M.P. Holzer

Intraocular lens power calculation: clinical comparison of 2 optical biometry devices.

PURPOSE: To evaluate intraocular lens (IOL) power calculation using a new optical low‐coherence reflectometry (OLCR) biometer and compare the results with those obtained with a partial coherence interferometry (PCI) optical biometer. SETTING: International Vision Correction Research Centre, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. METHODS: Biometry measurements in eyes of cataract patients were performed by the same examiner with an OLCR biometer (Lenstar LS 900/Allegro Biograph) and a PCI optical biometer (IOLMaster). After determination of axial length (AL), corneal radii values by keratometry (R1 and R2), and anterior chamber depth (ACD), power calculation for an AcrySof MA60AC IOL was compared between the 2 devices using 4 formulas and the corresponding IOL constants. The target was emmetropia. RESULTS: One hundred eyes of 100 cataract patients (mean age 70.0 years ± 10.6 [SD]) were measured. Of the biometry parameters, the only statistically significant differences between the 2 devices were in R2 (mean difference 0.02 ± 0.05 mm), (R1 + R2)/2 (mean difference 0.01 ± 0.04 mm), and ACD (mean difference 0.05 ± 0.11 mm) (P<.01, Wilcoxon test). The mean differences in IOL power calculations using the 4 formulas were not statistically significant between the 2 devices (P>.01, Wilcoxon test). CONCLUSION: The OLCR biometry device provided precise and valid measurements and thus can be used for the preoperative examination of cataract patients. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Combination of transepithelial phototherapeutic keratectomy and autologous serum eyedrops for treatment of recurrent corneal erosions

PURPOSE: To evaluate the clinical outcomes after transepithelial phototherapeutic keratectomy (t‐PTK) using an excimer laser and postoperative administration of autologous serum eyedrops. SETTING: Department of Ophthalmology, Ruprecht‐Karls‐University of Heidelberg, Heidelberg, Germany. METHODS: Twenty‐five eyes of 25 patients with 3 to 12 recurrent corneal erosions were treated with t‐PTK using the Schwind Keratom broad‐beam excimer laser (Schwind). Routine therapy consisted of 2 pulses × 40 pulses (18.82 ± 2.56 μm ablation). Postoperatively, autologous serum eyedrops were administered 6 times a day for 6 weeks. Postoperative outcomes and rate of recurrent erosions were evaluated. RESULTS: The median of the follow‐up after t‐PTK was 15.5 months (range 6 to 20 months), and the mean age of the patients was 40.6 years ± 12.0 (SD). Twenty of 25 eyes (80%) recovered without further corneal erosion. Five eyes had 1 further erosion, which was treatable in 4 cases with autologous serum eyedrops without additional excimer laser treatment. One patient requested additional t‐PTK treatment and recovered without further complications thereafter. CONCLUSIONS: Transepithelial phototherapeutic keratectomy is a safe and effective therapy for recurrent corneal erosions. Additional treatment with autologous serum eyedrops can support the healing process following corneal erosions and t‐PTK and can be given as a long‐term artificial tear treatment.

Performance of the 1CU accommodating intraocular lens in relation to capsulorhexis size

Purpose: To assess the correlation between continuous curvilinear capsulorhexis (CCC) size and visual outcomes in patients with an accommodating intraocular lens (IOL). Setting: Heidelberg IOL and Refractive Surgery Research Group, Department of Ophthalmology, Ruprecht‐Karls‐University of Heidelberg, Heidelberg, Germany. Methods: Nineteen eyes had phacoemulsification and implantation of a 1CU accommodating IOL (HumanOptics AG). Three months after surgery, the uncorrected and best corrected distance and near visual acuities and the distance corrected near visual acuity were measured. Retroillumination photographs were taken to assess CCC size and centration and the amount of overlap between the CCC and IOL optic. The photographs were analyzed using Evaluation of Posterior Capsule Opacification system software. Results: The mean age of the patients was 53.5 years (range 30 to 73 years). The mean uncorrected distance acuity improved from 0.05 preoperatively to 0.70 at 3 months and the best corrected near acuity, from 0.30 to 0.94. The mean postoperative distance corrected near acuity was 0.5 (range 0.1 to 1.0), which improved to 0.9 with near correction. The mean CCC size (4.3 mm) and amount of CCC decentration (0.35 mm) did not correlate with visual outcomes. However, there was a correlation between the amount of CCC–optic overlap (mean 35%; range 16% to 55%) and distance corrected near acuity (r = 0.641, P = .003). Distance corrected near acuity was better with less overlapping; that is, with a larger CCC. Conclusions: A larger capsulorhexis with less CCC–optic overlapping gave better near visual outcomes. Results indicate that an overlap between 25% and 35%, which correlates with a CCC between 4.5 mm and 5.0 mm, provides the best capsule strength without compromising accommodation with the single‐piece 1CU IOL.

Removal times for a dispersive and a cohesive ophthalmic viscosurgical device correlated with intraocular lens material

Purpose: To investigate the removal times of ophthalmic viscosurgical devices (OVDs) with different intraocular lens (IOL) designs and materials. Setting: Center for Research on Ocular Therapeutics and Biodevices, Department of Ophthalmology, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA, and Heidelberg IOL & Refractive Surgery Research Group, Department of Ophthalmology, Ruprecht‐Karls‐University of Heidelberg, Heidelberg, Germany. Methods: In a standardized laboratory setup, the Miyake‐Apple posterior view video technique was used to evaluate OVD removal from capsular bags in human autopsy eyes implanted with poly(methyl methacrylate) (PMMA), silicone, and acrylic IOLs. The cohesive OVD ProVisc® (sodium hyaluronate 1.0%) and the dispersive OVD Viscoat® (sodium hyaluronate 3.0% and chondroitin sulfate 4.0%) were stained with fluorescein for better visualization. The open‐sky preparation and an Alcon Series 20000® Legacy® phaco machine with a flow rate of 25 mL/min and a vacuum setting of +500 mm Hg (maximum irrigation/aspiration) were used. The time needed for complete removal of the cohesive and dispersive OVDs with each IOL type was measured and analyzed statistically. Results: The mean removal times for both OVDs were as follows: Alcon MZ60BD PMMA IOL—25.0 seconds ± 3.7 (SD) (Viscoat), 15.9 ± 6.9 seconds (ProVisc); Alcon AcrySof® MA60BM IOL—35.5 ± 10.0 seconds (Viscoat), 25.6 ± 4.7 seconds (ProVisc); Chiron/Bausch & Lomb C1043 silicone IOL—46.5 ± 10.5 seconds (Viscoat), 17.3 ± 2.1 seconds (ProVisc); AMO SI‐30 silicone IOL—33.5 ± 3.1 seconds (Viscoat), 15.3 ± 6.3 seconds (ProVisc); and Pharmacia 912 silicone IOL—18.3 ± 5.8 seconds (Viscoat), 19.8 ± 4.3 seconds (ProVisc). Conclusions: Differences in OVD removal times were detected. The removal time for the cohesive OVD correlated with the IOL material. Overall, the time needed for complete removal was significantly longer for the dispersive OVD than for the cohesive OVD.

Precision of NIDEK OPD-scan measurements.

PURPOSE To evaluate the repeatability of wavefront measurements using the NIDEK OPD-Scan. METHODS A total of 179 eyes from 90 healthy volunteers (57 women and 33 men) with no corneal or lenticular pathology and normal visual acuity were enrolled in this study. Mean patient age was 39 years (range: 17 to 85 years). All patients underwent four consecutive measurements by one examiner with the NIDEK OPD-Scan. Total, corneal, and internal wavefront errors were measured and calculated with the device, using slit retinoscopy. Repeatability of the measurements was evaluated for spherical aberration, coma, and trefoil. RESULTS The repeatability test revealed a good result for all three higher order aberrations evaluated. The best repeatability values were found for total aberrations, followed by internal and corneal aberrations. CONCLUSIONS The NIDEK OPD-Scan has good precision in the wavefront measurement of total, corneal, and internal optical aberrations.

Implantation of a multifocal toric intraocular lens with a surface-embedded near segment after repeated LASIK treatments.

UNLABELLED We report a 66-year-old patient who presented with increasing hyperopia, astigmatism, and presbyopia in both eyes 8 years after bilateral laser in situ keratomileusis (LASIK) and LASIK enhancement in the left eye aiming for spectacle independence. Bilateral multifocal toric Lentis Mplus intraocular lenses (IOLs) with an embedded near segment and individually customized cylinder correction were implanted uneventfully following phacoemulsification. The Haigis-L formula after previous hyperopia correction was chosen for IOL power calculation and provided reliable results. Emmetropia was targeted and achieved. Three months postoperatively, the uncorrected distance visual acuity had increased from 0.40 logMAR to 0.10 logMAR in the right eye and from 0.20 logMAR to 0.00 logMAR in the left eye. The patient gained 6 lines of uncorrected near visual acuity: 0.20 logMAR in the right eye and 0.10 logMAR in the left eye. This case shows that customized premium IOL implantation can provide accurate results even in challenging cases. FINANCIAL DISCLOSURE The International Vision Correction Research Centre, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany, has received research grants, lecture fees, and travel reimbursement from Oculentis GmbH.

Bilateral implantation of toric multifocal additive intraocular lenses in pseudophakic eyes

UNLABELLED A 41-year-old patient presented with hyperopia, astigmatism, and presbyopia for refractive treatment 6 years following cataract surgery. A toric multifocal additive intraocular lens with a near addition of +3.5 diopters (D) for sulcus implantation was chosen and implanted uneventfully. Follow-up examinations were performed from the first day until 9 months after surgery. A predictable refractive correction was seen, with a residual error of +0.125 D (spherical equivalent) in the right eye and emmetropia in the left eye. Monocular uncorrected distance visual acuity (UDVA) and uncorrected near visual acuity (UNVA) (40 cm) improved to 0.1 logMAR. It could not be improved further with near-add spectacles. Binocular UDVA and UNVA were 0.0 logMAR and 0.1 logMAR (80 cm), respectively. Both additive IOLs remained centered and on axis during the follow-up period. Spectacle independence was achieved, as was high patient satisfaction. FINANCIAL DISCLOSURE The International Vision Correction Research Centre received research grants related to this publication from the following companies: Dr. Schmidt Intraocularlinsen GmbH, Rayner Intraocular Lenses, Ltd., and Carl Zeiss Meditec AG. No author has a financial or proprietary interest in any material or method mentioned.

Intraocular lens power calculation after intrastromal femtosecond laser treatment for presbyopia: Theoretic approach

PURPOSE: To evaluate the accuracy of intraocular lens (IOL) power calculation after an intrastromal femtosecond laser procedure to treat presbyopia using a theoretic approach. SETTING: International Vision Correction Research Centre, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. DESIGN: Nonrandomized clinical trial. METHODS: Preoperatively and 12 months after intrastromal femtosecond laser treatment (IntraCor) of presbyopia, biometry was performed by partial coherence interferometry (PCI) (IOLMaster). The postoperative keratometry (K) values and IOL power calculation formulas (Holladay I, Haigis, SRK/T, Hoffer Q) were compared with results derived from the clinical history method, taking the manifest refraction change into account. RESULTS: The study enrolled 25 patients (median age 54 years). Three eyes were excluded for age‐related lens changes. The median spherical equivalent change in the other 22 eyes was −0.38 diopter (D). The median difference in K values between the clinical history method and PCI was −0.21 D, resulting in a median IOL power difference between −0.23 D (SRK/T) and −0.29 D (Haigis) (range −1.58 to +1.00 D). The IOL power was underestimated in 59.1% of cases with the Hoffer Q and 63.6% of cases with the Holladay I, Haigis, and SRK/T. There was a difference of ±0.75 D in 72.7% of eyes using the Holladay I, Haigis, and Hoffer Q and in 86.4% of eyes using the SRK/T. Neither K values nor IOL power differences were statistically significant (P > .17). CONCLUSION: Intraocular lens power calculation using modern standard formulas incorporated in a PCI biometry device after intrastromal femtosecond presbyopia treatment was reliable, with minimum underestimation on average. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Dynamic stimulation of accommodation

We describe the analysis of accommodation using wavefront measurements in phakic and pseudophakic eyes. Accommodation measurements were performed in phakic and pseudophakic eyes using a dynamic stimulation aberrometry (DSA) device (Optana) as an attachment to the WASCA aberrometer (Carl Zeiss Meditec AG). Aberrations were measured for distance fixation (3.0 m) and near fixation (0.3 to 0.11 m) presenting different accommodative stimuli (3.0 to 9.0 diopters). The device was able to detect changes in aberrations using near and distance stimulation. Eyes with phakic iris-fixated intraocular lenses (IOLs) showed normal age-correlated accommodation. In pseudophakic eyes, accommodation varied depending on the IOL. With monofocal IOLs (eg, MA60AC, Alcon), there was no accommodation; with an accommodating IOL (eg, Synchrony, Visiogen), there was a low level of accommodation. The DSA device is capable of measuring accommodation using wavefront data. It will help to further analyze changes in accommodation-related wavefront aberrations.

Effect of intrastromal correction of presbyopia with femtosecond laser (INTRACOR) on mesopic contrast sensitivity

BACKGROUND The aim of this study was to examine the mesopic contrast sensitivity (CS) and glare sensitivity following intrastromal femtosecond laser correction of presbyopia (INTRACOR). PATIENTS AND METHODS In this study 25 patients with slight hyperopia and presbyopia underwent femtosecond laser correction in the non-dominant eye. Mesotest II measurements (OCULUS Optikgeräte, Wetzlar, Germany) were performed with and without glare at each of four different contrast levels preoperatively as well as 3, 6, 12, 18 and 24 months postoperatively. Data were compared using the Wilcoxon-test with a level of significance of p < 0.05. RESULTS After 24 months the median CS decreased from 1:2 to 1:2.7 without glare and from 1:23 to 0 with glare. Of all patients 36% showed loss in CS without and 52% with glare and CS did not show any statistically significant differences between the treated and the untreated fellow eyes after 12 and 24 months. Overall 9 out of 18 monocular treated patients showed no binocular night driving ability according to the recommendations of the German Society of Ophthalmology (DOG) and the Professional Association of German Ophthalmologists (BVA) 24 months following INTRACOR. CONCLUSIONS INTRACOR can lead to a slight reduction of mesopic contrast sensitivity and an increase of glare sensitivity. Possible consequences on night driving ability should be discussed with the patients prior to treatment.