To assess the impact of axial length on the age-related peripapillary retinal nerve fiber layer (RNFL) thinning.
This cross-sectional observational comparative case series included 172 eyes from 172 healthy Korean subjects. Peripapillary RNFL thickness was measured using an Optic Disc Cube 200 × 200 scan of spectral domain Cirrus HD OCT and the axial length was measured using IOL Master Advanced Technology. In age groups based on decade, the normal ranges of peripapillary RNFL thickness for average, quadrant, and clock-hour sectors were determined with 95% confidence intervals. After dividing the eyes into two groups according to axial length (cut-off, 24.50 mm), the degrees of age-related RNFL thinning were compared.
Among the eyes included in the study, 53 (30.81%) were considered to be long eyes (axial length, 25.04 ± 0.48 µm) and 119 (69.19%) were short-to-normal length eyes (axial length, 23.57 ± 0.60 µm). The decrease in average RNFL thickness with age was less in long eyes (negative slope, -0.12 µm/yr) than in short-to-normal length eyes (negative slope, -0.32 µm/yr) (p < 0.001).
Age-related thinning of peripapillary RNFL thickness is attenuated in long eyes compared to short-to-normal length eyes.
Axial length; Glaucoma; Optical coherence tomography; Retinal ganglion cell
To assess the inter-device agreement of peripapillary retinal nerve fiber layer (RNFL) thickness measurements by 2 spectral domain Cirrus HD optical coherence tomography (OCT) devices in healthy Korean subjects.
Eleven eyes of 11 healthy volunteers were enrolled in the present study. Each eye was scanned with the Optic Disc Cube 200 × 200 scan of 2 Cirrus HD OCT devices for peripapillary RNFL thickness calculation. The inter-device agreements of the 2 Cirrus HD OCTs for average, quadrant, and clock-hour RNFL thickness values were determined with Wilcoxon signed rank test, Friedman test, Cronbach's alpha (α), intraclass correlation coefficient (ICC), coefficient of variation (COV), and Bland-Altman plot.
The mean age of the participants was 25.82 ± 3.28 years and all had a 0.00 logarithm of the minimum angle of resolution of best-corrected visual acuity. The signal strengths of scans from the 2 Cirrus HD OCT were not significantly different (p = 0.317). The inter-device agreement of average RNFL thickness was excellent (α, 0.940; ICC, 0.945; COV, 2.45 ± 1.52%). However, the agreement of nasal quadrant RNFL thickness was not very good (α, 0.715; ICC, 0.716; COV, 5.72 ± 4.64%). Additionally, on the Bland-Atman plot, the extent of agreement of the 2 Cirrus HD OCTs for RNFL thickness was variable according to scanned sectors.
The inter-device agreement of 2 spectral domain Cirrus HD OCT devices for peripapillary RNFL thickness measurements was generally excellent but variable according to the scanned area. Thus, physicians should consider this fact before judging a change of RNFL thicknesses if they were measured by different OCT devices.
Inter-device agreement; Optical coherence tomography; Retinal nerve fiber layer thickness
To describe the long-term results of deep sclerectomy with collagen implant (DSCI) with or without adjuvant mitomycin C in Korean patients with primary or secondary open-angle glaucoma (OAG).
This retrospective review was comprised of 65 Korean patients who received DSCI with or without adjuvant mitomycin C due to primary or secondary OAG. Patients were followed for 72 months after surgery. Complete success was defined as intraocular pressure (IOP) <21 mmHg without medication and qualified success was defined as IOP <21 mmHg with or without medication.
Mean postoperative follow-up period was 53.0 ± 16.2 months. Mean IOP was 30.5 ± 11.7 mmHg preoperatively, 8.4 ± 4.3 mmHg at postoperative day one and 13.4 ± 3.8 mmHg 60 months after surgery. The mean number of glaucoma medications was decreased from 3.6 ± 1.1 to 1.6 ± 1.3 at 60 months after the operation. Complete and qualified success rates were 36.7% and 79.6% at postoperative 60 months, respectively (Kaplan-Meier survival curve). No shallow or flat anterior chamber, endophthalmitis, or surgery-induced significant cataract was observed.
The results of DSCI in Korean patients presented here seem reasonably excellent with qualified success rates of over 70% at six years with negligible complications.
Deep sclerectomy; Koreans; Open-angle glaucoma; Small collagen implant
Heat shock protein 47 (Hsp47) is a well-known molecular chaperone in collagen synthesis and maturation. The aim of this study is to investigate its putative role in the transdifferentiation of Tenon’s fibroblasts to myofibroblasts.
Primary cultured human Tenon’s fibroblasts were exposed to transforming growth factor-β1 (TGF-β1) for up to 48 hours. The mRNA levels of Hsp47 and α smooth muscle actin (αSMA) were determined by quantitative real time RT-PCR. After delivery of small interfering RNA (siRNA) molecules targeting Hsp47 into the cells, the expression of Hsp47 and αSMA proteins was determined by western immunoblotting.
TGF-β1 increased the mRNA expressions of both Hsp47 and αSMA in human Tenon’s fibroblasts, as determined by quantitative real time RT-PCR. However, it induced the protein expression of only αSMA but not Hsp47, as determined by western immunoblots. When siRNAs specific for Hsp47 were introduced into those cells, the TGF-β1-induced expression of αSMA was significantly attenuated on western immunoblots; after 48 hours of exposure to TGF-β1, the relative densities of immunobands were 11.58 for the TGF-β1 only group and 2.75 for the siRNA treatment group, compared with the no treatment control group (p < 0.001).
Our data suggest that Hsp47 may be related to the TGF-β1-induced transdifferentiation of human Tenon’s fibroblasts to myofibroblasts.
Fibroblast; Fibrosis; Heat shock protein; Myofibroblast; Transforming growth factor-β
To investigate the role of focal adhesion kinase (FAK) in transforming growth factor (TGF)-β-induced myofibroblast transdifferentiation of human Tenon's fibroblasts.
Primary cultured human Tenon's fibroblasts were exposed to TGF-β1 for up to 48 hours. The mRNA levels of FAK, α smooth muscle actin (αSMA), and β-actin were determined by quantitative real time reverse transcription polymerase chain reaction. The protein levels of collagen type I, FAK, phospho-FAK, αSMA, and β-actin were determined by Western immunoblots. After the small interfering RNA targeting FAK (siRNAFAK) molecules were delivered into the cells, the expressions of αSMA proteins were determined by Western immunoblots.
In human Tenon's fibroblasts, TGF-β1 significantly increased the mRNA and protein expressions of αSMA. However, when the action of FAK was inhibited using siRNAFAK, the TGF-β1-induced expression of αSMA was attenuated.
Our data suggest that FAK may be associated with the TGF-β1-induced transdifferentiation of human Tenon's fibroblasts to myofibroblasts, which is the essential step of subconjunctival fibrosis.
Fibroblast; Focal adhesion protein-tyrosine kinases; Myofibroblast; Transforming growth factors
Based on the vascular theory of glaucoma pathogenesis, we wanted to evaluate the effect of Ginkgo biloba extract (GBE) on peripapillary blood flow in patients with normal tension glaucoma (NTG).
Thirty patients with NTG were randomly placed in the GBE-treated or control groups. The GBE-treated group received 80 mg GBE orally, twice a day for four weeks, and the control group received a placebo twice a day for four weeks. Complete ocular examinations including visual field, Heidelberg retina flowmeter, and systemic examinations were performed on the first study day and on the day treatment was completed.
After GBE treatment, the mean blood flow, volume, and velocity increased at almost all points, and there was a statistically significant increase in blood flow at almost all points, in comparison to the placebo. Blood volume significantly increased only in the superior nasal and superior temporal neuroretinal rim areas. GBE also significantly increased blood velocity in areas of the inferior temporal neuroretinal rim and superior temporal peripapillary area.
GBE administration appears to have desirable effect on ocular blood flow in NTG patients.
Ginkgo biloba extract; Heidelberg retina flowmeter; Normal tension glaucoma; Ocular blood flow
The purpose of this study was to investigate the prevalence and characteristics of glaucoma in the population of the rural Korean town, Sangju.
Residents of Sangju aged greater than 50 years old were included in this study. Participants completed an interview examining their medical and ophthalmic history Information was collected on the participants' uncorrected and best corrected vision scores, slit lamp examination results, angle width measurements using the Van Herick technique, gonioscopy if the angle width was less than 1 / 4 angle, intraocular pressure (IOP) assessed with the Goldmann applanation tonometry, optic disc examination results, and a visual field test results using frequency-doubling perimetry in cases in which glaucoma was suspected. Glaucoma was diagnosed according to the criteria described by the International Society for Geographic and Epidemiological Ophthalmology.
1,118 residents aged greater than 50 years were examined initially from a population of 2,984 people. Of these, 671 subjects (60%) participated in this study. The prevalence of glaucoma was determined to be 3.4% (95% confidence interval [CI], 2.1-4.8). Open-angle glaucoma with low IOP was determined to be the most common form with a prevalence rate as high as 2.5% (95% CI, 1.8-3.7). Additionally, primary angle closure glaucoma was determined to have a prevalence rate of 0.3% (95% CI, 0.1-0.9). Open-angle glaucoma with low IOP accounted for 94.4% of the open-angle glaucoma cases.
The prevalence of glaucoma among the population of rural Sangju was 3.4%, and open-angle glaucoma with low IOP was the most common form accounting for 94.4% of the total number of cases.
Epidemiology; Glaucoma; Open angle glaucoma; Prevalence
Surgical outcomes of phacoemulsification only and phacoemulsification combined with trabeculectomy were compared in patients with primary angle-closure glaucoma (PACG). Clinical records of 41 consecutive patients were retrospectively reviewed, and there was no difference in best-corrected visual acuity and intraocular pressure preoperatively and at the final follow-up in both study groups. Regarding the number of anti-glaucoma medications, it was higher in the phacoemulsification combined with trabeculectomy group preoperatively than the phacoemulsification only group (p = 0.045), but both groups were taking similar quantities of medication at the final follow-up (p = 0.6). In addition, postoperative hypotony (two cases) occurred only after phacoemulsification combined with trabeculectomy, but not after phacoemulsification only. In one case after phacoemulsification only, a second operation was needed. There were no additional postoperative complications. In conclusion, both phacoemulsification only and phacoemulsification combined with trabeculectomy showed good surgical outcomes in PACG patients. Both procedures might be equally effective in treating patients with PACG.
Phacoemulsification; phacoemulsification combined with trabeculectomy; primary angle-closure glaucoma
We report the effects of unilateral recession-resection surgery of the horizontal recti muscles with inferior displacement and augmented anterior transposition of the inferior oblique muscle with a posterior intermuscular suture in a patient with large exotropia and considerable hypertropia.
The purpose of this study is to assess patient attitudes towards anti-glaucoma medication and their association with adherence, visual quality of life, and personality traits.
Materials and Methods
One hundred and forty-seven glaucoma patients were enrolled this study. The participants were divided into 'pharmacophobic' and 'pharmacophilic' groups according to their scores on the Modified Glaucoma Drug Attitude Inventory (MG-DAI). To establish a correlation with patient drug attitude, each group had their subjective drug adherence, visual quality of life, and personality traits examined. For personality traits, the Myers-Briggs Type Indicator (MBTI) was used to sub-classify each group.
Among the patients analyzed, 91 (72.80%) patients showed a 'pharmacophobic' attitude and 34 (27.20%) patients showed a 'pharmacophilic' attitude. The pharmacophobic group tended to have worse adherence than the pharmacophilic group. Personality dichotomies from the MBTI also showed different patterns for each group.
In glaucoma patients, pharmacological adherence was influenced by their attitude towards drugs; an association might exist between drug attitude and underlying personality traits.
Adherence; drug attitude; glaucoma; personality
The purpose of this article is to report a case of nonarteritic anterior ischemic optic neuropathy (NAION) after uneventful cataract surgery. A 53-year-old Filipina underwent cataract surgery. She had a small optic disc with cup-to-disc ratio of 0.2 in the left eye and 0.3 in the right eye. On the first postoperative day, the uncorrected visual acuity (UCVA) was 20/20, with an intraocular pressure (IOP) of 20 mmHg in the left eye. At one week after operation, the UCVA was 20/20 and the IOP was 15 mmHg. Three weeks later, she underwent cataract surgery in the right eye. On the first postoperative day, her UCVA was 20/20 in both eyes, but she complained of a visual field decrease in the left eye. A relative afferent pupillary defect (RAPD) was noted and the optic disc was pallid and swollen diffusely. A red-free photo showed defect surrounding the optic disc. A visual field test showed tunnel vision sparing the central vision. In this report, the authors hypothesize an association between cataract extraction and delayed NAION. Since the risk of NAION in the fellow eye is 30-50%, visual acuity, visual field, fundus exam and RAPD should be routinely checked.
Cataract; Ischemic optic neuropathy
To assess efficacy of the Pentacam (PTC) and the anterior segment optical coherence tomography (AOCT) for detection of occludable angles.
Materials and Methods
Fourty-one eyes with gonioscopically diagnosed occludable angles and 32 normal open-angle eyes were included. Anterior chamber angle (ACA) and anterior chamber depth (ACD) were measured with PTC and AOCT. Receiver operating characteristic (ROC) curve was constructed for each parameter and the area under the ROC curve (AUC) was calculated.
Values of ACA and ACD measured by PTC and AOCT were similar not only in normal open angle eyes but also in occludable angle eyes. For detection of occludable angle, the AUCs of PTC with ACA and ACD were 0.935 and 0.969, respectively. The AUCs of AOCT with ACA and ACD were 0.904 and 0.947, respectively.
Both PTC and AOCT allow accurate discrimination between open and occludable angle eyes, so that they may aid to screening the occludable angles.
Pentacam; anterior segment optical coherence tomography; occludable angle; anterior chamber angle; anterior chamber depth
To assess the accuracy of intraocular lens (IOL) power predictions for cataract surgery in eyes with primary angle-closure glaucoma (ACG). Because of shifting of the capsular bag apparatus and shortening of the axial length, preoperative calculation of IOL power may be inaccurate for eyes with ACG.
Materials and Methods
This retrospective comparative case series comprised of 42 eyes from 42 patients with primary ACG and 45 eyes from 45 subjects with normal open-angles undergoing uneventful cataract surgery. Anterior segment biometry including anterior chamber depth, lens thickness, and axial length were compared. Using the SRK-II formula, the powers of the implanted IOL and the actual postoperative spherical equivalent (SE) refractive errors were compared between the two groups. Also, the absolute values of differences between predicted and residual SE refractive errors were also analyzed for each group.
In ACG patients, anterior chamber depth and axial length were shorter and the lens was thicker than normal controls (all p < 0.001). Even though residual SE refractive error was not significantly different (p = 0.290), the absolute value of the difference between predicted and residual SE refractive error was 0.64 ± 0.50 diopters in AGC patients and 0.39 ± 0.36 diopters in control subjects (p = 0.012). The number of eyes that resulted in inaccurate IOL power predictions of more than 0.5 diopters were 21 (50.00%) in the ACG group, but only 12 (26.67%) in the control group (p = 0.043).
IOL power predictions for cataract surgery in ACG patients can be inaccurate, and it may be associated with their unique anterior segment anatomy.
Angle-closure; cataract; glaucoma; intraocular lens
To gain a better understanding of the roles of interleukins (ILs) in subconjunctival fibrosis, we investigated their expression in transforming growth factor-β1 (TGF-β1)-stimulated Tenon’s fibroblasts and examined their association with the transdifferentiation of fibroblasts to myofibroblasts.
After primary culture, fibroblasts derived from human Tenon’s capsule were exposed to TGF-β1. The expression of α-smooth muscle actin (α-SMA) protein was assessed by western immunoblots and immunofluorescence. The mRNA levels of various ILs were also evaluated by multiplex reverse transcription (RT)-PCR. Using the small interfering RNAs (siRNAs) specific for IL-6 and IL-11 and the promoter deletion assay, the contributions of IL-6 and IL-11 to TGF-β1-induced induction of α-SMA were determined.
In human Tenon’s fibroblasts, TGF-β1 stimulated the expression of α-SMA protein determined by western blot analysis and also increased the mRNA levels of IL-6 and IL-11 determined by multiplex RT-PCR. On the western immunoblots and immunofluorescence, the increased expression of α-SMA was attenuated only by the siRNAs specific for IL-6 but not by the siRNAs specific for IL-11. When the activator protein-1 binding sites of the IL-6 promoter region were deleted, the stimulation effects of TGF-β1 decreased.
Our data show that autocrine IL-6 may participate in the TGF-β1-induced transdifferentiation of human Tenon’s fibroblasts to myofibroblasts, which is known to be an essential step for subconjunctival fibrosis.
To assess the reproducibility and agreement of anterior chamber measurements between the Pentacam (PTC) and the Anterior segment optical coherence tomography (AOCT) in normal healthy eyes with open angle.
Prospective cross-sectional comparative case series. A total of 162 eyes of 81 healthy volunteers with normal open angle were included in this study. Anterior chamber angle (ACA) and anterior chamber depth (ACD) were measured with PTC and AOCT. Intra-observer variability and inter-methods agreement of both instruments for ACA and ACD were evaluated.
Values of temporal and nasal ACA measured by two instruments were similar, and the results of ACD were also not significantly different between modalities (p>0.01). ACA and ACD measurements by PTC and AOCT showed good intra-observer and inter-method agreements (all >0.9).
PTC and AOCT are presumed to be very useful for the anterior chamber angle examination. They may provide good images and quantitative data about the angle structures including ACA and ACD.
Anterior chamber angle; Anterior chamber depth; Anterior segment optical coherence tomogaphy; Pentacam
To evaluate the relationship between optic disc and retinal nerve fiber layer (RNFL) measurements obtained with the optical coherence tomography (OCT) and the Heidelberg retina topography (HRT) in normal, normal tension glaucoma (NTG), and high tension glaucoma (HTG).
Normal, NTG and HTG subjects who met inclusion and exclusion criteria were evaluated retrospectively. One hundred seventy eyes of 170 patients (30 normal, 40 NTG, and 100 HTG) were enrolled. Complete ophthalmologic examination, HRT, OCT, and automated perimetry were evaluated.
Disc area, cup area and cup/disc area ratio measured with HRT were significantly different between NTG and HTG (all p<0.05). Mean RNFL thickness measured by OCT with ascanning diameter of 3.4 mm was larger in NTG than HTG (84.97±24.20 µm vs. 73.53±27.17 µm, p=0.037). Four quadrant RNFL thickness measurements were not significantly different between NTG and HTG (all p>0.05). Mean deviation and corrected pattern standard deviation measured by automated perimetry was significantly correlated with mean and inferior RNFL thickness in both NTG and HTG (Pearson's r, p<0.05). Mean RNFL thickness/disc area ratio was significantly larger in HTG than NTG (35.21±18.92 vs. 31.30±10.91, p=0.004).
These findings suggest that optic disc and RNFL damage pattern in NTG may be different from those of HTG.
High tension glaucoma; Normal tension glaucoma; Retinal nerve fiber layer
To assess the relationship between the retinal thickness analyzer (RTA) parameters, and those of the GDx VCC scanning laser polarimeter (GDx VCC), Stratus OCT optical coherence tomography (Stratus OCT), and Heidelberg retinal tomograph II confocal scanning laser ophthalmoscopy (HRT II).
Twenty-nine primary open-angle glaucoma patients were retrospectively included in this study. Measurements were obtained using the RTA, GDx VCC, Stratus OCT, and HRT II. We calculated the correlation coefficients between the parameters of RTA and those of the other studies.
Among the optic disc parameters of RTA, the cup volume was best correlated with Stratus OCT (R=0.780, p<0.001) and HRT II (R=0.896, p<0.001). Among the posterior pole retinal thickness parameters, the posterior pole abnormally thin area (PPAT) of the RTA and the inferior average of the GDx VCC were best correlated (R=-0.596, p=0.001). The PPAT of the RTA and the inferior maximum of the Stratus OCT were best correlated (R=-0.489, p=0.006). The perifoveal minimum thickness (PFMT) of the RTA and the cup shape measurement of the HRT II were best correlated (R=-0.565, p=0.004).
Many RTA optic disc parameters were significantly correlated with those of the Stratus OCT and HRT II. The RTA posterior pole retinal thickness parameters were significantly correlated with those of the GDx VCC, Stratus OCT and HRT II. The RTA optic disc and posterior pole retinal thickness parameters may be valuable in the diagnosis of glaucoma.
Glaucoma; Optical coherence tomography; Retinal thickness analyzer; Scanning laser polarimeter
To determine the normal reference range of pulsatile ocular blood flow (POBF) values in healthy Korean subjects and to find out the factors that may affect them.
A total of 280 eyes of 280 normal subjects were included in this study. Best corrected visual acuity (BCVA), intraocular pressure (IOP), axial length, POBF, systemic blood pressure, and pulse rate were measured. The mean, standard deviation, range, and the 5th and 95th percentiles of POBF were calculated, and the influences of various parameters to POBF were determined by multiple regression analyses.
The mean POBF value was 766.0±221.6 µl/min in men and 1021.1±249.5 µl/min in women. The 5th and 95th percentiles for POBF values were 486.0 µl/min and 1140.0 µl/min in men and 672.0 µl/min and 1458.0 µl/min in women. The POBF values were significantly influenced by gender, mean blood pressure, pulse rate, and axial length.
Even though the POBF values were influenced by gender, BP, and axial length, we could define the normal reference range of POBF in healthy Koreans.
Korean; Normal reference range; Pulsatile ocular blood flow
To evaluate retinal nerve fiber layer (RNFL) defect by a new scoring system for RNFL photography using the Heidelberg Retina Angiograph 1 (HRA1).
This retrospective study included 128 healthy eyes and 836 primary open-angle glaucoma eyes. The RNFL photography using HRA1 was interpreted using a new scoring system, and correlated with visual field indices of standard automated perimetry (SAP). Using the presence of RNFL defect, darkness, width, and location, we established the new scoring system of RNFL photos.
The mean RNFL defect score I in the early, moderate, severe, and control groups were 7.3, 9.2, 10.4, and 3.6, respectively. The mean RNFL defect score II in the early, moderate, severe, and control groups were 14.5, 28.5, 43.4, and 3.4, respectively. Correlations between the RNFL defect score II and the mean deviation of SAP was the strongest of the various combinations (r=-0.675, P<.001).
Using a new scoring system, we propose a method for semi-quantitative interpretation of RNFL photographs. This scoring system may be helpful to distinguish between normal and glaucomatous eyes, and the score is associated with the severity of visual field loss.
Glaucoma; Retinal nerve fiber layer; Photograph; Scoring system
Goggles are frequently worn in the sport of swimming and are designed to form a seal around the periorbital tissue orbit. The resultant pressure on the eye may have the potential to affect intraocular pressure and blood flow of the optic nerve head. This study evaluates the influence of wearing swimming goggles on intraocular pressure (IOP) and blood flow of the ocular nerve head (ONH) in normal subjects.
Materials and Methods
Thirty healthy participants took part in this study. The IOP of each participant was measured using a Goldmann tonometer. Measurements were taken immediately before putting on swimming goggles, at 5, 10, 30, and 60 minutes after putting on swimming goggles, and then immediately after taking off the goggles. Blood flow of the ONH was measured using the Heidelberg retinal flowmeter.
The average IOP before, during and after wearing the swimming goggles were 11.88 ± 2.82 mmHg, 14.20 ± 2.81mmHg and 11.78 ± 2.89 mmHg, respectively. The IOP increased immediately after putting on the goggles (p < 0.05) and then returned to normal values immediately after removal (p > 0.05). Blood flow of the ONH was 336.60 ± 89.07 Arbitrary Units (AU) before and 319.18 ± 96.02 AU after the goggles were worn (p < 0.05).
A small but significant IOP elevation was observed immediately after the swimming goggles were put on. This elevated IOP was maintained while the goggles were kept on, and then returned to normal levels as soon as they were taken off. Blood flow of the ONH did not change significantly throughout the experiment. These facts should be considered for safety concerns, especially in advanced glaucoma patients.
Swimming goggles; intraocular pressure; blood flow of optic nerve head
Agmatine is an endogenous polyamine formed by the decarboxylation of L-arginine. We investigated the protective effects of agmatine against hypoxia-induced apoptosis of immortalized rat retinal ganglion cells (RGC-5). RGC-5 cells were cultured in a closed hypoxic chamber (5% O2) with or without agmatine. Cell viability was determined by lactate dehydrogenase (LDH) assay and apoptosis was examined by annexin V and caspase-3 assays. Expression and phosphorylation of mitogen-activated protein kinases (MAPKs; JNK, ERK p44/42, and p38) and nuclear factor-kappa B (NF-κB) were investigated by Western immunoblot analysis. The effects of agmatine were compared to those of brain-derived neurotrophic factor (BDNF), a well-known protective neurotrophin for retinal ganglion cells.
After 48 hours of hypoxic culture, the LDH assay showed 52.3% cell loss, which was reduced to 25.6% and 30.1% when agmatine and BDNF were administered, respectively. This observed cell loss was due to apoptotic cell death, as established by annexin V and caspase-3 assays. Although total expression of MAPKs and NF-κB was not influenced by hypoxic injury, phosphorylation of these two proteins was increased. Agmatine reduced phosphorylation of JNK and NF-κB, while BDNF suppressed phosphorylation of ERK and p38.
Our results show that agmatine has neuroprotective effects against hypoxia-induced retinal ganglion cell damage in RGC-5 cells and that its effects may act through the JNK and NF-κB signaling pathways. Our data suggest that agmatine may lead to a novel therapeutic strategy to reduce retinal ganglion cell injury related to hypoxia.