Visual acuity Research Papers - Academia.edu (original) (raw)

OBJECTIVE: To assess the impact of laser peripheral iridotomy (LPI) on forward-scatter of light and subjective visual symptoms and to identify LPI parameters influencing these phenomena. DESIGN: Cohort study derived from a randomized... more

OBJECTIVE: To assess the impact of laser peripheral iridotomy (LPI) on forward-scatter of light and subjective visual symptoms and to identify LPI parameters influencing these phenomena. DESIGN: Cohort study derived from a randomized trial, using an external control group. PARTICIPANTS: Chinese subjects initially aged 50 or older and 70 years or younger with bilateral narrow angles undergoing LPI in 1 eye selected at random, and age- and gender-matched controls. METHODS: Eighteen months after laser, LPI-treated subjects underwent digital iris photography and photogrammetry to characterize the size and location of the LPI, Lens Opacity Classification System III cataract grading, and measurement of retinal straylight (C-Quant; OCULUS, Wetzlar, Germany) in the treated and untreated eyes and completed a visual symptoms questionnaire. Controls answered the questionnaire and underwent straylight measurement and (in a random one-sixth sample) cataract grading. MAIN OUTCOME MEASURES: Retina...

To evaluate the visual outcomes and patient satisfaction after unilateral implantation or stepwise bilateral implantation of an apodized diftractive multifocal intraocular lens (IOL). Private practice, Cincinnati, Ohio, USA. Patients... more

To evaluate the visual outcomes and patient satisfaction after unilateral implantation or stepwise bilateral implantation of an apodized diftractive multifocal intraocular lens (IOL). Private practice, Cincinnati, Ohio, USA. Patients requiring cataract surgery in 1 eye were recruited. AcrySof ReSTOR IOLs were implanted in 1 eye of patients with phakic contralateral eyes, patients with contralateral monofocal IOLs, and patients with a contralateral multifocal IOL of the same model. Six months postoperatively, patients were assessed for visual acuity (31.0 cm, 50.0 cm, 4.0 m), contrast sensitivity, and stereopsis. Patients were surveyed for visual disturbances and lifestyle visual quality. Of unilateral multifocal IOL patients, 75% were satisfied with their vision (score 7.3 out of 10) and a majority (56% multifocal-phakic, 65% multifocal-monofocal) achieved spectacle independence. These values were slightly lower than values for bilateral multifocal patients (92% satisfied, 77% spectacle independent), but not at a statistically significant level. Mean overall patient satisfaction was statistically significantly different: 8.9 for bilateral patients versus 7.3 for unilateral patients. Objectively, significant differences favored bilateral implantation over unilateral implantation for stereopsis, uncorrected near visual acuity, and best corrected near and intermediate visual acuities. Contrast sensitivity was similar between groups in most cases. The incidence of halos was lower in unilateral patients (57%) than in bilateral patients (77%), although the difference did not reach statistical significance. Although unilateral implantation of a multifocal IOL provided patients with high levels of spectacle freedom and good visual acuity without compromising contrast sensitivity, overall clinical results favored bilateral implantation.

METHODS. COMET enrolled 469 ethnically diverse children (ages, 6–11 years) with myopia between –1.25 and –4.50 D. They were randomly assigned to either progressive addition lenses (PALs) with a +2.00 addition (n = 235) or single vision... more

METHODS. COMET enrolled 469 ethnically diverse children (ages, 6–11 years) with myopia between –1.25 and –4.50 D. They were randomly assigned to either progressive addition lenses (PALs) with a +2.00 addition (n = 235) or single vision lenses (SVLs; n = 234), the ...

To describe the prevalence of retinal vein occlusion (RVO) and its risk factors in a multi-ethnic Asian population. This population-based study of 10,033 participants (75.7% response rate) included Chinese, Indian and Malay persons aged... more

To describe the prevalence of retinal vein occlusion (RVO) and its risk factors in a multi-ethnic Asian population. This population-based study of 10,033 participants (75.7% response rate) included Chinese, Indian and Malay persons aged 40 years and older. A comprehensive ophthalmic examination, standardized interviews and laboratory blood tests were performed. Digital fundus photographs were assessed for presence of RVO following the definitions used in the Blue Mountains Eye Study. Regression analysis models were constructed to study the relationship between ocular and systemic factors and RVO. Age-specific prevalence rates of RVO were applied to project the number of people affected in Asia from 2013 to 2040. The overall crude prevalence of RVO was 0.72% (n = 71; 95% confidence interval, CI, 0.54-0.87%). The crude prevalence of RVO was similar in Chinese, Indian and Malay participants (p = 0.865). In multivariable regression models, significant risk factors of RVO included increa...

The surgical management of macular holes has been a subject of controversy in recent years. Various techniques such as vitrectomy, membrane peeling, and gas tamponade with or without transforming growth factor-beta 2, and recently the use... more

The surgical management of macular holes has been a subject of controversy in recent years. Various techniques such as vitrectomy, membrane peeling, and gas tamponade with or without transforming growth factor-beta 2, and recently the use of autologous platelets have produced closure rates from 58% to 96%, depending on the stage of the hole. The authors present preliminary results in a study of 19 consecutive patients with stage 3 or stage 4 macular hole who underwent vitrectomy followed by placement of an absorbable partially cross-linked gelatin plug in the macular hole. The vitreous cavity was filled with a nonexpanding gas or air alone; the patient was instructed to maintain prone positioning for 2-3 days. Anatomic attachment of the edges of the macular hole was achieved in 19 out of 19 patients with a minimum follow-up period of 6 months (average 11.5 months). A cross-linked gelatin plug can effectively reattach the edges of macular holes of stages 3 and 4. Its use is recommend...

To examine the optical quality of healthy presbyopic eyes before and after implantation of the pseudoaccommodating AcrySof ReSTOR Natural intraocular lens (IOL) (Alcon Laboratories) by measuring visual acuity and wavefront... more

To examine the optical quality of healthy presbyopic eyes before and after implantation of the pseudoaccommodating AcrySof ReSTOR Natural intraocular lens (IOL) (Alcon Laboratories) by measuring visual acuity and wavefront aberrations.University of Valencia, Fernández-Vega Ophthalmological Institute, Valencia, Spain.Monocular refraction and photopic distance (6 m) and near (0.33 m) visual acuities were determined before and after clear lens extraction with bilateral AcrySof ReSTOR Natural IOL implantation in 30 hyperopic eyes (+0.50 to +4.00 diopters [D]) of presbyopic patients with low astigmatism (≤1.00 D). Postsurgical binocular visual acuity was measured over a range of effective distances. Wavefront aberrations were measured before and after surgery. Aberrations for 2 pupil diameters (3.0 mm and 5.0 mm) were decomposed using Zernike polynomials; total, defocus, astigmatism spherical, and coma aberration terms were studied separately. Postimplantation results were compared with preoperative values.Safety and efficacy indices for distance vision were 1.01 and 0.96, respectively. At near, they improved to 1.07 and 1.06, respectively. Vision at intermediate distances was noticeably poorer. Total, defocus, and spherical aberrations changed after IOL implantation with both pupil diameters (P<.01). Total and defocus aberrations were significantly reduced postoperatively. Spherical aberration coefficients changed to negative and less positive values for a 3.0 mm and a 5.0 mm pupil, respectively.Implantation of the pseudoaccommodating IOL in healthy eyes yielded uncorrected levels of high-contrast, distance, and near acuities comparable to preoperative best corrected values. Higher-order aberration levels appeared to be similar to the preoperative values.

To investigate factors associated with reduced visual acuity during long-term follow-up of patients with idiopathic central serous chorioretinopathy (ICSC). Retrospective consecutive case series that included patients with ICSC who were... more

To investigate factors associated with reduced visual acuity during long-term follow-up of patients with idiopathic central serous chorioretinopathy (ICSC). Retrospective consecutive case series that included patients with ICSC who were younger than 50 years of age at the time of initial examination and were followed up for &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; or =3 years. The mean follow-up for 101 involved eyes of 61 patients was 9.8 years (median, 8.0 years). Eyes were stratified into two groups based on visual acuity at the final examination: Group 1, visual acuity of 2040 or better; and Group 2, visual acuity of worse than 2040. Findings identified as potential risk factors for reduced vision at the final follow-up examinations for Group 1 versus Group 2 included the following: macular retinal pigment epithelium atrophy (90.8% versus 96.0%, respectively; P = 0.68); persistent pigment epithelial detachment or persistent subretinal fluid (5.3% versus 28.0%, respectively; P = 0.004); recurrences (39.5% versus 68.0%, respectively; P = 0.020); laser treatment (28.9% versus 32.0%, respectively; P = 0.80); and submacular choroidal neovascularization (0.0 versus 8.0%, respectively; P = 0.059). Factors associated with reduced visual acuity during long-term follow-up of patients with ICSC included persistent pigment epithelial detachment and/or subretinal fluid, recurrences, and submacular choroidal neovascularization.

A multi-modality treatment programme, where stereotactic methods were used preferentially, gave results in a consecutive series of craniopharyngiomas, not inferior to those reported after microsurgical removal. Fourty-two patients with a... more

A multi-modality treatment programme, where stereotactic methods were used preferentially, gave results in a consecutive series of craniopharyngiomas, not inferior to those reported after microsurgical removal. Fourty-two patients with a follow-up range of 10-23 years are reported.

This prospective multicenter study assessed personality characteristics that may influence patient satisfaction after implantation of multifocal intraocular lenses (MIOLs). One hundred eighty-three patients who underwent bilateral... more

This prospective multicenter study assessed personality characteristics that may influence patient satisfaction after implantation of multifocal intraocular lenses (MIOLs). One hundred eighty-three patients who underwent bilateral implantation of different MIOLs were enrolled. Uncorrected and corrected distance visual acuity for distance and near (ie, UDVA, UNVA, CDVA, and CNVA) were assessed preoperatively and 3 and 6 months after implantation. Before surgery, personality characteristics were evaluated using a questionnaire based on the NEO Personality Inventory Test and the Compulsiveness Inventory Test. At the 3- and 6-month postoperative visits, patients answered a questionnaire concerning overall satisfaction, need for spectacles at different distances, visual function at different distances and lighting conditions, photic phenomena, and ease of performing daily activities. Three months after surgery (n = 163), mean CDVA was 0.03 ± 0.09 logMAR, UDVA was 0.05 ± 0.09 logMAR, and ...

... Gabriel Simon, Jean-Marie A. Parel, Gerard N. Kervick, Pascal O. Rol, Khalil Hanna, Keith P. Thompson. ... Usually, the epithelium is mechanically removed, and Bowman's layer and stromal tissue are photoablated to precomputed... more

... Gabriel Simon, Jean-Marie A. Parel, Gerard N. Kervick, Pascal O. Rol, Khalil Hanna, Keith P. Thompson. ... Usually, the epithelium is mechanically removed, and Bowman's layer and stromal tissue are photoablated to precomputed depths and shapes that are based on known ...