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Purpose: The purpose of this study was to develop a concept for predicting the effects of both discrete intraocular lens (IOL) power steps (PS) and power labelling tolerances (LT) on the uncertainty of the refractive outcome (REFU)., Design: Retrospective non-randomised cross-sectional Monte Carlo simulation study., Methods: We evaluated a dataset containing 16 669 IOLMaster 700 preoperative biometric measurements. The PS and the delivery range of two modern IOLs (Bausch and Lomb enVista and Alcon SA60AT) were considered for this Monte Carlo simulation. The uncertainties from PS or LT were assumed to be normally distributed according to ±½ the IOL PS or the ISO 11979 LT. REFU was recorded and analysed for all simulations., Results: With both lenses the REFU from discrete PS ranged from 0.11 to 0.12 dpt. Due to the larger PS for low/high power lenses with the enVista/SA60AT, REFU is more dominant in initially myopic/hyperopic eyes. REFU from LT ranged from 0.18 to 0.19 dpt for both lenses. Since LT increases stepwise with IOL power, REFU is more prevalent in initially hyperopic eyes requiring high IOL power values, and for lenses with a wide delivery range towards higher powers., Conclusions: Since surgeons and patients are typically aware of the effect of discrete PS on REFU, these might be tolerated in cataract surgery. However, REFU resulting from LT is inevitable while the true measured IOL power is not reported on the package, leading to background noise in postoperative achieved refraction., Competing Interests: Competing interests: AL reports speaker fees from PH Surgical and J&J Vision outside the submitted work. NS and AC do not report any financial interests. MB reports speaker fees from CZM, AG outside the submitted work. PH reports speaker fees from Heidelberg engineering, PH Surgical and J&J outside the submitted work. JW reports speaker fees from CZ Meditec AG, Alcon and J&J Vision outside of the submitted work., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: To evaluate the accuracy of intraocular lens (IOL) power calculation in a patient cohort with short axial eye length to assess the performance of IOL power calculation schemes in strong hyperopes., Methodology: The study was a single centre, single surgeon retrospective consecutive case series at the Augen- und Laserklinik, Castrop-Rauxel, Germany. Inclusion of patients after uneventful cataract surgery implanting either spherical (SA60AT) or aspheric (ZCB00) IOLs. Inclusion criteria were axial eye length <21.5 mm and/or emmetropising IOL power >28.5 D. Lens constants were optimised on a separate patient cohort considering the full bandwidth of axial eye length. Data of one single eye per patient were randomly included. The outcome measures were: mean absolute prediction error (MAE), median absolute prediction error, mean prediction error with SD and median prediction error and the percentage of eyes with an MAE within 0.25 D, 0.5 D, 0.75 D and 1.0 D., Results: A total of 150 eyes from 150 patients were assessed. Okulix, PEARL-DGS, Kane and Castrop provided a statistically significantly smaller MAE compared with the Hoffer Q and SRK/T formulae., Conclusion: In our patient cohort with short axial eye length, the use of PEARL-DGS, Okulix, Kane or Castrop formulae showed the lowest MAE. The Castrop formula has not been published before, but will be disclosed with a ready-to-use Excel sheet as an addendum to this paper., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Aims: To investigate changes in ocular perfusion following three consecutive intravitreal injections with aflibercept for treatment of neovascular age-related macular degeneration (nAMD)., Methods: The study included 20 eyes from 20 Caucasian patients with unilateral nAMD and 20 fellow eyes. All nAMD eyes were treated with standard intravitreal injection of aflibercept (IVA; 2 mg). Measurements of ocular perfusion at the optic nerve head (ONH) and the choroid were performed with laser speckle flowgraphy (LSFG). Measurements were conducted at baseline, 1 week after the first injection, at the time point of the second and third injection as well as 1 month after the third injection., Results: In treated eyes, mean blur rate (the main output parameter of LSFG) in the ONH microvasculature and in the choroid was significantly reduced 1 week after the first IVA treatment. The effect persisted throughout the entire follow-up period (p<0.001). No change in ocular perfusion was observed in fellow eyes., Conclusions: IVA for treatment of nAMD leads to a reduction in perfusion of the ONH and the choroid in the treated eye with no apparent effect on the fellow eye., Competing Interests: Competing interests: The Department of Ophthalmology, Kepler University Clinic, Johannes Kepler University has received a research grant from Nidek. ASME has received lecture fees from Nidek., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background/aims: There is considerable interest in novel techniques to quantify choroidal blood flow (CBF) in humans. In the present study, we investigated a novel technique to measure CBF based on laser speckle flowgraphy (LSFG) in healthy subjects., Methods: This study included 31 eyes of 31 healthy, non-smoking subjects aged between 19 and 74 years. A commercial LSFG instrument was used to measure choroidal vessel diameter (CVD) and relative flow volume (RFV) in choroidal vessels that were identified on fundus photos, an approach that was used previously only for retinal vessels. The reproducibility and the effect of isometric exercise on these parameters were investigated. The latter was compared with measurement of subfoveal CBF using laser Doppler flowmetry (LDF)., Results: Intraclass correlation coefficients for CVD and RFV were higher than 0.8 indicating excellent reproducibility. During isometric exercise, we observed an increase in ocular perfusion pressure of approximately 60% (P<0.001). The increase in RFV and CBF was lower, but also highly significant versus baseline (at minute 6 of isometric exercise: RFV 10.5%±4.2%, CBF 8.3%±3.6%; P<0.001 each) indicating choroidal autoregulation., Conclusion: LSFG may be a novel approach to study blood flow in choroidal vessels. Data are reproducible and show good agreement with LDF data., Trial Registration Number: NCT02102880, Results., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background/aims: To identify characteristic retinal pigment epithelium (RPE) changes in fellow eyes of patients with neovascular age-related macular degeneration (nAMD) using polarisation-sensitive optical coherence tomography (PS-OCT)., Methods: Thirty-one fellow eyes of 31 patients with unilateral nAMD were evaluated in this cohort study of a prospective interventional trial. PS-OCT as well as conventional imaging including spectral-domain (SD)-OCT and fluorescein angiography (FA) were performed using a standardised protocol. Monitoring visits were performed continuously at 1-month intervals. Morphological RPE features associated with the development of choroidal neovascularisation (CNV) were systematically analysed., Results: Mean follow-up was 29 months (±17, SD). Thirteen (42%) of 31 eyes developed de novo CNV: 9 eyes type I CNV, 2 eyes type II CNV, 2 eyes a retinal angiomatous proliferation lesion. RPE thickening and reticular pseudodrusen (RPD) were observed significantly more often in eyes that developed CNV than in eyes without CNV development (p<0.01). Monthly increase in drusen volume was higher in the CNV group with a median increase of +2.2% in area and +2.9% in volume compared with +0.8% and +0.6% in the non-progressing group. RPE migration within the neurosensory retina and at the level of the RPE resulting in RPE thickening was seen topographically and chronologically associated with CNV development., Conclusions: Conversion to CNV is associated with RPE-related changes such as RPE migration, RPE thickening, drusen volume or the presence of RPD. Early detection of these features may allow more efficient screening in risk eyes and timely vision-preserving treatment in eyes developing neovascular disease., Competing Interests: Competing interests: US-E receives consultancy, lecture fees and travel support from Alcon Laboratories (Fort Worth, Texas), Bayer Healthcare (Vienna, Austria), Novartis (Basel, Switzerland), Allergan (Irvine, California) and Boehringer (Ingelheim, Germany). PKR, CKH, MP and BB have received support from Canon (Tokyo, Japan)., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Background/aims: To investigate the impact of antiangiogenic monotherapy and photodynamic therapy (PDT) as add-on strategy on retinal morphology, and to analyse prognostic biomarkers for visual outcome and retreatment frequency in neovascular age-related macular degeneration (nAMD)., Methods: 255 patients participating in the MONT BLANC study were evaluated. Patients were randomised to receive as-needed ranibizumab monotherapy or combination therapy (verteporfin PDT and ranibizumab). Outcome measures included visual acuity (VA), retinal morphology assessed by optical coherence tomography and retreatment frequency., Results: The proportion of scans showing intraretinal cysts (IRC) or subretinal fluid (SRF) decreased more intensively in the combination than in the monotherapy group. Pigment epithelial detachments (PED) decreased significantly only in the combination group. Patients with IRC presented the lowest initial VA, and IRC had the strongest negative predictive value for functional improvement in both groups. SRF showed a predictive value for a higher number of ranibizumab injections (combination, +0.9; monotherapy, +0.8) and a higher number of PDT treatments in the combination group (+0.3). PED was associated with a higher number of ranibizumab injections only in the monotherapy group (+1.2)., Conclusions: Combination and monotherapy showed a distinct response pattern for morphological parameters in nAMD. IRC was the only relevant prognostic parameter for functional outcome., Trial Registration Number: NCT00433017., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Aim: To analyse a new grading protocol for clinically significant diabetic macular oedema (CSME) based on spectral domain optical coherence tomography (SD-OCT) and fluorescein angiography (FA)., Methods: 56 eyes of 40 patients with CSME were examined by Cirrus OCT (Carl Zeiss Meditec), Spectralis HRA and OCT (Heidelberg Engineering) on the same day. Three graders analysed images based on a newly developed grading protocol integrating all relevant information from OCT and FA. The protocol defined four categories: (1) subretinal fluid (category 'S'); (2) the planimetrically measured oedematous area (category 'A'); (3) vitreo-retinal interface abnormalities (category 'V'); and (4) CSME aetiology (category 'E') defining the leakage source., Results: The new grading protocol allowed for a detailed characterisation of each individual type of CSME. It defines four aetiological types of CSME and analyses four further categories important in diagnosis and during follow-up in clinical and study settings. Atrophic, a new type of CSME, was described and characteristic combinations of triggers of CSME were revealed. Inter-grader agreement, analysed using Fleiss' κ values for Cirrus OCT and Spectralis OCT, respectively, was good for 'S' (0.9; 0.82), 'A' (1.0; 1.0) and 'E' (range 0.63-0.8; 0.57-0.77), and lower for 'V' (0.25; 0.42)., Conclusions: The 'SAVE' grading protocol of CSME integrates information from two imaging techniques, OCT and FA. Its clinical approach allows examiners to define and further categorise clinical characteristics to find tailored therapeutic strategies., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Aims: This study has been designed to describe the functional impact of distinct pathologies within the retinal layers in patients with geographic atrophy (GA) by means of a point-to-point correlation between optical coherence tomography (OCT) and microperimetry., Methods: Retinal morphology and function of 23 patients suffering from GA of the retinal pigment epithelium (RPE) have been investigated using the Spectralis OCT (Heidelberg Engineering) and the MP1 microperimeter (Nidek Technologies). The point-to-point overlay of morphology and function has been done using proprietary software, allowing OCT image grading to define distinct alterations of the neurosensory retina, the RPE and the choroid. By overlaying the retinal sensitivity map on the OCT data set, retinal layer alterations could be evaluated regarding their impact on visual function., Results: A total of 1005 stimulation points in the lesion area in 2107 spectral domain OCT B-scans were graded in 43 eyes of 23 patients (mean best corrected visual acuity=20/70). Retinal sensitivity decreases with an increasing number of morphological alterations graded (p<10(-13)). Alterations of the RPE and the external limiting membrane (p<0.02) were associated with absolute scotomas. Furthermore, the loss of the external limiting membrane as the largest area of morphological alteration among our patients with GA (mean area=5.65 mm(2)), had a significant impact (p<10(-4)) on sensitivity (-1.3 dB)., Conclusions: Mapping retinal sensitivity to distinct retinal pathologies revealed outer retinal layers, in addition to the RPE, as significant for sensitivity loss. Therefore in GA the RPE loss and the alteration of outer retinal layers should be analysed, which could also provide insight into lesion progression., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Aim: To quantify and correlate the morphological and functional effects of the recommended loading regimen with intravitreal ranibizumab in neovascular age-related macular degeneration (AMD)., Methods: In a prospective, interventional clinical trial, 29 consecutive patients (29 eyes) with choroidal neovascularisation secondary to AMD received three initial monthly intravitreal injections of ranibizumab. During this loading regimen, best corrected visual acuity (BCVA) and microperimetry (MP) testing, as well as optical coherence tomography and fluorescein angiography (FA), were performed using a standardised protocol and the results correlated., Results: Significant morphological and functional therapeutic effects were observed as early as 1 week following the first treatment. Throughout the loading-dose period, central retinal thickness, including intraretinal cysts and subretinal fluid, decreased fast and significantly (p<0.01); pigment epithelial detachment resolved less rapidly. The mean leakage area by FA decreased (p<0.01) and retinal function (BCVA and MP) increased significantly (both p<0.01). However, the change in morphology and function was only significant between baseline and week 1. There was no significant additional morphological or functional benefit following the second and third injection., Conclusion: The initial administration of intravitreal ranibizumab in neovascular AMD induced a significant effect on intra- and subretinal fluid and visual function; subsequent injections had a less pronounced effect. It remains to be determined whether this loading regimen should be mandatory in all patients or if a single dose regimen would lead to a comparable functional and morphological retinal improvement.

Background: To evaluate the effect of systemic bevacizumab (Avastin) therapy on pigment epithelial detachment (PED) secondary to age-related macular degeneration (AMD) and to identify prognostic factors for PED regression and improvement in best corrected visual acuity (BCVA)., Study Design: Prospective uncontrolled pilot study., Methods: Nine patients (nine eyes) received three systemic bevacizumab treatments at 2 week intervals and were examined at baseline, weeks 1, 2, 4, 6 and month 3 by using optical coherence tomography (Stratus OC, Carl Zeiss Meditec, Dublin, California, USA). Changes in maximum PED height and greatest linear diameter (GLD) were planimetrically analysed by using Adobe Photoshop CS and correlated with retinal morphological changes and changes in BCVA., Results: Systemic bevacizumab therapy was well tolerated. Mean maximum PED height decreased significantly by 21% as early as 1 week (-96 microm (SD 48.8), p<0.01). At 3 months follow-up, two PEDs resolved completely, mean maximum PED height decreased significantly by 39% (-179 microm (SD 178), p = 0.02) and mean PED GLD by 24% (-714 microm (SD 1010), p = 0.07). Mean BCVA improved significantly by week 2 (+8.7 letters (SD 5.7), p<0.01) and at 3 months with 12.7 letters (SD 6.4) (p<0.01)., Conclusion: In the examined nine patients, systemic bevacizumab therapy showed evidence for an effect on PED secondary to neovascular AMD in terms of a decrease in lesion height and diameter. A high PED at baseline was found to be a negative predictive factor for visual outcome.

Aim: Aim of this study was to investigate the relationship between refractive changes in the eye and biometric changes of the human crystalline lens during accommodation. Furthermore, differences in these relationships between young, healthy emmetropic and myopic subjects were analyzed., Methods: Mean relative change in anterior chamber depth (ACD), lens thickness (LT), anterior segment length (ASL = ACD + LT) and in objective refraction were simultaneously assessed during near-point-induced accommodation in 10 emmetropic and 10 myopic subjects. Via a beam splitter, measurements were performed simultaneously using partial coherence interferometry (PCI) and infrared (IR) photorefraction., Results: On average, for each diopter of accommodation LT increased by 0.063 mm in emmetropic and by 0.072 mm in myopic eyes, and ACD decreased by 0.047 mm and 0.057 mm, respectively. Mean ASL, indicating the position of the posterior lens pole, increased by 0.009 mm in emmetropic and by 0.013 mm in myopic eyes. The correlation between refractive and biometric changes was found to be essentially linear in both subgroups. Differences in ACD between emmetropic and myopic eyes were statistically significant at an accommodative stimulus of -1 D (p<0.04) and -2 D (p<0.02)., Conclusion: The biometric and refractive changes of the human lens are highly correlated and linear in function in both emmetropic and myopic eyes.

Background/aim: Owing to the complex topographical aspects of ophthalmic surgery, teaching with conventional surgical videos has led to a poor understanding among medical students. A novel multimedia three dimensional (3D) computer animated program, called "Ophthalmic Operation Vienna" has been developed, where surgical videos are accompanied by 3D animated sequences of all surgical steps for five operations. The aim of the study was to assess the effect of 3D animations on the understanding of cataract and glaucoma surgery among medical students., Method: Set in the Medical University of Vienna, Department of Ophthalmology, 172 students were randomised into two groups: a 3D group (n=90), that saw the 3D animations and video sequences, and a control group (n=82), that saw only the surgical videos. The narrated text was identical for both groups. After the presentation, students were questioned and tested using multiple choice questions., Results: Students in the 3D group found the interactive multimedia teaching methods to be a valuable supplement to the conventional surgical videos. The 3D group outperformed the control group not only in topographical understanding by 16% (p<0.0001), but also in theoretical understanding by 7% (p<0.003). Women in the 3D group gained most by 19% over the control group (p<0.0001)., Conclusions: The use of 3D animations lead to a better understanding of difficult surgical topics among medical students, especially for female users. Gender related benefits of using multimedia should be further explored.