Rubicon regulates A2E-induced autophagy impairment in the retinal pigment epithelium implicated in the pathology of age-related macular degeneration.

Waste product deposition and light stress in the retinal pigment epithelium (RPE) are crucial factors in the pathogenesis of various retinal degenerative diseases, including age-related macular degeneration (AMD), a leading cause of vision loss in elderly individuals worldwide. Given that autophagy in the RPE suppresses waste accumulation, determining the molecular mechanism by which autophagy is compromised in degeneration is necessary. Using polarized human RPE sheets, we found that bis-retinoid N-retinyl-N-retinylidene ethanolamine (A2E), a major toxic fluorophore of lipofuscin, causes significant impairment of autophagy and the simultaneous upregulation of Rubicon, a negative regulator of autophagy. Importantly, this impairment was reversed in Rubicon-specific siRNA-treated RPE sheets. In a retinal functional analysis using electroretinograms (ERGs), mice with the RPE-specific deletion of Rubicon showed no significant differences from control cre-expressing mice but presented partially but significantly enhanced amplitudes compared with Atg7 knockout mice. We also found that an inflammatory reaction in the retina in response to chronic blue light irradiation was alleviated in mice with the RPE-specific deletion of Rubicon. In summary, we propose that upregulating basal autophagy by targeting Rubicon is beneficial for protecting the RPE from functional damage with ageing and the inflammatory reaction caused by light-induced cellular stress.

Additional anti-vascular endothelial growth factor therapy for eyes with a retinal pigment epithelial tear after the initial therapy.

PURPOSE: To evaluate the effects of additional anti-vascular endothelial growth factor (VEGF) therapy for eyes with a retinal pigment epithelial (RPE) tear after anti-VEGF therapy and treated with additional anti-VEGF injections for recurrent or persistent exudative change. PATIENTS AND METHODS: Ten eyes (10 patients) followed up for >12 months after a recurrent RPE tear were evaluated retrospectively. The RPE tears on fundus autofluorescence images were measured and changes in the best-corrected visual acuity were evaluated. RESULTS: Patients were followed up for >12 months (mean, 27.3; range, 13-44 months). During 12 months of follow-up, additional anti-VEGF injections (mean, 3.3; range, 1-7) were administered. The mean size of the RPE tear at the onset was 6.5 mm² (range, 1.3-16.3 mm²). At 12 months, the RPE tear increased in size >20% in 5 eyes and remained unchanged or decreased in the remaining half of eyes. The mean logarithm of the minimum angle of resolution best-corrected visual acuity was 0.43 at the time the RPE tear developed and 0.85 at 12 months. The RPE tear grade and age were prognostic factors for best-corrected visual acuity at 12 months. CONCLUSION: Under continued anti-VEGF therapy, RPE tears may be stable in size and visual acuity could be maintained in some eyes; however, the visual acuity prognosis is still unsatisfactory in nonresponsive eyes.

Fungal dysbiosis and decreased tear mucin at the conjunctiva in patients with conjunctival mucosa-associated lymphoid tissue lymphoma.

OBJECTIVE: This study aimed to examine the differences in the fungal microbiome between patients with conjunctival mucosa-associated lymphoid tissue (MALT) and healthy controls using metagenomic analysis. METHODS AND ANALYSIS: This case-control study was conducted at Osaka University Hospital in Osaka, Japan, from April 2015 to March 2022. Twenty-five consecutive patients with conjunctival MALT lymphoma and 25 healthy volunteers were included. Metagenomic analysis using Internal Transcribed Spacer (ITS)1 deep sequencing and hierarchical clustering was performed to investigate differences in the fungal microbiome. To assess tear environmental change, we measured tear mucin concentrations using ELISA. RESULTS: Detailed analyses showed fungal dysbiosis and changes in ß-diversity within the conjunctiva of patients with conjunctival MALT lymphoma. Hierarchical clustering revealed that the participants could be divided into three clusters according to the Malassezia abundance: cluster I (Malassezia abundance above 70%), cluster II (Malassezia abundance 25%-70%) and cluster II (Malassezia abundance below 25%). Most patients were included in cluster I, whereas most of healthy controls were included in cluster III. The differences were significant. Tear mucin concentrations were significantly lower in patients with MALT compared with healthy controls. CONCLUSION: The metagenomic analysis using ITS1 deep sequencing was useful for identifying the differences in commensal fungi between patients with MALT lymphoma and healthy individuals. The increased prevalence of the Malassezia genus and the decreased levels of tear mucin can lead to an allergic response of the conjunctiva, resulting in the pathogenesis associated with conjunctival MALT lymphoma. Therefore, it may be beneficial to initiate treatment when a high abundance Malassezia is detected.

Comparative evaluation of 16S rRNA metagenomic sequencing in the diagnosis and understanding of bacterial endophthalmitis.

OBJECTIVE: To evaluate the usefulness of metagenomic analysis in the search for causative organisms of bacterial endophthalmitis. METHODS AND ANALYSIS: Twenty-one consecutive treatment-naïve patients (13 men and 8 women; mean age, 60.8±19.8 years) with suspected endophthalmitis were recruited. Vitrectomy was performed to diagnose and treat endophthalmitis. Bacterial culture and metagenomic analysis of the vitreous body were performed. Extracted DNA was analysed using 16S rRNA sequences, and libraries were sequenced on an Illumina MiSeq sequencer. To compare the bacterial composition in each case, α and ß diversities were determined. RESULTS: Patients were categorised into three groups: endophthalmitis cases with matching predominant organisms according to metagenomic analysis and bacterial culture, those with negative results for bacterial culture and those with negative results in both cases. In 7 of 15 culture-negative cases, results from metagenomic analysis could detect pathogens. The diversity of bacterial populations was significantly lower in the group with positive results for predominant bacteria according to culture and metagenomic analysis. All patients with uveitis were included in the group for which the causative pathogen could not be determined by culture or metagenomic analysis. The structures of bacterial populations significantly differed between the positive and negative groups by culture and metagenomic analysis. CONCLUSIONS: Metagenomic analysis could be useful for prompt detection of causative pathogens, for precise diagnosis of infection, and as a marker of inflammation processes such as uveitis.

Mitochondrial DNA as a Biomarker for Acute Central Serous Chorioretinopathy: A Case-Control Study.

Background: The literature suggests that stress may play a pivotal role in the precipitation of acute central serous chorioretinopathy (CSC) because chorioretinal integrity can be affected by the psychosocial state of the patient, indicating the need for a biomarker. Not only physical stress but also psychological stress causes many types of physical disorders. However, little is known about the pathophysiology of stress-induced disease. The objective of this study was to investigate whether serum factors might be involved in the development of stress-induced ocular diseases. Methods: This observational case series included 33 eyes of 33 consecutive patients with treatment-naïve acute CSC. Fifty eyes of 50 age-matched healthy volunteers were included in this study as non-CSC controls. Serum samples were collected from all participants, and the levels of mitochondrial DNA (mtDNA) were measured by quantitative real-time (RT)-PCR. Serum levels of high-mobility group box (HMGB) 1 and 8-hydroxy-2'-deoxyguanosine (8-OHdG), biological markers of acute/chronic inflammation and oxidative stress, were also measured. The relationships between serum mtDNA, 8-OHdG, and HMGB1 concentrations were investigated by multivariate regression analysis, alongside an assessment of clinical data. Results: In the treatment-naïve acute CSC group, the serum mtDNA levels (36.5 ± 32.4 ng/mL) were significantly higher than the levels in the control group (7.4 ± 5.9 ng/mL; p < 0.001). Serum levels of 8-OHdG and HMGB1 in treatment-naïve acute CSC patients measured 0.12 ± 0.08 ng/mL and 18.1 ± 35.0 ng/mL, respectively, indicating that HMGB1 levels were elevated in CSC compared with the control group. Multivariable regression analysis demonstrated that increased serum mtDNA levels were significantly associated with the height of serous retinal detachment. Conclusion: We showed serum mtDNA and HMGB1 level elevation and its relation to the clinical activities of CSC, indicating that serum mtDNA and HMGB1 could serve as biomarkers for the acute phase of the disease. The use of these biomarkers makes it possible to predict disease onset and determine disease severity.

Cornea Findings of Spectral Domain Anterior Segment Optical Coherence Tomography in Uveitic Eyes of Various Etiologies.

PURPOSE: To evaluate the morphologic appearance of keratic precipitates (KPs) with spectral domain anterior segment optical coherence tomography (AS-OCT) for the diagnosis of uveitic eyes of various etiologies. METHODS: In all, 153 eyes of 153 patients with different types of uveitis were examined to investigate the morphologic appearance of KPs. The study included 63 eyes with herpetic iridocyclitis/endotheliitis, 58 eyes with ocular sarcoidosis, 5 eyes with Fuchs heterochromic iridocyclitis, and 27 eyes with masquerade syndrome with primary intraocular lymphoma (PIOL). AS-OCT was used to analyze the different KP types among various uveitic groups. RESULTS: KPs were observed in 30 eyes (51.7%) from the ocular sarcoidosis group and in 15 eyes (55.6%) from the PIOL group. In the herpetic iridocyclitis/endotheliitis group, all cases showed KPs (16 cases were positive for herpes simplex virus, 22 cases for varicella zoster virus, and 27 cases for cytomegalovirus). The reflectivity and morphology of the KPs in the AS-OCT images demonstrated different patterns depending on the causative virus. Hemispheric and relatively large KPs were observed in ocular sarcoidosis cases. KPs with Fuchs heterochromic iridocyclitis appeared as small dots. By contrast, relatively high-intensity and dense KPs were observed in PIOL cases. The morphologic features of the KPs in different types of uveitis also showed other patterns such as hemispheric and rectangular-shaped KPs protruding from the retrocornea. CONCLUSIONS: AS-OCT images showed characteristic and specific morphological patterns. AS-OCT examination is a noninvasive and repeatable method for the diagnosis of uveitis by evaluating the morphologies of KPs and treatment effectiveness.

Chronological Observations of Iris Flocculi in a Japanese Family with Thoracic Aortic Aneurysm and Dissections.

Iris flocculi, a type of hereditary iris pigment epithelial cyst, have been reported in association with smooth muscle α-2 actin (ACTA2) gene as the causative gene of familial thoracic aortic aneurysm and dissections (FTAAD). The purpose of the report was to examine morphological changes in the shape of flocculi and iris features over time by comparing infants to adults with FTAAD combined with iris flocculi. A Japanese family with FTAAD and bilateral iris flocculi and the Arg149Cys gene mutation was included. A slit-lamp photograph and anterior segment optical coherence tomography (AS-OCT) were used to evaluate the structure and location of iris flocculi. AS-OCT was also used to measure the internal shape and iris thickness of the dilated pupil muscle. A morphological change in the cyst was confirmed to be existent in the youngest cases. Pigment discoloration and iris atrophy of the iris body were observed in all cases. Besides, a decrease in iris thickness was observed with AS-OCT measurement. Changes across generations in iris flocculi occurred in a Japanese family with TAAD. ACTA2 gene abnormalities may cause iris atrophy and decrease thickness in addition to iris flocculi in early life. The prognosis is poor when FTAAD is combined with iris flocculi, and prevention of cardiovascular disease is necessary based on earlier findings of its emergence.

Rare Histological Type of Adenoma of the Nonpigmented Ciliary Epithelium.

We report the rare case of an adenoma of the nonpigmented ciliary epithelium (NPCE). A 67-year-old healthy man presented with a regularly shaped and nonpigmented mass at the iris root of his right eye. His best-corrected visual acuity was 1.5 with normal intraocular pressure. During observation, the size of the tumor remained stable for 1.5 years but then rapidly grew, extending through the iris, and gradually enlarged to the point of compressing the iris. Ultimately, an iridocyclectomy with scleral resection under a lamellar scleral flap was performed. The histopathologic features of the resected tissue were consistent with adenoma of the NPCE. Histopathological analysis showed that the tumor consisted of both tubular and solid components. There were solid lesions inside of the ciliary epithelium and tubular lesions outside. We observed positive immunoreactivity to vimentin and cytokeratin CK (AE1/AE3) and negative reactivity to S-100 and CD68, both rarely associated with adenoma of NPCE. During 1 year of follow-up after the iridocyclectomy, no signs of tumor recurrence were observed.

Conjunctival dysbiosis in mucosa-associated lymphoid tissue lymphoma.

To investigate the conjunctival microbiota and the association between the development of conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma and dysbiosis, DNA samples were collected from 25 conjunctival MALT lymphoma patients and 25 healthy controls. To compare the microbiota, samples were collected from the following four body locations: conjunctiva, meibomian gland, periocular skin and hand. Extracted DNA was analyzed by 16S rRNA sequences, and libraries were sequenced on an Illumina MiSeq sequencer. The differences in bacteria were characterized by using principal coordinate analysis of metagenomics data, and the differences in bacterial compositions were evaluated by linear discriminant analysis effect size. The conjunctival microbiota of MALT lymphoma patients was compositionally different from that of healthy controls. For the conjunctival MALT lymphoma patients, alterations in the microbial composition were detected, and a remarkable change was detected at the conjunctiva. Detailed analysis showed that a specific population of the microbiota, the genus Delftia, was significantly more abundant in conjunctival MALT lymphoma patients, and the genera Bacteroides and Clostridium were less abundant in the MALT lymphoma patients. A specific microbiota on the ocular surface in conjunctival MALT lymphoma patients was detected, and dysbiosis may play an important role in the pathophysiology of conjunctival MALT lymphoma.

Chronic Retinal Necrosis Severely Complicated by Neovascular Glaucoma: A Case Report.

BACKGROUND: Chronic retinal necrosis (CRN) is a rare chronic granular necrotizing retinitis that was first described in 2013. CRN is characterized by intraocular inflammation accompanied by occlusive vasculitis, granular retinitis, and slowly progressing necrosis around the retina in a host with partial immune dysfunction. Cytomegalovirus (CMV) is reported to be a causative agent. There are several ocular complications such as retinal detachment and neovascular glaucoma; however, there has been no description of a clinical manifestation of neovascular glaucoma in CRN. We herein present a case of severe neovascular glaucoma in association with CRN. CASE PRESENTATION: An 80-year-old man was referred to our hospital with poor control of inflammation and intraocular pressure (IOP). The IOP in his left eye was 29 mm Hg. Anterior chamber cells (2+) and keratic precipitates were observed. In the peripheral retina, vitreous opacities and granular necrotizing retinitis were noticed. Fluorescein angiography revealed extensive retinal nonperfusion area from the macula lesion to the periphery. PCR analysis of aqueous humor showed the presence of CMV. A diagnosis of CRN was made soon afterwards. Antiviral drug and systemic corticosteroid were administered. The treatment temporally resolved the symptom; however, panretinal photocoagulation and intravitreal injection of bevacizumab were performed to treat iris neovascularization. During the follow-up, trabeculectomy was performed because of poor IOP control. At the final visit, severe uncontrolled neovascular glaucoma caused hyphema, and his left eye lost light perception. CONCLUSION: The prognosis of CRN is poor because of severe neovascular glaucoma and careful observation and active treatments are necessary.

Choroidal nevus in an eye with polypoidal choroidal vasculopathy.

PURPOSE: To report an eye with polypoidal choroidal vasculopathy (PCV) and a choroidal nevus. METHODS: This is an observational case report. RESULTS: A healthy 69-year-old woman was referred to the Osaka University Hospital with a diagnosis of a macular tumor. She complained of having distorted vision in her left eye. The medical history of the patient was unremarkable. At the initial examination, her best-corrected visual acuity (BCVA) was 20/20 in both eyes, and the intraocular pressure was 18 mm Hg in both eyes. A slit-lamp examination showed no abnormalities in the anterior segment of both eyes and a fundus examination of the left eye showed a slightly elevated juxtafoveal chorioretinal lesion and polyp-like reddish-orange lesions. The juxtafoveal choroidal lesion was located beneath a choroidal neovascularization (CNV). An optical coherence tomography confirmed CNV with pigment epithelial detachment (PED). Fluorescein angiography showed juxtafoveal hyperfluorescence due to CNV. Indocyanine green angiography demonstrated a branching choroidal vascular network that resembled polypoidal lesions. A fundus autofluorescence showed a mosaic pattern and a slight hyperautofluorescence at the CNV. We diagnosed the patient as having PCV. Aflibercept was injected intravitreally because of her PED. After the injection, PED improved and her visual acuity remained stable during the 12-month follow-up period. CONCLUSIONS: In cases of PCV, FAF images are helpful in determining the status of the posterior pole. Intravitreal injections of aflibercept can improve PED associated with CNV, and the BCVA will remain stable for at least 12 months.

Vitreous hemorrhage caused by ruptured retinal macroaneurysm.

PURPOSE: To report the clinical findings of 7 patients with a vitreous hemorrhage (VH) caused by a ruptured retinal macroaneurysm. METHODS: Interventional case series. The medical records of 7 patients with a VH caused by a ruptured macroaneurysm and treated by either medication or vitrectomy were reviewed. The main outcome measures were the visual acuity, appearance of the fundus and optical coherence tomographic findings. RESULTS: Two patients, aged 49 and 58 years, had retinal macroaneurysms at the optic disc. The retinal macroaneurysm in the other 5 eyes (mean age 79.0 years) was not at the optic disc. The VH was completely resolved in all 7 patients. The visual acuity improved in all eyes and remained stable for at least 6 months after the treatments (p = 0.0478). CONCLUSIONS: The improvement of the visual acuity in all eyes indicates that the prognosis of eyes with a VH caused by a ruptured retinal macroaneurysm is good.

Choroidal excavation in eye with normal tension glaucoma.

PURPOSE: To report the case of an eye with normal tension glaucoma and a choroidal excavation. METHODS: This is an observational case report. RESULTS: A 59-year-old woman with normal tension glaucoma had a choroidal excavation in the left eye. Her best-corrected visual acuity and intraocular pressure were within normal limits and had been stable for 5 years. Fundus examination showed a small white lesion inferior to the macula and a nerve fiber layer defect at the inferior edge of the optic disc. Humphrey Field Analyzer (HFA) showed visual field defects corresponding to the nerve fiber layer defect with C30-2, and a central scotoma superior to the macula with C10-2. Optical coherence tomography (OCT) showed a 150-µm deep choroidal excavation. Disruptions of the IS/OS line were detected only in the area inferior to the choroidal excavation. During the 5 months of follow-up, her best-corrected visual acuity remained at 1.0 and the IOP ranged from 12 to 14 mm Hg in the left eye. The fundus and OCT images did not deteriorate and the choroidal excavation did not enlarge. CONCLUSIONS: The disruption of the inner/outer segment (IS/OS) line was detected only at the area surrounding the choroidal excavation. OCT examinations are useful in assessing the area of the residual IS/OS line, and HFA can be used to estimate the residual central visual field.