Sabine Schriefl

Imaging of the parafoveal capillary network and its integrity analysis using fractal dimension

Using a spectral domain OCT system, equipped with a broadband Ti:sapphire laser, we imaged the human retina with 5 µm x 1.3 µm transverse and axial resolution at acquisition rate of 100 kHz. Such imaging speed significantly reduces motion artifacts. Combined with the ultra-high resolution, this allows observing microscopic retinal details with high axial definition without the help of adaptive optics. In this work we apply our system to image the parafoveal capillary network. We demonstrate how already on the intensity level the parafoveal capillaries can be segmented by a simple structural high pass filtering algorithm. This data is then used to quantitatively characterize the capillary network of healthy and diseased eyes. We propose to use the fractal dimension as index for capillary integrity of pathologic disorders.

Quantification of the therapeutic response of intraretinal, subretinal, and subpigment epithelial compartments in exudative AMD during anti-VEGF therapy

PURPOSE To analyze the functional and morphologic effects of different ranibizumab treatment regimens on retinal and subretinal as well as sub-RPE compartments in neovascular age-related macular degeneration (nAMD) using spectral-domain optical coherence tomography (SD-OCT) and manual segmentation software. METHODS Twenty-seven eyes of 27 patients with nAMD were examined over a 12-month period. Two treatment arms received either monthly or quarterly administered intravitreal ranibizumab. Intraretinal, subretinal, and sub-RPE volume equivalents were delineated using manual segmentation software over a defined series of B-scans obtained by SD-OCT. The mean area in pixels was calculated for each compartment at each time interval. RESULTS SD-OCT and manual segmentation allowed for exact identification of intraretinal, subretinal and sub-RPE compartments and their responses to different treatment regimens. The loading dose demonstrated a corresponding treatment effect on all anatomic parameters. In contrast to the sub-RPE compartment, intraretinal fluid accumulation and subretinal fluid accumulation (SRFA) demonstrated an immediate response to ranibizumab therapy. The overall plasticity of the morphologic response declined over time. In general, SRFA demonstrated greater sensitivity for therapeutic effects and was more frequently associated with recurrent disease. CONCLUSIONS An exact quantification of fluid in different anatomic compartments based on SD-OCT imaging, using appropriate segmentation software systems, may be useful to determine optimal treatment and retreatment parameters and explains the lack of correlation of best-corrected visual acuity and conventional OCT values.

Posterior Capsule Opacification with the iMics1 NY-60 and AcrySof SN60WF 1-Piece Hydrophobic Acrylic Intraocular Lenses: 3-Year Results of a Randomized Trial

PURPOSE To compare the intensity of posterior capsule opacification (PCO) 3 years after implantation of 2 different 1-piece foldable hydrophobic acrylic intraocular lenses (IOLs). DESIGN Randomized, prospective, patient- and examiner-masked clinical trial with intraindividual comparison. METHODS One hundred patients with bilateral age-related cataract (200 eyes) had standard cataract surgery with implantation of an iMics1 NY-60 IOL (Hoya Corp) in one eye and an AcrySof SN60WF IOL (Alcon Laboratories) in the other eye. Follow-up examinations were performed at 1 week and 3 years. Digital retroillumination images were obtained of each eye. The main outcome measure was PCO score (scale, 0 to 10) assessed subjectively at the slit lamp and objectively using automated image analysis software (Automated Quantification of After-Cataract) 3 years after surgery. RESULTS The objective PCO score (mean ± standard deviation) was 3.0 ± 2.0 for the iMics1 NY-60 IOL and 1.9 ± 1.4 for the AcrySof SN60WF IOL (P < .001). Three years after surgery, 35.6% of patients underwent a neodymium:yttrium-aluminum-garnet capsulotomy in the iMics1 NY-60 eye and 13.7% underwent a capsulotomy in the AcrySof SN60WF eye (P = .001). There was no statistically significant difference in best-corrected visual acuity, rhexis-IOL overlap, capsular folds, or anterior capsule opacification. Glistening formations were found in no iMics1 NY-60 IOLs, but in 97% of the AcrySof SN60WF IOLs. CONCLUSIONS Comparison of 2 sharp-edged single-piece IOLs of similar design and hydrophobic acrylic material indicated a statistically significant difference in PCO and neodymium:yttrium-aluminum-garnet capsulotomy rate 3 years after surgery.

Posterior capsule opacification and neodymium:YAG rates with 2 single-piece hydrophobic acrylic intraocular lenses: Three-year results

Purpose To compare the incidence and intensity of posterior capsule opacification (PCO) between 2 similar 1‐piece foldable hydrophobic acrylic intraocular lenses (IOLs) over 3 years. Setting Department of Ophthalmology, Medical University Vienna, Vienna, Austria. Design Randomized prospective patient‐ and examiner‐masked clinical trial with intraindividual comparison. Methods Patients with bilateral age‐related cataract had cataract surgery and implantation of a Tecnis ZCB00 continuous‐optic‐edge IOL in 1 eye and an Acrysof SA60AT interrupted‐optic‐edge IOL in the other eye. Postoperative examinations were performed at 6 months and 3 years. Digital retroillumination images were taken of each eye. The amount of PCO (score 0 to 10) was assessed subjectively at the slitlamp and objectively using automated image‐analysis software. Results The study comprised 54 patients (108 eyes). The mean objective PCO score was 1.3 ± 1.7 (SD) for the continuous‐optic‐edge IOLs and 0.9 ± 1.3 for the interrupted‐optic‐edge IOLs (P=.10). Three years postoperatively, a neodymium:YAG (Nd:YAG) capsulotomy was performed in 26.1% of eyes with the continuous‐optic‐edge IOL and 21.7% with the interrupted‐optic‐edge IOL (P=.56). There was no significant difference in corrected distance visual acuity, capsulorhexis–IOL overlap, capsule folds, or anterior capsule opacification 3 years after surgery. Conclusions Both IOLs had comparable PCO and Nd:YAG rates 3 years postoperatively. The optimized barrier function of the continuous‐optic‐edge IOL and the material properties of the interrupted‐optic‐edge IOL seemingly outbalanced the effect on lens epithelial cell migration and proliferation beneath the optic. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Posterior capsule opacification and neodymium:YAG laser capsulotomy rates with 2 microincision intraocular lenses: Four-year results

Purpose To compare the development of posterior capsule opacification (PCO) and neodymium:YAG (Nd:YAG) capsulotomy rates between 2 microincision intraocular lenses (IOLs) 4 years after surgery. Setting Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. Design Prospective randomized clinical trial. Methods Patients randomly received a Y‐60H 3‐piece hydrophobic IOL (hydrophobic group) in 1 eye and an MI60 1‐piece hydrophilic IOL (hydrophilic group) in the contralateral eye during simultaneous bilateral cataract surgery. Eyes were examined 1 week, 20 months, and 4 years postoperatively. Digital retroilluminated images of each eye were evaluated using Automated Quantification of After‐Cataract software. The Nd:YAG laser capsulotomy rate was recorded. Results Sixty patients were enrolled. Objective PCO was significantly higher in the hydrophobic group than in the hydrophilic group before capsulotomy 2 years after cataract surgery (mean score 2.1 ± 1.8 (SD) versus 1.2 ± 1.4) (P =.031). At the 4‐year follow‐up, the hydrophobic group had a statistically significantly higher Nd:YAG rate than the hydrophilic group (77% versus 50%) (P =.012). Conclusion Comparison of 2 microincision IOLs indicated a statistically significant difference in PCO and Nd:YAG capsulotomy rates, with very high Nd:YAG rates 4 years after surgery. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Posterior capsular opacification and Nd:YAG capsulotomy rates with the iMics Y‐60H and Micro AY intra‐ocular lenses: 3‐year results of a randomized clinical trial

To compare the incidence and intensity of posterior capsular opacification (PCO) and neodymium:yttrium‐aluminium‐garnet (Nd:YAG) capsulotomy rates between two microincision intra‐ocular lenses (IOLs) 3 years after surgery.

Impact of low versus high fluidic settings on the efficacy and safety of phacoemulsification

Purpose:  To compare intraoperative efficiency and postoperative outcomes of cataract surgery with low and high fluidic settings.

True rotational stability of a single-piece hydrophobic intraocular lens

Background To evaluate rotation and its influencing factors of an aspheric one-piece hydrophobic acrylic intraocular lens (IOL) Vivinex XY1 during 6 months after operation. Methods In this institutional trial, 122 eyes of 66 patients were implanted with a non-toric aspheric IOL Vivinex XY1 (Hoya Corporation, Tokyo, Japan). IOL alignment was assessed at the end of surgery, 1 hour, 1 week, 1 month and 6 months after implantation. Confounding factors such as axial length, presence of anterior fibrosis and randomised implantation in four different intended axes (0°, 45°, 90°, 135°) were evaluated. Decentration and tilt were measured using a Purkinje metre. Results Assessment of rotational stability was possible for 103 of 122 implanted IOLs 6 months after eye surgery. The median absolute rotation was 1.1° (range: 0°–5°). Rotation was significantly increased within the first hour after operation compared with later time-points (p<0.001). No correlation was found with axial length and rotation (Spearman’s r=0.048, p=0.63). No significant difference was observed regarding different implantation axes (p=0.75). Rotation was not influenced by the presence of anterior fibrosis (p=0.98). Conclusion Assessing the true IOL position at the end of surgery is crucial for the evaluation of rotational stability of IOLs. No IOL rotation exceeding 5° could be detected 6 months after surgery.