The factors associated with retinal pigment epithelium tear development in the early phase after treatment initiation for age-related macular degeneration.

PURPOSE: This study aimed to evaluate the factors associated with retinal pigment epithelium (RPE) tear development in the early phase after anti-vascular endothelial growth factor (VEGF) drug initiation in eyes with neovascular age-related macular degeneration (nAMD) and retinal pigment epithelial detachment (PED). METHODS: Treatment-naive eyes with nAMD and PED for which anti-VEGF drug injections had been initiated and followed up for at least 3 months after the 1st anti-VEGF drug injection, were retrospectively investigated. Baseline characteristics of the PEDs, including type, height, and area, were evaluated using fundus photographs, fluorescein angiography, and optical coherence tomography images. The association between patient age, sex, medical history, PED characteristics, and the development of RPE tears within 3 months of starting anti-VEGF therapy was examined. RESULTS: This study included 244 eyes (230 patients; mean age 75.0 years, 159 males and 71 females). RPE tears occurred in 13 eyes (5.3%) within 3 months of the start of anti-VEGF therapy. Multivariate analysis showed an association of the development of RPE tears with PED height (every 100 µm, odds ratio [OR]: 1.50, 95% confidence interval [CI]: 1.07-2.12, p = 0.019), PED area (every 10 mm2, OR: 3.02, CI: 1.22-7.46, p = 0.016), and the presence of fibrovascular PED (OR: 59.22, CI: 4.12-850.59, p = 0.002). Eyes with cleft (the hypo-reflective space beneath the fibrovascular PED) were more likely to develop an RPE tear (p = 0.01, χ-square test). CONCLUSIONS: Fibrovascular PED, large PED area, high PED height, and the cleft finding are independent risk factors for the development of RPE tears early after the administration of anti-VEGF drugs.

Wide-Field Choroidal Thickness Analysis after Half-Fluence Photodynamic Therapy Combined with Intravitreal Aflibercept Injection in Pachychoroid Neovasculopathy.

Background: Pachychoroid neovasculopathy (PNV) is a pachychoroid-spectrum disease. As blood circulation throughout the choroid may be involved in PNV pathogenesis, analysis using ultra-wide-field (UWF) fundus imaging is crucial. We evaluated choroidal thickness after half-fluence photodynamic therapy (PDT) combined with intravitreal aflibercept injection for PNV using UWF swept-source optical coherence tomography. Methods: Seventeen eyes with PNV that underwent half-fluence PDT with an adjuvant single intravitreal aflibercept injection were analyzed. To compare choroidal thicknesses in the central and peripheral choroids, we set subfields <3, <9, and 9-18 mm from the fovea. The <9 and 9-18 mm subfields were divided into four quadrants. Results: Choroidal thickness in each subfield decreased significantly after half-fluence PDT (p < 0.001); this reduction was more pronounced in the central area. We also investigated the relationship between the dominant side of the deep choroidal veins that harbor choroidal vein efflux from the macula. When choroidal thickness in the supratemporal and infratemporal 9 mm subfields were evaluated, the ratio of choroidal thickness reduction was not significantly different between the dominant and non-dominant sides. The dominant side was not associated with the extent of choroidal thickness reduction in PNV. Conclusions: Half-fluence PDT caused thinning of the entire choroid, especially in the central area, in PNV.

Clinical Characteristics of Eyes with Neovascular Age-Related Macular Degeneration and Retinal Pigment Epithelium Tears.

BACKGROUND: Although anti-vascular endothelial growth factor (anti-VEGF) therapy is the first choice of treatment for eyes with neovascular age-related macular degeneration (AMD), it sometimes results in retinal pigment epithelium (RPE) tears. This study presents the detailed clinical characteristics of RPE tears to help predict their occurrence before anti-VEGF therapy initiation. METHODS: This study retrospectively analyzed neovascular age-related macular degeneration (nAMD) patients who visited the Kyushu University Hospital and started anti-VEGF therapy between April 2013 and June 2020. Using medical records, we collected the clinical data of patients with RPE tears, including age, sex, best-corrected visual acuity (BCVA), number of anti-VEGF drug injections and the type and size of pigment epithelial detachment (PED). RESULTS: RPE tears occurred in 16 (1.50%) eyes of 16 patients in all 1068 nAMD eyes of 987 patients. The mean age of these patients with RPE tear was 81.7 ± 8.7 years. Fifteen eyes had typical AMD and one eye had polypoidal choroidal vasculopathy. The mean number of anti-VEGF drug injections before RPE tears was 5.0 ± 5.1. All patients experienced PED before the RPE tear (hemorrhagic, 4 eyes; serous vascular, 2 eyes; fibrovascular, 10 eyes). The average PED height and area were 615.7 ± 175.3 µm and 21.0 ± 7.2 mm2, respectively. The sub-RPE cleft was observed in 10 eyes. The logMAR BCVA immediately after the RPE tear (0.73 ± 0.40) at 6 months (0.86 ± 0.51) and 12 months (0.84 ± 0.43) after the RPE tear were significantly worse than that before the RPE tear (0.58 ± 0.31; p < 0.05). The BCVA of patients with RPE tears that spread to the fovea was poorer than that of patients without RPE tears. CONCLUSIONS: In patients with nAMD, RPE tears tended to occur in typical AMD eyes with high or large PEDs, and sub-RPE clefts. The visual prognosis depended on whether the RPE tear included the fovea.

Differences in Central and Peripheral Choroidal Thickness among the Subtypes of Age-Related Macular Degeneration in an Asian Population.

Age-related macular degeneration (AMD) causes visual impairment in individuals who are >50 years of age. However, no study has investigated AMD when using ultra-wide-field swept-source optical coherence tomography (UWF SS-OCT). We aimed to evaluate central and peripheral choroidal thicknesses using UWF SS-OCT, and to compare these across the AMD subtypes. We included 75 eyes of patients with typical AMD (tAMD), 56 with polypoidal choroidal vasculopathy (PCV), 29 with pachychoroid neovasculopathy (PNV), and 12 with retinal angiomatous proliferation (RAP). To compare choroidal thicknesses in the central and peripheral choroids, we established subfields of <3 mm, <9 mm, and 9-18 mm from the fovea. PNV patients were significantly younger than those with tAMD (p = 0.01). The choroidal thicknesses of PNV were significantly greater than that of tAMD in all subfields (p < 0.01), and choroidal thickness significantly correlated with age and axial length in all subfields (p < 0.05). Even after adjusting for age and axial length, the choroidal thickness in PNV was significantly greater than that in tAMD (p < 0.05). In addition, the ratio of the posterior <9 mm to a peripheral 9-18 mm choroidal thickness in PNV was significantly greater than that in tAMD (p < 0.01). A thickened choroid in PNV was more pronounced in the posterior choroid than in the periphery.

Persistence of vascular empty sleeves in choroidal neovascularization after VEGF therapy in both animal models and humans.

PURPOSE: Choroidal neovascularization (CNV) often recurs during anti-vascular endothelial growth factor (VEGF) therapy; however, little is known about the mechanism of vascular regrowth. Vascular regrowth along the empty sleeves of basement membranes was proposed as a mechanism for recurrence after the reversal of VEGF inhibition in tumors. This study investigated whether the proposed mechanism is involved in CNV during VEGF therapy. METHODS: We made two observations using a mice model, as well as patients with CNV. Laser-induced CNV mice were used to examine the vascular empty sleeves of the basement membrane and CNV with the immunohistochemistry of type IV collagen and CD31, respectively. A retrospective cohort study included 17 eyes from 17 patients with CNV treated with anti-VEGF treatment. Vascular regrowth during anti-VEGF treatment was assessed using optical coherence tomography angiography (OCTA). RESULTS: In the CNV mouse model, the CD31+ vascular endothelium area was decreased during anti-VEGF treatment compared with the IgG control (33516.7 ± 10864.7 vs. 10745.9 ± 5755.9 µm2, P < 0.05), whereas a significant difference was not observed in the area of type IV collagen+ vascular empty sleeve after the treatment compared with the control (29135.0 ± 7432.9 vs. 24592.0 ± 5935.3 µm2, P = 0.7). The proportions of CD31+ to type IV collagen+ areas were significantly decreased after the treatment (38.7 ± 7.4% vs. 17.1 ± 5.4%, P < 0.05). In the OCTA observations, the follow-up period in the retrospective cohort study was 58.2 ± 23.4 months. CNV regrowth was observed in 682 neovessels of the 17 eyes. In group 1, CNV regression and regrowth are in the same form (129 neovessels, 18.9%). In group 2, CNV regression and regrowth are in a different form (170 neovessels, 24.9%). In group 3, CNV regrowth is with a different form without the regression (383 neovessels, 56.2%). CONCLUSIONS: Parts of CNV regrowth may occur along the vascular empty sleeve, which remain after anti-VEGF treatment.

Characteristics of retinal pigment epithelium elevations preceding exudative age-related macular degeneration in Japanese.

INTRODUCTION: Drusen and pigmentary abnormality are found as the hallmark to predict progression of age-related macular degeneration (AMD). In Asian populations, exudative AMD often appears in the absence of drusen but are rather accompanied by pigmentary abnormality. Recently, shallow irregular retinal-pigment-epithelium (RPE) elevations (SIRE) has been shown as a sign of subclinical non-exudative macular neovascularization. In this study, we aimed to investigate the characteristics of optical coherence tomography (OCT) findings including SIRE before the appearance of exudative AMD. METHODS: We retrospective reviewed 32 cases of exudative AMD that occurred in the fellow eye within the 5-years-observation period. Color fundus photography, OCT, and fluorescein/indocyanine green angiography at the beginning of observation and at the time when exudative AMD appeared were examined to diagnose SIRE and the subtype of exudative AMD. RESULTS: Exudative AMD were found in 19 eyes with large drusen and 13 eyes without large drusen. Mean sub-foveal choroidal thickness without large drusen were significantly thicker than those with large drusen (336 ± 109 and 220 ± 96 µm, respectively; mean± SD). Six eyes with pachychoroid neovasculopathy, 4 eyes with Type 1 macular neovascularization, and 3 eyes with PCV had occurred in the fellow eye without large drusen. Among those, 6 eyes had been accompanied by SIRE with a greatest transverse linear dimension of 1 mm or more at the beginning of observation-period. Besides, small RPE elevations with a longest diameter of less than 1 mm had been observed in other 5 eyes. Three cases of polypoidal choroidal vasculopathy had originated from small RPE elevations. Moreover, pachyvessels, choriocapillaris thinning, or choroidal hyperpermeability were observed with SIRE or small RPE elevation. CONCLUSIONS: There is a non-drusen type of exudative AMD that originates from small RPE elevations as well as SIRE.

A Case of Bullous Central Serous Chorioretinopathy Treated with Surgical Removal of Submacular Fibrin and Subsequent Photodynamic Therapy under Silicone Oil.

Bullous retinal detachment is a rare complication in the chronic phase of central serous chorioretinopathy (CSC). Only a small subset of eyes with chronic CSC develops into the bullous variant of CSC (bCSC). In patients with bCSC, the elevated concentration of fibrin in the subretinal space leads to persistent retinal detachment and eventually, severe vision loss. We experienced a case of unilateral bCSC with a massive accumulation of subretinal fibrin. Multiple leakage points and dilated choroidal veins were also observed. The patient underwent surgical removal of subretinal fibrin and silicone oil injection followed by photodynamic therapy (PDT). After this treatment, the retina was successfully reattached, and the affected eye was free from recurrent exudative changes for more than 18 months. Massive subretinal fibrin could be surgically removed to prevent the formation of subretinal fibrosis and retinal fold, and PDT under silicone oil can control the underlying exudative changes in bCSC.

Postoperative follow-up of submacular hemorrhage displacement treated with vitrectomy and subretinal injection of tissue plasminogen activator: ultrawide-field fundus autofluorescence imaging in gas-filled eyes.

PURPOSE: To investigate the utility of Optos ultrawide-field fundus autofluorescence (UWF-FAF) imaging for postoperative follow-up of gas-filled eyes after vitrectomy with subretinal tissue-plasminogen activator (t-PA) injection for subretinal hemorrhage (SRH) displacement. STUDY DESIGN: Retrospective consecutive case series. METHODS: This study included 24 eyes with SRH. Vitrectomy with subretinal t-PA injection was performed, followed by postoperative prone positioning. FAF images acquired using Optos California were examined and the SRH occupancy in the macula was calculated. The main outcome measures were displacement rate and direction of SRH for 3 days postoperatively, and postoperative best-corrected visual acuity (BCVA). RESULTS: The postoperative BCVA ranged from improvement (23 eyes; 95.8%) to no change (one eye; 4.2%). Analysis was done using postoperative Optos FAF images for 20 eyes (83.3%). Postoperative SRH occupancy was significantly reduced, by 27.4%, compared with the preoperative occupancy (P = 0.03). A statistically significant reduction was found between the preoperative and postoperative day (POD)1 (P = 0.04), but not between POD1 and POD2 (P = 0.7), or between POD2 and POD3 (P = 1.0). CONCLUSION: UWF-FAF imaging is useful for postoperative follow-up of gas-filled eyes after vitrectomy with subretinal t-PA injection for SRH displacement.

TNFRSF10A downregulation induces retinal pigment epithelium degeneration during the pathogenesis of age-related macular degeneration and central serous chorioretinopathy.

Age-related macular degeneration (AMD) and central serous chorioretinopathy (CSC) are common diseases that can cause vision loss in older and younger populations. These diseases share pathophysiological conditions derived from retinal pigment epithelium (RPE) dysfunction. Tumor necrosis factor receptor superfamily 10A (TNFRSF10A)-LOC389641 with the same lead single-nucleotide polymorphism (SNP) (rs13278062) is the only overlapped susceptibility locus found in both AMD and CSC through genome-wide association studies. This lead SNP has been reported to alter the transcriptional activity of TNFRSF10A. This study aimed to elucidate the function of TNFRSF10A in RPE degeneration using human primary RPE cells and Tnfrsf10 knockout (Tnfrsf10-/-) mice. TNFRSF10A was found to be localized in human RPE. In vitro assays revealed that a T allele of rs13278062, the risk allele for AMD and CSC, downregulated TNFRSF10A transcription in RPE, leading to decreased cell viability and increased apoptosis through protein kinase C-α (PKCA) downregulation. Treatment with phorbol 12-myristate 13-acetate, a PKC activator, rescued the cell viability. Morphological RPE abnormality was found in the retina of Tnfrsf10-/- mice. Our data suggest that downregulation of TNFRSF10A expression inactivates PKCA signaling and causes cellular vulnerability of the RPE, which may contribute to the pathogenesis of AMD and CSC.

One-year efficacy of "rescue photodynamic therapy" for patients with typical age-related macular degeneration, polypoidal choroidal vasculopathy, and pachychoroid neovasculopathy refractory to anti-vascular endothelial growth factor therapy.

PURPOSE: This study aimed to evaluate the one-year outcomes of photodynamic therapy (PDT) as a rescue treatment for age-related macular degeneration (AMD) refractory to anti-vascular endothelial growth factor (VEGF) therapy. METHODS: Patients with AMD refractory to anti-VEGF therapy, treated with "rescue-PDT" were retrospectively investigated. The time of PDT was defined as the baseline value. Baseline characteristics including sex, age, best-corrected visual acuity (BCVA), central macular thickness (CMT), and foveal choroidal thickness (FCT) were examined. The changes in BCVA, CMT, and recurrence were also assessed at the 1-year follow-up. The logMAR VA change of 0.3 or more was defined as "improved" or "declined." RESULTS: Twenty-three consecutive eyes (typical AMD: 10 eyes, polypoidal choroidal vasculopathy: 10 eyes, and pachychoroid neovasculopathy: 3 eyes), which underwent "rescue-PDT," were analyzed in this study. The BCVA was improved in three patients and maintained in 20 patients at 12 months after PDT (mean BCVA change: 0.11 ± 0.19). The CMT improved in 19 patients (82.6%), and the mean CMT changed from 318.5 ± 93.7 µm to 225.9 ± 51.6 µm (p < 0.01) 12 months after PDT. "Retreatment" of anti-VEGF drug injections was considered if the retinal fluid or retinal hemorrhage recurred after PDT. The baseline FCT of the "retreatment group (15 eyes)" was significantly lower than that of the "no retreatment group (8 eyes)" (206.3 ± 50.7 µm vs 293.9 ± 85.7 µm: p = 0.033). CONCLUSIONS: PDT could be an effective treatment option for anti-VEGF refractory AMD to maintain visual acuity and control retinal fluid for up to 12 months.

Optical coherence tomography angiography of choroidal neovascularization in immune choroiditis following acute retinal necrosis.

PURPOSE: To report optical coherence tomography angiography (OCTA) findings in a case of immune choroiditis following contralateral acute retinal necrosis (ARN) with choroidal neovascularization (CNV) during anti-vascular endothelial growth factor (VEGF) therapy. CASE REPORT: A 64-year-old woman with immune choroiditis following contralateral ARN and secondary CNV presented with decreased visual acuity. Fundus examination revealed macular and peripheral yellowish lesions in the right eye. Inflammatory cells were observed in the anterior chamber and the vitreous. OCT revealed retinal exudative changes and subretinal lesions suggestive of CNV. OCTA detected an abnormal vascular net in the outer retina as well as choriocapillaris, corresponding to type 2 CNV, that reduced following intravitreous anti-VEGF therapy. Two weeks after treatment, OCTA showed re-dilated choroidal neovasculature at the outer retina despite no exudative recurrence in OCT. Six weeks after treatment, OCT detected exudative changes around the neovascular lesion. CONCLUSION: This case discusses the use of OCTA detection of CNV in a case of immune choroiditis following contralateral ARN. During anti-VEGF therapy for inflammatory CNV-related diseases, OCTA may be useful not only for CNV detection but also for the follow-up of CNV activity.

Spatial pattern of retinal pigment epithelium tear development and progression after anti-vascular endothelial growth factor therapy for neovascular age-related macular degeneration.

PURPOSE: To demonstrate the spatial pattern of retinal pigment epithelium (RPE) tear development and progression following anti-vascular endothelial growth factor (VEGF) therapy for neovascular age-related macular degeneration (nAMD). METHODS: We retrospectively reviewed six eyes with nAMD that showed RPE tears after administration of intravitreal anti-VEGF agents and were followed up for 12 months. The patterns of RPE tear development and progression were evaluated by analyzing positional relationships among the locations of the choroidal neovascularization membrane (CNVM) and pigment epithelial detachment (PED) area at baseline and the tear area via spectral-domain optical coherence tomography (SD-OCT), color photography, fluorescein angiography, and fundus autofluorescence images. RESULTS: Pre-tear OCT images revealed fibrovascular PED in all eyes, one of which showed complications of hemorrhagic PED after treatment. In five eyes, RPE tears developed at the PED edge located on the opposite side of the CNVM. In the eye showing hemorrhagic PED, the RPE tear developed along the wide area of the PED edge. The torn RPE monolayer contracted toward the side of the CNVM in all eyes and RPE loss involved the fovea in five eyes that showed significantly worse visual acuity (VA) after 12 months in comparison with the baseline value before the tear (logMAR VA; 0.3 vs. 1.29; P < 0.02). CONCLUSION: The location of CNVM in PED determines the spatial pattern of RPE tear development and progression and helps to predict the visual outcome after RPE tears.

Drusen and pigment abnormality predict the development of neovascular age-related macular degeneration in Japanese patients.

Drusen are known to be the important hallmark to predict the development of age-related macular degeneration (AMD). The prevalence of drusen is lower in Asians compared with Caucasians so that the role of signs constituting early AMD is not well established in Asian populations as in Western countries. In this study, we retrospectively investigated clinical characteristics and 5-year incidence of neovascular AMD (nAMD) in the fellow eye of unilateral nAMD patients. Of 296 consecutive unilateral nAMD patients who had been followed up more than 5 years, 170 typical AMD, 119 polypoidal choroidal vasculopathy, and 7 retinal angiomatous proliferation were included. To examine factors associated with nAMD occurrence in the fellow eye, drusen and pigmentary abnormality in the fellow eye were classified into 4 categories; Category 1: no or small drusen < 63 µm (37.2%), Category 2: 63-125 µm medium drusen or pigmentary abnormality (22.2%), Category 3: large drusen > 125 µm (25.0%), Category P: pachydrusen (15.5%). The mean sub-foveal choroidal thickness (SFCT) was Category 1: 276 µm, Category 2: 308 µm, Category 3: 246 µm, and Category P: 302 µm, respectively. Of note, SFCT in Category 2 and Category P was significantly larger than those of Category 3. Finally, the 5-year incidence of nAMD in the fellow eye was 32/296 (10.8%); Category 1: 0/110 (0%), Category 2: 12/66 (18.2%), Category 3: 20/74 (27.0%), and Category P: 0/46 (0%). Thus, signs of intermediate AMD (large drusen) as well as those of early AMD, especially the pigmentary abnormality, may contribute to development of bilateral nAMD in Japanese patients.

Vitrectomy with peripapillary internal limiting membrane peeling for macular retinoschisis associated with normal-tension glaucoma.

PURPOSE: Although vitrectomy has been reported to be effective for the treatment of macular retinoschisis associated with glaucoma in a few case series, the surgical techniques have yet to be established. This article aimed to describe the cases of two patients with macular retinoschisis who underwent vitrectomy with peripapillary internal limiting membrane peeling around the defective area of the retinal nerve fiber layer. OBSERVATIONS: Both patients had been diagnosed with normal tension glaucoma and treated with eye drops to stabilize intraocular pressure. Progression of macular retinoschisis and accompanied vision loss were observed in both cases. Twelve months after the surgery, both patients had resolution of the retinoschisis and improvement in best corrected visual acuity. CONCLUSIONS AND IMPORTANCE: Our surgical technique may be effective for the resolution of macular retinoschisis in eyes with normal tension glaucoma.

Five-year treatment outcomes following intravitreal ranibizumab injections for neovascular age-related macular degeneration in Japanese patients.

PURPOSE: To assess the real-world 5-year treatment outcomes of ranibizumab therapy in Japanese patients with neovascular age-related macular degeneration (AMD). METHODS: This was a retrospective, observational, and open-label effectiveness study that included 295 eyes. The participants were patients with treatment-naïve neovascular AMD who received intravitreal ranibizumab (IVR) monthly injection at least three times as the loading phase, followed by further injections as needed (pro re nata (PRN)) and follow-up assessments for 5 years. Outcomes were determined at least 5 years after the first ranibizumab injection. RESULTS: Mean logMAR best-corrected visual acuity (BCVA) at baseline was 0.52. The mean BCVA significantly improved after three loading injections; however, it declined gradually. The BCVA at 1 year was significantly better than the baseline BCVA, whereas the 3-year, 4-year, and 5-year BCVA values were significantly lower than the baseline values. The average central foveal thickness improved significantly from 366 ± 125 µm to 268 ± 134 µm (p < 0.0001). Macular atrophy was significantly more likely to occur in cases with classic choroidal neovascularization (CNV) than in cases with other AMD (p = 0.01). CONCLUSIONS: IVR is well tolerated in eyes with AMD. However, a PRN regimen for AMD may have limited real-world effectiveness for long-term maintenance of improved visual acuity. Macular atrophy may occur more frequently in classic CNV. To maintain good vision, IVR treatment should be started earlier and performed continuously.

Primary amines protect against retinal degeneration in mouse models of retinopathies.

Vertebrate vision is initiated by photoisomerization of the visual pigment chromophore 11-cis-retinal and is maintained by continuous regeneration of this retinoid through a series of reactions termed the retinoid cycle. However, toxic side reaction products, especially those involving reactive aldehyde groups of the photoisomerized product, all-trans-retinal, can cause severe retinal pathology. Here we lowered peak concentrations of free all-trans-retinal with primary amine-containing Food and Drug Administration (FDA)-approved drugs that did not inhibit chromophore regeneration in mouse models of retinal degeneration. Schiff base adducts between all-trans-retinal and these amines were identified by MS. Adducts were observed in mouse eyes only when an experimental drug protected the retina from degeneration in both short-term and long-term treatment experiments. This study demonstrates a molecular basis of all-trans-retinal-induced retinal pathology and identifies an assemblage of FDA-approved compounds with protective effects against this pathology in a mouse model that shows features of Stargardt's disease and age-related retinal degeneration.

Toll-like receptor 3 is required for development of retinopathy caused by impaired all-trans-retinal clearance in mice.

Chronic inflammation is an important component that contributes to many age-related neurodegenerative diseases, including macular degeneration. Here, we report a role for toll-like receptor 3 (TLR3) in cone-rod dystrophy (CORD) of mice lacking ATP-binding cassette transporter 4 (ABCA4) and retinol dehydrogenase 8 (RDH8), proteins critical for all-trans-retinal clearance in the retina. Increased expression of toll-like receptor-signaling elements and inflammatory changes were observed in Rdh8(-/-)Abca4(-/-) eyes by RNA expression analysis. Unlike 3-month-old Rdh8(-/-)Abca4(-/-) mice that developed CORD, 6-month-old Tlr3(-/-)Rdh8(-/-)Abca4(-/-) mice did not evidence an abnormal retinal phenotype. Light-induced retinal degeneration in Tlr3(-/-)Rdh8(-/-)Abca4(-/-) mice was milder than that in Rdh8(-/-)Abca4(-/-) mice, and a 2-fold increased TLR3 expression was detected in light-illuminated retinas of Rdh8(-/-)Abca4(-/-) mice compared with nonilluminated retinas. Poly(I-C), a TLR3 ligand, caused caspase-8-independent cellular apoptosis. Whereas poly(I-C) induced retinal cell death in Rdh8(-/-)Abca4(-/-) and WT mice both in vivo and ex vivo, this was not seen in mice lacking Tlr3. Far fewer invasive macrophage/microglial cells in the subretinal space and weaker activation of Muller glial cells were exhibited by Tlr3(-/-)Rdh8(-/-) Abca4(-/-) mice compared with Rdh8(-/-)Abca4(-/-) mice at 3 and 6 months of age, indicating that loss of TLR3 inhibits local inflammation in the retina. Both poly(I-C) and endogenous products emanating from dying/dead retinal cells induced NF-κB and IRF3 activation. These findings demonstrate that endogenous products from degenerating retina stimulate TLR3 that causes cellular apoptosis and retinal inflammation and that loss of TLR3 protects mice from CORD.

WITHDRAWN: Retinol dehydrogenase RDH11 protects the mouse retina from light-induced degeneration.

Withdrawn at the request of the author.