Validation of a novel iPhone application for evaluating near functional visual acuity.

Monitoring dynamic changes in near vision is important for early detection of presbyopia. This study assessed the accuracy and reliability of a new smartphone-based application, the Smart Vision Check (SVC), compared with those of a conventional device (AS-28; Kowa, Aichi, Japan), for measuring near functional visual acuity (NFVA). We enrolled 115 healthy volunteers aged ≥ 20 years with bilateral best-corrected visual acuity of ≥ 20/25. The SVC was designed for use on an Apple iPhone SE2 to measure NFVA by tapping on the orientation icon manually. Conventional FVA was measured using the AS-28 with - 2.50 D added to the best distance correction at baseline. There was no significant difference in NFVA-related measurements between the AS-28 and SVC (P > 0.05). The Spearman correlation coefficients of NFVA measurements between the two devices were over 0.60 (P < 0.001). The Bland-Altman plot indicated minimal bias with limits of agreements of ± 0.34 logMAR for NFVA with habitual correction when comparing the AS-28 and SVC. The intraclass correlation coefficient of the repeated SVC-measured NFVA was 0.915 (95% CI 0.800-0.969). In summary, the SVC has the potential to evaluate NFVA in a relatively easy manner. Applied clinically, the SVC can be useful for presbyopia screening.

Resveratrol prevents light-induced retinal degeneration via suppressing activator protein-1 activation.

Light damage to the retina accelerates retinal degeneration in human diseases and rodent models. Recently, the polyphenolic phytoalexin resveratrol has been shown to exert various bioactivities in addition to its classical antioxidant property. In the present study, we investigated the effect of resveratrol on light-induced retinal degeneration together with its underlying molecular mechanisms. BALB/c mice with light exposure (5000-lux white light for 3 hours) were orally pretreated with resveratrol at a dose of 50 mg/kg for 5 days. Retinal damage was evaluated by TdT-mediated dUTP nick-end labeling, outer nuclear layer morphometry, and electroretinography. Administration of resveratrol to mice with light exposure led to a significant suppression of light-induced pathological parameters, including TdT-mediated dUTP nick-end labeling-positive retinal cells, outer nuclear layer thinning, and electroretinography changes. To clarify the underlying molecular mechanisms, the nuclear translocation of activator protein-1 subunit c-fos was evaluated by enzyme-linked immunosorbent assay, and the retinal activity of sirtuin 1 was measured by deacetylase fluorometric assay. Retinal activator protein-1 activation, up-regulated following light exposure, was significantly reduced by application of resveratrol. In parallel, retinal sirtuin 1 activity, reduced in animals with light damage, was significantly augmented by resveratrol treatment. Our data suggest the potential use of resveratrol as a therapeutic agent to prevent retinal degeneration related to light damage.

Randomized, crossover clinical efficacy trial in humans and mice on tear secretion promotion and lacrimal gland protection by molecular hydrogen.

The incidence of dry eye disease is increasing worldwide because of the aging population and increasing use of information technology. Dry eye disease manifests as tear-layer instability and inflammation caused by osmotic hypersensitization in tear fluids; however, to our knowledge, no agent that treats both pathologies simultaneously is available. Molecular hydrogen (H2) is known to be effective against various diseases; therefore, we aimed to elucidate the effects of H2 on tear dynamics and the treatment of dry eye disease. We revealed that administering a persistent H2-generating supplement increased the human exhaled H2 concentration (p < 0.01) and improved tear stability (p < 0.01) and dry eye symptoms (p < 0.05) significantly. Furthermore, H2 significantly increased tear secretion in healthy mice (p < 0.05) and significantly suppressed tear reduction in a murine dry eye model (p = 0.007). H2 significantly and safely improved tear stability and dry eye symptoms in a small exploratory group of 10 human subjects, a subset of whom reported dry eye symptoms prior to treatment. Furthermore, it increased tear secretion rapidly in normal mice. Therefore, H2 may be a safe and effective new treatment for dry eye disease and thus larger trials are warranted.

Determination of the Standard Visual Criterion for Diagnosing and Treating Presbyopia According to Subjective Patient Symptoms.

Presbyopia treatments using various modalities have been developed recently; however, no standard criteria exist for the diagnosis and treatment endpoint. This study assessed the relationship between the near visual acuity (NVA) and the subjective symptoms of phakic presbyopia and determined the numerical NVA threshold to diagnose phakic presbyopia and evaluate the effectiveness of presbyopia treatment. The binocular distance, NVA with habitual correction, and monocular conventional VA were measured. Patients were asked about their awareness of presbyopia and difficulty performing near tasks. This prospective observational study included 70 patients (mean age, 56 years; range, 32-77). Most patients became aware of presbyopia in their late forties, although some had difficulty with vision-related near tasks before becoming aware of presbyopia. Eighty three percent of patients (20/24) experienced difficulty with near vision-related tasks even with excellent NVA at 40 cm with habitual correction of 0.0 logMAR (20/20 in Snellen VA). In conclusion, the current study showed that patients became aware of presbyopia in their late forties, although some had difficulty with near vision-related tasks before becoming aware of presbyopia. Further investigation should include the proposal of appropriate diagnostic criteria for presbyopia and better management for patients with presbyopia.

Difference in Pupillary Diameter as an Important Factor for Evaluating Amplitude of Accommodation: A Prospective Observational Study.

Presbyopia is increasing globally due to aging and the widespread use of visual display terminals. Presbyopia is a decrease in the eye's amplitude of accommodation (AA) due to loss of crystalline lens elasticity. AA differs widely among individuals. We aimed to determine the factors that cause presbyopia, other than advanced age, for early medical intervention. We examined 95 eyes of 95 healthy volunteers (33 men, 62 women) aged 22-62 years (mean: 37.22 ± 9.77 years) with a corrected visual acuity of ≥1.0 and without other eye afflictions except ametropia. Subjective refraction, AA, maximum and minimum pupillary diameters during accommodation, axial length of the eye, and crystalline lens thickness were measured. AA was measured using an auto refractometer/keratometer/tonometer/pachymeter. The difference between maximum and minimum pupillary diameters was calculated. On multiple regression analysis, age and difference in pupillary diameter were both significantly and independently associated with AA in participants aged <44 years, but not in those aged ≥45 years. Our results suggest that the difference in pupillary diameter could be an important age-independent factor for evaluating AA in healthy individuals without cataract. Thus, improving the difference in pupillary diameter values could be an early treatment target for presbyopia.

Telmisartan treatment decreases visceral fat accumulation and improves serum levels of adiponectin and vascular inflammation markers in Japanese hypertensive patients.

Hypertension contributes to the occurrence and progression of cardiovascular diseases. The angiotensin II type 1 receptor blocker telmisartan is reported to activate the peroxisome proliferator-activated receptor gamma and improve insulin sensitivity. We investigated the effects of telmisartan treatment on visceral fat, serum adiponectin and vascular inflammation markers in Japanese hypertensive patients. This was an open-label, non-controlled study. Twenty-eight essential hypertensive patients (22 men and 6 women; age 60.6+/-1.9 years; body mass index [BMI] 25.5+/-0.6 kg/m(2)) participated. Fat area was assessed with computerized tomography. All the subjects were started on telmisartan 40 mg/day, which was increased to 80 mg/day to achieve the blood pressure target of less than 130/80 mmHg. We assessed the visceral and subcutaneous fat areas, serum adiponectin levels, and vascular inflammation markers at baseline and 24 weeks of telmisartan treatment. There were significant reductions in visceral fat area (from 103.1+/-7.9 to 93.3+/-8.4 cm(2), p<0.01) and pulse wave velocity (from 1,706+/-52 to 1,587+/-51 cm/s, p<0.01) at 24 weeks. In contrast, significant increases in serum high-density lipoprotein cholesterol (from 5.06+/-0.15 to 5.32+/-0.13 mmol/L, p<0.05) and adiponectin levels (from 8.27+/-0.76 to 9.13+/-0.81 microg/mL, p<0.05) were observed. Also, there were reductions in the interleukin-6 level (from 2.26+/-0.27 to 1.60+/-0.14 pg/mL, p<0.01). We also conducted these investigations in male subjects alone and similar findings were obtained for all of these parameters. In conclusion, telmisartan treatment was associated with an improvement of vascular inflammation, reductions in visceral fat and increases in serum adiponectin.

Expression Profiling of Ascorbic Acid-Related Transporters in Human and Mouse Eyes.

PURPOSE: Ascorbic acid (AsA) is an important antioxidant in the eye. Ascorbic acid is usually transported by sodium-dependent AsA transporters (SVCTs), and dehydroascorbic acid (DHA) by glucose transporters (GLUTs). This study investigates these AsA-related transporters in human compared with mouse eyes. METHODS: Five pairs of human donor eyes and 15 pairs of mouse eyes were collected. Immunofluorescence and in situ hybridization were performed to detect SVCTs and GLUTs expression in the ciliary epithelium, retina, and lens epithelial cells (LECs). These tissues were isolated with laser microdissection followed by extraction of total RNA. Quantitative PCR (qPCR) was performed to examine the mRNA level of SVCTs and GLUTs in human and mouse ocular tissues. RESULTS: Immunofluorescence and in situ hybridization showed SVCT2 and GLUT1 expression in human ciliary epithelium with varied distributions. Sodium-dependent AsA transporter 2 is expressed only in the pigmented epithelium (PE), and GLUT1 is predominately expressed in the nonpigmented epithelium (NPE). However, SVCT2 was not identified in mouse ciliary epithelium, whereas GLUT1 expressed in both PE and NPE. Laser microdissection and qPCR revealed high levels of SVCT2 mRNA in human RPE cells and murine neural retina. Sodium-dependent AsA transporter 1 mRNA could be detected only in human and murine LECs. Glucose transporter 3 and GLUT4 mRNA could not be detected in either the human or mouse ciliary processes or in the lens epithelium. CONCLUSIONS: These fundamental findings indicate AsA transporter expression in eyes of humans is significantly different compared with mice. This may explain why human aqueous and vitreous humors contain higher AsA levels compared with other animals.

NAMPT-Mediated NAD(+) Biosynthesis Is Essential for Vision In Mice.

Photoreceptor death is the endpoint of many blinding diseases. Identifying unifying pathogenic mechanisms in these diseases may offer global approaches for facilitating photoreceptor survival. We found that rod or cone photoreceptor-specific deletion of nicotinamide phosphoribosyltransferase (Nampt), the rate-limiting enzyme in the major NAD(+) biosynthetic pathway beginning with nicotinamide, caused retinal degeneration. In both cases, we could rescue vision with nicotinamide mononucleotide (NMN). Significantly, retinal NAD(+) deficiency was an early feature of multiple mouse models of retinal dysfunction, including light-induced degeneration, streptozotocin-induced diabetic retinopathy, and age-associated dysfunction. Mechanistically, NAD(+) deficiency caused metabolic dysfunction and consequent photoreceptor death. We further demonstrate that the NAD(+)-dependent mitochondrial deacylases SIRT3 and SIRT5 play important roles in retinal homeostasis and that NAD(+) deficiency causes SIRT3 dysfunction. These findings demonstrate that NAD(+) biosynthesis is essential for vision, provide a foundation for future work to further clarify the mechanisms involved, and identify a unifying therapeutic target for diverse blinding diseases.

[Short and long-term hypotensive effect of timolol-gel and latanoprost instillation in normal-tension glaucoma].

PURPOSE: To confirm the predictive value of the results of a 4-week trial of latanoprost alone, timolol-gel alone, or a combination of the two in normal-tension glaucoma (NTG) patients, when compared with the hypotensive response after a 6-month trial using the same combination of eye drops for the same patients. METHODS: One eye each of 45 NTG patients was used in a prospective 4-week trial of latanoprost alone, timolol-gel alone, or a combination of the two. Patients continued using the eye drops for 6 months, according to the results of the trial. The correlation of the results of the 6-moth use and the baseline data, and the baseline data and the results of the 4-week trial were evaluated by the paired-t test. RESULTS: The intraocular pressure(IOP)s of patients using timolol-gel alone were 13.9 mmHg at the base line, 9.7 mmHg after the trial, and 12.0 mmHg after 6-month use(baseline, trial: p < 0.05). IOPs when using latanoprost alone were 15.3 mmHg at baseline, 11.7 mmHg after the trial, and 11.5 mmHg after 6-month use(baseline: p < 0.05, trial: p = 0.33). IOPs using timolol-gel and latanoprost in combination were 14.8 mmHg at baseline, 11.4 mmHg after the trial, and 12.0 mmHg after 6-month use (baseline: p < 0:05, trial: p = 0.14). CONCLUSION: The result of the 4-weeks trial of latanoprost alone or in combination with timolol-gel can be indicative of the IOP after 6-month use.

Hydrogen and N-acetyl-L-cysteine rescue oxidative stress-induced angiogenesis in a mouse corneal alkali-burn model.

PURPOSE: To investigate the role of reactive oxygen species (ROS) as the prime initiators of the angiogenic response after alkali injury of the cornea and observe the effects of antioxidants in preventing angiogenesis. METHODS: The corneal epithelia of SOD-1-deficient mice or wild-type (WT) mice were removed after application of 0.15 N NaOH to establish the animal model of alkali burn. ROS production was semiquantitatively measured by dihydroethidium (DHE) fluorescence. Angiogenesis was visualized by CD31 immunohistochemistry. The effects of the specific NF-κB inhibitor DHMEQ, the antioxidant N-acetyl-L-cysteine (NAC), and hydrogen (H2) solution were observed. RESULTS: ROS production in the cornea was enhanced immediately after alkali injury, as shown by increased DHE fluorescence (P<0.01). NF-κB activation and the upregulation of vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein-1 (MCP-1) were significantly enhanced (P<0.01), leading to a significantly larger area of angiogenesis. Angiogenesis in SOD-1-/- mice corneas were significantly higher in WT mice (P<0.01), confirming the role of ROS. Pretreatment with the specific NF-κB inhibitor DHMEQ or the antioxidant NAC significantly reduced corneal angiogenesis by downregulating the NF-κB pathway (P<0.01) in both WT and SOD-1-/- mice. Furthermore, we showed that irrigation of the cornea with hydrogen (H2) solution significantly reduced angiogenesis after alkali-burn injury (P<0.01). CONCLUSIONS: Immediate antioxidant therapy with H2-enriched irrigation solution is a new potent treatment of angiogenesis in cornea to prevent blindness caused by alkali burn.

The anti-oxidative role of ABCG2 in corneal epithelial cells.

PURPOSE: ABCG2 is a putative marker of progenitor cells, including the corneal epithelium. The authors investigated whether ABCG2 functions in the homeostasis of corneal epithelial cells using abcg2 knockout (KO) mice and corneal epithelial cell lines. METHODS: abcg2 KO mice and a spontaneously immortalized murine corneal epithelial cell line (TKE2) were used for experiments. Flow cytometry was used to determine the presence of side population (SP) cells based on the ability of ABCG2 to efflux Hoechst 33342 dye. Expression of ABCG2 was also examined by RT-PCR. Cytotoxicity assay (IC(50)) and propidium iodide staining were performed in semiconfluent cells treated with hypoxia (1% O(2)) or with the pro-oxidant mitoxantrone. RESULTS: abcg2 KO mice had a normal corneal epithelial phenotype; however, cultured abcg2 KO epithelial cells were prone to oxidative damage by mitoxantrone. TKE2 cells were resistant to mitoxantrone at low doses, but higher concentrations were toxic in a dose-dependent manner. Coculture with the ABCG2 inhibitors reserpine and Ko143 inhibited resistance to mitoxantrone, with a statistically higher cell death ratio. abcg2 KO cells were also significantly more sensitive to hypoxia than were wild-type control cells. CONCLUSIONS: ABCG2 may protect corneal epithelial progenitor SP cells against oxidative stress induced by toxins and hypoxia.

Long-term culture and growth kinetics of murine corneal epithelial cells expanded from single corneas.

PURPOSE: To develop a reproducible procedure for the long-term culture of corneal epithelial cells from a single mouse cornea. METHODS: Corneal limbal explants of C57BL6/J mice were cultured in serum-free, low-Ca(2+) medium supplemented with EGF and cholera toxin. Epithelial cells were subcultured at a 1:3 split until passage (P)4 and at lower densities after P4. Colony-forming efficiency, population-doubling times, and population doublings were determined. The expression of p63, keratin (K)19, K12, and involucrin was analyzed by RT-PCR, immunocytochemistry, and Western blotting. Differentiation potential was examined by switching the medium to serum or high Ca(2+)-containing medium. Stratification ability was analyzed by air-lift culture. RESULTS: Thirty of 32 (93.8%) corneal explants were successfully subcultured to P1. Cultures without cholera toxin did not proliferate past P2 (n = 12), but 55% of cultures supplemented with cholera toxin achieved P4 (n = 20). After P4, cells were stably subcultured over 25 passages. Colony-forming efficiency increased from 9.7% +/- 2.6% at P5 to 29.0% +/- 3.3% at P20. The cells showed cobblestone appearance and expressed p63, K19, and involucrin but were negative for K12. Serum and high Ca(2+) induced differentiation, and cells cultured in DMEM/F12 with serum showed K12 mRNA expression. Stratified epithelium was formed by air-lifting. CONCLUSIONS: With this procedure, corneal epithelial cells from a single cornea can be cultured long term and can retain the potential to differentiate and stratify. This procedure can be a powerful tool for studies that require comparison of corneal epithelial cells from normal and transgenic mice in vitro.

Relationships of serum haptoglobin concentration with HbA1c and glycated albumin concentrations in Japanese type 2 diabetic patients.

BACKGROUND: The stable fractions of glycated hemoglobin (Hb), particularly HbA(1c), and glycated albumin (GA) were measured to monitor chronic glycemic control. Haptoglobin (Hp) is a Hb-binding protein, which plays a major role in preventing free Hb-induced tissue oxidative damage. The aim of this study was to clarify the relationships of serum Hp concentration with HbA(1c) and GA concentrations. METHODS: A cross-sectional study to determine the relationship of serum Hp concentration with GA and HbA(1c) concentrations was conducted. The subjects were 125 Japanese type 2 diabetic patients with stable HbA(1c) levels for more than 3 consecutive months. Patients with altered albumin and red blood cell turnover, which are observed in those with chronic renal failure, liver cirrhosis, and anemia among others, were excluded from the study. RESULTS: Serum Hp concentration positively correlated with HbA(1c) concentration (r=0.30, p<0.001), but not with GA concentration (r=0.15, p=0.10). There was a weak inverse correlation between serum Hp concentration and GA/HbA(1c) ratio (r=-0.19, p=0.03). Moreover, GA /HbA(1c) ratio inversely correlated with body mass index (BMI) (r=-0.31, p<0.001). In contrast, there was no significant correlation between Hb concentration and HbA(1c) (r=0.01, p=0.88) or GA (r=0.12, p=0.21) concentrations. We also analyzed the correlation of serum Hp concentration with GA and HbA(1c) concentrations in patients with the Hp 2-1 and Hp 2-2 genotypes, separately. Hp concentration positively correlated with HbA(1c) concentration in patients with the Hp 2-1 (r=0.32, p=0.03) and Hp 2-2 (r=0.29, p=0.02) phenotypes. Multiple regression analysis revealed that the observed correlation between Hp and HbA(1c) concentrations was significant after adjustment for age, gender, and BMI. In contrast, there was no significant correlation between GA and Hp concentrations in patients with either phenotype. Then, we analyzed how Hp concentration affects GA/HbA(1c) ratio in patients with these Hp phenotypes. There was an inverse correlation between Hp concentration and GA/HbA(1c) ratio in patients with Hp 2-1 (r=-0.44, p=0.003), but not in those with Hp 2-2 (r=-0.03, p=0.75). Multiple regression analysis revealed that the inverse correlation between Hp concentration and GA/HbA(1c) ratio in patients with Hp 2-1 was independent of age, gender, and BMI. CONCLUSIONS: Hp phenotype and concentration should be considered in interpreting HbA(1c) and GA levels as glycemic control indicators in diabetic patients. We suggest that in type 2 diabetic patients with Hp 2-1 and high Hp concentrations, HbA(1c) level may be overestimated relative to GA level.

Decreased ADP-ribosyl cyclase activity in peripheral blood mononuclear cells from diabetic patients with nephropathy.

AIMS/HYPOTHESIS: ADP-ribosyl-cyclase activity (ADPRCA) of CD38 and other ectoenzymes mainly generate cyclic adenosine 5'diphosphate-(ADP-) ribose (cADPR) as a second messenger in various mammalian cells, including pancreatic beta cells and peripheral blood mononuclear cells (PBMCs). Since PBMCs contribute to the pathogenesis of diabetic nephropathy, ADPRCA of PBMCs could serve as a clinical prognostic marker for diabetic nephropathy. This study aimed to investigate the connection between ADPRCA in PBMCs and diabetic complications. METHODS: PBMCs from 60 diabetic patients (10 for type 1 and 50 for type 2) and 15 nondiabetic controls were fluorometrically measured for ADPRCA based on the conversion of nicotinamide guanine dinucleotide (NGD(+)) into cyclic GDP-ribose. RESULTS: ADPRCA negatively correlated with the level of HbA1c (P = .040, R(2) = .073), although ADPRCA showed no significant correlation with gender, age, BMI, blood pressure, level of fasting plasma glucose and lipid levels, as well as type, duration, or medication of diabetes. Interestingly, patients with nephropathy, but not other complications, presented significantly lower ADPRCA than those without nephropathy (P = .0198) and diabetes (P = .0332). ANCOVA analysis adjusted for HbA1c showed no significant correlation between ADPRCA and nephropathy. However, logistic regression analyses revealed that determinants for nephropathy were systolic blood pressure and ADPRCA, not HbA1c. CONCLUSION/INTERPRETATION: Decreased ADPRCA significantly correlated with diabetic nephropathy. ADPRCA in PBMCs would be an important marker associated with diabetic nephropathy.