Circulating inflammatory monocytes oppose microglia and contribute to cone cell death in retinitis pigmentosa.

Retinitis pigmentosa (RP) is an intractable inherited disease that primarily affects the rods through gene mutations followed by secondary cone degeneration. This cone-related dysfunction can lead to impairment of daily life activities, and ultimately blindness in patients with RP. Paradoxically, microglial neuroinflammation contributes to both protection against and progression of RP, but it is unclear which population(s) - tissue-resident microglia and/or peripheral monocyte-derived macrophages (mφ) - are implicated in the progression of the disease. Here we show that circulating blood inflammatory monocytes (IMo) are key effector cells that mediate cone cell death in RP. Attenuation of IMo and peripherally engrafted mφ by Ccl2 deficiency or immune modulation via intravenous nano-particle treatment suppressed cone cell death in rd10 mice, an animal model of RP. In contrast, the depletion of resident microglia by a colony-stimulating factor 1 receptor inhibitor exacerbated cone cell death in the same model. In human patients with RP, IMo was increased and correlated with disease progression. These results suggest that peripheral IMo is a potential target to delay cone cell death and prevent blindness in RP.

RECURRENCE RATE OF CYSTOID MACULAR EDEMA WITH TOPICAL DORZOLAMIDE TREATMENT AND ITS RISK FACTORS IN RETINITIS PIGMENTOSA.

PURPOSE: To investigate the rate of the recurrence of cystoid macular edema (CME) secondary to retinitis pigmentosa (RP) after the initiation of topical dorzolamide and the recurrence risk factors. METHODS: We retrospectively analyzed the data of RP patients at Kyushu University Hospital. We included patients who showed a treatment response to 1.0% topical dorzolamide. The day of treatment initiation was set as the baseline. Topical dorzolamide treatment was continued during the follow-up. The recurrence of CME (defined as a >20% increase in central subfield thickness compared to previous visit, or a central subfield thickness value that exceed baseline value) was evaluated at each follow-up visit. Risk factors for RP-CME recurrence were analyzed by Cox proportional hazards modeling. A Kaplan-Meier survival analysis was used to evaluate the time to recurrent RP-CME. RESULTS: Forty RP-CME patients showed a treatment response to topical dorzolamide. During the mean 3.9-year follow-up, 14 patients exhibited recurrence; its rate was 15.6%, 34.7%, and 48.7% at 1, 3, and 5 years, respectively. A high baseline central subfield thickness was significantly associated with recurrent (hazard ratio 1.11, 95% CI: 1.05-1.18, P = 0.0004). CONCLUSION: The recurrence rate of RP-CME increased with time. A high baseline central subfield thickness value was a risk factor for recurrence.

Mucosal-associated invariant T cells have therapeutic potential against ocular autoimmunity.

Autoimmune uveitis is a sight-threatening disease induced by pathogenic T cells that recognize retinal antigens; it is observed in disorders including Vogt-Koyanagi-Harada disease (VKH). The roles of specific T cell subsets and their therapeutic potential against autoimmune uveitis are not fully understood. Here we conducted multi-parametric single-cell protein quantification which shows that the frequency of CD161highTRAV1-2+ mucosal-associated invariant T (MAIT) cells that recognize vitamin B2 metabolite-based antigens is decreased in relapsing VKH patients compared to individuals without active ocular inflammation. An experimental autoimmune uveitis (EAU) mouse model revealed that genetic depletion of MAIT cells reduced the expression of interleukin (Il) 22 and exacerbated retinal pathology. Reduced IL-22 levels were commonly observed in patients with relapsing VKH compared to individuals without active ocular inflammation. Both mouse and human MAIT cells produced IL-22 upon stimulation with their antigenic metabolite in vitro. An intravitreal administration of the antigenic metabolite into EAU mice induced retinal MAIT cell expansion and enhanced the expressions of Il22, as well as its downstream genes related to anti-inflammatory and neuroprotective effects, leading to an improvement in both retinal pathology and visual function. Taken together, we demonstrate that a metabolite-driven approach targeting MAIT cells has therapeutic potential against autoimmune uveitis.

Long-term Outcomes of Cataract Surgery in Patients with Retinitis Pigmentosa.

PURPOSE: To investigate the long-term outcomes of cataract surgery in patients with retinitis pigmentosa (RP). DESIGN: Retrospective, observational study. PARTICIPANTS: Sixty-four patients with typical RP (22 men, 42 women; average age, 62.8 ± 10.1 years) who underwent cataract surgery at Kyushu University Hospital between May 2007 and October 2015 and were followed up for ≥3 years after the surgery. METHODS: Differences between presurgery and postsurgery visual function, including best-corrected visual acuity (BCVA) and parameters in the Humphrey field analyzer (HFA) examination using the central 10-2 program, were investigated. The presurgery conditions of the foveal ellipsoid zone (EZ) were classified into 3 grades (grade 1: invisible; grade 2: abnormal; grade 3: normal) based on OCT findings. MAIN OUTCOME MEASURES: BCVA, the retinal sensitivity in the HFA 10-2 test. RESULTS: Cataract surgery was performed in 96 eyes, with an average follow-up period of 5.8 ± 2.4 years. The mean presurgery BCVA was 0.64 ± 0.52 logarithm of the minimum angle of resolution (logMAR), and the final postsurgery BCVA was 0.61 ± 0.67 logMAR (P = 0.57). Significant improvement in the postsurgery BCVA was observed only in eyes with preserved foveal EZ (grade 3) (P < 0.01). In 62 eyes of 45 patients who underwent the HFA 10-2 test, the mean values of deviation, macular sensitivity, and foveal sensitivity at the final visit were significantly decreased compared with preoperative values (P < 0.01), whereas those in grade 3 eyes did not change significantly after the surgery (P = 0.13). CONCLUSIONS: In the long-term course after cataract surgery in patients with RP, many patients experienced vision loss with progression of the disease. The preoperative finding of preserved foveal EZ was associated with a better visual prognosis, suggesting that EZ evaluation is useful for predicting the long-term visual outcome of cataract surgery in patients with RP.

Changes of Serum Inflammatory Molecules and Their Relationships with Visual Function in Retinitis Pigmentosa.

Purpose: Retinal degeneration involves neuroinflammation, and pro-inflammatory cytokines/chemokines are markedly increased in the eyes of patients with retinitis pigmentosa (RP). In this study, we investigated the changes of serum cytokines/chemokines in RP, and their relationships with visual parameters. Methods: Forty-five consecutive patients with typical RP aged 20 to -39 years and 28 age-matched and gender-matched controls were included. Fifteen cytokines (interleukin [IL]-1α, IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p70, IL-13, 1L-15, IL-17, IL-23, interferon [IFN]-γ, and tumor necrosis factor [TNF]-α, TNF-ß) and 9 chemokines (eotaxin, growth-related oncogene [GRO]-α, I-309, IL-8, IFN-γ-inducible protein [IP]-10, monocyte chemotactic protein [MCP]-1, MCP-2, regulated activation normal T-cell expressed and secreted [RANTES], and thymus and activated regulated chemokine [TARC]) in the serum were simultaneously measured by a multiplexed immunoarray (Q-Plex). Relationships between these cytokines/chemokines and indices of central vision, such as visual acuity (VA), the values of static perimetry tests (Humphrey Field analyzer, the central 10-2 program), and optical coherence tomography measures were analyzed in the patients with RP. Results: Among the 15 cytokines and 9 chemokines, serum IL-8 and RANTES levels were significantly increased in patients with RP compared with controls (IL-8: P < 0.0001; RANTES: P < 0.0001). Among the elevated cytokines/chemokines, the levels of IL-8 were negatively correlated with VA (ρ = 0.3596 and P = 0.0165), and the average retinal sensitivity of four central points (ρ = -0.3691 and P = 0.0291), and 12 central points (ρ = -0.3491 and P = 0.0398), as well as the central subfield thickness (ρ = -0.3961 and P = 0.0094), and ellipsoid zone width (ρ = -0.3841 and P = 0.0120). Conclusions: Peripheral inflammatory response may be activated and serum IL-8 levels are associated with central vision in patients with RP.

Aqueous Flare and Progression of Visual Field Loss in Patients With Retinitis Pigmentosa.

Purpose: To investigate the association between aqueous flare and progression of visual field loss using the Humphrey Field Analyzer in patients with retinitis pigmentosa (RP). Methods: We examined a total of 101 eyes of 101 patients who were diagnosed with typical RP. Sixty-one percent of the patients were female, and the mean age of the total group was 47.4 years. Aqueous flare, visual field (by an Humphrey Field Analyzer, the central 10-2 SITA-Standard program), and optical coherence tomography measurements were obtained for all patients. The slope, which was derived from serial values of mean deviation, macular sensitivity, or foveal sensitivity for each eye with univariate linear regression, was used for analysis. Results: Aqueous flare values were significantly correlated with the mean deviation slope (r = -0.20, P = 0.046), macular sensitivity slope (r = -0.28, P = 0.005) and foveal sensitivity slope (r = -0.20, P = 0.047). The values of the retinal sensitivity slope significantly decreased as the aqueous flare level increased (all P < 0.05). These associations remained unchanged after adjustment for age, sex, and posterior subcapsular cataract, and epiretinal membrane. Conclusions: Elevation of aqueous flare is a risk factor for the decline of central visual function in RP. Aqueous flare may be a useful marker for disease progression in RP.

Direct comparison of retinal structure and function in retinitis pigmentosa by co-registering microperimetry and optical coherence tomography.

PURPOSE: To evaluate the retinal structure-function relationships in the macula of retinitis pigmentosa (RP) patients by comparing microperimetry-3 (MP-3) images with co-registered optical coherence tomography (OCT) images. METHODS: Thirty patients with typical RP were recruited from our hospital. The maculae of patients were examined with MP-3 and OCT. The retinal sensitivity was measured by MP-3 at 40 testing points arranged concentrically in a 16° diameter of the central retina, and we divided the 40 points into four zones according to degree from the fovea (2°, 4°, 6°, and 8°). We analyzed the correlation coefficients between the retinal sensitivity and the total retinal thickness (TRT), the length from the inner limiting membrane to the retinal pigment epithelium (RPE), and between the retinal sensitivity and the outer retinal thickness (ORT), the length from the outer plexiform layer to the RPE at each stimulus point. RESULTS: TRT showed moderate correlations with the retinal sensitivity at 2° (median ρ = 0.59 interquartile range (IQR) [0.38-0.72]), 4° (ρ = 0.59 [0.55-0.68]) and 6° (ρ = 0.60 [0.54-0.63]), and TRT was weakly-to-moderately related to the retinal sensitivity at 8° (ρ = 0.27 [0.19-0.48]). ORT exhibited strong correlations at 2° (ρ = 0.72 [0.60-0.81]), 4° (ρ = 0.71 [0.75-0.67]) and 6° (ρ = 0.70 [0.54-0.74]), and a weak-to-moderate correlations at 8° (ρ = 0.34 [0.29-0.53]). ORT was more strongly correlated with the retinal sensitivity compared to TRT (p = 0.018). CONCLUSION: ORT, rather than TRT, within 6° eccentricity was strongly correlated with the retinal sensitivity, suggesting that measuring ORT in those areas will help evaluate the macular status and progression in RP.

Relationships Between Serum Antioxidant and Oxidant Statuses and Visual Function in Retinitis Pigmentosa.

Purpose: To investigate the serum changes of antioxidant/oxidant markers and the relationship between these factors and visual function in patients with retinitis pigmentosa (RP). Methods: Fifty-two RP patients <40 years old and 25 controls were included. Serum samples were analyzed for superoxide dismutase 3 (SOD3) activity, glutathione peroxidase (GPx), potential antioxidant (PAO), and hexanoyl-lysine (HEL). The relationships between these markers and visual parameters, including best-corrected visual acuity (BCVA), mean deviation (MD), and average retinal sensitivity of 4 or 12 central points on static perimetry tests (Humphrey Field Analyzer, the central 10-2 program) were examined in the RP patients. Results: Although there was no significant difference in the serum SOD3 activity between RP patients and controls, serum SOD3 activity in the severe degeneration group with macular involvement (16.3 ± 11.3 U/mL) was significantly lower compared with those in the mild degeneration group (those with midperipheral scotomas; 28.5 ± 16.6 U/mL, P = 0.0459). SOD3 was significantly related to visual acuity (r = -0.3701, P = 0.0069) and the average retinal sensitivity of four central points (r = 0.3463, P = 0.0137) in RP patients. The linear trends of these two parameters across SOD3 levels were also significant (P = 0.0264 and 0.0172, respectively). There was no consistent correlation between other serum antioxidant/oxidant markers and visual parameters. Conclusions: Lower serum SOD3 activity was associated with the severe retinal degeneration in RP patients. Our results suggest that serum SOD3 activity may be related to disease severity in RP.