Angela Ehmer

Early Outcomes of INTRACOR Femtosecond Laser Treatment for Presbyopia

PURPOSE To investigate early functional outcomes of the INTRACOR femtosecond laser-based intrastromal procedure to treat presbyopia. METHODS Twenty-five eyes of 25 presbyopic patients were enrolled in this prospective, ethics committee-approved study. Following detailed preoperative examination, the INTRACOR procedure was performed using the TECHNOLAS femtosecond laser (Technolas Perfect Vision GmbH) in the non-dominant eye. Postoperatively, follow-up examinations were performed at 1 day, 1 week, and 1 and 3 months, including near and distance visual acuity, slit-lamp microscopy, and corneal topography. RESULTS All 25 surgeries were uneventful. The mean postoperative uncorrected near visual acuity increased from 0.7+/-0.16 logMAR to 0.26+/-0.21 logMAR and the mean uncorrected distance visual acuity changed slightly from 0.11+/-0.11 logMAR to 0.05+/-0.1 logMAR at 3 months postoperative. Regarding best distance correction, mean sphere changed from +0.75+/-0.23 diopters (D) preoperatively to +0.15+/-0.31 D postoperatively and mean cylinder from -0.33+/-0.17 D to -0.42+/-0.23 D. Postoperative healing was uneventful, and in all eyes, the cornea was clear within a few hours after surgery without any remaining cavitation gas bubbles. CONCLUSIONS The INTRACOR procedure for presbyopia showed good visual acuity outcomes in the early postoperative period. The short treatment time in combination with maintained corneal integrity suggests this new technique has good potential for the treatment of presbyopia.

Impact of axis misalignment of toric intraocular lenses on refractive outcomes after cataract surgery

PURPOSE: To theoretically and clinically evaluate the impact of axis misalignment of toric intraocular lenses (IOLs) on postoperative refraction. SETTING: International Vision Correction Research Center, University of Heidelberg, Heidelberg, Germany. DESIGN: Case series. METHODS: A method based on mathematical solutions to obliquely crossed spherocylinders was derived according to the pseudophakic refractive properties and used to analyze the impact of toric IOL misalignment on postoperative refraction. The refractive outcomes were theoretically analyzed and actual postoperative outcomes assessed to confirm the theoretically identified impact. RESULTS: The mean IOL misalignment was 12.5 degrees ± 6.7 (SD). Three main factors had an impact on refractive outcomes: hyperopic change in refractive sphere, reduction in astigmatic correction, and rotation of the astigmatic axis. The mean calculated spherical change was 0.32 ± 0.23 diopters (D) and the actual change, 0.36 ± 0.71 D. The mean calculated reduction in astigmatic correction was 0.65 ± 0.45 D and the actual reduction, 0.95 ± 0.54 D, indicating undercorrection of preexisting astigmatism. The mean calculated absolute astigmatic rotation was 32.7 ± 13.2 degrees (range 8 to 55 degrees) and the actual rotation, 29.1 ± 17.4 degrees. There was a correlation between the calculated and actual reduction (r2 = 0.51; P = .001) and between the calculated and actual rotation (r2 = 0.86; P<.001). CONCLUSION: In addition to a reduction in astigmatic correction, misalignment of toric IOLs induced hyperopic spherical change and astigmatic rotation. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Retropupillary Fixation of Iris-claw Intraocular Lens Versus Transscleral Suturing Fixation for Aphakic Eyes Without Capsular Support

PURPOSE Retropupillary fixation of an iris-claw intraocular lens (IOL) (Verisyse, Abbott Medical Optics) was performed for aphakic eyes without sufficient capsular support, and safety and recovery of the procedure were compared with transscleral suturing fixation. METHODS This interventional case series comprised 11 eyes of 10 aphakic patients without capsular support undergoing retropupillary fixation of the Verisyse, and 21 eyes of 20 patients undergoing transscleral suturing fixation of foldable acrylic IOLs (15 eyes of 14 patients, SuperFlex620H [Rayner Intraocular Lenses Ltd]) and polymethylmethacrylate IOLs (6 eyes of 6 patients, CP60NS [CORNEAL Laboratoire]). Surgical time was measured. Corrected distance visual acuity (CDVA) and intraocular pressure (IOP) were examined preoperatively and 1 day, 1 and 2 weeks, and 1 and 6 months postoperatively. RESULTS No complications occurred in the Verisyse group, whereas complications were reported in seven eyes in the transscleral suturing fixation group throughout follow-up. Mean CDVA (logMAR) in the transscleral suturing group 1 day after surgery was significantly worse than preoperative CDVA (P<.05). In the Verisyse group, no significant changes in CDVA were noted at any time point. Mean IOP at postoperative day 1 in the transscleral suturing fixation group was significantly higher than that in the Verisyse group (P=.0126). Mean surgical time of Verisyse implantation (20.0 ± 8.9 min) was significantly shorter than transscleral suturing fixation (49.7 ± 18.9 min) (P<.0001). CONCLUSIONS Retropupillary fixation of an iris-claw IOL provides early visual recovery, has a low risk of postoperative increase in IOP, and is a time-saving method compared with transscleral suturing fixation for aphakic eyes without sufficient capsular support.

Comparison of ray-tracing method and thin-lens formula in intraocular lens power calculations

PURPOSE: To compare the accuracy of the thin‐lens and ray‐tracing methods in intraocular lens (IOL) power calculations in normal eyes and eyes after corneal refractive surgery. SETTING: International Vision Correction Research Centre, University of Heidelberg, Heidelberg, Germany. METHODS: Pseudophakic eye models were constructed using Zemax optical software, importing corneal radii (normal ray tracing) and corneal surface elevation data (individual ray tracing) measured by Pentacam Scheimpflug photography. Algorithms to predict IOL position (effective lens position [ELP]) or postoperative anterior chamber depth [ACDpost]) (Haigis, Hoffer Q, Norrby, Olsen 2) were used in the thin‐lens and ray‐tracing methods. Intraocular lens power was calculated in 25 eyes after corneal refractive surgery using normal and double‐K modified thin‐lens and ray‐tracing methods. RESULTS: Back‐calculation of ELP and ACDpost were well correlated. Using algorithms of Haigis, Hoffer Q, Norrby, and Olsen 2 to predict IOL position, mean absolute prediction errors (MAEs) of the thin‐lens formula were 0.64 diopters (D) ± 0.52 (SD), 0.57 ± 0.46 D, 0.59 ± 0.42 D, and 0.61 ± 0.47 D, respectively; MAEs of normal ray‐tracing method were 0.64 ± 0.50 D, 0.58 ± 0.44 D, 0.59 ± 0.41 D, and 0.62 ± 0.45 D, respectively; MAEs of individual ray‐tracing method were 0.66 ± 0.52 D, 0.59 ± 0.45 D, 0.59 ± 0.43 D, and 0.62 ± 0.50 D, respectively. No statistical differences were found between the thin‐lens and ray‐tracing methods. CONCLUSION: Theoretical thin‐lens formulas were as accurate as the ray‐tracing method in IOL power calculations in normal eyes and eyes after refractive surgery.

Pseudophakic eye with obliquely crossed piggyback toric intraocular lenses.

A 72-year-old man presented with high astigmatism (2.25 -5.0 x 45) induced by long-term rotation of a toric intraocular lens (IOL). Corneal astigmatism was 3.78 diopters (D). The corrected distance visual acuity (CDVA) was 20/32. Because of the risk of repositioning, a secondary toric IOL of -3.0/6.0 D especially designed for sulcus implantation was piggybacked through 3.5 mm sutureless clear-corneal incision with a cylindrical axis obliquely crossed with that of the primary IOL. Eight months postoperatively, the corneal astigmatism was 5.04 D. The CDVA was 20/25 with a refraction of 1.0 -2.5 x 70. No interlenticular opacification or significant rotation or decentration of the secondary toric IOL was observed. The refractive properties of this pseudophakic eye were analyzed using a mathematical approach. The calculated postoperative refraction was 0.84 -1.7 x 47. A piggyback toric IOL can be implanted in an obliquely crossed style that allows a secondary toric IOL to correct astigmatism induced by long-term toric IOL rotation.

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.

Visual function and reading speed after bilateral implantation of 2 types of diffractive multifocal intraocular lenses: Add-on versus capsular bag design.

Purpose To compare the functional outcomes of primary implantation of a monofocal intraocular lens (IOL) in the capsular bag and an add‐on multifocal IOL in the sulcus with the functional results of a conventional multifocal posterior chamber IOL and to evaluate the multifocal add‐on IOL as an effective alternative to a conventional multifocal IOL. Setting Ernst von Bergmann Eye Clinic, Potsdam, Germany. Design Prospective nonrandomized case series. Methods Cataract surgery patients were assigned to have bilateral implantation of a monofocal IOL (Aspira‐aAY) in the capsular bag followed by a multifocal add‐on IOL (Diff‐sPB) in the sulcus (Group A) or with a conventional multifocal IOL (Diffractiva‐s) in the capsular bag (Group B). The main study outcomes were assessed at the last follow‐up visit (6 months postoperatively) and included refraction, intraocular pressure, visual acuity, reading speed, contrast sensitivity, defocus curve, and patient satisfaction. Results The study comprised 26 patients (52 eyes) Cataract surgery was uneventful in all cases. No severe complications were observed 6 months postoperatively. Visual performance with a multifocal diffractive add‐on IOL was equivalent to that achieved with a conventional multifocal diffractive posterior chamber IOL. Similarly, there were no significant differences in patient satisfaction and reading speed for any type of letter size between groups (P > .05). Conclusion Implanting a multifocal add‐on IOL in the sulcus in addition to a monofocal IOL in the capsular bag produced outcomes similar to those of single implantation of a standard multifocal IOL in the capsular bag. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Wavefront analysis in ophthalmologic diagnostics

ZusammenfassungDie moderne Aberrometrie erfasst neben den Standardrefraktionsfehlern des Auges auch die sog. Aberrationen höherer Ordnung. In der Ophthalmologie und Optometrie werden Zernike-Polynome verwendet, um Aberrationen der Hornhaut sowie der Linse, die durch Refraktionsfehler entstehen, zu beschreiben. Aberrationen höherer Ordnung können nach erfolgreicher Laserchirurgie die Ursache von Visusminderung und Patientenunzufriedenheit sein. Auf den Wellenfrontdaten basierende „enhancements“ können hier Abhilfe bringen. In der Akkommodationsforschung werden Aberrometer auch zur objektiven Messung einer Refraktionsänderung verwendet. Die Wellenfronttechnologie und ihre individualisierte klinische Anwendung haben dem Ophthalmologen eine Vielzahl von Alternativen beschert, die delikate Balance der Optik des Auges zu verstehen. Die Zukunft der refraktiven Chirurgie besteht in vermehrten individualisierten Behandlungen zur Unterdrückung induzierter höherer Aberrationen und damit verbesserten klinischen Ergebnissen. Im Intraokularlinsenbereich werden die Patienten weitere Forderungen nach individualisierten IOL stellen, welche Aberrationen höherer Ordnung korrigieren.AbstractModern aberrometry measures standard and so-called higher-order refractory aberrations. Ophthalmology and optometry use Zernike polynomials to describe aberrations of the retina and lens causing refractory errors. Aberrations of a higher order sometimes follow successful laser surgery, causing reduced vision and inducing patient dissatisfaction; enhanced wavefront data can help to avoid this. Aberrometry is used also for objective measurement of refractory changes. Wavefront techniques and their clinical application enable many options for understanding the delicate balance of eye optics. The future of refractive surgery lies in increasingly individualized treatment to suppress higher degrees of aberration and thus improve clinical results. Patients will continue placing greater demand on individualized intraocular lenses that correct higher-order aberrations.Modern aberrometry measures standard and so-called higher-order refractory aberrations. Ophthalmology and optometry use Zernike polynomials to describe aberrations of the retina and lens causing refractory errors. Aberrations of a higher order sometimes follow successful laser surgery, causing reduced vision and inducing patient dissatisfaction; enhanced wavefront data can help to avoid this. Aberrometry is used also for objective measurement of refractory changes. Wavefront techniques and their clinical application enable many options for understanding the delicate balance of eye optics. The future of refractive surgery lies in increasingly individualized treatment to suppress higher degrees of aberration and thus improve clinical results. Patients will continue placing greater demand on individualized intraocular lenses that correct higher-order aberrations.

Die Wellenfrontanalyse in der ophthalmologischen Diagnostik

ZusammenfassungDie moderne Aberrometrie erfasst neben den Standardrefraktionsfehlern des Auges auch die sog. Aberrationen höherer Ordnung. In der Ophthalmologie und Optometrie werden Zernike-Polynome verwendet, um Aberrationen der Hornhaut sowie der Linse, die durch Refraktionsfehler entstehen, zu beschreiben. Aberrationen höherer Ordnung können nach erfolgreicher Laserchirurgie die Ursache von Visusminderung und Patientenunzufriedenheit sein. Auf den Wellenfrontdaten basierende „enhancements“ können hier Abhilfe bringen. In der Akkommodationsforschung werden Aberrometer auch zur objektiven Messung einer Refraktionsänderung verwendet. Die Wellenfronttechnologie und ihre individualisierte klinische Anwendung haben dem Ophthalmologen eine Vielzahl von Alternativen beschert, die delikate Balance der Optik des Auges zu verstehen. Die Zukunft der refraktiven Chirurgie besteht in vermehrten individualisierten Behandlungen zur Unterdrückung induzierter höherer Aberrationen und damit verbesserten klinischen Ergebnissen. Im Intraokularlinsenbereich werden die Patienten weitere Forderungen nach individualisierten IOL stellen, welche Aberrationen höherer Ordnung korrigieren.AbstractModern aberrometry measures standard and so-called higher-order refractory aberrations. Ophthalmology and optometry use Zernike polynomials to describe aberrations of the retina and lens causing refractory errors. Aberrations of a higher order sometimes follow successful laser surgery, causing reduced vision and inducing patient dissatisfaction; enhanced wavefront data can help to avoid this. Aberrometry is used also for objective measurement of refractory changes. Wavefront techniques and their clinical application enable many options for understanding the delicate balance of eye optics. The future of refractive surgery lies in increasingly individualized treatment to suppress higher degrees of aberration and thus improve clinical results. Patients will continue placing greater demand on individualized intraocular lenses that correct higher-order aberrations.Modern aberrometry measures standard and so-called higher-order refractory aberrations. Ophthalmology and optometry use Zernike polynomials to describe aberrations of the retina and lens causing refractory errors. Aberrations of a higher order sometimes follow successful laser surgery, causing reduced vision and inducing patient dissatisfaction; enhanced wavefront data can help to avoid this. Aberrometry is used also for objective measurement of refractory changes. Wavefront techniques and their clinical application enable many options for understanding the delicate balance of eye optics. The future of refractive surgery lies in increasingly individualized treatment to suppress higher degrees of aberration and thus improve clinical results. Patients will continue placing greater demand on individualized intraocular lenses that correct higher-order aberrations.