigmatism of more than 1.50 diopters (D). Paired 3.2 mm OCCIs were made in the steep axis in Group 1 and single CCIs in Group 2. Preoperative evaluation included uncorrected visual acuity, refraction, applanation tonometry, dilated fundoscopy, biomicroscopic examination, keratometry, and topography. The steep axis was marked before sub-Tenon's anesthesia was given and routine phacoemulsification was performed through a 3.2 mm CCI on the steep axis. An additional opposite 3-step self-sealing CCI was made in Group 1. Patients were examined 1, 4, and 12 weeks postoperatively. Visual acuity, refraction, keratometry, and topography were evaluated. Results The mean preoperative and postoperative topographic corneal astigmatism was 2.51 D ± 0.92 (SD) and 0.91 ± 0.54 D, respectively, in Group 1 and 2.16 ± 0.80 D and 1.57 ± 0.70 D, respectively, in Group 2. Mean astigmatic correction was 1.66 ± 0.5 D and 0.85 ± 0.75 D in Group 1 and Group 2, respectively. Mean surgically induced astigmatism, measured by a vector-corrected method, was 1.66 ± 0.50 D and 0.85 ± 0.75 D in Group 1 and Group 2, respectively (P = .00). The coupling ratio was −0.96 in Group 1 and −0.87 in Group 2. The spherical equivalent was +0.23 ± 0.41 D in Group 1 and +0.11 ± 0.17 D in Group 2 at 12 weeks. Uncorrected visual acuity was better in Group 1 than in Group 2 (P = .032). There was no difference in best corrected visual acuity between the groups. There were no incision-related complications. Conclusion Paired OCCIs were predictable and effective in providing an enhanced effect for correcting preexisting corneal astigmatism in cataract surgery.

Corneal astigmatism correction with opposite clear corneal incisions or single clear corneal incision: comparative analysis

Purpose. To analyze the prevalence and presentation patterns of corneal astigmatism in cataract surgery candidates in a teaching hospital in northern China. Methods. From May 1, 2012, to April 30, 2013, partial coherence interferometry (IOLMaster) measurements of all qualified cataract surgery candidates were retrospectively collected and analyzed. Results. The study evaluated 12,449 eyes from 6,908 patients with a mean age of (SD) years. The corneal astigmatism was 0.5 diopters (D) or less in 20.76% of eyes, 1.0 D or more in 47.27% of eyes, 2.0 D or more in 13.16% of eyes, and 3.0 D or more in 3.75% of eyes. With-the-rule astigmatism was found in 30.36% of eyes, while against-the-rule was found in 52.41% of eyes. The percentage of against-the-rule astigmatism increased with age. Conclusion. Our study showed that almost one-half of preoperative eyes (47.27%) in northern China have a corneal astigmatism of 1.0 D or more, indicating that more surgical techniques or toric IOLs are needed to achieve better visual rehabilitation.

/pdf/prevalence-of-corneal-astigmatism-in-patients-before-4isbwfr4qf.pdf

Prevalence of Corneal Astigmatism in Patients before Cataract Surgery in Northern China

Purpose:To study and compare the corneal thickness values of postmenopausal women with dry eye and postmenopausal women without dry eye.Methods:The corneal thickness value of 30 postmenopausal women with dry eye (dry eye group; aged 52 to 55 years) and 32 postmenopausal women without dry eye (normal

Reduced corneal thickness values in postmenopausal women with dry eye.

Introduction Neurotrophic keratitis is a rare degenerative corneal disease caused by an impairment of trigeminal corneal innervation, leading to a decrease or absence of corneal sensation. Here, we present a case of neurotrophic keratopathy caused by B12 deficiency in a 34 years old man who had a progressive decrease in visual acuity and corneal involvement since 3 months before being referred to our ophthalmology clinic. Result and discussion Based on our clinical findings and with the diagnosis of B12 deficiency we started B12 treatment for the patient. After 3 weeks the patient showed a dramatic response with corneal sensation reversal, an increase of visual acuity, improved neurotrophic keratopathy and significantly improved neurological findings. To the best of our knowledge, there is no report regarding vitamin B12 deficiency induced keratopathy and this is the first report that describes this aspect of vitamin B12 deficiency.

/pdf/vitamin-b12-deficiency-as-a-cause-of-neurotrophic-50seugou0v.pdf

Vitamin B12 Deficiency as a Cause of Neurotrophic Keratopathy

Kinetic study of sulfur dioxide removal reaction with manganese dioxide by random pore model using thermogravimetry

Purpose: To evaluate the effect of Isotretinoin on tear secretion among patients with Acne Vulgaris Patients and Methods: In this prospective study patients candidate for isotretinoin (Accutane) therapy for two months underwent complete eye examination The best corrected visual acuity was measures and slit lamp examination of anterior segment, evaluation of tear break-up-time and Schirmer’s test were performed The post surgical examination carried out two months post therapy consisted of complete eye examination and evaluation of dry eye level Findings: Thirty nine patients entered the study There were 5 patients complaining of eye strain before treatment, which rose to 19 patients after Isotretinoin therapy (p<0001) The tear break up time was 13±1 seconds which decreased to 9±1 (p<0001) after therapy and the Schirmer’s test mean reading was 22±2mm, which was reduced to 18±5 (p<0001) after treatment There were 4 patients with blepharitis before the treatment which rose to 19 patients after the end of Isotretinoin treatment (p<0001) Conclusion: Isotretinoin usage (05-1mg/kg for two months) impairs the tear secretion and causes dry eye and blepharitis among patients Considering the young age of patients using this drug, some of them candidates for keratorefractive surgery, a history of Isotretinoin usage should be considered before commencing the surgery We recommend postponing the refractive surgery among these patients until the signs of dry eye are subsided

Evaluation of Tear Function among Acne Vulgaris Patients Undergoing Treatment with Isotretinoin

Purpose: To evaluate the corneal endothelial cell density and Polymegathism after laser assisted keratomileusis with mitomycin C. Patients and Methods: One hundred and three eyes from 52 patients undergoing laser assisted sub-epithelial keratomileusis using mitomycin-C 0.02% for 30 seconds entered this study. Specular microscopy was utilized to study the corneal endothelial cells before and one year after the surgery to evaluate the endothelial cell density and polymegathism. The corneal thickness was measured before and one year after the surgery. Results: The mean endothelial cell density before surgery was 2870±368/mm2, which changed to 2828±300/mm2 one year after the surgery (P=0.182). Endothelial cell size variation coefficient was 24±7 before the surgery, which changed to 25±7 one year after the surgery (P=0.039). The average stromal ablation dept was 65 micron (22 to 131 micron) and the remaining corneal thickness one year after the surgery was 488±42 micron (405 to 567 micron) (p<0.001). Conclusion: Using mitomycin C (0, 02% for 30 seconds) during the laser assisted sub-epithelial keratomileusis did not significantly change the corneal endothelial cell density one year after the surgery but the change in polymegathism was significant.

/pdf/effect-of-mitomycin-c-on-endothelial-cell-density-and-4l584k4ei6.pdf

Effect of Mitomycin-C on Endothelial Cell Density and Polymegathism in Laser Assisted Sub-Epithelial Keratectomy

Purpose: To evaluate the corneal endothelial cell density and Polymegathism one year after laser assisted keratomileusis using mitomycin C. Methods: One hundred and three eyes from 52 patients who underwent laser assisted sub-epithelial keratomileusis using mitomycin C 0.02% for 30 seconds entered this study. Corneal endothelial cells were evaluated using specular microscopy before and one year after the surgery considering endothelial cell density and polymegathism. Also the corneal thickness was measured before and one year after the surgery. Results: The mean endothelial cell density before surgery was 2870±368/mm, which changed to 2828±300/mm one year after the surgery (P=0.182). Polymegathism was 24±7 before the surgery, which changed to 25±7 one year after the surgery (P=0.039). The average stromal ablation dept was 65 micron (22 to 131 micron) and the remaining corneal thickness one year after the surgery was 488±42 micron (405 to 567 micron) (p<0.001). Conclusion: Using mitomycin C (0, 02% for 30 seconds) during the laser assisted sub-epithelial keratomileusis did not significantly change the corneal endothelial cell density one year after the surgery but the change in polymegathism was significant.

The effect of mitomycin-c on endothelial cell density and polymegathism after laser assisted sub-epithelial keratectomy: a one year follow-up

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