Effectiveness and safety of VISULAS® green selective laser trabeculoplasty: a prospective, interventional multicenter clinical investigation.

PURPOSE: To evaluate the effectiveness and safety of Selective Laser Trabeculoplasty (SLT) with the SLT mode of the VISULAS® green laser in patients with primary open-angle glaucoma (POAG). METHODS: This prospective, interventional multicenter clinical investigation included patients with POAG who either needed a treatment escalation because the individual intraocular pressure (IOP) target was not met or treatment initiation and had an IOP ≥ 17 mmHg at baseline in the study eye. The study was conducted in five research centers across Germany. Approximately 100 laser applications were delivered to 360° of the trabecular meshwork. Glaucoma medications were not modified during the 3-month follow-up to allow evaluation of the sole effect of VISULAS® green with SLT. Efficacy outcomes were postoperatively absolute and relative IOP changes at 1 and 3 months. Safety outcomes analyzed the rate of intra- and postoperative adverse events. RESULTS: Thirty-four eyes of 34 POAG patients were included. The overall mean number of preoperative glaucoma medications was 2.2 ± 1.4 in 29 treated eyes, 5 eyes were treatment naïve. Mean baseline IOP (mmHg) was 21.0 ± 2.69 and was reduced by - 3.53 ± 3.34 [95% CI - 4.61; - 2.45] and - 3.59 ± 3.41 [95% CI - 4.64; - 2.53] at the 1- and 3-month follow-up, respectively (p < 0.0001), with 48.5% of cases achieving a ≥ 20% IOP reduction at 3 months [95% CI = 30.8%; 66.5%]. The mean relative IOP reduction was - 16.4% and - 16.3% at 1 and 3 months, respectively (p < 0.0001). Potentially device- or procedure-related adverse events were mild to moderate and included 3 postoperative IOP-spikes and 6 reports regarding eye pain and discomfort. All were resolved without sequelae. CONCLUSIONS: SLT performed with the VISULAS® green laser achieved clinically significant additional IOP reductions in medically treated as well as in treatment naïve eyes with POAG and there were no relevant safety issues. The results are comparable to other reported SLT studies.

Response of Retinal Pigment Epithelium (RPE)-Choroid Explants to Thermal Stimulation Therapy of the RPE (TSR).

BACKGROUND AND OBJECTIVES: The thermal stimulation therapy of the retinal pigment epithelium (TSR) is a sublethal laser technique for thermal stimulation of the retinal pigment epithelium (RPE)-Bruch's membrane (BrM)-complex. The aim of this study was to investigate the influence of TSR on the release of age-related macular degeneration (AMD)-relevant cell mediators. STUDY DESIGN/MATERIALS AND METHODS: Porcine RPE-BrM-choroid explants were irradiated with a 532 nm continuous wave laser using different spot sizes (100-300 µm, duration 100 milliseconds, 15-100 mW). Cell death was investigated by calcein staining. Explants were treated with grids of sublethal spots and cultivated in modified Ussing chambers. The effect on matrix metalloproteinase-2 (MMP-2) and -9 was investigated by zymography and quantitative reverse transcription polymerase chain reaction. Secretion of vascular endothelial growth factor (VEGF), pigment epithelium derived factor (PEDF), and transforming growth factor-ß (TGF-ß) was analyzed by enzyme-linked immunosorbent assay and expression of HSP70 was examined by western blot. Integrity of the RPE/BrM-complex was analyzed by scanning electron microscopy. RESULTS: Laser powers of 15 mW (100 µm) and 45 mW (300 µm) did not induce RPE cell death. The integrity of the RPE/BrM-complex was not impaired after TSR. After TSR with 300 µm spot size, we observed a significant increase of active MMP-2 in the basal compartments. The content of PEDF significantly increased in treated explants in both compartments with 100 and 300 µm spot sizes. VEGF and TGF-ß secretion was not triggered by TSR. CONCLUSIONS: TSR represents a possible RPE stimulating treatment for dry AMD. TSR increases the basal release of active MMP-2, which might reverse age-related thickening of BrM. VEGF secretion was not triggered by TSR while anti-angiogenic PEDF was increased, indicating an induction of an anti-angiogenic and neuroprotective environment. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Retinal volume change is a reliable OCT biomarker for disease activity in neovascular AMD.

PURPOSE: Current algorithms for automated computer interpretation of optical coherence tomography (OCT) imaging of patients suffering from neovascular age-related macular degeneration (AMD) mostly rely on fluid detection. However, fluid detection itself and correct interpretation of the fluid currently limits diagnostic accuracy. We therefore performed a detailed analysis of the requirements that would have to be met for fluid detection approaches. We further investigated if monitoring retinal volume would be a viable alternative to detect disease activity. METHODS: Retrospective analysis and manual grading of 764 OCT volume scans of 44 patients with exudative AMD treated with intravitreal anti-VEGF injections at a pro-re-nata (PRN) treatment regimen for at least 24 months. RESULTS: Detection of subretinal fluid (SRF) or intraretinal fluid (IRF) alone is not sufficient for disease detection. A combination of SRF and IRF can detect disease activity with a sensitivity of 98.6% and a specificity of 82%. With further characterization of IRF into exudative and degenerative cysts, specificity can be increased to 100%. However, correct characterization is currently not achieved by published fluid detection approaches. Change of macular retinal volume (MRV) can depict disease activity with sensitivity of 88.4% and specificity of 89.6%. Combination with the detection of SRF can further improve diagnostic accuracy to a specificity of 93.3% and sensitivity of 93.9% without relying on IRF or IRF characterization. CONCLUSION: Fluid detection without further characterization is not sufficient for AMD monitoring. Either further distinction between exudative and degenerative cysts is necessary, or other activity markers have to be taken into account. MRV offers good potential to fill this diagnostic gap and might become an important monitoring marker.

Release of Different Cell Mediators During Retinal Pigment Epithelium Regeneration Following Selective Retina Therapy.

Purpose: To investigate the effect of selective retina therapy (SRT) on the release of AMD-relevant cell mediators, such as matrix metalloproteinases (MMPs), VEGF, and pigment epithelium derived factor (PEDF) using different laser spot sizes and densities. Methods: Porcine RPE-choroid explants were treated with a pulsed 532 nm Nd:YAG laser using (1) large spot sizes, (2) small spot sizes with a high-density (hd) treatment, and (3) small spot sizes with a low-density (ld) treatment. Explants were cultivated in modified Ussing chambers. RPE regeneration and RPE cell death were investigated by calcein-AM staining and immunofluorescence. The MMP release was examined via zymography and immunofluorescence. VEGF and PEDF secretion was analyzed by ELISA. Results: During pigment epithelium regeneration (PER), mitosis and RPE cell migration were observed. Four days after SRT (large spot size) the content of active MMP2 increased significantly (P < 0.01). Hd treatment with small spot sizes resulted also in an increase of active MMP2 (P < 0.05). In immunofluorescence explants showed a localized expression of MMP2 within the healing lesions after irradiation. The PEDF level increased significantly (P = 0.01) after SRT with large spot sizes. VEGF secretion decreased significantly (P < 0.05) following SRT with large spot sizes and with hd treatment of small spot sizes. Conclusions: SRT induces a cytokine profile, which may improve the flux across Bruch's membrane, slows down progression of early AMD by RPE regeneration, and inhibits the formation of choroidal neovascularization. The cytokine release depends on the size and density of applied laser spots.

Power-controlled temperature guided retinal laser therapy.

Laser photocoagulation has been a treatment method for retinal diseases for decades. Recently, studies have demonstrated therapeutic benefits for subvisible effects. A treatment mode based on an automatic feedback algorithm to reliably generate subvisible and visible irradiations within a constant irradiation time is introduced. The method uses a site-individual adaptation of the laser power by monitoring the retinal temperature rise during the treatment using optoacoustics. This provides feedback to adjust the therapy laser power during the irradiation. The technique was demonstrated on rabbits in vivo using a 532-nm continuous wave Nd:YAG laser. The temperature measurement was performed with 523-nm Q-switched Nd:YLF laser pulses with 75-ns pulse duration at 1-kHz repetition rate. The beam diameter on the fundus was 200 µm for both lasers, respectively. The aim temperatures ranged from 50°C to 75°C in 11 eyes of 7 rabbits. The results showed ophthalmoscopically invisible effects below 55°C with therapy laser powers over a wide range. The standard deviation for the measured temperatures ranged from 2.1°C for an aim temperature of 50°C to 4.7°C for 75°C. The ED50 temperature value for ophthalmoscopically visible lesions in rabbits was determined as 65.3°C. The introduced method can be used for retinal irradiations with adjustable temperature elevations.

Intravitreal injection of anti-Interleukin (IL)-6 antibody attenuates experimental autoimmune uveitis in mice.

PURPOSE: To evaluate the effect of an intravitreally applied anti-IL-6 antibody for the treatment of experimental autoimmune uveitis (EAU). METHODS: EAU was induced in female B10.RIII mice by Inter-Photoreceptor-Binding-Protein (IRBP) in complete Freund's adjuvant, boosted by Pertussis toxin. Single blinded intravitreal injections of anti-IL-6 antibody were applied 5-7days as well as 8-10days (3day interval) after EAU induction into the randomized treatment eye and phosphate buffered saline (PBS) into the fellow control eye. Clinical and fluorescein angiography scoring (6 EAU grades) was done at each injection day and at enucleation day 14. Enucleated eyes were either scored histologically (6 EAU grades) or examined by ELISA for levels of IL-6, IL-17 and IL-6 soluble Receptor (sIL-6R). RESULTS: Uveitis developed in all 12 mice. Clinical uveitis score was significantly reduced (p=0.035) in treated eyes (median 2.0, range 0-4.0, n=12) compared to the fellow control eyes (median 3.0, range 1.0-4.0, n=12). Angiography scores were reduced in 9/12 treated eyes and histological scores in 3/4 treated eyes compared to the fellow control eyes. Cytokine levels were determined in 8 mice, of which 4 responded to anti-IL-6 treatment and 4 did not respond. All mice responding to treatment had a significant reduction of IL-6 (p<0.01) and IL-17 (p=0.01) levels in treated eyes compared to the fellow control eyes. This difference was not seen in non-responding mice. CONCLUSIONS: Intravitreal anti-IL-6 treatment significantly attenuates experimental autoimmune uveitis in mice. EAU activity correlates with ocular IL-6 and IL-17 levels.

Long-term, therapy-related visual outcome of 49 cases with retinal arterial macroaneurysm: a case series and literature review.

PURPOSE: Retinal arterial macroaneurysms (RAMAs) are acquired dilations of branches of the central retinal artery. Treatment depends on vision-limiting complications. We compare the long-term visual acuity (VA) in three groups according to treatment. METHODS: 49 charts of patients with RAMA were reviewed. 16 remained untreated, 15 received photocoagulation and 18 vitrectomy. Patients underwent full ophthalmological examinations and up-to-date imaging. We evaluated chosen therapy, complications and final VA at the last visit. RESULTS: 65% of the cohort was female, aged 75±11 years (mean±SD). Follow-up was 34±23 months. These parameters did not differ significantly between the three groups. In the observed group, initial VA was 0.48 (mean log MAR) vs 0.35 at the final visit, in the photocoagulation group 0.55 vs 0.59, and in the vitrectomy group 1.8 vs 0.77. VA was significantly worse at enrolment in the vitrectomy group, while all other VA differences were not significant. CONCLUSIONS: The overall visual prognosis of RAMA was good, even after macular complications. VA remained unchanged in the observed and the laser groups and was comparable in all groups after 3 years. Based on an individual treatment decision, all therapies were effective and efficient. If subfoveal haemorrhage caused a macular hole, the VA outcome was limited.

Photocoagulation in rabbits: optical coherence tomographic lesion classification, wound healing reaction, and retinal temperatures.

BACKGROUND AND OBJECTIVE: The rabbit is the most common animal model to study retinal photocoagulation lesions. We present a classification of retinal lesions from rabbits, that is based on optical coherence tomographic (OCT) findings, temperature data, and OCT-follow-up data over 3 months. MATERIALS AND METHODS: Four hundred eighty-six photocoagulation lesions (modified Zeiss Visulas® 532 nm CW laser, lesion diameter 133 µm, exposure duration 200 milliseconds or variable, power variable) were analyzed from six eyes of three chinchilla gray rabbits. During the irradiation of each lesion, we used an optoacoustics-based method to measure the retinal temperature profile. Two hours, 1 week, 1 month, and 3 months after the treatment, we obtained fundus color and OCT (Spectralis®) images of each lesion. We classified the lesions according to their OCT morphology and correlated the findings to ophthalmoscopic and OCT lesion diameters, and temperatures. RESULTS: Besides an undetectable lesion class 0, we discerned subthreshold lesions that were invisible on the fundus but detectable in OCT (classes 1 and 2), very mild lesions that were partly visible on the fundus (class 3), and 3 classes of suprathreshold lesions. OCT greatest linear diameters (GLDs) were larger than ophthalmoscopic lesion diameters, both increased for increasing classes, and GLDs decreased over 3 months within each class. Mean peak end temperatures for 200 milliseconds lesions ranged from 61°C in class 2 to 80°C in class 6. CONCLUSION: The seven step rabbit lesion classifier is distinct from a previously published human lesion classifier. Threshold lesions are generated at comparable temperatures in rabbits and humans, while more intense lesions are created at lower temperatures in rabbits. The OCT lesion classifier could replace routine histology in some studies, and the presented data may be used to estimate lesion end temperatures from OCT images.

Toll-like receptor 3 activation in retinal pigment epithelium cells - Mitogen-activated protein kinase pathways of cell death and vascular endothelial growth factor secretion.

PURPOSE: Toll-like receptor 3 (TLR3) is a receptor of the innate immune system, recognizing double-stranded RNA. TLR3 can lead to cytokine release or apoptosis and has recently been associated with the development of geographical atrophy via cytotoxic effects on the retinal pigment epithelium (RPE). The current study was conducted to elucidate the underlying pathways of TLR3 effects in the RPE. METHODS: TLR3 activation via polyinosinic acid/polycytidylic acid (Poly I:C) was investigated in primary porcine RPE cells, focussing on cell death and vascular endothelial growth factor (VEGF) secretion. Primary cells were stimulated with different concentrations of Poly I:C. Cell death was investigated in trypan blue exclusion assay and cell death detection ELISA. VEGF and IFN-ß secretion were also detected in ELISA. As Mitogen-activated protein kinases (MAPK) play an important part in TLR3-mediated signal transduction, we investigated the influence of JNK, ERK1/2 and p38 on cell death and VEGF secretion, using commercially available inhibitors. RESULTS: Activation of TLR3 by Poly I:C induced concentration-dependent cell death, partly mediated by JNK. ERK1/2 was activated and exerted some protection. Furthermore, higher concentrations of Poly I:C increased VEGF secretion after 4 and 24 hr, which was independent of MAPK. CONCLUSION: The induction of cell death in RPE cells by TLR3 activation confirms possible involvement of TLR3 activation in GA. As cell death is partly mediated by JNK, more studies should be conducted investigating the role of JNK in RPE cell death to evaluate whether its inhibition might be a new therapeutic opportunity for the treatment of geographical atrophy. Additionally, effects on VEGF secretion can be found.

Cataracta ossea - Ultrastructural and specimen analysis.

BACKGROUND: Although intraocular osseous metaplasia is a well-known phenomenon, ossification of the lens is a rare phenomenon nowadays. MATERIAL AND METHODS: An enucleated phthisical eye showed a rock-hard intraocular particle. Lens status after a trauma 36 years ago had been unclear. Differential diagnosis included an intraocular foreign body or ossification of the lens. X-ray diffraction analysis showed microcrystalline apatite indicating a mineralized structure. Histologic specimens revealed a mineralized lens that underwent secondary osseous metaplasia. CONCLUSIONS: Due to the small number of cases, the mechanisms and preconditions of osseous metaplasia of the lens are not understood in detail, but injury to the lens capsule and availability of blood supply are being discussed. Both were present in this case, in which the luxated lens ended up in the ciliary body region. The mechanism resembled enchondral ossification rather than intramembranous ossification, which is seen in osseous metaplasia of other intraocular structures.

Selective retina therapy (SRT) of chronic subfoveal fluid after surgery of rhegmatogenous retinal detachment: three case reports.

BACKGROUND: Shallow subfoveal fluid accumulation after successful surgery for retinal detachment can be the reason for compromised visual acuity. To date, therapeutical options to tackle this problem have not been established. Selective retina therapy (SRT) is a new laser technology that uses a train of mus-laser pulses to selectively damage retinal pigment epithelial (RPE) cells while sparing retinal structures. METHODS: We treated three patients with chronic subfoveal fluid accumulation after retinal detachment surgery. The median period between retinal surgery and SRT treatment was 7 months. For SRT, we used a prototype frequency-doubled, Q-switched Nd:YLF laser (lambda = 527 nm). Each laser exposition contained 30 pulses (t = 1,7 micros, 100 Hz, E = 100-400 microJ). Two of the three patients were treated subfoveally. OCT III (optical coherence tomography) examinations were performed to evaluate changes in subretinal fluid accumulation. RESULTS: In all three patients, we observed complete resolution of subfoveal fluid within 1-5 months. Follow-up has been 16 months to 2 years. Visual acuity improved in all patients. In one patient, cystoid macular edema developed 3 months after treatment. Additional SRT treatments were not necessary. CONCLUSION: SRT is a safe treatment. Visual acuity improved after SRT, even in subfoveal irradiations. SRT is an option to support subretinal fluid reabsorption. In this situation where no other therapeutical options are established, SRT may be a beneficial treatment for chronic subfoveal fluid accumulation after retinal detachment surgery.