Tm Rabsilber

Anterior chamber measurements using Pentacam rotating Scheimpflug camera.

PURPOSE: To investigate the mean values and standard deviations according to age, reliability, and correlation between different parameters of anterior chamber measurements using the Pentacam rotating Scheimpflug camera. SETTING: Heidelberg IOL and Refractive Surgery Research Group, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. METHODS: This prospective clinical study comprised 76 healthy volunteers (mean age 46.6 years ± 16.8 [SD]). Three consecutive measurements were made of only 1 eye and anterior chamber depth (ACD), mean and minimum anterior chamber angle (ACA), and anterior chamber volume (ACV) were evaluated. RESULTS: Mean ACD was 2.93 ± 0.36 mm, mean ACA was 34.81 ± 5.05 degrees, minimum ACA was 29.99 ± 5.53 degrees, and mean ACV was 160.3 ± 36.81 mm3. Increasing age was associated with reduced ACD and ACV; however, mean and minimum ACAs were lowest in patients aged 40 to 59 years. Excellent correlation was found between ACD and ACV (R = 0.92). Anterior chamber depth and mean ACA correlated only moderately (R = 0.65). The correlation coefficient between ACD and minimum ACA was smaller (R = 0.58). There was no correlation between ACV and ACA (R = 0.37). Minor standard deviations were noted (ACD 0.02 ± 0.02 mm, mean ACA 1.12 ± 0.94 degrees, minimum ACA 2.04 ± 2.67 degrees, and ACV 2.48 ± 1.65 mm3). CONCLUSIONS: Using the Pentacam, it was possible to examine different parameters of the anterior chamber within a short period and with good reliability. The evaluation of the ACA in different positions can help to classify the potential risk for angle‐closure glaucoma.

Central and peripheral pachymetry measurements according to age using the Pentacam rotating Scheimpflug camera.

PURPOSE: To investigate the mean values and standard deviations as well as the reliability of consecutive examinations of central and peripheral corneal thickness measurements according to age using the Pentacam rotating Scheimpflug camera (Oculus, Inc.). SETTING: Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. METHODS: Seventy‐six healthy volunteers were enrolled in a clinical prospective study. Three consecutive Pentacam measurements of 1 eye per subject were taken. Evaluated were the central corneal thickness (CCT), corneal thickness at 4 peripheral points (3.0 mm superior, inferior, nasal, and temporal), and the thinnest point of the cornea. The volunteers were then assigned to 3 groups to assess the influence of increasing age on the study parameters. RESULTS: The mean age of the subjects was 46.6 years ± 16.8 (SD). The mean CCT was 539.62 ± 31.87 μm. Peripherally, the corneal thickness was between 11% and 19% higher than centrally, with the superior cornea being the thickest followed by the nasal, the inferior, and the temporal cornea. The thinnest point was located in the inferotemporal quadrant in 92% of eyes and in the superotemporal quadrant in 8%. There was no correlation between age and corneal thickness. Minor mean standard deviations of consecutive measurements were noted in the corneal center (4.33 μm), increasing significantly toward the periphery (mean 8.31 μm). Increasing age was not associated with decreasing reliability. CONCLUSIONS: Using the Pentacam, it was possible to acquire information about corneal thickness across the entire cornea. No correlation was found between increasing age and change in peripheral or CCT. Good reliability was noted for pachymetry measurements decreasing slightly toward the periphery, which was independent of age.

Anterior chamber depth in relation to refractive status measured with the Orbscan II Topography System

Purpose: To evaluate the anterior chamber depth (ACD) according to refractive status, assess the reliability of repeated ACD measurements using the Orbscan II Topography System (Bausch & Lomb), compare Orbscan II and IOLMaster (Carl Zeiss Meditec AG) ACD measurements, and investigate the correlation between refraction, axial length (AL), and ACD. Setting: Department of Ophthalmology, Ruprecht‐Karls‐University of Heidelberg, Heidelberg, Germany. Methods: In this clinical study, 60 patients with a mean age of 43.8 years ± 18.74 (SD) were assigned to 1 of 3 groups of 20 patients each according to refraction: emmetropia group; hyperopia group (mean +4.84 ± 1.60 diopters [D]); myopia group (mean –9.64 ± 3.79 D). Using the Orbscan II system, 3 consecutive ACD measurements (apex and 3.0 mm zone) were performed. The IOLMaster was used to measure ACD and AL. Results: The mean ACD (from epithelium) with the Orbscan II and IOLMaster, respectively, was 3.61 ± 0.24 mm and 3.61 ± 0.24 mm in the emmetropia group, 3.03 ± 0.21 mm and 3.06 ± 0.24 mm in the hyperopia group, and 3.72 ± 0.26 mm and 3.73 ± 0.23 mm in the myopia group. The standard deviation of the repeated Orbscan II measurements increased from 13 to 15 &mgr;m from the apex to the 3.0 mm zone. The difference between the apex and 3.0 mm zone of the cornea in all groups ranged from 0.1 to 0.12 mm. The mean AL was 23.52 ± 0.82 mm in the emmetropia group, 22.14 ± 0.64 mm in the hyperopia group, and 27.44 ± 1.67 mm in the myopia group. There was a significant correlation between the spherical equivalent and AL (r = 0.94). Conclusions: Significantly lower ACD values were found in the hyperopia group than in the other 2 groups. There was no difference in ACD between the emmetropia and myopia groups even though the AL in the myopia group was 4.0 mm longer. No statistical difference in ACD measurements was found between the Orbscan II and IOLMaster.

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.

Comparison of the maximum applicable stretch force after femtosecond laser–assisted and manual anterior capsulotomy

Purpose To objectively measure the strength of the capsulotomy performed with a femtosecond laser‐assisted technique or performed manually in a pig‐eye laboratory study. Setting International Vision Correction Research Centre, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. Design Experimental study. Methods Ten fresh pig eyes were randomly assigned to femtosecond laser–assisted capsulotomy or manual capsulotomy. The capsule was immersed in hyaluronic acid, and retractors were fixed in the capsule opening with a pull‐force measuring device. The force necessary to break the capsulotomy was measured in millinewtons (mN); the maximum stretching ratio was also assessed. Results The observed mean rupture force (ie, maximum amount of force measured immediately before tissue rupture) was 113 mN ± 12 (SD) in the laser‐assisted procedure and 73 ± 22 mN in the manual procedure (P<.05). The stretching ratios were 1.60 ± 0.10 (femtosecond) and 1.35 ± 0.04 (manual) (P<.05). Conclusion In this laboratory pig‐eye study, femtosecond laser–assisted capsulotomy resulted in a significantly stronger anterior capsule opening than the standard manually performed capsulotomy. Financial Disclosure Drs. Auffarth, Reddy, and Holzer have received research and travel grants from Technolas Perfect Vision GmbH. Mr. Ritter is an employee of Technolas Perfect Vision GmbH, Munich, Germany.

Influence of 360-degree enhanced optic edge design of a hydrophilic acrylic intraocular lens on posterior capsule opacification

PURPOSE: To compare the rate of posterior capsule opacification (PCO) with the single‐piece hydrophilic acrylic foldable Rayner Centerflex 570H intraocular lens (IOL), which has a sharp optic edge design excluding the optic–haptic junction, and the Rayner C‐flex 570C IOL, which has an improved 360‐degree sharp edge. SETTING: Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany. METHODS: As part of a multicenter U.S. Food and Drug Administration (FDA) study, 42 patients who had implantation of a C‐flex IOL in 1 eye after uneventful phacoemulsification were enrolled. Six and 12 months postoperatively, PCO was evaluated by retroillumination photographs using Evaluation of Posterior Capsule Opacification (EPCO) 2000 image‐analysis software. The data were then compared with those in a matched group of patients with a Centerflex IOL who participated in a previous FDA study. RESULTS: The mean age of the patients with the C‐flex IOL was 71.5 years ± 8.2 (SD) There was a statistically significant difference in EPCO scores between the C‐flex group and Centerflex group. Six months after surgery, the mean EPCO value (total IOL optic) was 0.07 ± 0.17 in the C‐flex group (n = 37) and 0.20 ± 0.20 in the Centerflex group (n = 36) (P<.01, Wilcoxon test). By 12 months, the mean had increased to 0.16 ± 0.20 in the C‐flex group (n = 37) and 0.35 ± 0.22 in the Centerflex group (n = 31) (P<.01, Wilcoxon test). CONCLUSIONS: The C‐flex IOLs showed good functional results and significantly lower PCO formation than the earlier model Centerflex IOL. The enhanced edge of the C‐flex IOL seemed to improve PCO prevention clinically.

Long‐term results of sealed capsule irrigation using distilled water to prevent posterior capsule opacification: a prospective clinical randomised trial

Background: We investigated long-term safety and efficacy of sealed capsule irrigation (SCI) during cataract surgery to prevent posterior capsule opacification (PCO). Methods: One eye of each of 17 patients (mean age: 70.1±9.7 years) who presented with bilateral cataracts was randomly chosen for SCI treatment. After phacoemulsification, the capsular bag was vacuum sealed with the PerfectCapsule device (Milvella) followed by SCI using distilled water for two minutes. No vacuum loss occurred during irrigation. Each patient’s fellow eye served as a control. One hydrophilic acrylic intraocular lens model was implanted in all eyes. Five patients had to be excluded due to deep anterior chamber, small pupil or unilateral surgery. Follow-up examinations took place one day and one, three, six, 12 and 24 months after surgery. We evaluated safety parameters, anterior capsule (AC) overlapping and PCO. Results: Postoperatively, mean best corrected visual acuity, pachymetry, endothelial cell count, intraocular pressure, AC overlapping and PCO showed no statistically significant difference between SCI and the control group (p>0.05, Wilcoxon test). Conclusion: SCI is a safe procedure and enables the specific pharmacological targeting of lens epithelial cells inside the capsular bag. Using distilled water, however, it is not possible to reduce PCO development significantly. Thus, alternative substances should be evaluated.

Reliability of Orbscan II topography measurements in relation to refractive status

PURPOSE: To investigate the reliability of corneal topography measurements using the Orbscan II topography system (Bausch & Lomb) not only referring to a normal cohort but also to different refractive conditions. SETTING: Department of Ophthalmology, Ruprecht‐Karls‐University of Heidelberg, Heidelberg, Germany. METHODS: Eighty patients (mean age 46.4 ± 19.0 years) were assigned to 4 refractive groups (Group A: emmetropia (n = 20); Group B: astigmatism (n = 20) (−1.98 ± 1.77 diopters [D]); Group C: hyperopia (n = 20) (+4.84 ± 1.6 D); Group D: myopia (n = 20) (−9.64 ± 3.79 D). Three measurements were performed in a series. Thirteen defined, standardized points of the entire cornea (apex, 3.0 mm, 5.0 mm, and 7.0 mm zone) were evaluated for 3 different maps (anterior elevation, pachymetry, keratometry). RESULTS: In all 80 patients, the following mean values were found in relation to analyzed zones: with regard to the anterior elevation map, the values decreased from 5.53 μm (center) to −6.52 μm (7.0 mm zone), the corneal thickness increased from 549.41 μm to 638.63 μm peripheral and the keratometry from 43.86 D (apex) to 45.4 D (7.0 mm zone), respectively. Analysis of the 3 different maps in all 4 refraction groups showed a tendency toward an increase in SD from the center to the 7.0 mm zone for anterior elevation and pachymetry maps. For keratometry, however, the lowest SD was found in the 7.0 mm zone. In particular, patients with hyperopia showed significant differences (P<.01), compared with emmetropic patients; the SD was higher with regard to anterior elevation as well as keratometry in peripheral zones. Group B (astigmatism) showed significantly higher SD for anterior elevation in zones 3.0, 5.0, and 7.0 mm when compared with emmetropic patients. CONCLUSIONS: The repeated Orbscan II measurements showed SD in the micrometer range for anterior elevation and pachymetry but values between 0.48 D and 0.97 D for keratometric data. Patients with astigmatism and especially hyperopia showed significantly higher SD values in peripheral zones for anterior elevation and keratometry, indicating a lower reliability, compared with the emmetropic cohort. However, the different ages of the patients could also be a possible explanation for these findings. Therefore, the Orbscan II seems to be a predictable and useful device for measuring corneal topography.

Induction of the cytokine TWEAK and its receptor Fn14 in ischemic stroke

Stroke outcome is determined by delayed neuronal cell death and edema formation. TWEAK, a cytokine of the TNF superfamily, and its membrane receptor Fn14 promote ischemia-induced neuronal apoptosis and leakage of the blood-brain barrier. Both TWEAK and Fn14 are upregulated in experimental stroke models. In this study, we investigated whether TWEAK and Fn14 are upregulated in stroke patients. We measured serum concentrations of TWEAK in stroke patients and matched control subjects by ELISA. Expression of Fn14 in the brain was evaluated by real-time RT-PCR and immunohistochemistry. TWEAK serum concentrations were elevated in stroke patients. In autopsy samples, we found elevated mRNA levels of the receptor Fn14 and a trend towards higher TWEAK mRNA levels. In the infarcted and peri-infarct tissue immunostaining for Fn14 was enhanced. These data show that the cytokine TWEAK and its membrane receptor Fn14 are upregulated in stroke and suggest that they contribute to stroke outcome.

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.