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Dive into the research topics where Carroll A.B. Webers is active.

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Featured researches published by Carroll A.B. Webers.


Journal of Cataract and Refractive Surgery | 2008

Astigmatism management in cataract surgery with the AcrySof toric intraocular lens.

Noel Bauer; Niels E. de Vries; Carroll A.B. Webers; Fred Hendrikse; Rudy M.M.A. Nuijts

PURPOSE: To present clinical data from a single‐center prospective clinical trial of the AcrySof toric intraocular lens (IOL). SETTING: Academic Hospital Maastricht, Maastricht, The Netherlands. METHODS: Fifty‐three eyes (43 patients) had implantation of an AcrySof toric IOL. Three toric models were evaluated in cylinder powers of 1.50 diopters (D) (SN60T3; T3 group, n = 16), 2.25 D (SN60T4; T4 group, n = 14), and 3.00 D (SN60T5; T5 group, n = 23) at the IOL plane. The T5 group was subdivided into eyes that could be fully corrected (T5a, n = 13) and eyes that could be partially corrected (T5b, n = 10). RESULTS: Four months postoperatively, the mean uncorrected visual acuity (UCVA) was 0.77 ± 0.23 in the T3 group, 0.93 ± 0.23 in the T4 group, 0.82 ± 0.15 in the T5a group, and 0.47 ± 0.13 in the T5b group. More than 90% of the combined eyes in the T3, T4, and T5a groups achieved a UCVA of 20/40 or better, and almost 80% achieved a UCVA of 20/25 or better. Residual refractive astigmatism of less than 0.75 D was achieved in 74% of eyes and of less than 1.00 D in 91%. The mean IOL misalignment was 2.5 ± 2.1 degrees in the T3 group, 3.5 ± 2.3 degrees in the T4 group, and 4.1 ± 3.5 degrees in the T5 group. CONCLUSION: Implantation of the AcrySof toric IOL proved to be an effective, safe, and predictable method of managing corneal astigmatism in cataract patients.


Journal of Cataract and Refractive Surgery | 2011

Dissatisfaction after implantation of multifocal intraocular lenses

Niels E. de Vries; Carroll A.B. Webers; Wouter Touwslager; Noel Bauer; John de Brabander; Tos Tjm Berendschot; Rudy M.M.A. Nuijts

PURPOSE: To analyze the symptoms, etiology, and treatment of patient dissatisfaction after multifocal intraocular lens (IOL) implantation. SETTING: Department of Ophthalmology, Maastricht University Medical Center, The Netherlands. DESIGN: Case series. METHODS: In this retrospective chart review, the main outcome measures were type of complaints, uncorrected and corrected distance visual acuities, uncorrected and distance‐corrected near visual acuities, refractive state, pupil diameter and wavefront aberrometry measurements, and type of treatment. RESULTS: Seventy‐six eyes of 49 patients were included. Blurred vision (with or without photic phenomenon) was reported in 72 eyes (94.7%) and photic phenomena (with or without blurred vision) in 29 eyes (38.2%). Both symptoms were present in 25 eyes (32.9%). Residual ametropia and astigmatism, posterior capsule opacification, and a large pupil were the 3 most significant etiologies. Sixty‐four eyes (84.2%) were amenable to therapy, with refractive surgery, spectacles, and laser capsulotomy the most frequent treatment modalities. Intraocular lens exchange was performed in 3 cases (4.0%). CONCLUSION: The cause of dissatisfaction after implantation of a multifocal IOL can be identified and effective treatment measures taken in most cases. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.


American Journal of Ophthalmology | 2009

Use of Anterior Segment Optical Coherence Tomography to Study Corneal Changes After Collagen Cross-linking

Muriël Doors; Nayyirih G. Tahzib; Fred A.G.J. Eggink; Tos T. J. M. Berendschot; Carroll A.B. Webers; Rudy M.M.A. Nuijts

PURPOSE To investigate the stromal demarcation line after corneal cross-linking using anterior segment optical coherence tomography (AS-OCT) and its influence on the short-term results of cross-linking in patients with progressive keratoconus. DESIGN Prospective, nonrandomized study. METHODS Twenty-nine eyes of 29 patients with progressive keratoconus (n = 28) or after laser in situ keratomileusis ectasia (n = 1) were included and treated with corneal cross-linking at our institution. Measurements at 1, 3, 6, and 12 months after corneal cross-linking were: refraction, best-corrected visual acuity (BCVA), tonometry, corneal topography, AS-OCT, specular microscopy, and aberrometry. Demarcation line depth was measured centrally, 2 mm temporally, and 2 mm nasally by two independent observers using AS-OCT and was correlated with clinical parameters. RESULTS The stromal demarcation line was visible with AS-OCT at 1 month after surgery in 28 of 29 eyes. Pairwise comparisons between the two observers of the AS-OCT measurements did not show a statistically significant difference. After an initial steepening of maximal keratometry values and a decrease in BCVA at 1 month after surgery (both with P < .012), no significant changes were found at 3, 6, and 12 months after surgery compared with before surgery. Refractive cylinder, topographic astigmatism, aberration values, endothelial cell density, and intraocular pressure remained stable during all postoperative visits. A deeper demarcation line depth was associated with a larger decrease in corneal thickness (r = -0.506; P = .012). CONCLUSIONS AS-OCT is a useful device to detect the stromal demarcation line after corneal cross-linking. At 3 to 12 months follow-up, all clinical parameters remained stable, indicating stabilization of the keratoconic disease.


Eye | 2010

The relationship between visual field loss in glaucoma and health-related quality-of-life

A van Gestel; Carroll A.B. Webers; Henny J. M. Beckers; M C J M van Dongen; Johan L. Severens; Fred Hendrikse; Jan S. A. G. Schouten

PurposeTo investigate the relationship between visual field loss and health-related quality-of-life (HRQOL) in patients with ocular hypertension (OHT) or primary open-angle glaucoma (POAG).MethodsWe conducted a cross-sectional study among 537 OHT and POAG patients from seven hospitals in The Netherlands. Clinical information was obtained from medical files. Patients completed a questionnaire, containing generic HRQOL instruments (EQ-5D and Health Utilities Index mark 3), vision-specific National Eye Institute Visual Functioning Questionnaire (VFQ-25), and glaucoma-specific Glaucoma Quality-of-Life questionnaire (GQL-15). The impact of visual field loss on HRQOL scores was analysed with multiple linear regression analyses.ResultsA relationship between mean deviation (MD) and HRQOL was found after adjusting for age, gender, visual acuity, medication side effects, laser trabeculoplasty, and glaucoma surgery. We found interaction between MD in both eyes for GQL and VFQ-25 scores. The relationship between MD and utility was non-linear, with utility only affected at MD-values below −25 dB in the better eye. Visual acuity, side effects, and glaucoma surgery independently affected HRQOL. Binocular MD and MD in the better eye had similar impacts on HRQOL, whereas MD in the worse eye had an independent effect. HRQOL was affected more by binocular defects in the inferior than in the superior hemifield.ConclusionVisual field loss in progressing glaucoma is independently associated with a loss in both disease-specific and generic quality-of-life. It is important to prevent progression, both in early and in advanced glaucoma, especially in patients with inferior hemifield defects and severe defects in either eye.


American Journal of Ophthalmology | 1993

Hyperhomocysteinemia in Retinal Artery and Retinal Vein Occlusion

Erwin M. Wenzler; Adrianus J.J.M. Rademakers; Godfried H.J. Boers; J. R. M. Cruysberg; Carroll A.B. Webers; August F. Deutman

In 19 patients who had retinal vein occlusion or retinal artery occlusion before the age of 50 years, the incidence of hyperhomocysteinemia, as observed in heterozygosity for homocystinuria, was studied by the performance of a standardized, oral methionine-loading test. In four of the 19 patients (21%), two with retinal artery occlusion and two with central retinal vein occlusion, the after-load peak levels of homocysteine exceeded the mean level, established in normal control subjects, by more than two standard deviations and were as well within the ranges established in obligate heterozygotes for homocystinuria. Because the frequency of heterozygosity for homocystinuria in the normal population is one in 70 (1.4%) at the most, we conclude that hyperhomocysteinemia predisposes to the development of premature retinal artery and retinal vein occlusion (P < .01; chi 2 test).


Journal of Cataract and Refractive Surgery | 2008

Intraocular straylight after implantation of the multifocal AcrySof ReSTOR SA60D3 diffractive intraocular lens.

Niels E. de Vries; Luuk Franssen; Carroll A.B. Webers; Nayyirih G. Tahzib; Yanny Y.Y. Cheng; Fred Hendrikse; Khiun Tjia; T. Berg; Rudy M.M.A. Nuijts

PURPOSE: To measure intraocular straylight (as a measure of glare) after cataract surgery and implantation of an AcrySof ReSTOR SA60D3 multifocal or AcrySof SA60AT monofocal intraocular lens (IOL) (both Alcon Laboratories). SETTING: University Hospital Maastricht, Maastricht; Isala Clinics, Zwolle; Netherlands Institute for Neurosciences, Amsterdam, The Netherlands. METHODS: In a prospective open observational case series, a newly developed straylight meter was used to objectively measure straylight 6 months postoperatively in 66 eyes with a diffractive AcrySof ReSTOR SA60D3 IOL (multifocal group) and 40 eyes with a monofocal AcrySof SA60AT IOL (monofocal group). A comparison of straylight levels in an age‐matched population without cataract (control group) was performed. RESULTS: The straylight level was 1.20 log units ± 0.16 (SD) in the multifocal group and 1.10 ± 0.19 log units in the monofocal group. When the difference in mean level of straylight was adjusted for age, mean straylight levels were 0.078 log units lower in the monofocal group than in the multifocal group (P = .026). Straylight levels in both pseudophakic groups were lower than in the control group without cataract (P<.0001). CONCLUSIONS: Levels of intraocular straylight log(s) were significantly lower for both types of IOL than in age‐matched subjects from the normal population. The mean level of intraocular straylight 6 months postoperatively was higher in patients with an AcrySof ReSTOR SA60D3 IOL than in patients with a monofocal AcrySof SA60AT IOL. Implantation of the former IOL would therefore result in a smaller gain in contrast sensitivity and a smaller reduction in glare and halos than implantation of the latter IOL.


Ophthalmology | 2013

An evidence-based review of prognostic factors for glaucomatous visual field progression.

Paul J. G. Ernest; Jan S. A. G. Schouten; Henny J. M. Beckers; Fred Hendrikse; Martin H. Prins; Carroll A.B. Webers

PURPOSE To examine which prognostic factors are associated with glaucomatous visual field progression. DESIGN Knowledge of prognostic factors helps clinicians to select patients at risk of glaucomatous visual field progression and intensify their treatment. METHODS By consulting relevant databases, we identified 2733 articles published up to September 2010, of which 85 articles investigating prognostic factors for visual field progression in patients with open-angle glaucoma (OAG) were eligible. We summarized results for each factor in tables, noting the direction of the association between the prognostic factor and progression, and the accompanying P value. Four authors, working blind to the factors, independently judged the extent to which a prognostic factor was associated with glaucomatous visual field progression. If there were different associations for normal-tension glaucoma (NTG) studies, they were judged separately. Consensus was reached during group meetings. MAIN OUTCOME MEASURES A ranking of all studied prognostic factors for glaucomatous visual field progression according to their likelihood of being prognostic. RESULTS A total of 103 different prognostic factors were investigated in 85 articles. The following factors were clearly associated with glaucomatous visual field progression: age, disc hemorrhages (for NTG), baseline visual field loss, baseline intraocular pressure (IOP), and exfoliation syndrome. An association was unlikely for family history of glaucoma, atherosclerosis, systemic hypertension, visual acuity, sex (for NTG), systolic blood pressure, myopic refractive error (for NTG), and Raynauds phenomenon. CONCLUSIONS The factors we found clearly associated with progression could be used in clinical practice and for developing clinical prediction models. For many other factors, further research is necessary.


Journal of Cataract and Refractive Surgery | 2010

Value of optical coherence tomography for anterior segment surgery

Muriël Doors; Tos T. J. M. Berendschot; John de Brabander; Carroll A.B. Webers; Rudy M.M.A. Nuijts

&NA; Anterior segment optical coherence tomography (AS‐OCT) is an important new noncontact imaging technology that uses a 1310 nm super luminescent diode. It can be used to assess anterior chamber biometry, corneal thickness, lens thickness, and angle configuration; to visualize pathological processes; to evaluate postsurgical anatomy and posttraumatic eyes; and to image phakic intraocular lenses and intracorneal ring segments. Because it is a noncontact technique, it can also be used intraoperatively, which could be useful during trabeculectomy and after deep anterior lamellar keratoplasty to detect abnormalities in the cornea and interface. A disadvantage of AS‐OCT is its inability to penetrate the iris pigment epithelium, which makes it impossible to evaluate the structures behind the iris. The most frequently used devices are time‐domain AS‐OCT, but new Fourier‐domain OCT devices, which have faster image acquisition and higher resolution, are currently under investigation. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.


Journal of Cataract and Refractive Surgery | 2010

Visual outcomes after cataract surgery with implantation of a +3.00 D or +4.00 D aspheric diffractive multifocal intraocular lens: Comparative study

Niels E. de Vries; Carroll A.B. Webers; Robert Montés-Micó; Teresa Ferrer-Blasco; Rudy M.M.A. Nuijts

PURPOSE: To compare the visual performance after cataract surgery with implantation of +3.00 diopter (D) or +4.00 D aspheric multifocal intraocular lenses (IOLs). SETTING: Department of Ophthalmology, Maastricht University Medical Center, The Netherlands. METHODS: This prospective study compared the results of bilateral cataract surgery with implantation of a +3.00 D AcrySof ReSTOR SN6AD1 IOL or a +4.00 D AcrySof ReSTOR SN6AD3 IOL. The main outcome measures were binocular uncorrected (UDVA) and corrected distance visual acuities, binocular uncorrected (UNVA) and corrected near visual acuities, binocular uncorrected (UIVA) and corrected intermediate visual acuities, preferred working distance, straylight and contrast sensitivity levels, and wavefront aberrometry measurements. RESULTS: The +3.00 D IOL was implanted in 68 eyes and the +4.00 D IOL, in 46 eyes. The UIVA was significantly better in the +3.00 D IOL group than in the +4.00 D IOL group at 40, 50, 60, and 70 cm. The preferred working distance for near tasks was significantly lower in the +3.00 D IOL group (38.9 cm) than in the +4.00 D IOL group (31.0 cm). The UDVA was better in the +3.00 D IOL group; the UNVA at the preferred working distance was similar in the 2 groups. Contrast sensitivity and intraocular straylight levels were also similar. The mean levels of higher‐order and spherical aberrations were lower in the +3.00 D IOL group. CONCLUSION: Cataract surgery with the +3.00 D IOL resulted in better intermediate vision than with the +4.00 D model without compromising distance and near visual acuity. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.


Journal of Clinical Epidemiology | 2009

A network meta-analysis combined direct and indirect comparisons between glaucoma drugs to rank effectiveness in lowering intraocular pressure

Rikkert van der Valk; Carroll A.B. Webers; Thomas Lumley; Fred Hendrikse; Martin H. Prins; Jan S. A. G. Schouten

OBJECTIVE It is difficult to rank treatments according to their effect size when several treatments are available and not all treatments have been compared directly. The purpose of this study was to show a new statistical technique (network meta-analysis) to address this problem and to rank glaucoma drugs according to their intraocular pressure (IOP)-reducing effect. STUDY DESIGN AND SETTING Network meta-analysis of randomized controlled trials was used to combine direct and indirect estimates of the effect of eight drugs and placebo from 28 randomized controlled trials in patients with primary open-angle glaucoma or ocular hypertension patients, 6,841 for the peak effect and 6,953 patients for the trough effect. RESULTS All drugs differ from placebo in lowering IOP. At the peak, the rank order from high to low in terms of the mean IOP reduction reached is bimatoprost, travoprost and latanoprost, brimonidine, timolol, dorzolamide, betaxolol, brinzolamide. At the trough, this rank order is bimatoprost, latanoprost, travoprost, timolol, betaxolol, dorzolamide, brinzolamide, brimonidine. The results based on direct or indirect estimates were similar. This ranking differed from the ranking based on the mean IOP change from baseline of all arms including the study drug from all randomized controlled trials. CONCLUSIONS A network meta-analysis can be used to combine direct and indirect treatment effects in a formal way. Applied to glaucoma medications, it shows that there is a rank order in treatment effects on IOP.

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Harsha L. Rao

L V Prasad Eye Institute

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Johan L. Severens

Erasmus University Rotterdam

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