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Purpose: To investigate the relationship of ocular blood flow (via arteriovenous passage time, AVP) and contrast sensitivity (CS) in healthy as well as normal tension glaucoma (NTG) subjects. Design: Mono-center comparative prospective trial Methods: Twenty-five NTG patients without medication and 25 healthy test participants were recruited. AVP as a measure of retinal blood flow was recorded via fluorescein angiography after CS measurement using digital image analysis. Association of AVP and CS at 4 spatial frequencies (3, 6, 12, and 18 cycles per degree, cpd) was explored with correlation analysis. Results: Significant differences regarding AVP, visual field defect, intraocular pressure, and CS measurement were recorded in-between the control group and NTG patients. In NTG patients, AVP was significantly correlated to CS at all investigated cpd (3 cpd: r = − 0.432, p< 0.03; 6 cpd: r = − 0.629, p< 0.0005; 12 cpd: r = − 0.535, p< 0.005; and 18 cpd: r = − 0.58, p< 0.001), whereas no significant correlations were found in the control group. Visual acuity was significantly correlated to CS at 6, 12, and 18 cpd in NTG patients (r = − 0.68, p< 0.002; r = − 0.54, p<.02, and r = − 0.88, p< 0.0001 respectively), however not in healthy control patients. Age, visual field defect MD, and PSD were not significantly correlated to CS in in the NTG group. MD and PSD were significantly correlated to CS at 3 cpd in healthy eyes (r = 0.55, p< 0.02; r = − 0.47, p< 0.03). Conclusion: Retinal blood flow alterations show a relationship with contrast sensitivity loss in NTG patients. This might reflect a disease-related link between retinal blood flow and visual function. This association was not recorded in healthy volunteers. [ABSTRACT FROM AUTHOR]

Purpose: Nonperfusion of retinal tissue due to arterial occlusion leads inevitably to mostly irreversible retinal damage. Until today no evidence-based treatment exists. Inhalation of 100% oxygen at high atmospheric pressure causes an increased solubility of oxygen in the blood that helps the retinal tissue to survive through diffusion in case of an artery occlusion till vascular recanalization occurs. Hence the purpose of this study is to compare the visual outcome in patients with retinal branch artery obstruction treated with hyperbaric oxygen versus patients treated with hemodilution only. Methods: Non-randomized, monocentric, retrospective study. Patients with diagnosis of non-arteritic retinal branch artery occlusion (BRAO) treated with hyperbaric oxygen therapy between 1997 and 2017. Exclusion criteria were central retinal artery occlusion, presence of a cilioretinal artery and arteritic cases. The control group was matched based on visual acuity (VA) at admission, age, and delay between symptoms and beginning of clinical care. Results: The control group and the matching oxygen group contained 14 patients each. Initial VA in the matched HBO group was 0.18 ± 0.19 and 0.23 ± 0.19 in the control group (p = 0.57). Final VA at discharge was 0.69 ± 0.29 in the matched oxygen group and 0.32 ± 0.23 in the control group (p = 0.0009). HBO-treated patients had a significant visual increase compared with the control group. The most common comorbidities were arterial hypertension and vascular sclerosis. Conclusion: HBO treatment appears to have a beneficial effect on visual outcome in patients with retinal branch artery occlusion. HBO treatment could be a rescue therapy at an early stage of BRAO, especially to bridge the time of a potential reperfusion. However, further, prospective, randomized clinical trials are required to verify this assumption. [ABSTRACT FROM AUTHOR]

Purpose: To test if an encircling band improves outcomes in vitrectomy for pseudophakic retinal detachment (PRD) with inferior or with multiple (4 or more) breaks.Methods: Subgroup analysis of a prospective randomized controlled multicenter trial in patients with uncomplicated PRD assigned either to 20 G vitrectomy plus encircling band (group E1), or 20 G vitrectomy without any buckle (group C), or 23/25 G vitrectomy without any buckle (group E2). The primary endpoint was defined as no indication for any retina reattaching procedure during the review period of 6 months. One hundred out of 257 patients were identified with inferior breaks and 63 patients had 4 or more breaks.Results: In patients with retinal breaks between 5:00 and 7:00, treatment was successful in 77.4% (24/31, treatment arm E1) versus 57.1% (16/28, treatment arm C) (p = 0.301, odds ratio (OR) 1.83, 95% confidence interval (CI) 0.48 to 7.17). In patients with multiple breaks, success rates were 68.2% (15/22, E1) versus. 72.4% (21/29, C, p = 0.46, OR 0.52, CI 0.08-3.65).Conclusion: Combining an encircling band with vitrectomy in patients with pseudophakic retinal detachment and inferior or multiple breaks does not significantly improve primary anatomical success in comparison to treatment with 20 G or 23/25 G vitrectomy alone. [ABSTRACT FROM AUTHOR]

Purpose: Blue-yellow short wavelength testing (BY-VEPs) has proven diagnostic relevance in detecting early ganglion cell damage, e.g., in glaucoma. To date testing has generally been conducted using individual protocols without consideration of the lens status. In this study, we compared changes in BY-VEPs and standard pattern VEPs in phakic and pseudophakic glaucoma patients and controls. Methods: The eyes of 57 healthy controls (18 pseudophakic and 39 phakic) and 67 glaucoma patients (29 pseudophakic and 38 phakic) were included in a prospective study. Phakic eyes were arranged in three groups according to the Lens Opacities Classification System III. Transient on/off isoluminant blue-yellow 2° checks were used for BY-VEPs, transient large 1° (M1) and small 0.25° (M2) black-white checks for standard pattern reversal VEPs, according to the ISCEV standards. Results: Latencies and amplitudes of M1 and M2 did not differ significantly between groups or lens status. ANOVA analysis revealed significantly longer BY-VEP latencies in glaucoma compared to controls ( p = 0.002), independently of the lens status. The amplitudes showed no such pattern ( p = 0.93). Mean defect (MD) was significantly negatively correlated to BY-VEP latency ( r = −0.54, p = 0.003) only in pseudophakic glaucoma patients. Different stages of cataract did not show a significant effect on the BY-VEP latencies. Conclusions: Glaucoma led to a significant increase of BY-VEPs latencies, while standard pattern VEPs were not influenced. The correlation of MD and BY-VEP latency only in pseudophakic glaucoma patients indicates a substantial confounding effect of lens opacifications on the diagnostic value of BY-VEPs in glaucoma. [ABSTRACT FROM AUTHOR]

Background: To characterize the effects of intravitreal injections of iodoacetic acid (IAA) in comparison to its systemic application as a measure to induce unilateral photoreceptor degeneration. Methods: Seven-week-old C57BL/6 J mice received either intravitreal injections of IAA or systemic treatment (intraperitoneal vs intravenous) and were observed in the following 5 weeks using ERG, OCT, and histology. Results: Systemic treatment with IAA induced high toxic effects and a high mortality in contrast to the intravitreal injection. Intraperitoneal application had no effect on the retina. Intravenous application of 2 × 30 mg/kg BW IAA (time between injections 3.5 h) resulted in an extinction of the ERG and a thinning of the retina, in particular of the outer nuclear layer (ONL) indicating photoreceptor degeneration. Animals receiving intravitreal injections developed cataracts already at low concentrations (up to 100 % at 0.25 mg/kg BW). Higher intravitreal IAA doses led to extinguished ERGs. In histology, a thinning of the entire retina was observed that was most prominent in the inner part of the retina. Conclusions: In contrast to intraperitoneal administration, intravenous application of IAA led to a selective photoreceptor degeneration. After intravitreal injection, dense cataracts were already observed at concentrations lower than those needed to induce changes in the ERG. ERG results must be interpreted carefully. A thinning of all retinal layers rather than a specific outer retinal degeneration was observed upon intravitreal injection. IAA is not a useful model to induce outer retinal degeneration in mice. [ABSTRACT FROM AUTHOR]

Purpose: Blue-yellow visual-evoked potentials (BY-VEPs) may be used for diagnostics of functional ganglion cell damage in glaucoma and other ocular diseases. In this study we investigated the impact of lenticular opacities on BY- and standard pattern reversal VEPs by examining patients before and after cataract surgery. Methods: Eighteen patients with moderate cataract were included in a prospective study. Transient on/off isoluminant blue-yellow 2° checks were used for short-wavelength stimulation (BY-VEP), transient large 1° (M1) and small 0.25° (M2) black-white checks for standard pattern reversal VEPs. VEPs were acquired before (24 ± 30 days) and after cataract surgery (14 ± 16 days). The contralateral eye was used as a control. Results: Amplitude and latency of M1 and M2 peaks did not change significantly from before to after surgery. The amplitude of the BY-VEPs did not change significantly after cataract surgery (pre-surgery, −7.42 ± 3.43 μV, post-surgery, −7.93 ± 3.65 μV, p = 0.42), yet the latency of the main negative peak showed a significant decrease (pre-surgery, 143.9 ± 12.9 ms, post-surgery, 133.2 ± 7.7 ms, p = 0.0006). The BCVA improvement was significant from before to after cataract surgery (pre-surgery, 0.344 ± 0.125 LogMAR, post-surgery, 0.224 ± 0.179 LogMAR, p = 0.013) yet not correlated to the absolute decrease in latency of the BY-VEP after surgery ( r = 0.309, p = 0.22). No significant changes were found in the contralateral eye. Conclusions: The BY-VEP is sensitive to lenticular opacities of the human lens, presumably due to the increased short-wavelength absorption in the aging eye. This fact should be considered when applying BY-VEPs for diagnostics. [ABSTRACT FROM AUTHOR]

Background: The fixation of polyimide stimulator foils as the basic substrate of epiretinal prostheses by using retinal tacks may cause retinal or choroidal alterations such as retinal proliferations or choroidal neovascularizations. During the prospective trial for the semichronical testing of a wireless intraocular retinal implant (EPIRET3) we investigated alterations in angiographic findings during implantation and after explantation of the device, to detect potential vascular pathologies at the fixation site or elsewhere. Methods: As the final step of the implantation surgery in six blind patients, the stimulator was placed on the retinal surface using retinal tacks. For the detection of possible morphological or vascular alterations committed by the implant fluorescein angiography (FA) was performed 1 day before and 4 weeks after implantation surgery, as well as at the final visit 5 months after explantation. Results: Following implantation surgery funduscopy and FA did not reveal any evidence of either vascular pathologies or choroidal neovascularisations (CNV), in addition, no cystoid macular edema (CME) occurred after 4 weeks. At the 6-month follow-up visit, we found a mild epiretinal gliosis formation in four patients. In one patient a retinal break occurred during explantation, requiring a temporary silicone-oil endotamponade. At the final visit, we observed a focal proliferative vitreoretinopathy (PVR) reaction without activity, while there was no evidence for a CNV formation in that area. Conclusions: The FA findings confirm our previous results on the safety of the EPIRET3 system, which was tolerated in all patients but revealed a certain risk profile in regard to the stimulator fixation. While there was no evidence for newly occurred CME or CNV during the follow-up visits, nevertheless gliosis or even PVR reaction at the tack's fixation site suggests the need to develop alternative fixation procedures of epiretinal stimulators. [ABSTRACT FROM AUTHOR]

AbstractBackground??In multifocal flicker stimulation, each step of the M-sequence consists of four consecutive flashes with a frequency of 30?Hz. The resulting amplitudes can be calculated by means of a discrete fourier transformation (DFT). With this method, amplitudes can be calculated without having to localise peaks and troughs and set cursors. The purpose of this study is to compare the re-test stability of this method to conventional mfERG stimulation.Methods??We examined 27 healthy subjects using a RETI-scan device (Roland Consult, Wiesbaden). We used 61 hexagons within a 30 deg. visual field. We compared the classic first order kernel (FOK) stimulation with the multifocal 30?Hz Flicker (mfFlicker-ERG) stimulation. Repeatability was calculated using coefficients of variation.Results??Both methods had coefficients of 15% for the sum P1-amplitude and the DFT results, respectively. The amplitudes calculated by flicker and DFT were approximately 25% smaller than the FOK amplitudes.Conclusions??This study showed no difference of re-test repeatability between the mfFlicker-ERG and the conventional first order kernel method. Since the mfFlicker-ERG method does not require a definition of peaks and troughs in order to calculate the amplitudes, we believe that a common source of error is eradicated, especially when dealing with distorted or atypical curves. [ABSTRACT FROM AUTHOR]