Retinal Straylight Before and After Penetrating Keratoplasty in an Eye with a Post-Herpetic Corneal Scar (original) (raw)
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Clinical and Experimental Optometry, 1991
Acreptcxi f o i publication: 12 Noveinber 1991 .A glare score based on intra-ocular light scatter and a questionnaire-based subjective assessment of glare were determined for 18 patients who had undergone radial keratotomy (RK) h V 0 weeks to 27 months previously. Results were compared to those of 15 control subjects. T-tests showed no significant difference in glare experienced under photopic conditions by RK patients and control subjects. There was no systematic relationship between glare scores and the subjective assessment of glare, nor between glare scores or subjective assessment of glare and the time which had elapsed since surgery. However, a weak relationship (r2=0.36) was found between glare scores and absolute refractive error. It was concluded that RK did not produce significant levels of intra-ocular light scatter under photopic conditions (155 lux).
Cornea, 2012
Long-term quality of vision after Descemet stripping endothelial keratoplasty (DSEK) was evaluated and correlated with corneal characteristics and subjective complaints. methods Thirty-four eyes were examined; patients had a single visit 6 to 64 months after DSEK for Fuchs' dystrophy. Best-corrected distance acuity (BCDA) and straylight were analyzed. To better evaluate long-term postoperative BCDA changes, longitudinal data were used from earlier visits. Corneal thickness was measured with the Visante anterior segment Optical Coherence Tomography (OCT). Interface, stromal and endothelial haze were semi-quantitatively graded using the slitlamp. Vision-related quality of life was evaluated with the 39-item National Eye Institute Visual Function Questionnaire (NEI VFQ-39) and a straylight questionnaire. Correlation analysis comparing corneal characteristics with visual quality was performed. results Mean postoperative time was 1027 ± 453 days. Mean BCDA at this time was 0.33 ± 0.19 logMAR. BCDA remained stable with long-term postoperative follow-up. Straylight averaged 1.47 ± 0.19, on average 0.12 log units higher than normal values for age-related pseudophakic eyes (P < 0.001). BCDA correlated with corneal haze (r = 0.50), whereas straylight showed a non-significant association (P = 0.12). Neither BCDA nor straylight correlated with corneal thickness. Mean VFQ-39 score was 77/100, and mean score of the straylight questionnaire was 46/100. Conclusion Quality of vision after DSEK does not return to normal levels of age-matched pseudophakic eyes, with decreased BCDA and increased straylight. Questionnaire scores indicate mild (VFQ-39) to moderate (straylight) subjective visual impairment. Corneal thickness and haze do not offer an adequate explanation for the decreased visual quality.
Study of visual outcome in patients undergoing penetrating keratoplasty
IP innovative publication pvt. ltd, 2019
Introduction: To study the visual outcome in patients undergoing penetrating keratoplasty (PK). Materials and Methods: This was a prospective interventional study concerning patients who underwent optical and therapeutic PK in Hamidia hospital Bhopal during a period of Dec 2016 to May 2108. Age, gender, eye, indication of PKP, and best-corrected visual acuity (BCVA) constituting the preoperative data were recorded in a predesigned proforma. Penetrating keratoplasty was performed using similar technique and patients were followed up till a period of 1 year and post operative complications were identified and managed accordingly. The outcome was assessed in terms of percentage improvement in logMAR visual acuity and the variables affecting the final visual outcome were studied. Results: Of the total 50 cases of penetrating keratoplasty that were analyzed 33 were done for therapeutic purposes and 17 were done for optical reasons. Mean recipient age was 39.88 years ±2.9 years, range 3-68. Follow up period was 1 year. The indications were therapeutic (34%), post traumatic or post infective corneal scarring (50%), previous graft failure (6%) and pseudophakic bullous keratopathy (4%). In optical PK, 62.5% recipient eyes showed good visual improvement (improvement of more than -0.8 log MAR). 21.8% eyes showed moderate visual improvement, and 15.6% eyes showed no visual improvement. In eyes with therapeutic PK, 46.7% showed good visual improvement, 13.3% moderate and 40% showed no visual improvement. Conclusion: Penetrating keratoplasty done for both optical and therapeutic indications resulted in fairly good visual outcome. The pre-operative host risk factors were associated with an increased probability of graft rejection. Careful workup of recipients for corneal transplantation with reference to local and systemic risk factors is of utmost importance in the outcome of corneal transplantation with regards to graft survival.
Quality of vision following clinically successful penetrating keratoplasty
Journal of Cataract and Refractive Surgery, 2004
Methods: Patient group (PG) included 9 patients (12 eyes) who had clinically successful PKP in our department. The control group (CG) included 12 people (18 eyes) who had no ocular disease other than refractive errors. Those with a visual acuity level less than 20/25 were not included in the study. Contrast sensitivity levels and light threshold values of the central retina were measured; scanning-slit corneal topography-pachymetry and aberrometric analysis were performed.
Straylight before and after LASEK in Myopia: Changes in Retinal Straylight
Investigative Ophthalmology & Visual Science, 2010
To quantify the changes in retinal straylight that occur after laser-assisted subepithelial keratectomy (LASEK). METHODS. This prospective study included 86 eyes of 49 patients who were scheduled for LASEK surgery. Patients were divided into groups based on their preoperative contact lens wear habits: rigid lenses (RCL), soft lenses (SCL), spectacles after a period of contact lenses (SaC), and spectacles only (Specs). Retinal straylight was tested before surgery and 6 months after surgery with the compensation comparison method. Straylight was also compared to a normal reference database. The difference with the average straylight increase with age, called base-and age-corrected (BAC) straylight, was also studied. RESULTS. Before surgery, BAC straylight was found to be strongly elevated, with a value of 0.15 Ϯ 0.14 log units. After LASEK, this decreased to 0.00 Ϯ 0.14 log units. The reduction was significant (paired t-test, P Ͻ Ͻ 0.01) and correlated with preoperative BAC straylight levels (r 2 ϭ 0.332; P Ͻ Ͻ 0.01). There was no correlation between the straylight change and the spherical equivalent of the laser refractive correction (r 2 ϭ 0.042; P ϭ 0.059). Preoperative wear of soft contact lenses increased the BAC straylight by approximately 0.06 log units, with respect to the spectacles groups (P Ͻ 0.05, unpaired t-test), but after surgery, this difference was no longer found (P Ͼ 0.05). CONCLUSIONS. Higher than normal preoperative BAC straylight was found to normalize after LASEK refractive surgery. Wearing soft contact lenses causes an additional increase in preoperative BAC straylight that is eliminated after LASEK. (Invest Ophthalmol Vis Sci.
Method for in vitro assessment of straylight from intraocular lenses
Biomedical Optics Express, 2015
Ocular straylight has been measured by means of psychophysical methods over the years. This approach gives a functional parameter yielding a straight comparison with optically defined light scattering, and the pointspread-function. This is of particular importance when the effect of intraocular lenses (IOLs) on postoperative straylight is sought. An optical system for straylight measurements of IOLs was adapted to a commercial device (C-Quant, Oculus), which employs such psychophysical method. The proposed modifications were validated using light-scattering filters and some sample IOLs. The measurements were performed by 3 observers to prove that results are independent from straylight of the eye. Other applications will be discussed.
Corneal Light Transmission and Roughness After Refractive Surgery
Optometry and Vision Science, 2010
To determine the relation between the corneal light transmission measurements and the epithelial surface properties in hen corneas after different refractive surgery techniques photorefractive keratectomy, laser in situ keratomileusis, and laser-assisted subepithelial keratomileusis, and a group with only epithelial corneal removal (deepithelialization). Methods. Five groups of hen corneas with different treatments and a control group were analyzed at 30 days. Direct transmittance and corneal light scattering were measured by a scatterometer developed by our group. Quantitative and systematic measurements of external and internal roughness and epithelium thickness were assessed using standard techniques developed for quantitative analysis of microphotographs of the corneal epithelium. Results. Data analysis revealed that the roughness in the epithelial surface was associated with the corneal light transmission. The direct transmittance of light showed a significant correlation with the epithelial roughness in the control (r ϭ Ϫ0.99, p Ͻ 0.05) and photorefractive keratectomy (r ϭ Ϫ0.99, p Ͻ 0.05) groups. However, there was no relation between the epithelial thickness and the corneal light transmission measurements. Conclusions. The experimental results suggested that the roughness of the epithelial surfaces is related to the light transmission in the cornea. (Optom Vis Sci 2010;87:1-•••)
British Journal of Ophthalmology, 2000
Aims-To evaluate visual function and vision specific health status in patients undergoing penetrating keratoplasty for keratoconus. Methods-A prospective longitudinal study measuring logMAR visual acuity, contrast sensitivity, disability glare, binocular visual field, stereoacuity, and subjective visual function (VF-14) was conducted on 18 patients with keratoconus undergoing penetrating keratoplasty (PK), including six patients who had already had PK in the fellow eye. Data were collected preoperatively and at 3, 9, and 18 months after surgery. Results-Within 3 months of surgery there was significant improvement in aided visual acuity, contrast sensitivity, and stereoacuity (p<0.05); disability glare (p<0.05) no longer had a significant detrimental eVect on these variables. VF-14 score improved significantly throughout the postoperative period (p<0.05). There was significant correlation of the VF-14 score with aided visual acuity, binocular visual field, and stereoacuity. Postoperative astigmatism (<4D v >4D) did not aVect the VF-14 score significantly. Conclusions-There is substantial and rapid improvement in visual function and vision specific health status in keratoconic patients as a result of uncomplicated penetrating keratoplasty. (Br J Ophthalmol 2000;84:60-66)
Cornea, 2000
Purpose. To determine whether visual acuity (VA) measurements performed at low levels of contrast and glare are a better diagnostic tool for determining whether corneal clouding warrants surgery. Methods. Fifty-nine subjects were recruited from among the candidates for corneal graft. Monocular VA was measured with three Regan contrast VA charts: 96, 25, and 11%, with and without glare provided by the Brightness Acuity Tester (BAT). The discriminative ability of the tests was estimated using the area (A R) under receiver operating characteristic (ROC) curves. Associations between the different VA tests and the Visual Function Index (VF-14) score were studied, using Spearman coefficients. Results. When comparing candidate eyes with contralateral eyes with corneal disease, lower contrasts VA tests provided greater discriminative power. VA measurements made with glare also tended to provide greater discrimination. In fact, discrimination was best with 11% contrast VA with glare, but "testability" was poor. The most practical test in a clinical setting, which retained high discriminative ability (0.798), was the 25% contrast VA with glare. The eye with the best VA correlated strongly with the VF-14, especially at 25% contrast without glare, resulting in an R s of −0.729. Conclusion. Twenty-five percent contrast VA with BAT could help the practitioner to decide whether a corneal transplant is warranted when symptoms of reduced vision are more important than what high-contrast VA might indicate.