Non-Perfusion Area Index for Prognostic Prediction in Diabetic Retinopathy.

Fundus fluorescent angiography is a standard examination in Japan that can directly visualize the circulatory failure in diabetic retinopathy but is not used in Western countries. In this study, we examine the relationship between the non-perfusion area in fundus fluorescent angiography and the progression of diabetic retinopathy. We evaluated 22 eyes between 22 patients who had their first fundus fluorescent angiography during a clinical episode at Keio University Hospital from January 2012 to May 2015, were diagnosed as having preproliferative diabetic retinopathy, and could be followed for at least three years. The non-perfusion area index (%) in nine segmented fundi in the initial fundus fluorescent angiography was calculated, and the progression to proliferative diabetic retinopathy over three years was evaluated. Three out of the 22 eyes (13.6%) developed proliferative diabetic retinopathy over three years. The non-perfusion area index for the initial fundus fluorescent angiography was significantly associated with progression to proliferative diabetic retinopathy. The non-perfusion area index in the posterior pole was most strongly correlated with the progression to proliferative diabetic retinopathy. Thus, the non-perfusion area index in the posterior pole among those with preproliferative diabetic retinopathy may predict the progression to proliferative diabetic retinopathy in the subsequent three years.

Association between axial length and choroidal thickness in early age-related macular degeneration.

The clinical course of age-related macular degeneration (AMD) is related to choroidal conditions, and can be determined by the evaluation of the central choroidal thickness (CCT). The aim of this study was to determine the association between the axial length (AL) and choroidal thickness in AMD by measuring these parameters in patients with and without AMD. Seventy eyes of 70 patients (34 men and 36 women; age, 64-88 years; mean age, 77.0 ± 6.5 years) who underwent cataract surgery from February 2015 to March 2020 at the Department of Ophthalmology, Keio University School of Medicine were retrospectively analyzed. The AMD group (29 patients, 29 eyes) included eyes with early AMD, whereas the control group (41 patients, 41 eyes) included those without ocular diseases other than cataract. Optical coherence tomography images were used to measure the CCT and the choroidal vessel diameter (CVD). The IOL Master was used to measure the AL. The results revealed that mean CCT was greater in the AMD group (238.3 ± 108.3 µm) compared with the age-matched control group (187.2 ± 66.8 µm) (p = 0.03). The CCT was negatively correlated with AL in the overall sample (r = -0.42, p = 0.001), the AMD group (r = -0.42, p = 0.02), and the control group (r = -0.42, p = 0.006). Note that all eyes with CCT > 350 µm were included in the AMD group. CCT and CVD were positively correlated in the overall sample (r = 0.76, p < 0.001) as well as in the individual groups (AMD: r = 0.82, p < 0.001; control: r = 0.76, p = 0.004). Given that CCT is an important parameter for predicting the prognosis of subfoveal diseases, routine evaluation of AL may be valuable for a better understanding of the pathogenesis of AMD.

Hyperreflective Material in Optical Coherence Tomography Images of Eyes with Myopic Choroidal Neovascularization May Affect the Visual Outcome.

The visual outcome of myopic choroidal neovascularization (CNV) after anti-vascular endothelial growth factor (anti-VEGF) therapy varies among individuals. We retrospectively analyzed the data of 24 eyes (24 patients) with treatment-naïve myopic CNV who underwent anti-VEGF monotherapy following a pro-re-nata regimen at the Division of Medical Retina Clinic, Department of Ophthalmology, Keio University Hospital between May 2014 and December 2017. The mean age was 70.6 ± 2.1 years, and 16 (66.7%) patients were female. Overall, the mean best-corrected visual acuity (BCVA) improved (p = 0.034), and the mean height of the hyperreflective material (HRM), involving the CNV lesion recorded by optical coherence tomography, decreased (p < 0.01) 12 months after the initial treatment. Fifteen eyes (62.5%) achieved a BCVA of better than 0.10 in LogMAR at 12 months; they had a better BCVA (p = 0.015) and lower HRM intensity (p = 0.033) at baseline than the others. Remarkably, the BCVA improved (p < 0.05) and the HRM height (p < 0.01) decreased only in eyes with a final BCVA better than 0.10 as early as 1 month after the initial treatment, which was still present at 12 months. The HRM height and intensity, not only the BCVA, would be valuable in evaluating the prognosis of myopic CNV after anti-VEGF therapy, although further study is required.

Macular Pigment Optical Density and Photoreceptor Outer Segment Length as Predisease Biomarkers for Age-Related Macular Degeneration.

To explore predisease biomarkers, which may help screen for the risk of age-related macular degeneration (AMD) at very early stages, macular pigment optical density (MPOD) and photoreceptor outer segment (PROS) length were analyzed. Thirty late AMD fellow eyes, which are at high risk and represent the predisease condition of AMD, were evaluated and compared with 30 age-matched control eyes without retinal diseases; there was no early AMD involvement in the AMD fellow eyes. MPOD was measured using MPS2® (M.E. Technica Co. Ltd., Tokyo, Japan), and PROS length was measured based on optical coherence tomography images. MPOD levels and PROS length in the AMD fellow eyes were significantly lower and shorter, respectively, than in control eyes. MPOD and PROS length were positively correlated in control eyes (R = 0.386; p = 0.035) but not in AMD fellow eyes. Twenty (67%) AMD fellow eyes met the criteria of MPOD < 0.65 and/or PROS length < 35 µm, while only five (17%) control eyes did. After adjusting for age and sex, AMD fellow eyes more frequently satisfied the definition (p < 0.001; 95% confidence interval, 3.50-60.4; odds ratio, 14.6). The combination of MPOD and PROS length may be a useful biomarker for screening predisease AMD patients, although further studies are required in this regard.

Correlation between Macular Pigment Optical Density and Neural Thickness and Volume of the Retina.

Macular pigment (MP), which is composed of lutein/zeaxanthin/mezo-zeaxanthin, is concentrated in the central part of the retina, the macula. It protects the macula by absorbing short-wavelength light and suppressing oxidative stress. To evaluate whether MP levels are related to retinal neural protection and resulting health, we analyzed the association between the MP optical density (MPOD), and the macular thickness and volumes. Forty-three eyes of 43 healthy adult volunteers (21 men and 22 women; age: 22-48 (average 31.4 ± 1.1) years) were analyzed. Highly myopic eyes (<-6 diopters) were excluded. MPOD was measured using MPS2®, and the neural retinal thickness and volume were measured using optical coherence tomography. The mean MPOD was 0.589 ± 0.024, and it positively correlated with the central retinal thickness (P = 0.017, R = 0.360) and retinal volume of the fovea (1-mm diameter around the fovea; P = 0.029, R = 0.332), parafovea (1-3-mm diameter; P = 0.002, R = 0.458), and macula (6-mm diameter; P = 0.003, R = 0.447). In the macular area (diameter: 6 mm), MPOD was correlated with the retinal neural volume of the ganglion cell layer (P = 0.037, R = 0.320), inner plexiform layer (P = 0.029, R = 0.333), and outer nuclear layer (P = 0.020, R = 0.353). Thus, MPOD may help in estimating neural health. Further studies should determine the impact of MP levels on neuroprotection.

Predicting recurrences of macular edema due to branch retinal vein occlusion during anti-vascular endothelial growth factor therapy.

PURPOSE: To determine the predictive factors for recurrent macular edema due to branch retinal vein occlusion (BRVO) during intravitreal ranibizumab (IVR) monotherapy. METHODS: Clinical records were retrospectively reviewed for 65 patients (mean age 66.5 years, 65 eyes) who were diagnosed with macular edema due to BRVO and treated with IVR monotherapy for 12 months at the Medical Retina Division, Department of Ophthalmology, Keio University Hospital between October 2013 and August 2017. Best-corrected visual acuity (BCVA), fundus findings, and sectional optical coherence tomography (OCT) images were analyzed. RESULTS: Overall BCVA and central retinal thickness (CRT) improved (all p < 0.01). BCVA at 12 months was significantly worse in patients with recurrent macular edema (40 eyes [61.5%]) (p < 0.01) than in those without, while CRT decreased and was comparable in both groups at 12 months. Logistic regression analyses showed association of recurrence with disorganization of the retinal inner layer (DRIL) temporal to the fovea at baseline (odds ratio = 7.74; 95% confidence interval 1.62-37.08, p = 0.01), after adjusting for age, gender, and initial CRT. CONCLUSION: Recurrent macular edema due to BRVO affects visual outcome and is associated with initial DRIL temporal to the fovea, evaluated using OCT sectional images before treatments. DRIL may facilitate determination of follow-up schedules in clinical practice.

Effect of axial length and age on the visual outcome of patients with idiopathic epiretinal membrane after pars plana vitrectomy.

We evaluated predictive factors for visual outcomes in patients with idiopathic epiretinal membrane (iERM) after pars plana vitrectomy (PPV). Clinical records for 114 eyes (114 patients, mean age: 70.6 years) with iERM treated by PPV between March 2012 and March 2018 were retrospectively reviewed. Overall, the mean postoperative best-corrected visual acuity (BCVA) and central retinal thickness measured by optical coherence tomography improved as early as 1 month after surgery, and further improved until 3 months (P < 0.01). Multiple linear regression analyses adjusted for the preoperative BCVA showed that older age (B, 0.010; 95% confidence interval, 0.003 to 0.016; P = 0.003) and a shorter axial length (AL; B, -0.059; 95% confidence interval, -0.099 to -0.019; P = 0.005) predicted worse postoperative BCVA. The Mann-Whitney U test showed that the postoperative BCVA was worse in eyes with AL < 23.6 mm than in eyes with AL ≥ 23.6 mm (P = 0.037), and in patients aged ≥69 years than in patients aged <69 years (P = 0.024). The findings may help in evaluating surgical indications for each patient to obtain satisfactory outcomes, irrespective of the preoperative BCVA.

Spatial-sweep steady-state pattern electroretinography can detect subtle differences in visual function among healthy adults.

We aimed to establish a highly sensitive method for measuring visual function using spatial-sweep steady-state pattern electroretinography (swpPERG). Overall, 35 eyes of 35 healthy adults (18 men; mean age, 32.3 years) were examined using swpPERG, and the data were recorded using spatial-patterned and contrast-reversed stimuli of size 1 (thickest) to 6. Data were converted into frequency-domain using a Fourier transform and expressed by signal-to-noise ratio (SNR). The number of participants who showed SNR ≥ 1 was significantly lesser at stimulus sizes 5 and 6 compared with those at greater stimulus sizes. Among the data with SNR ≥ 1, SNRs were negatively correlated with age at stimulus size 5 (r = -0.500, P = 0.029), and positively correlated with macular volume evaluated by optical coherence tomography (OCT) within a 6-mm circle diameter from the fovea of the retinal nerve fibre layer at size 4 (r = 0.409, P = 0.025) and of the ganglion cell layer at size 5 (r = 0.567, P = 0.011). We found that SNRs of swpPERG, recorded using the EvokeDx system, were correlated with age and macular morphology in participants without diagnosed eye diseases. The system detected subtle differences in retinal function, which may help in early disease diagnosis and visual evaluation in neuroprotective interventions in the future.

Dynamic changes in choroidal conditions during anti-vascular endothelial growth factor therapy in polypoidal choroidal vasculopathy.

We defined the relationships between initial choroidal conditions and their dynamics and exudative changes during anti-vascular endothelial growth factor (anti-VEGF) therapy in polypoidal choroidal vasculopathy (PCV). One hundred treatment-naïve eyes of 100 patients with PCV treated for 24 months at Keio University Hospital with intravitreal ranibizumab or aflibercept monotherapy (three injections and PRN thereafter) were retrospectively analyzed. Wet macula risk after three induction injections, which affected visual prognosis, was predicted by initial pachyvessels in the choroid (foveal greatest vertical choroidal vessel diameter [CVD] ≥180 µm) and pachychoroid (central choroidal thickness [CCT] ≥220 µm) recorded by optical coherence tomography. The risk for recurrent exudative change was greater in the pachyvessel groups irrespective of presence or absence of pachychoroid. Mean CVD and CCT decreased with anti-VEGF therapy when achieving a dry macula, suggesting that exudative changes are regulated by VEGF. Mean CVD and CCT at remission were greater in patients with initial pachyvessels and pachychoroid than in those without; the basal levels of CVD and CCT most likely represent VEGF-unrelated conditions. CVD increase preceded CCT increase and recurrent exudative changes, suggesting that the VEGF-related CVD increase may regulate CCT and exudative change; and that CVD may be a biomarker of exudative change.

QD laser eyewear as a visual field aid in a visual field defect model.

Visual field defects interfere with free actions and influence the quality of life of patients with retinitis pigmentosa; the prevalence of this disease is increasing in aging societies. Patients with progressive disease may require visual aids; however, no such devices are currently available. We utilized a retinal projection eyewear system, QD laser eyewear, which includes a projector inside the spectacle frame, to draw the image taken by a connected portable camera with a wide field lens. The images are projected onto the retina using a Maxwellian view optical system, which is not influenced by refractive error or the amount of incident light. Goldmann perimetry and figure recognition tests with the QD laser eyewear showed increased visual field areas and angles, and shortened the time for recognition of the number of figures in a sheet, in a limited visual field model that we developed by using a pin-hole system to simulate the tunnel vision of retinitis pigmentosa in 19 healthy adults. The device supported the quality of vision. Additionally, the visual field defect model used in healthy adults was useful for validating the device in the development stage of the study, to clarify both advantages and future goals for improving the device.

A novel and innovative paper-based analytical device for assessing tear lactoferrin of dry eye patients.

PURPOSE: To elucidate the correlation between lactoferrin concentration in the tear film and signs and symptoms of severe dry eye disease (DED) using a novel microfluidic paper-based analytical device (µPAD) and enzyme-linked immunosorbent assay (ELISA). METHODS: Twenty-four patients were recruited at the Keio University Hospital. Using a novel µPAD, lactoferrin concentrations were measured in 4 patients with GVHD-related DED, 3 patients with other types of DED and 2 controls (Group A). For validation by ELISA, 22 patients (7 patients from Group A) comprising 9 patients with GVHD-related DED, 6 patients with other types of DED and 7 controls were examined (Group B). The link between lactoferrin concentration and clinical data about the severity of aqueous tear deficient DED was also investigated by both µPAD and ELISA. RESULTS: The lactoferrin concentration in tear fluid of the DED patients was positively correlated between µPAD and ELISA (p = 0.006, r = 0.886). The tear fluid of the GVHD patients showed low or undetectable lactoferrin concentration. Analysis by ELISA demonstrated that lactoferrin concentrations in the tear film from the GVHD patients were significantly lower than those from the non-GVHD patients (p = 0.010576). ELISA revealed lactoferrin concentration correlated with the value of Schirmer test and tear film breakup time, whereas it was inversely correlated with OSDI, fluorescein and rose bengal scores. CONCLUSIONS: The novel µPAD may pave the way for measuring lactoferrin concentration in tear fluid from DED patients. Our results suggested that lactoferrin concentration in tear fluid reflect the severity of DED.

Benefits of aflibercept treatment for age-related macular degeneration patients with good best-corrected visual acuity at baseline.

Currently, age-related macular degeneration (AMD) is treated while patients exhibit good best-corrected visual acuity (BCVA). However, previous clinical trials only include patients with poor BCVA. We prospectively analyzed the benefits of intravitreal aflibercept (IVA) treatment for AMD patients exhibiting good BCVA at baseline. Twenty-nine treatment-naive AMD patients (29 eyes) with BCVA better than 0.6 (74 letters in ETDRS chart) were treated with IVA once a month for 3 months and every 2 months thereafter with no additional treatments. Improvement in mean BCVA, measured using the conventional Landolt C chart, contrast VA chart, and functional VA (FVA) system, and reductions in mean central retinal thickness (CRT), central choroidal thickness, macular volume (MV), and choroidal area on optical coherence tomography images were observed at 6 and 12 months. Improvements in contrast VA and FVA scores, in contrast to conventional BCVA, correlated with MV reduction; no VA scores correlated with a reduced CRT. The MV correlated with choroidal area after IVA. No severe adverse events occurred. IVA improved visual function, retinal condition, and quality of life evaluated by Visual Function Questionnaire, and was beneficial in these patients. The contrast VA and FVA scores and MVs, which detect subtle changes, helped demonstrate the benefits.

Selective vulnerability to ischemia in the rat spinal cord: a comparison between ventral and dorsal horn neurons.

STUDY DESIGN: Whole-cell patch-clamp recordings were performed from ventral horn (VH) and dorsal horn (DH) neurons obtained from the rat spinal cord slices. OBJECTIVE: This study investigated which is more vulnerable to ischemia, spinal VH neurons or DH neurons. SUMMARY OF BACKGROUND DATA: Spinal cord ischemia or injury sometimes causes a greater loss of motor function than of sensory function in patients. However, it is difficult to evaluate whether spinal motor neurons are more vulnerable than sensory neurons because of the anatomic complexity and a variety of physiologic factors in the spinal cord. METHODS: Whole-cell patch-clamp recordings were performed from VH and DH neurons obtained from the spinal cord slices. Ischemia was simulated by superfusing an oxygen- and glucose-deprived medium (ischemia simulating medium [ISM]). RESULTS: Perfusion with ISM generated an agonal depolarization in all VH and DH neurons recorded in current-clamp mode. Following ISM superfusion, an agonal inward current was produced at a holding potential of -70 mV in all VH and DH neurons tested in voltage-clamp mode. The agonal inward current consisted of a slow and subsequent rapid inward current. The average latency of the rapid inward currents after ISM exposures in VH neurons was significantly shorter than that in DH neurons. The average amplitude of the agonal inward currents in VH neurons was significantly bigger than that of DH neurons. Moreover, the recovery ratio by the reintroduction of oxygen and glucose in VH neurons was smaller than that in DH neurons. CONCLUSIONS: These results suggest that VH neurons are more vulnerable to ischemia than DH neurons. This finding may help in achieving a better understanding of the difference between motor and sensory disturbance in spinal cord ischemia or injury patients.

Improved method of the MALDI-TOF analysis of DNA with nanodot sample target plate.

We report a new sample target plate for MALDI-TOF mass spectrometry made of SiO2 with 30 nm Pt dots for which a highly reproducible and improved DNA analysis was achieved.

Distinct roles of P2X receptors in modulating glutamate release at different primary sensory synapses in rat spinal cord.

Using spinal cord slice preparations and patch-clamp recordings in lamina II and lamina V regions, we tested a hypothesis that P2X receptor subtypes differentially modulate glutamate release from primary afferent terminals innervating different sensory regions. We found that activation of P2X receptors by alpha,beta-methylene-ATP increased glutamate release onto >80% of DH neurons in both lamina regions. However, two distinct types of modulation, a transient and a long-lasting enhancement of glutamate release were observed. In lamina II recordings, >70% of the modulation was transient. In contrast, P2X receptor-mediated modulation was always long-lasting in lamina V. Pharmacologically, both transient and long-lasting types of modulation were blocked by 10 microM pyridxal-phosphate-6-azophenyl-2',4'-disulphonic acid tetrasodium, a broad-spectrum P2X receptor antagonist. Transient modulation was not observed in the presence of 1 microM trinitrophenyl-ATP (TNP-ATP), a subtype-selective P2X receptor antagonist, suggesting that homomeric P2X3 receptors may be involved in the transient modulation in lamina II. The long-lasting modulation remained in the presence of 1 microM TNP-ATP. Selective removal of P2X3-expressing afferent terminals by the targeting toxin saporin-conjugated isolectin B4 or surgical removal of superficial DH did not affect P2X receptor-mediated long-lasting modulation in lamina V. Taken together, these results suggest that P2X receptor subtypes play distinct roles in sensory processing in functionally different sensory regions.