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.

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.

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.

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.

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.

Usability of a gravity- and tilt-compensated sensor with data logging function to measure posturing compliance in patients after macular hole surgery: a pilot study.

BACKGROUND: To investigate the use of a small gravity- and tilt-compensated, head-fixed sensor with data-logging function to measure compliance and head posture of patients after macular hole surgery based on the recommendation of a face-down position. Main outcome measures were the median inclination, the times with correct or incorrect head position and the acceptance/annoyance of a data-logging device. METHODS: A small battery-driven electronic sensor device with gravity and tilt compensations was placed within a plastic box and fixed on a patient's head with a headband. Face-down position data were logged every half second for 24 h after macular hole surgery and were stored on a memory card. RESULTS: Thirteen patients were involved (seven females, six males, median age, 68 years, range, 50-75 years), two cases with early dropout. Ten of 11 datasets could be evaluated showing a complete data record file. The average percentage for face-down >45° was 18% within 24 h and 17% in the daytime. The median inclination was -6.7° (min: -89.7° max: 90°). The sensor system was well tolerated and disturbance was rated low by all ten patients. CONCLUSIONS: While the patients' face-down posture considerably varied over time in extent and continuity, the assessment might lead to optimizing the patients' compliance with the optimal position. Results showed an excellent acceptance of the motion sensor.

Is cyclophotocoagulation an option in the management of glaucoma secondary to Fuchs' uveitis syndrome?

BACKGROUND: Glaucoma is one of the sight-threatening complications of Fuchs' uveitis syndrome (FUS) and the most difficult to manage. The goal of this study was to assess the efficacy and safety of cyclophotocoagulation (CPC) in the management of glaucoma secondary to FUS. METHODS: In a retrospective analysis, the charts of all patients with FUS referred to our clinic from January 2002 to December 2012 were reviewed. In patients with glaucoma or ocular hypertension, controlled eye pressure was defined using two alternative upper limits of 6 ≤ IOP ≤ 21 mmHg and 6 ≤ IOP ≤ 18 mmHg at 1 year follow-up. RESULTS: One hundred and seventy-six patients with FUS were included in this study. Of those, 28 had ocular hypertension (OHT) or glaucoma. Mean maximal intraocular pressure (IOP) of patients with glaucoma/OHT was 40.8 mmHg. Twenty-three patients (82.1 %) had maximal IOP levels of 35 mmHg or higher. Sixteen patients with glaucoma/OHT underwent CPC alone (ten patients) or in combination with other surgical procedures (six patients). After 1 year, control of IOP for both upper limits (6 ≤ IOP ≤ 18 mmHg) and (6 ≤ IOP ≤ 21 mmHg) was achieved in six of ten patients (60 %) who received CPC alone, and in five of six patients (83.3 %) who required additional surgery after CPC. The mean number of cycloablative procedures was 1.3 (range 1-2) in the CPC alone group and 1.2 (range 1-2) in patients for whom CPC was used as adjunct therapy. There was no exacerbation of intraocular inflammation, no postoperative hypotony and no phthisis bulbi in the 16 patients who underwent CPC. CONCLUSIONS: CPC is a safe and effective procedure that should be considered if medical treatment has failed to control glaucoma in FUS.

Early postoperative changes of the foveal surface in epiretinal membranes: comparison of 23-gauge macular surgery with air vs. balanced salt solution.

OBJECTIVE: To analyze the foveal surface using binary image analysis after spectral-domain optical coherence tomography (SD-OCT) following 23-gauge macular surgery in epiretinal membranes (ERM) using either air tamponade (AIR) or balanced salt solution (BSS). METHODS: One hundred twenty-four eyes (124 patients) with ERM that had undergone membrane peeling with installation of air or BSS were analyzed retrospectively. Ophthalmic examination was performed at baseline and 3 months. OUTCOME MEASURES: The foveal area and surface symmetry, area matched thickness, area matched contour, and best-corrected visual acuity (BCVA). The OCT images were analyzed after binary conversion with ImageJ software. RESULTS: Eighty eyes (80 patients) of 124 screened patients were included (AIR group: 39 patients, BSS group: 41 patients). Median follow-up time was 14 weeks (range, 9-19 weeks). Three months after surgery, the median horizontal area decreased significantly in both groups (p < 0.0001). At follow-up, the foveal surface symmetry values for the BSS group (median, 22.73 µm, range, 0-153) were significantly lower than for the AIR group (median, 23.95 µm, range, 0-160.43) (p < 0.0001). The area-matched thickness increased significantly in both groups (p < 0.001). The AIR group showed a significant increase of the area matched contour for the nasal located measurement-areas N1 (p < 0.0003), N2 (p < 0.0079), N3 (p < 0.007). The BSS group showed a significant increase of the area-matched contour for the measurement areas N1 (p < 0.019), N2 (p < 0.0014), and N4 (p < 0.022). After surgery, median BCVA for both groups increased significantly to 0.3 logMAR. CONCLUSIONS: The analysis of early contour changes after ERM surgery was technically possible. Long-term data have to be looked at before the clinical impact of this methodology can be estimated. Although there were no big differences between both groups (AIR vs. BSS), this could change within a longer and more representative follow-up.

Critical evaluation of the usability of augmented reality ophthalmoscopy for the training of inexperienced examiners.

PURPOSE: To measure the value of augmented reality technology usage to teach the medical students performing binocular indirect ophthalmoscopy. METHODS: Thirty-seven medical students were randomly assigned to the training of binocular indirect ophthalmoscopy either in the conventional way or with augmented reality ophthalmoscopy (ARO). For testing student's skills, they had to examine a real person using a conventional ophthalmoscopy system and draw the optic disk. They also had to fill out a questionnaire. Subjective and objective evaluations were performed. RESULTS: Thirty-seven students were randomly assigned to two groups. Eighteen students were trained with conventional ophthalmoscopy and 19 students with ARO. The questionnaires showed no differences. Performing an objective analysis, the median ophthalmoscopy training score for the conventional ophthalmoscopy group was 1.2 (range, 0.67-2) and showed a significant difference (P < 0.0033) to the ARO group (median 2; range, 0.67-2). CONCLUSION: The study provides evidence that a single ARO training is efficient to improve ophthalmoscopy skills. As the objective analysis showed, the ARO group had a significantly superior performance. Our study also indicates that subjective evaluation of the fundus drawings without systematic analysis is prone to errors.

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.

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.

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.

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.

One-year results after intravitreal bevacizumab therapy for macular edema secondary to branch retinal vein occlusion.

BACKGROUND: To investigate the long-term effectiveness of intravitreal bevacizumab treatment in eyes with perfused macular edema due to branch retinal vein occlusion (BRVO). METHODS: In this prospective interventional case series, 23 consecutive, previously untreated eyes with perfused macular edema were treated with intravitreal bevacizumab (1.25 mg) injections and followed for 1 year. The main outcome measures were visual acuity (VA) and central retinal thickness (CRT). In addition, VA data were adapted to the non-logarithmic VA charts used in the previously published grid laser photocoagulation BRVO Study. RESULTS: The median VA gained 3.0 lines from baseline at 48 weeks. This was accompanied by a significant decrease of 39% of the median CRT. The mean number of re-injections was 1.6 during the first 6 months of follow-up and only 0.8 during the subsequent 6 months. In 65% of the cases, adapted VA data showed a gain of 1 or more lines and no eye lost more than 1 line. CONCLUSIONS: Repetitive intravitreal bevacizumab injections result in a significant long-term improvement of VA and CRT. The number of re-injections necessary to maintain this effect declined over time. However, the treatment seems to be only slightly better than grid laser photocoagulation.

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.

The retinal tolerance to bevacizumab in co-application with a recombinant tissue plasminogen activator.

AIM: To investigate the retinal toxicity of bevacizumab in co-application with a commercially available recombinant tissue plasminogen activator (rt-PA), and to facilitate a new therapeutic concept in the treatment of massive subretinal haemorrhage caused by neovascular age-related macular degeneration (AMD). METHODS: Isolated bovine retinas were perfused with an oxygen-preincubated nutrient solution. The electroretinogram (ERG) was recorded as a transretinal potential using Ag/AgCl electrodes. Bevacizumab (0.25 mg/ml) and rt-PA (20 microg/ml) were added to the nutrient solution for 45 min. Thereafter, the retina was reperfused for 60 min with normal nutrient solution. Similarly, the effects of rt-PA (20 microg/ml, 60 microg/ml and 200 mug/ml) on the a- and b-wave amplitudes were investigated. The percentages of a- and b-wave reduction during application and at washout were calculated. RESULTS: During application of bevacizumab (0.25 mg/ml) in co-application with 20 microg/ml (rt-PA), the ERG amplitudes remained stable. The concentrations of rt-PA alone (20 microg/ml and 60 microg/ml) did not induce significant reduction of the b-wave amplitude. In addition, 20 microg/ml rt-PA did not alter the a-wave amplitude. However, 60 microg/ml rt-PA caused a slight but significant reduction of the a-wave amplitude. A full recovery was detected for both concentrations during the washout. At the highest tested concentration of 200 microg/ml rt-PA, a significant reduction of the a- and b-wave amplitudes was provoked during the exposure. The reduction of ERG amplitudes remained irreversible during the washout. CONCLUSION: The present study suggests that a subretinal injection of 20 microg/ml rt-PA in co-application with bevacizumab (0.25 mg/ml) for the treatment of massive subretinal haemorrhage seems possible. This is a safety study. Therefore, we did not test the clinical effectiveness of this combined treatment.