A new digitised screen test for strabismus measurement.

PURPOSE: Our study presents a digitised tangent screen test for ocular motility analysis according to the Harms and Hess tests (measurement of the squint angle in all fields of vision). This test uses an image beamer to display the tangent screen, a position sensor to measure the patient's head orientation, and a distance sensor to measure the fixation distance. Digital measurement of head orientation allows for a test procedure that eliminates the conventional requirement for a light pointer in the patient's hand. Thus, the digital screen test is presented, and the uncertainty of the measurement system is evaluated. METHODS: A mathematical relationship was given between the measured squint angles, as well as the angle of diagnostic gaze direction, and the influence quantities on their measurement uncertainty. The individual uncertainties resulted from deviations in the measured values by the position and distance sensors, the calibration of the projection image of the beamer in length units, and the finite image resolution of the beamer. The individual standard uncertainties of the influence quantities were determined. The combined standard measurement uncertainties of the squint and gaze direction angles were given based on the model equation of the error propagation law at the tangent table according to Harms at a test distance of 2.5 m. The patient's uncertainty contribution to the mobility analysis was not considered. RESULTS: The combined standard uncertainty of the measurement system (coverage factor k = 2 for 95% confidence level) for the squint angle is ≤ 0.43° for the angle of diagnostic gaze direction ≤ 3.13° at the test distance of 2.5 m. The individual standard uncertainties of the influence quantities on the angles are (k = 1): 1.55°/1.01° (horizontal/vertical angle of the position sensor), 0.19° (distance sensor), 0.06° (calibration of the projection image of the beamer), and 0.02° (image resolution of the beamer). The maximum valid test distance of the digital screen test is 3.8 m. CONCLUSION: The digital screen test is compact and can be used at different locations. Compared to the traditional test, the time required for examination via the digitised test is less; additionally, its documentation is simplified. The measurement uncertainty of the diagnostic gaze direction angle is dominated by the sensor drift of the position sensor in the horizontal direction (yaw angle) and is due to the sensor technology. However, this drift error does not affect the squint angle measurement result nor its measurement uncertainty because the measurement principle used here is based on the congruence between the position cross and the fixation object and the confusion principle and compensates for the drift error. The measurement uncertainties of the determined measurement system are the lower limits of the uncertainties in the clinical use of the digital screen test if there are no effects due to significant patient deviations.

High-addition segmented refractive bifocal intraocular lens in inactive age-related macular degeneration: A multicenter pilot study.

This multicenter, open-label study aimed to determine the safety and functional outcome of a high-addition segmented refractive bifocal intraocular lens (IOL) in late inactive age-related macular degeneration (AMD). Twenty eyes of 20 patients were enrolled and followed until 12 months after the intervention. Patients underwent cataract surgery with implantation of a LS-313 MF80 segmented refractive bifocal intraocular lens with a near addition of +8.0 D (Teleon Surgical Vertriebs GmbH, Berlin, Germany). The main outcome measures were distance corrected near visual acuity (DCNVA) and safety as determined by intra- and post-operative complications. Secondary outcomes included distance corrected visual acuity (CDVA), uncorrected distance visual acuity (UDVA), uncorrected near visual acuity (UNVA), the need for magnification to read newspaper, preferred reading distance, speed and performance (logRAD), as well as patient satisfaction. Mean DCNVA improved from 0.95 (±0.19) to 0.74 (±0.35) logMAR, until 6 months after surgery, P<0.05. CDVA improved from 0.70 (±0.23) to 0.59 (±0.30) logMAR, UDVA from 0.94 (±0.25) to 0.69 (±0.34) logMAR, UNVA from 1.08 (±0.19) to 0.87 (±0.43) logMAR. The mean need for magnification decreased from 2.9- to 2.3-fold, preferred reading distance from 23 to 20 cm. No intraoperative complications occurred during any of the surgeries. One patient lost > 2 lines of CDVA between 6 and 12 months, in another case, the study IOL was exchanged for a monofocal one due to dysphotopsia and decreased CDVA. Implantation of a segmented refractive bifocal IOL with +8.0 D addition improves near and distance vision in patients with late AMD and has a satisfactory safety profile.

Comparison of spherical and aspherical intraocular lenses with decentration and tilt error using a physical model of human contrast vision and an image quality metric.

PURPOSE: In this study, two intraocular lenses (spherical IOL SA60AT and aspherical IOL SN60WF) are examined in an eye model under conditions of misalignment (defocus, decentration and tilt). The lenses are rated using the contrast sensitivity function (CSF) based on Barten's physical model. The square root integral (SQRI) method is used as a quality criterion comparable to the subjective image quality assessment of the human eye. METHODS: The IOLs to be tested are decentered from 0 to 1mm and tilted from -5 to +5 degrees in the Navarro eye model (optimized for far-point 6m and pupil aperture 3mm). The defocus of the IOLs is ±0.1mm at the anterior chamber depth (ACD). The optical modulation transfer function (MTF) is simulated with a ray tracing program. The SQRI is calculated using this MTF and the Barten CSF model (for in-focus at aperture 3 and 4.5mm and for defocus at 3mm). RESULTS: With increasing decentration, the spherical IOL shows a significantly smaller loss of quality for both apertures compared to the aspherical lens. With an aperture of 4.5mm, the image quality of the aspherical IOL is better for small decentration and tilt. The loss of quality of the spherical IOL increases with increasing tilt in both directions. In contrast, the image quality of the aspherical IOL is reduced under decentration for certain tilt values. For ACD-0.1mm, both IOLs behave similarly to the in-focus situation. For ACD+0.1mm, the influence of tilt without decentration is small for both IOLs. With increasing decentration, the quality loss of the aspherical IOL is similar to that in-focus and greater than that of the spherical lens. CONCLUSION: In general, under the same conditions the spherical SA60AT displays a lower tolerance in loss of quality of subjective vision with lens alignment errors, in comparison to the aspherical SN60WF, limited by certain combinations of decentration and tilt according to this study. This study shows a way to evaluate IOLs based on the subjective visual performance of the eye.

Results of different strategies to manage complicated retinal re-detachment.

PURPOSE: Complicated retinal re-detachment with inferior proliferative vitreoretinopathy (PVR) remains a challenge. This study's aim was to compare vitrectomy with conventional silicon oil (CSO) combined with an encircling band (EB) and vitrectomy with heavy silicon oil (HSO) alone to treat retinal re-detachment through inferior PVR, where standard procedures have already failed. METHODS: A retrospective analysis was done on patients with inferior complex re-detachment with secondary PVR after primary surgery, who received pars plana vitrectomy (PPV) with CSO combined with EB (group 1) or PPV alone with HSO (group 2) between December 2006 and August 2017. The primary endpoint was retinal reattachment, and the secondary endpoint was visual acuity (VA) change and complications in both groups. RESULTS: This study included 119 eyes. Total single surgery anatomical success (SSAS) was 64%, with 80% (52/65) achieved in group 1 and 44.5% (24/54) in group 2 (p < 0.0001). The total final anatomical success (FAS) rate was 79% (94/119). In group 1, FAS was 91% (59/65) compared with 65% (35/54) in group 2 (p = 0.003). The pretreatment VA of group 1 had a median of 1.4 logMAR (95% CI 0.3-1.8), and group 2 showed a median of 1.4 logMAR (95% CI 0.2-1.8). The post-treatment decrease in group 1 was a median equal to - 0.6 versus - 0.1 for group 2 (p = 0.0001). Serious complications were similar in both groups. CONCLUSION: For complicated retinal re-detachment through inferior PVR, the combination of PPV with EB may lead to better anatomical (SSAS, FAS) and functional success compared with PPV alone with HSO.

New retinal tack designs: an analysis of retention forces in human scleral tissue.

PURPOSE: The study aimed to construct a new retinal tack design with high retention forces to prevent spontaneous disentanglement in cases of complicated retinal surgery. METHODS: Six new forms for the peak of a retinal tack were developed using computer-aided design (CAD); then a prototype was produced for each model. Finally, standardised design testing was conducted using human (ex vivo) sclera by logging 15 consecutive measurements for each model. RESULTS: Seven different models underwent pull-out testing (six new models and the original tack model), but two tack models (Model 4, Model 5) failed to penetrate the human tissue. The highest pull-out forces (median) were measured for Model 3, followed by Model 6, Model 2 and Model 1. The original Heimann tack (Model H) was found to have the lowest retention forces. CONCLUSION: The different tack designs altered the penetration and holding forces. The retention forces of the proposed peak design led to a significant increase in the retention forces that were more than twice as high as those in the original Heimann Model.

The Cosine Similarity Technique: A new method for smart EXCIMER laser control.

PURPOSE: To introduce additional steps towards smart laser control in eye surgery, with the use of the cosine similarity technique to analyze the spectra of organic polymers obtained using non-contact photoacoustic spectroscopy (NCPAS). METHODS: The experiments were performed with two organic polymers: polyethylene and polyamide. A 193 nm excimer laser was used for photoablation at a repetition rate of 200Hz. The resulting acoustic signal of the ablation process was recorded by a capacitor microphone and then preamplified and digitized. For each specimen, four measurements with 1000 single pulses were taken. The cosine similarity technique was then used to compare the spectra of the polymers. The performance of the discrimination technique was evaluated by receiver operating characteristic analysis. RESULTS: It was possible to correctly recognize a material with a probability of approximately 98% using the cosine similarity technique at a laser repetition rate and recording rate of 200 Hz, which represents the acoustic signal of one laser pulse. CONCLUSIONS: The determination of materials with the cosine similarity method (CSM) is a fast, precise and promising approach towards smart laser control. Additional steps could include the design of a database containing generic spectra, using higher repetition rates, and the combination of NCPAS results with the position of the laser beam.

PROSPECTIVE RANDOMIZED TRIAL ASSESSING THE IMPACT OF FEEDBACK MECHANISMS ON PATIENT POSITIONING.

PURPOSE: To investigate the use of a head-fixed feedback sensor to improve good positioning times after macular hole or retinal detachment surgery. The instructional methods, macular hole closure rates, and questionnaire responses were also evaluated. METHODS: After randomization, sensor devices with different feedback types (none/acoustic/vibration) were fixed on the patients' heads. Two positioning recommendations (verbal/illustrated) were used. The posturing data were logged every 500 ms for 24 hours. RESULTS: Forty-eight data sets (24 per group) were evaluated. Using sensory feedback, the median time for face-down positioning after macular hole surgery (Group 1) was significantly boosted from 463 minutes (range: 61-1,168) to 1,257 minutes (range: 1,024-1,327). The side positioning time after retinal detachment surgery (Group 2) increased from a median of 1,032 minutes (range: 520-1,165) to 1,284 minutes (range: 1,231-1,437). The night-time alarm records were reduced; however, the instructional methods exhibited no noteworthy effects. The questionnaires indicated positive acceptance of the sensors. CONCLUSION: Sensory feedback may help in cases where face-down or side positioning is recommended. These constant reminders were superior to verbal or written reminders; however, further studies are required to assess the clinical impact of sensory feedback on patient positioning.

A systematic comparison and evaluation of three different Swept-Source interferometers for eye lengths biometry.

This study reviews the development of Swept-Source interferometers and compares systematically three different Swept-Source interferometer designs for biometric measurements of the eye. Principles characteristics, conveniences and accessibilities of the three developed systems are presented. The main difference between the three Swept-Source systems is the method of tuning the wavelength at the broadband optical amplifier. The implementation of a "quasi-phase-continuous method" (QPC) for wavelength tuning led to longer measuring depth but was more time-consuming. The wavelength tuning using a rotating polygon mirror scanner was faster. The wavelength tuning via Fourier Domain Mode Locking (FDML), where the tuning frequency ft of the filter must be matched to the inverse cavity roundtrip time τ, achieved the widest tuning range combined with a rather better resolution and signal to noise ratio (SNR). The swept sources were compared using a fiber-optic based Michelson interferometer setup. Measurements of a self-made human model eye demonstrate excellent capturing of the biometric data, with all interfaces of eye optical components and their contours being clearly detected.

New digital methods: remodelling the harms tangent scale setting.

PURPOSE: The aim of this study is to present a feasibility study to evaluate and compare a self-constructed, digital-based tangent scale using the Harms tangent screen test for the examination of patients' strabismus angles. METHODS: The documented strabismus angles of 10 patients were measured at nine gaze-positions and compared using the Harms tangent screen test (Harms Screen) and a self-constructed digital screen test (Digital Screen). The primary outcome is the difference in the measured angles between both methods. Secondary outcomes include the duration of the examinations and the diagnostic conclusion based on the results of the measurements. RESULTS: The datasets from 10 of 13 patients were used for comparisons (median age 52 years; females 5; males 5). All measurements showed a mean of 1.77° (SD 2.95°) in horizontal deviations and 1.11° (SD 2.23°) in vertical deviations. The two methods showed differences (> 5°) in 12 cases (13.3%) for horizontal angle measurements and in four cases (4.4%) for vertical angle measurements. The median examination time was 238 s (range 60-430 s) for the Harms Screen and 150 s (range 120-600 s) for the Digital Screen tests. The diagnostic conclusions were identical for both methods. CONCLUSIONS: The feasibility of the experimental digital setup in principle is shown. Despite some deviations in the measured strabismus angles, the resulting diagnosis of the paresis was identical. The new method showed a reduction of examination time.

Quality and learning curve of handheld versus stand-alone non-mydriatic cameras.

PURPOSE: Nowadays, complex digital imaging systems allow detailed retinal imaging without dilating patients' pupils. These so-called non-mydriatic cameras have advantages in common circumstances (eg, for screening or emergency purposes) but present limitations in terms of image quality and field of view. We compare the usefulness of two non-mydriatic camera systems (ie, a handheld versus a stand-alone device) for fundus imaging. The primary outcome was image quality. The secondary outcomes were learning effects and quality grade-influencing factors. METHODS: The imaging procedures followed standard protocol and were all performed by the same investigator. Camera 1 (DRS®) was a stand-alone system, while Camera 2 (Smartscope® PRO) was a mobile system. In order to evaluate possible learning effects, we selected an examiner with no prior training in the use of these systems. The images were graded separately by two experienced and "blinded" ophthalmologists following a defined protocol. RESULTS: In total, 211 people were enrolled. Quality grade comparisons showed significantly better grades for Camera 1. Both systems achieved better quality grades for macular images than for disc-centered images. No remarkable learning effects could be demonstrated. CONCLUSIONS: Both camera systems are useful for fundus imaging. The greater mobility of Camera 2 was associated with lower image quality. For screening scenarios or telemedicine, it must be determined whether image quality or mobility is more important.

Design, Implementation and Operation of a Reading Center Platform for Clinical Studies.

Clinical reading centers provide expertise for consistent, centralized analysis of medical data gathered in a distributed context. Accordingly, appropriate software solutions are required for the involved communication and data management processes. In this work, an analysis of general requirements and essential architectural and software design considerations for reading center information systems is provided. The identified patterns have been applied to the implementation of the reading center platform which is currently operated at the Center of Ophthalmology of the University Hospital of Tübingen.

Outcomes of Ahmed Glaucoma Valve Implantation for Glaucoma Secondary to Fuchs Uveitis Syndrome.

PURPOSE: To present the outcomes of Ahmed glaucoma valve implantation (AGV) in glaucoma secondary to Fuchs uveitis syndrome (FUS). METHODS: In this retrospective chart review, two definitions of success were used: 6 mmHg ≤intraocular pressure (IOP) ≤21 mmHg (success 1), and 6 mmHg ≤ IOP ≤21 mmHg and at least 25% reduction from baseline (success 2). Depending on the need of postoperative antiglaucoma medication, success was defined as either complete or qualified. RESULTS: In total, 17 eyes of 17 patients were included. Complete success rates (both definitions) were 23.5% (n = 17) after 1 year and 23% (n = 13) after 3 years. Qualified success rates (both definitions) were 58.3% (n = 17) after 1 and 38.4% (n = 13) after 3 years. Encapsulated bleb formation was the most common complication (47% of eyes). CONCLUSIONS: AGV was moderately successful in the management of glaucoma secondary to FUS. Success rates are improved by medications, needling, and cycloablative procedures.

Comparison of ab externo trabeculotomy in primary open-angle glaucoma and uveitic glaucoma: long-term outcomes.

BACKGROUND: The aim of this study was to compare the long-term outcomes of ab externo trabeculotomy in primary open-angle glaucoma (POAG) and uveitic glaucoma (UG). DESIGN: This was a retrospective single-center case series study. PARTICIPANTS: Twenty eyes of 17 patients with POAG and 22 eyes of 18 patients with UG were included in this study. PATIENTS AND METHODS: The medical records of all consecutive patients with POAG and UG who underwent ab externo trabeculotomy since 2004 were reviewed. MAIN OUTCOME MEASURE: The main outcome measure was change in median intraocular pressure (IOP). Success was defined as IOP ≤21 mmHg (success 1) and IOP ≤21 mmHg and at least 25% reduction from baseline (success 2). RESULTS: In the POAG group, the median IOP decreased significantly from 22 mmHg (95% CI 21-25 mmHg; n=20) at baseline to 14 mmHg (95% CI 12-16; n=13) after 4 years, P<0.001. In the UG group, the median IOP decreased significantly from 27 mmHg (95% CI 24.5-30.5 mmHg; n=22) at baseline to 12 mmHg (95% CI 9-15 mmHg; n=15) after 4 years, P<0.001. Seven eyes in the UG group failed within the first year after surgery compared to none in the POAG group. Of these, four eyes had Fuchs' uveitis syndrome and two had granulomatous uveitis. No sight-threatening complications occurred in both POAG and UG groups. CONCLUSION: Ab externo trabeculotomy effectively reduced IOP in both UG and POAG groups. However, the success rates in the UG group were significantly lower due to the high failure rate in patients with Fuchs' uveitis syndrome and granulomatous uveitis. The procedure demonstrated a high safety profile in both UG and POAG patients.

Human Vision-Motivated Algorithm Allows Consistent Retinal Vessel Classification Based on Local Color Contrast for Advancing General Diagnostic Exams.

PURPOSE: Abnormalities of blood vessel anatomy, morphology, and ratio can serve as important diagnostic markers for retinal diseases such as AMD or diabetic retinopathy. Large cohort studies demand automated and quantitative image analysis of vascular abnormalities. Therefore, we developed an analytical software tool to enable automated standardized classification of blood vessels supporting clinical reading. METHODS: A dataset of 61 images was collected from a total of 33 women and 8 men with a median age of 38 years. The pupils were not dilated, and images were taken after dark adaption. In contrast to current methods in which classification is based on vessel profile intensity averages, and similar to human vision, local color contrast was chosen as a discriminator to allow artery vein discrimination and arterial-venous ratio (AVR) calculation without vessel tracking. RESULTS: With 83% ± 1 standard error of the mean for our dataset, we achieved best classification for weighted lightness information from a combination of the red, green, and blue channels. Tested on an independent dataset, our method reached 89% correct classification, which, when benchmarked against conventional ophthalmologic classification, shows significantly improved classification scores. CONCLUSIONS: Our study demonstrates that vessel classification based on local color contrast can cope with inter- or intraimage lightness variability and allows consistent AVR calculation. We offer an open-source implementation of this method upon request, which can be integrated into existing tool sets and applied to general diagnostic exams.

Long-term results of ab externo trabeculotomy for glaucoma secondary to chronic uveitis.

PURPOSE: To present the long-term results of ab externo trabeculotomy in the management of glaucoma secondary to chronic uveitis. METHODS: In this retrospective single-centre case series, medical records of patients with glaucoma secondary to chronic uveitis, who underwent ab externo trabeculotomy, were evaluated. Two definitions of success were used: intraocular pressure (IOP) 6 ≤ IOP ≤ 21 mmHg (success 1) or 6 ≤ IOP ≤ 21 mmHg and at least 25 % reduction from baseline (success 2). Success was complete when no additional medication was required or qualified when additional medication or cycloablative procedures were required to achieve the specific IOP definition. RESULTS: Twenty-two eyes of 18 patients were included. After 3 years, median IOP decreased from 27 mmHg [range 17-43 mmHg, mean 27.5 mmHg, 95 % confidence interval of the mean (CI) 24.5-30.5 mmHg] to 15 mmHg (range 9-19 mmHg, mean 14.5 mmHg, CI 13-16.1 mmHg). Complete and qualified success 1 was 23 and 45 % after 3 years, respectively. For success 2, the rates were 23 and 32 %, respectively. Hyphema was the most common complication, which resolved completely within 1 month after surgery without further intervention. CONCLUSION: Trabeculotomy ab externo was moderately successful in glaucoma secondary to chronic uveitis after 3 years. No sight-threatening complications were observed during the follow-up period.

Submacular predominantly hemorrhagic choroidal neovascularization: resolution of bleedings under anti-VEGF therapy.

PURPOSE: To report the visual and morphological outcomes following intravitreal bevacizumab in neovascular age-related macular degeneration (nAMD) with submacular, predominantly hemorrhagic, lesions. METHODS: Retrospective study of patients with a follow-up after 1 year. All eyes with submacular hemorrhages larger than 50% of the total lesion size and received only anti-VEGF (vascular endothelial growth factor) monotherapy (intravitreous administration of 1.25 mg bevacizumab, PRN). The primary endpoint was the change in hemorrhage size and time to resolution, in association with the mean best-corrected visual acuity (BCVA). The eyes were grouped based on the size of the hemorrhage: group A (≥1 to <4 disc area [DA]), group B (≥4 to <9 DA), and group C (≥9 DA). RESULTS: Forty-six consecutive eyes were included. The mean area of the hemorrhage was 6 DA at baseline. Eyes with smaller bleeding (group A) had better chances of stabilized or improved vision. Complete resolution of the hemorrhage was seen in 96% of the eyes within 1 year. The mean BCVA increased from 0.81 logarithm of the minimum angle of resolution (logMAR) (95% confidence interval [CI]: 0.70-0.92) (Snellen 20/125) at baseline to 0.75 logMAR (95% CI: 0.62-0.88) (20/125) after 1 year (P=0.11). BCVA improved (one or more ETDRS [Early Treatment of Diabetic Retinopathy Study] lines) in 57% of the eyes (13/23) in group A; 53% (8/15) in group B; and 38% (3/8) in group C. CONCLUSION: Many of the eyes with hemorrhagic lesions showed stabilization or improvement of the mean BCVA after treatment within 1 year. Anti-VEGF treatment can be considered as a useful treatment option in eyes with hemorrhages secondary to nAMD.

Exit strategies in canaloplasty: intraoperative conversion into 180-degree trabeculotomy or 360-degree trabeculotomy in cases of unsuccessful catheterisation of Schlemm's canal: influence of degree of canal cleavage.

PURPOSE: To investigate the safety and efficacy of intraoperative conversion of unsuccessful canaloplasty technique into 180-degree metal or 360-degree suture trabeculotomy. METHODS: In this retrospective observational case series, 35 eyes of 35 patients with open-angle glaucoma (OAG) who had undergone unsuccessful canaloplasty technique and underwent intraoperative conversion were studied. In 17 eyes (group A), the procedure was converted into 180-degree metal trabeculotomy because of unsuccessful circumferential Schlemm's canal (SC) catheterisation. Group B included 18 eyes that were converted into 360-degree trabeculotomy because of cheese wiring of tension suture through the trabecular meshwork (TM) after successful complete catheterisation of SC. RESULTS: Median preoperative IOP was 22.0 mmHg (range 16-34) in group A, and 22.0 mmHg (range 15-48) in group B. Median IOP was significantly reduced in both groups postoperatively, at the 12-month examination to 15.0 mmHg (range 9-21) representing a reduction of 36 % in group A, and to 14.5 mmHg (range 8-21) representing a reduction of 34 % in group B. Median glaucoma medication number decreased significantly from 4 (range 2-4) and 3 (range 1-4) preoperatively to 2 (range 0-4) and 1 (range 0-3) at 12 months in groups A and B respectively. Hyphema was the commonest complication, with an incidence of 76 % in group A and 78 % in group B. CONCLUSION: 180-degree metal or 360-degree suture/catheter trabeculotomy are safe and effective surgical backup methods to control IOP in cases of unsuccessful intracanalicular placement of tension suture during canaloplasty surgery.

Switching intravitreal anti-VEGF treatment in neovascular age-related macular degeneration.

PURPOSE: To compare the outcomes after switching between bevacizumab and ranibizumab therapy due to poor treatment effect in neovascular age-related macular degeneration (AMD). METHODS: This is a retrospective review of patients with neovascular AMD with first treatment using intravitreal bevacizumab (group 1) or ranibizumab (group 2) who switched to the other drug due to poor treatment effect. Primary outcome measures were change in mean best-corrected visual acuity (BCVA) and mean central retinal thickness (CRT) at 1 year and last visit. RESULTS: Eighty-seven eyes met the inclusion criteria. In group 1 (43 eyes), the mean BCVA decreased from 20/94 to 20/100 at 1 year after being switched (p = 0.573) and to 20/150 (p = 0.015) at final visit (mean 29.2 months, range 12-53). In group 2 (44 eyes), mean BCVA decreased from 20/72 to 20/90 (p = 0.401) and 20/100 (p = 0.081) at 1 year after switch and at final visit (mean 20.1 months, range 10-40), respectively. The mean CRT at switch, 1 year after switch, and at final visit were 344.4 ± 140 µm (mean ± SD), 286.26 ± 155 µm (p = 0.019), and 290.58 ± 196 µm (p = 0.009) in group 1 and 329.36 ± 144 µm, 302.0 ± 179 µm (p = 0.215), and 309.5 ± 220 µm (p = 0.154) in group 2, respectively. CONCLUSIONS: The mean BCVA decreased over time in both groups; however, nearly 30% of the eyes in each group showed vision improvement after switching. Mean CRT decreased in both groups, which was more pronounced after being switched from bevacizumab to ranibizumab. In neovascular AMD, a switch between ranibizumab and bevacizumab can be considered as a further therapy option if poor treatment effect is seen with the initial therapy.