Inter-Device Agreement of Retinal Nerve Fiber Layer Thickness Measurements Using Spectral Domain Cirrus HD OCT

PURPOSE: 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. METHODS: Eleven eyes of 11 healthy volunteers were enrolled in the present study. Each eye was scanned with the Optic Disc Cube 200 x 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 (alpha), intraclass correlation coefficient (ICC), coefficient of variation (COV), and Bland-Altman plot. RESULTS: 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 (alpha, 0.940; ICC, 0.945; COV, 2.45 +/- 1.52%). However, the agreement of nasal quadrant RNFL thickness was not very good (alpha, 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. CONCLUSIONS: 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.ope

Change in Prostaglandin Expression Levels and Synthesizing Activities in Dry Eye Disease

Objective To investigate the expression level of prostaglandins (PGs) and their de novo synthesis in dry eye (DE) disease. Design Cross-sectional case-control study and in vivo mouse experimental study. Participants Forty-six eyes from 23 DE patients and 33 eyes from 17 age- and sex-matched controls were studied. Also, DE-induced murine eyes were compared with control eyes. Methods Patients completed a symptom questionnaire using a 100-mm visual analog scale (VAS). Nanoliquid chromatography tandem mass spectrometry was used for the quantification of PGE2 and PGD2. A DE disease environmental chamber was used to induce DE in mice. One week after induction, enzyme expressions of cyclooxygenase-1, cyclooxygenase-2 (COX-2), PG E synthase (PGES), and PG D synthase (PGDS) in the lacrimal glands, meibomian glands, and corneas were examined using immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR). Main Outcome Measures The mean PGE2 and PGD2 levels in the tears of DE patients were measured and compared with symptom severity scores. Immunohistochemistry staining patterns and qRT-PCR data of DE mice were quantified. Results The mean PGE2 level in the tears of DE patients (2.72±3.42 ng/ml) was significantly higher than that in the control group (0.88±0.83 ng/ml; P = 0.003). However, the mean PGD2 level in the tears of DE patients (0.11 ±0.22 ng/ml) was significantly lower (0.91 ±3.28 ng/ml; P = 0.028). The mean PGE2-to-PGD2 ratio correlated strongly with VAS scoring (P = 0.008). In DE mice, COX-2 mRNA was significantly higher in ocular surface tissue and lacrimal glands. Furthermore, PGES mRNA was significantly higher in ocular surface tissue, whereas PGDS mRNA was decreased. Immunohistochemistry staining showed elevated COX-2 expression in the lacrimal glands, meibomian glands, corneas, and conjunctivas. Furthermore, PGES expression was found in periductal infiltrated cells of the lacrimal glands and conjunctival epithelium. Also, PGDS expression was decreased in meibomian glands and increased focally in the conjunctival epithelium. Conclusions A reciprocal change in PGE2 and PGD2 levels was found in the tears of DE patients, which correlated with patients’ symptom scores. These clinical results were supported by increased COX-2 and PGES expression levels found in tear-producing tissues of DE mice. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article

Ocular hypotensive effects of topically administered agmatine in a chronic ocular hypertensive rat model

a b s t r a c t Agmatine, a primary polyamine and potential neuromodulator, exhibits a high affinity to the a 2 -adrenergic receptor as well as imidazoline receptors. As a 2 -adrenergic receptor agonists display positive ocular hypotensive effects, we assessed whether agmatine effectively lowers intraocular pressure (IOP) using a chronic ocular hypertensive rat model. We raised IOP in unilateral eyes of Sprague-Dawley rats by cauterizing three episcleral veins per eye. Four weeks later, we topically administered 10 À3 M agmatine solution 4 times a day for 6 consecutive weeks. After confirming the recovery of IOP to pretreatment level at 13 weeks after cauterization, the retinal ganglion cells (RGCs) were retrogradely labeled and counted. Eyes subjected to episcleral vein cauterization (EVC) demonstrated significant increases in IOP (48.39% increase over baseline IOP), and the elevated IOP was well maintained until 12 weeks. Topically administered agmatine powerfully lowered IOP to 30.29% of its pretreatment level, and the associated washout period was about two weeks. EVC was associated with a 55.44% loss of RGCs in the control group, but agmatine appeared to attenuate this RGC loss to 18.65%. Overall, topically administered agmatine appeared to effectively lower IOP and rescue RGCs in a chronic ocular hypertensive rat model. Although the mechanism underlying these effects is not yet established, it is possible that agmatine offers a powerful new ocular hypotensive agent for eyes with chronic ocular hypertension and/or glaucoma