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Ian H Gillespie - One of the best experts on this subject based on the ideXlab platform.
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changes in scanning laser polarimetry before and after laser capsulotomy for Posterior Capsular Opacification
Journal of Glaucoma, 2007Co-Authors: Christopher J Brittain, Kenneth C S Fong, Christopher C Hull, Ian H GillespieAbstract:PurposeTo investigate changes in scanning laser polarimetry with variable corneal compensation (GDx-VCC) parameters caused by Posterior Capsular Opacification (PCO).MethodsIn this comparative case-control series, 20 eyes due to undergo YAG laser capsulotomy for PCO were recruited. GDx-VCC was perfor
Emma J Hollick - One of the best experts on this subject based on the ideXlab platform.
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Posterior Capsular Opacification with hydrogel polymethylmethacrylate and silicone intraocular lenses two year results of a randomized prospective trial
American Journal of Ophthalmology, 2002Co-Authors: Emma J Hollick, David J Spalton, Will R Meacock, Paul G Ursell, Sarah Barman, James F BoyceAbstract:Abstract PURPOSE: To compare the visual outcome, percentage of Posterior Capsular Opacification, and laser capsulotomy rates with polymethylmethacrylate, silicone, and hydrogel intraocular lens implants at 1 and 2 years postoperatively. METHODS: Ninety-three eyes of 93 patients were randomized to receive a polymethylmethacrylate, silicone, or hydrogel intraocular lens implant. A standardized surgical protocol was followed by a single surgeon using phacoemulsification with capsulorhexis; any patients with surgical complications were excluded, and all patients received standardized medication and follow-up. Patients were examined at days 1 and 7, months 1, 3, and 6, and years 1 and 2 after surgery. At each assessment, best-corrected logMAR visual acuity and Pelli-Robson contrast sensitivity were measured. Posterior Capsular Opacification was objectively assessed by digital retroillumination imaging with the use of a dedicated software program and calculated as the percentage area of opacified capsule. Laser capsulotomy was performed if the eye had lost 2 lines of visual acuity with a clinically opaque capsule. RESULTS: At 2 years postoperatively, the mean percentage area of Posterior Capsular Opacification for hydrogel lenses was 63%; for polymethylmethacrylate, 46%; and for silicone, 17%. Hydrogel intraocular lenses were associated with 17% more Posterior capsule Opacification than were polymethylmethacrylate lenses (95% confidence interval, 1–33; P = .037) and 45% more than were silicone lenses (95% confidence interval, 33–58; P P P = .014). Visual acuity was not significantly different among the three groups, but patients with silicone intraocular lenses had significantly better contrast sensitivity than those with hydrogel lenses ( P = .046). CONCLUSIONS: Intraocular lenses made of this specific hydrogel were associated with a significantly higher degree of Posterior Capsular Opacification and more laser capsulotomies than polymethylmethacrylate and silicone intraocular lenses.
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quantification of Posterior Capsular Opacification in digital images after cataract surgery
Investigative Ophthalmology & Visual Science, 2000Co-Authors: Sarah Barman, Emma J Hollick, David J Spalton, James F Boyce, Bunyarit Uyyanonvara, Giorgia Sanguinetti, Will R MeacockAbstract:PURPOSE. To describe a software program developed to provide an objective assessment of the amount of Posterior Capsular Opacification (PCO) in high-resolution digital images of the Posterior capsule after cataract surgery. METHODS. Images are analyzed by a set protocol of defining the area of the Posterior capsule, removing the Purkinje light reflexes by intensity segmentation, contrast enhancement, filtering to enhance low-density PCO, and variance analysis using a co-occurrence matrix to assess texture. The accuracy of the system was tested for validity and repeatability. RESULTS. The software developed has been demonstrated to be an objective method of quantifying PCO. In validation tests, the image analysis- derived measure of PCO showed good agreement with clinically derived measures of PCO. Clinicians assessed PCO on a computer screen image and also under slit lamp examination (Pearson correlation coefficient for both methods >0.92). The entire acquisition and analysis system was demonstrated to have a confidence limit for 2 SDs of 9.8% for group data. CONCLUSIONS. This system is capable of producing an accurate and reproducible measure of PCO that is relevant to assessing techniques of PCO prevention.
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the effect of capsulorhexis size on Posterior Capsular Opacification one year results of a randomized prospective trial
American Journal of Ophthalmology, 1999Co-Authors: Emma J Hollick, David J Spalton, Will R MeacockAbstract:Abstract PURPOSE: Posterior Capsular Opacification is the most common surgically related cause of reduced vision after cataract surgery. We studied the effect of capsulorhexis size on the pattern and severity of Posterior Capsular Opacification. METHODS: In this prospective study 75 patients underwent standardized phacoemulsification with capsulorhexis and in-the-bag placement of a 5.5-mm polymethylmethacrylate intraocular lens implant. The patients were randomly assigned to receive either a small capsulorhexis of 4.5 to 5 mm to lie completely on the intraocular lens optic or a large capsulorhexis of 6 to 7 mm to lie completely off the lens optic. Patients were examined at days 1, 14, 30, 90, and 180 and at year 1 with logMAR visual acuity assessment, Pelli-Robson contrast sensitivity testing, anterior chamber flare and cell measurement, and high-resolution digital retroillumination imaging of the Posterior capsule. The pattern of Posterior Capsular Opacification was determined, and the percentage area of Posterior Capsular Opacification was calculated for each image with dedicated image analysis software. RESULTS: Large capsulorhexes were associated with significantly more wrinkling of the Posterior capsule and worse Posterior Capsular Opacification than small capsulorhexes. At 1 year the average percentage area of Posterior Capsular Opacification was 32.7% for small capsulorhexes (95% confidence interval, 19.8 to 45.6) and 66.2% for large capsulorhexes (95% confidence interval, 57.7 to 74.6) ( P = .0001). The patients with large capsulorhexes had significantly poorer visual acuities and a trend toward worse contrast sensitivities. CONCLUSION: This study demonstrated significantly greater wrinkling and Opacification of the Posterior capsule and worse visual acuity with large capsulorhexes than with small capsulorhexes. In cataract surgery with a polymethylmethacrylate intraocular lens, a small capsulorhexis with the edge completely on the surface of the implant is preferable to a large capsulorhexis in reducing Posterior Capsular Opacification.
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the effect of polymethylmethacrylate silicone and polyacrylic intraocular lenses on Posterior Capsular Opacification 3 years after cataract surgery
Ophthalmology, 1999Co-Authors: Emma J Hollick, David J Spalton, Paul G Ursell, Sarah Barman, James F Boyce, Milind V Pande, Kate TillingAbstract:Abstract Objective To compare the visual outcome, neodymium:YAG (Nd:YAG) capsulotomy rates, and percentage of Posterior Capsular Opacification (PCO) seen with polymethylmethacrylate (PMMA), silicone, and polyacrylic intraocular lens implants 3 years after surgery. Design Randomized, prospective trial. Participants Ninety eyes of 81 patients were examined at a British teaching hospital. Intervention Ninety eyes were prospectively randomized to receive a PMMA, silicone, or polyacrylic (AcrySof, Alcon, Fort Worth, TX) implant. All lenses had 6-mm disc optics with PMMA haptics. A standardized surgical protocol was performed by a single surgeon using an extraCapsular technique with capsulorhexis; any surgical complications were excluded and all patients had standardized postoperative medication and follow-up. Main outcome measures Patients were seen at 6 months and 1, 2, and 3 years after surgery. At 3 years, logarithm of the minimum angle of resolution (LogMAR) visual acuity and Pelli-Robson contrast sensitivity were measured and YAG capsulotomy rates determined. Posterior Capsular Opacification was assessed objectively by digital retroillumination imaging using dedicated software and calculated as the percentage area of opacified capsule. Results At 3 years, the overall follow-up rate was 71%: 19 patients were available for examination with polyacrylic lens implants, 22 with silicone, and 23 with PMMA. There was a significant difference in percentage PCO at 3 years among the lens types ( P = 0.0001). Polyacrylic lenses were associated with less PCO (10%) than silicone (40%) and PMMA lenses (56%). The YAG capsulotomy rate was 0% for polyacrylic, 14% for silicone, and 26% for PMMA ( P = 0.05). The visual acuity and contrast sensitivity were not significantly different among the three groups if patients with age-related macular degeneration and those requiring YAG capsulotomies are excluded. Conclusions Intraocular lenses made from polyacrylic are associated with a significantly reduced degree of PCO and lower YAG rates.
Vicente Zanonmoreno - One of the best experts on this subject based on the ideXlab platform.
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the influence of Posterior Capsular Opacification removal on anterior segment birefringence parameters as measured by scanning laser polarimetry
Clinical and Experimental Ophthalmology, 2007Co-Authors: Jose Javier Garciamedina, Manuel Garciamedina, Roberto Gallegopinazo, Vicente Zanonmoreno, Sheila Ponsvazquez, Samuel Gonzalezocampo, Maria Dolores PinazoduranAbstract:Purpose: To determine the effect of Posterior Capsular Opacification (PCO) removal on anterior segment birefringence (ASB) and its influence on peripapillary retinal nerve fibre layer (RNFL) retardation measurements obtained by means of scanning laser polarimetry. Methods: In this prospective interventional study, scanning laser polarimetry was performed using GDx variable corneal compensation on 26 eyes of 26 patients who developed clinically significant PCO (after uncomplicated cataract surgery and with no other ocular pathology) both before and between 1 and 4 weeks after Nd:YAG capsulotomy. Best-corrected visual acuity (BCVA), intraocular pressure, corneal polarization axis (CPA), corneal polarization magnitude (CPM) were compared using the Student t-test and Wilcoxon signed ranks test. Spearman correlations between changes (differences between values after and before capsulotomy) in the CPA, CPM, BCVA and RNFL data were also performed. Results: PCO removal is associated with a shift in CPA (from 10.86 to 15.03 degrees, P = 0.004) and CPM (from 28.54 to 37.92 nm, P = 0.004). Significant correlations were found between changes in the parameters of ASB and BCVA. Furthermore, RNFL measurements (nerve fibre indicator, temporal-superior-nasal-inferior-temporal average and superior average) were also well related to the CPA and CPM shifts. Conclusions: PCO induces an inaccurate compensation of ASB which affects RNFL assessment. Thus, it is necessary to recompensate ASB after Posterior capsulotomy.
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effect of Posterior Capsular Opacification removal on scanning laser polarimetry measurements
Graefes Archive for Clinical and Experimental Ophthalmology, 2006Co-Authors: Jose Javier Garciamedina, Manuel Garciamedina, Samuel Gonzalezocampo Dorta, Maria Dolores Pinazoduran, Roberto Gallegopinazo, Vicente ZanonmorenoAbstract:Purpose To evaluate the effect of Posterior Capsular Opacification (PCO) on retinal nerve fiber layer (RNFL) retardation measurements obtained during scanning laser polarimetry (SLP). We are unaware of previous studies undertaken in this sense.
Baljean Dhillon - One of the best experts on this subject based on the ideXlab platform.
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Use of Nd:YAG laser capsulotomy.
Survey of Ophthalmology, 2003Co-Authors: Tariq Aslam, Hilary Devlin, Baljean DhillonAbstract:Surgery for cataract removal has become successively refined such that Posterior Capsular Opacification is the most common problem presenting after modern cataract extraction. Various techniques and treatments exist to manage patients with Posterior Capsular Opacification using Nd:YAG capsulotomy. There are many possible variations in initial assessment, pre-laser treatments, laser techniques, and follow-up routines. The literature on the use of Nd:YAG laser for capsulotomy was reviewed and interpreted. This article presents the currently available knowledge in a format that allows the practitioner to tailor an evidence-based protocol for treating patients with symptomatic Posterior capsule Opacification.
Jose Javier Garciamedina - One of the best experts on this subject based on the ideXlab platform.
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effect of Posterior Capsular Opacification removal on macular optical coherence tomography
European Journal of Ophthalmology, 2008Co-Authors: S Gonzalezocampodorta, Jose Javier Garciamedina, A Felicianosanchez, G ScalerandiAbstract:PURPOSE. To evaluate the influence of Posterior Capsular Opacification (PCO) on macular optical coherence tomography (OCT) imaging quality and measurements of macular retinal thickness. METHODS. In this prospective interventional case series, 32 eyes of 23 patients with PCO were recruited. Best-corrected visual acuity (BCVA), a complete ophthalmologic assessment, and macular OCT scans (OCT Stratus 3000) before and after Nd:YAG capsulotomy were performed. Two parameters for image quality (signal strength (SS) and number of tomographic messages) and 10 macular retinal thickness measurements were compared. Spearman correlations between BCVA and SS and macular retinal thickness measurements before and after capsulotomy were also performed. R ESULTS. PCO removal was associated with an increase of best-corrected visual acuity (p<0.0001). The mean SS (n=32) went from 3.34±2.31 to 6.38±1.93 (p<0.0001) after Nd:YAG capsulotomy. The SS improved in 26 of 32 eyes. No significant difference between mean preoperative and postoperative macular retinal thickness measurements was observed (p<0.05) in valuable scans. Before capsulotomy, a correlation existed between BCVA and SS. After capsulotomy this correlation was no longer found. C ONCLUSIONS. OCT image quality is influenced by PCO. Nd:YAG capsulotomy results in a measurable improvement in SS and improvement in the number of valuable examinations. Valuable OCT scans in patients with PCO seem to yield reliable measurements of macular retinal thickness even in the presence of severe PCO. The correlation between BCVA and SS before capsulotomy suggests that the SS could be considered an objective indicator of the degree of PCO. (Eur J Ophthalmol 2008; 18: 435-41)
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the influence of Posterior Capsular Opacification removal on anterior segment birefringence parameters as measured by scanning laser polarimetry
Clinical and Experimental Ophthalmology, 2007Co-Authors: Jose Javier Garciamedina, Manuel Garciamedina, Roberto Gallegopinazo, Vicente Zanonmoreno, Sheila Ponsvazquez, Samuel Gonzalezocampo, Maria Dolores PinazoduranAbstract:Purpose: To determine the effect of Posterior Capsular Opacification (PCO) removal on anterior segment birefringence (ASB) and its influence on peripapillary retinal nerve fibre layer (RNFL) retardation measurements obtained by means of scanning laser polarimetry. Methods: In this prospective interventional study, scanning laser polarimetry was performed using GDx variable corneal compensation on 26 eyes of 26 patients who developed clinically significant PCO (after uncomplicated cataract surgery and with no other ocular pathology) both before and between 1 and 4 weeks after Nd:YAG capsulotomy. Best-corrected visual acuity (BCVA), intraocular pressure, corneal polarization axis (CPA), corneal polarization magnitude (CPM) were compared using the Student t-test and Wilcoxon signed ranks test. Spearman correlations between changes (differences between values after and before capsulotomy) in the CPA, CPM, BCVA and RNFL data were also performed. Results: PCO removal is associated with a shift in CPA (from 10.86 to 15.03 degrees, P = 0.004) and CPM (from 28.54 to 37.92 nm, P = 0.004). Significant correlations were found between changes in the parameters of ASB and BCVA. Furthermore, RNFL measurements (nerve fibre indicator, temporal-superior-nasal-inferior-temporal average and superior average) were also well related to the CPA and CPM shifts. Conclusions: PCO induces an inaccurate compensation of ASB which affects RNFL assessment. Thus, it is necessary to recompensate ASB after Posterior capsulotomy.
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effect of Posterior Capsular Opacification removal on automated perimetry
Eye, 2006Co-Authors: Jose Javier Garciamedina, Manuel Garciamedina, M T Arbonanadal, Maria Dolores PinazoduranAbstract:Although Posterior Capsular Opacification (PCO) is a common phenomenon in a considerable number of ophthalmologic patients, no prospective controlled trials assessing its influence on automated perimetry exist. This technique continues as a standard in the diagnosis of glaucoma and neuro-ophthalmological diseases. The aim of the present report is to investigate the effect of PCO on automated visual field examination. A total of 26 PCO affected eyes of 26 patients had Humphrey SITA standard (program 24-2) immediately before, and between 1 and 8 weeks after Neodymium : YAG capsulotomy. The effect of learning associated with repeated testing was controlled with automated perimetry before enrolment and visual fields of the fellow eye. Best-corrected visual acuity (BCVA), intraocular pressure (IOP), and global perimetric pre- and post-laser indices were compared using the Student's t-test for paired samples. Correlation and linear regression analyses were also performed. BCVA and mean deviation (MD) improved following capsulotomy. Pattern standard deviation (PSD), an indicator of localized defects in the field, also improved significantly when PCO was solved. Moreover, a strong association among BCVA, MD, and PSD was shown both prior to and after capsulotomy. PCO is a heterogeneous mean opacity. This polymorphism may alter visual field results, and may even simulate the perimetric behaviour of other pathologies such as glaucoma. Consequently, the presence of PCO should be considered in the interpretation of any automated perimetry in pseudophakic patients. In addition, the values obtained before capsulotomy may partially predict the values obtained after capsulotomy.
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effect of Posterior Capsular Opacification removal on scanning laser polarimetry measurements
Graefes Archive for Clinical and Experimental Ophthalmology, 2006Co-Authors: Jose Javier Garciamedina, Manuel Garciamedina, Samuel Gonzalezocampo Dorta, Maria Dolores Pinazoduran, Roberto Gallegopinazo, Vicente ZanonmorenoAbstract:Purpose To evaluate the effect of Posterior Capsular Opacification (PCO) on retinal nerve fiber layer (RNFL) retardation measurements obtained during scanning laser polarimetry (SLP). We are unaware of previous studies undertaken in this sense.