R. M. M. A. Nuijts

Evaluation of the Lenstar LS 900 non-contact biometer.

Background/aims: Evaluation of the reproducibility of the Lenstar LS 900 non-contact biometer, and a comparison with the Visante anterior-segment optical coherence tomography (AS-OCT) and the IOLMaster. Methods: Central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), keratometry (K) values, corneal diameter (CD) and axial length (AL) were obtained in 38 healthy volunteers (76 eyes) to determine the reproducibility of the Lenstar. CCT, ACD, CD, K values and AL measurements measured with the Lenstar were compared with the AS-OCT and IOLMaster. Intraocular lens (IOL) power calculations were done to study the significance of the difference between AL measurements. Results: The reproducibility of the Lenstar was better than 0.9% for CCT, ACD, LT, K values and AL measurements. Although all correlations were highly significant (p<0.001), all comparisons showed a significant difference, except for the comparison of CD measurements using the Lenstar and IOLMaster (pu200a=u200a0.175). The differences in IOL power calculations for an AL of 20, 25 and 30 mm with a mean difference between Lenstar and IOLMaster AL measurements of 0.03 mm, were 0.13 D, 0.10 D and 0.08 D, respectively. Conclusion: The reproducibility of the Lenstar was excellent. Small but significant differences exist between the Lenstar, Visante OCT and the IOLMaster. Therefore, measurements of the Lenstar, AS-OCT and IOLMaster are not interchangeable. Despite the significant difference between AL measurements, there is no clinically significant difference in the IOL power calculation results.

Endothelial cell loss and visual outcome of deep anterior lamellar keratoplasty versus penetrating keratoplasty: a randomized multicenter clinical trial

OBJECTIVEnTo compare endothelial cell (EC) loss, visual and refractive outcomes, and complications after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK).nnnDESIGNnRandomized, multicenter clinical trial.nnnPARTICIPANTSnFifty-six eyes of 56 patients with a corneal stromal pathology not affecting the endothelium were randomized to DALK or PK.nnnMETHODSnThe DALK procedure was performed according to Anwars big-bubble technique. Patients underwent an ophthalmic examination preoperatively and 3, 6, and 12 months postoperatively.nnnMAIN OUTCOME MEASURESnEndothelial cell loss, refractive and topographic astigmatism, spherical equivalent, uncorrected visual acuity, and best spectacle-corrected visual acuity (BSCVA) were measured, and complications were recorded.nnnRESULTSnEndothelial cell loss was significantly higher after PK compared with DALK procedures performed without perforation of Descemets membrane (12 months: 27.7% ± 11.1% vs. 12.9% ± 17.6%). The BSCVA was significantly better in the PK group at 3 and 6 months after surgery but was not significantly different 12 months after surgery (0.39 ± 0.3 logarithm of the minimum angle of resolution [logMAR] in DALK and 0.31 ± 0.3 logMAR in PK). At 12 months postoperatively, refractive and topographic astigmatism in the DALK and PK groups were -3.37 ± 2.3 diopters (D) and -3.76 ± 2.1 D (P = 0.53), and 3.57 ± 2.3 D and 4.16 ± 2.0 D (P = 0.34), respectively. (Micro)perforation of the Descemets membrane occurred in 32% (9/28) of the DALK eyes, and 18% (5/28) of the patients required conversion to PK. Endothelial cell loss was not significantly different between DALK and PK when cases with perforation of Descemets membrane were included in the (intention-to-treat) analysis (12 months: 19.1 ± 21.6 vs. 27.7 ± 11.1 P = 0.112). Rejection episodes were reported in 1 patient in the DALK group (epithelial rejection) and 3 patients in the PK group (all endothelial rejections). No graft failure occurred.nnnCONCLUSIONSnOne year after DALK performed without perforation of Descemets membrane, EC loss is significantly lower, whereas the BSCVA is comparable to that in the PK group. In addition, no endothelial rejection occurred in the DALK group. However, Descemets membrane perforation remains a major complication in DALK and warrants improvements to standardize the big-bubble technique.

Accuracy of toric intraocular lens implantation in cataract and refractive surgery

PURPOSE: To determine the accuracy of a commonly used 3‐step procedure for toric pseudophakic and phakic intraocular lens (IOL) implantation. SETTING: University Eye Clinic, Maastricht University Medical Centre, Maastricht, The Netherlands. DESIGN: Cohort study. METHOD: In this analysis of toric IOL implantation, 6 preoperative images of the eye per patient and the surgery video were obtained using a digital imaging system. All 3 steps for toric IOL implantation were analyzed as follows: reference axis marking, alignment axis marking, and IOL alignment. In addition, vector analysis was used to calculate the errors in toric IOL alignment. RESULTS: Forty eyes (26 pseudophakic, 14 phakic) were analyzed. The mean errors in reference axis marking, alignment axis marking, and toric IOL alignment were 2.4 degrees ± 0.8 (SD), 3.3 ± 2.0 degrees, and 2.6 ± 2.6 degrees, respectively. Together, these 3 errors led to a mean total error in toric IOL alignment of 4.9 ± 2.1 degrees. Subgroup analysis showed no significant difference in mean error between pseudophakic IOL and phakic toric IOL alignment (P=.501). Vector analysis showed a mean angle or error of −2 ± 8 degrees (pseudophakic IOLs) and 6 ± 14 degrees (phakic IOLs). CONCLUSIONS: A commonly used 3‐step ink‐marker procedure to implant toric IOLs led to a mean error in IOL placement of approximately 5 degrees. The error was especially relevant in cases in which higher cylinder power IOLs were implanted. Orienting the toric IOL with great accuracy is necessary in all patients to achieve the best cylinder correction. Financial Disclosure: Drs. Visser, Berendschot, Bauer, and Nuijts have no financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Evaluation of the comparability and repeatability of four wavefront aberrometers.

PURPOSEnTo compare total ocular aberrations and corneal aberrations identified with four different aberrometers and to determine the repeatability and interobserver variability.nnnMETHODSnIn this prospective comparative study, 23 healthy subjects underwent bilateral examination with four aberrometers: the Irx3 (Hartmann-Shack; Imagine Eyes, Orsay, France), Keratron (Hartmann-Shack; Optikon, Rome Italy), iTrace (ray-tracing; Tracey Technologies, Houston, TX), and OPD-Scan (Automated Retinoscopy; Nidek, Gamagori, Japan). Six images per eye were obtained. Second-, third- and fourth-order spherical aberrations were exported for 5.0-mm pupils.nnnRESULTSnSignificant differences in measurements were found for several total ocular aberrations (defocus [2,0], astigmatism [2,2], trefoil [3,-3], trefoil [3,3], and spherical aberration [4,0]) and corneal aberrations (defocus [2,0] and astigmatism [2,2]). The Irx3 showed the highest repeatability in measuring total ocular aberrations, followed by the Keratron, OPD-Scan, and iTrace. The repeatability of the corneal aberration measurements was highest for the iTrace, followed by the Keratron and OPD-Scan. The OPD-Scan showed a lower interobserver variability, compared with the Irx3, Keratron, and iTrace.nnnCONCLUSIONSnTotal ocular and corneal aberrations are not comparable when measured with different aberrometers. Hartmann-Shack aberrometers showed the best repeatability for total ocular aberrations and iTrace for corneal aberrations. It would be worthwhile in the future to evaluate aberrometers in patients with more aberrant eyes.

Comparability and repeatability of corneal astigmatism measurements using different measurement technologies

PURPOSE: To determine the comparability and repeatability of corneal astigmatism measurements obtained with different devices and determine the interobserver variability of a new automated keratometer. SETTING: University Eye Clinic Maastricht, the Netherlands. DESIGN: Prospective cohort study. METHODS: The right eye of healthy subjects was examined with the following 6 devices: IOLMaster (automated keratometry), Lenstar (automated keratometry), SMI Reference Unit 3 (automated keratometry), Javal (manual keratometry), KR‐1W (corneal topography), and Pentacam (Scheimpflug imaging). An experienced operator obtained 3 repeated measurements. An inexperienced operator obtained additional measurements with the SMI Reference Unit 3. Astigmatism vector analysis was used to determine the comparability, repeatability, and interobserver variability. RESULTS: Corneal astigmatism vectors measured by automated, manual, or simulated keratometry were comparable except for the Pentacam equivalent keratometry (K) (P<.001, repeated‐measures analysis of variance [ANOVA]). The mean difference between the equivalent K and other K values was 0.18 to 0.29 diopter (D) (P<.05, Hotelling trace multivariate ANOVA). The mean differences between automated, manual, and simulated keratometry were small (≤0.12 D). The within‐subject standard deviation ranged from 0.05 D @ 21 degrees (KR‐1W) to 0.18 D @ 23 degrees (Lenstar). The SMI Reference Unit showed small mean differences and comparable repeatability between the experienced operator and the inexperienced operator. CONCLUSIONS: Vector analysis showed comparable corneal astigmatism measurements using automated, manual, and simulated keratometry. Pentacam equivalent K values were not comparable with those of the other keratometers. The repeatability of astigmatism magnitudes was acceptable; however, the repeatability of astigmatism meridians was moderate. The SMI Reference Unit showed good interobserver variability. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Femtosecond laser-assisted inverted mushroom keratoplasty.

PURPOSEnTo evaluate best-corrected visual acuity (BCVA), refractive outcome, corneal topography, optical coherence tomography, and endothelial cell density 12 months after femtosecond laser-assisted inverted mushroom keratoplasty.nnnMETHODSnWe performed a prospective study of a surgical case series of 5 patients undergoing femtosecond laser-assisted inverted mushroom keratoplasty for pseudophakic bullous keratopathy or pre-Descemet X-linked ichthyosis. The femtosecond laser was used to create a top-hat configuration in the donor cornea and recipient cornea. Laser parameters were as follows: energy, 4.0 (anterior inner vertical side cut and horizontal lamellar cut) and 7.0 microJ (posterior outer vertical side cut); spiral pattern with a firing rate of 15 kHz. The size of the anterior inner diameter was 7.4 mm in the donor cornea and 7.0 mm in the recipient cornea. The posterior outer diameter was 9.0 mm in all eyes.nnnRESULTSnAt 6 and 12 months after surgery, all corneal grafts were clear and showed an excellent adaptation of the lamellar donor and recipient wound surfaces. At 12 months postoperatively, BCVA averaged 20/32 (range, 20/60-20/20), refractive cylinder averaged -3.20 +/- 2.0 D, topographical cylinder averaged 3.26 +/- 2.1 D, and the mean endothelial cell density was 1793 +/- 491 cells/mm2 (range, 954-2237 cells/mm2). The mean central corneal thickness and thickness of the posterior shelf was 517 +/- 3 and 175 +/- 8 microm, respectively.nnnCONCLUSIONSnThe femtosecond laser-assisted inverted mushroom keratoplasty shows good promise in surgical treatment of corneal diseases. The multiplanar fit between the donor and recipient cornea allows early suture removal and visual rehabilitation.

Quality of care from the perspective of the cataract patient: the reliability and validity of the QUOTE-Cataract

Background/aims: To assess reliability and validity of the QUOTE-cataract, a questionnaire that measures the quality of care from the perspective of cataract patients. Methods: The QUOTE-cataract was tested in a multicentre study among 540 cataract patients in three different hospitals. Reliability was represented by internal consistency (Cronbach’s α), and repeatability (intraclass correlation coefficient (ICC)). Validity was evaluated qualitatively and by factor analyses. Results: A strong internal consistency coefficient (0.89), and high repeatability (ICC = 0.76) demonstrated good reliability. Content validity was assured by involvement of patients in the development of the questionnaire. Factor analysis confirmed an underlying taxonomy of generic and disease specific items. Conclusion: The QUOTE-cataract has good reliability and provides a valid assessment of quality of care in cataract surgery.

Treatment of negative dysphotopsia with supplementary implantation of a sulcus-fixated intraocular lens

PurposeOur aim was to evaluate the resolution of negative dysphotopsia after supplementary implantation of a sulcus-fixated intraocular lens (IOL).MethodsThis was a retrospective case series. Patients with severe negative dysphotopsia were treated with supplementary implantation of the Rayner Sulcoflex Aspheric (653xa0L) IOL. Primary outcome measurements were subjectively reported complaints of dysphotopsia, best corrected distance visual acuity (CDVA), iris-IOL distance, anterior chamber depth (ACD) and volume (ACV), angle opening distance and trabecular-iris space area at 500 and 750xa0μm.ResultsA Rayner Sulcoflex IOL was implanted in seven patients (nine eyes) with negative dysphotopsias. Symptoms resolved completely in six eyes, partially in one eye and remained unchanged in two eyes. We did not find any significant changes in CDVA. Angle opening distance, ACD, ACV and iris-IOL distance reduced significantly after Sulcoflex IOL implantation.ConclusionsSupplementary implantation of a Sulcoflex IOL can successfully treat negative dysphotopsia. The decrease in anterior segment dimensions in combination with the displacement of light rays by the rounded edges of a Sulcoflex IOL may contribute to the resolution of symptoms.

Cost effectiveness of foldable multifocal intraocular lenses compared to foldable monofocal intraocular lenses for cataract surgery

Aim: To analyse the cost effectiveness of foldable monofocal intraocular lenses (IOLs) compared to foldable multifocal IOLs in cataract surgery alongside a prospective, multicentre randomised clinical trial (RCT). Methods: Patients underwent cataract surgery with bilateral monofocal (nu200a=u200a97) or multifocal (nu200a=u200a93) IOL implantation. Cost data and patient preferences, using the visual analogue scale (VAS), the time trade-off (TTO), and the standard gamble (SG) technique were obtained preoperatively and postoperatively by structured interviews. The incremental costs (multifocal minus monofocal), mean costs per patient, and differences in preferences were computed. Results: Mean costs for glasses per patient in the monofocal group were €41.67 and in the multifocal group €149.58. The difference in costs between the multifocal and monofocal group was €−92.09 and was statistically significant (pu200a=u200a0.008). No significant differences were found in total costs or in effectiveness between the monofocal and multifocal IOL group. Conclusion: The cost effectiveness of multifocal IOLs is reduced to a cost minimisation analysis, because of the inability to demonstrate significant differences in effects. The use of multifocal IOLs in cataract surgery resulted in a significant reduction in costs for patient’s postoperative spectacles.

Objective evaluation of negative dysphotopsia with Goldmann kinetic perimetry

Purpose To compare the extension of peripheral visual fields in phakic and pseudophakic patients and to evaluate whether Goldmann kinetic perimetry can be used as an objective measure of negative dysphotopsia. Setting University Eye Clinic, Maastricht University Medical Centre, Maastricht, the Netherlands. Design Prospective and case‐control study. Methods Kinetic perimetry was performed with V4e and I4e stimuli. Visual fields were assessed in the following 4 quadrants: superior temporal, superior nasal, inferior temporal, and inferior nasal. In the control group, patients were evaluated before and 1 month after cataract surgery. Biometric and perimetric data in the control group were compared with data in the patients with negative dysphotopsia (study group). Results Each group comprised 10 patients. In the control group, the extension of visual field did not change after surgery. Patients in the study group had a significantly shorter axial length and higher intraocular lens powers than those in the control group. The inferior temporal and inferior nasal quadrants were, respectively, 10 degrees and 6 degrees (P < .05) smaller in the study group than in the control group. In 3 patients with negative dysphotopsia, a shadow was drawn in the superior temporal and the inferior temporal quadrants during perimetry and the position of this shadow matched their subjective description of negative dysphotopsia. Conclusions The peripheral visual field did not change after cataract surgery in patients without negative dysphotopsia. Kinetic perimetry can be used for objective evaluation of patients with negative dysphotopsia because these patients had constricted peripheral visual fields or a relative temporal scotoma corresponding to the position of the shadow. Financial Disclosure Proprietary or commercial disclosures are listed after the references.