Correlation between retinal vessel density and retinal nerve fiber layer in acute primary angle-closure glaucoma / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To observe circumpapillary and macular vessel density(cpVD/MVD), and to evaluate correlations of cpVD/MVD with retinal nerve fiber layer(RNFL)in patients with acute primary angle-closure glaucoma(APACG).<p>METHODS: Patients with monocular APACG(<i>n</i>=29)visited the Affiliated Hospital of Xuzhou Medical University from March 1, 2019 to December 31, 2019 were prospectively enrolled. Moreover, 29 eyes with APACG attack were included in the experimental group to be performed with combined trabeculectomy, and 29 contralateral eyes were served as the control group to receive preventive laser peripheral iridotomy. Changes in the MVD, the cpVD and the thickness of optic nerve fiber layer(RNFL)before operation and 1wk, 1mo, 3mo and 6mo after operation were observed by oraphyptical coherence tomography angiography(OCTA), respectively.<p>RESULTS: Before operation, the experimental group showed lower cpVD in the superotemporal(ST)quadrant and the temporosuperior(TS)quadrant compared with the control group(all <i>P</i><0.01). In addition, a brief rise was observed in each quadrant of the experimental group 1wk after operation, but with lower cpVD in the supero-nasal(SN)quadrant, the ST quadrant and the TS quadrant than the control group(all <i>P</i><0.05). Furthermore, 1mo, 3mo and 6mo after operation, there was a steady downward trend in the cpVD and the MVD in each quadrant of the experimental group over time, and the RNFL thickness was increased at first within 6mo after operation, and then gradually thinned, but the RNFL thickness of the experimental group were thinner than those of the control group 6mo after operation. Correlation analysis showed that there was a positive correlation between the cpVD and the RNFL thickness in the SN, ST, temporoinferior(TI), IT, IN and nasoinferior(NI)quadrants in the experimental group 6mo after operation(all<i> P</i><0.05). <p>CONCLUSION: The RNFL was thickened in the affected eyes in the early stage after acute attack of APACG, and gradually thinned 3-6mo after operation. However, the cpVD was decreased continuously, and there was a correlation between the RNFL thickness and the cpVD 6mo after operation.

Clinical correlation of retinal nerve fiber layer thickness in multiple sclerosis patients- A North Indian study

Background: Axonal loss is thought to occur early in the course multiple sclerosis (MS) and is supposed to be associated with, and predictive of, neurologic deficits progressing to permanent disability.Axonal loss in the retinal nerve fiber layer (RNFL) is measured by optical coherence tomography (OCT). Material and Methods: A longitudinal observational study, conducted on 30 MS patients. All subjects underwent neurological examination, including expanded disability status scale (EDSS) scoring and OCT on two visits, minimum 2 months apart. Results: Total of 60 eyes of 30 patients were subdivided into 21 eyes having optic neuritis (ON) [‘MS – ON’] and 39 eyes without ON. The RNFL thickness (RNFLt) was found to be significantly reduced in all parameters except in temporal quadrant, as the duration of disease increases. Average RNFLt were found to have negative correlation (r = -0.450) with disease duration. Negative correlation (r=-0.657) was also found between EDSS score change and average RNFLt change. The eyes having ON showed statistically significant RNFL thinning as compared to the non – ON fellow eyes. The baseline EDSS score was found to be negatively correlated (moderate degree, r = -0.348) with baseline average RNFL thickness, with p-value of 0.006. Conclusions: The RNFLt is not only significantly thinner in those with history of ON, but it is also affected remarkably even in absence of prior ON, suggesting subclinical ongoing axonal loss in patients with MS. The EDSS score is inversely correlated with RNFL thickness.

Linear discriminant score for differentiating early primary open angle glaucoma from glaucoma suspects

Purpose: To determine the diagnostic accuracy of a linear discriminant function (LDF) based on macular ganglion cell complex (GCC), optic nerve head (ONH) and retinal nerve fibre layer (RNFL) for differentiating early primary open-angle glaucoma (POAG) from glaucoma suspects. Methods: In this cross-sectional study, data from consecutive 127 glaucoma suspects and 74 early POAG eyes were analysed. Each patient underwent detailed ocular examination, standard automated perimetry, GCC and ONH and RNFL analysis. After adjusting for age, gender and signal strength using the analysis of covariance; Benjamin–Hochberg multiple testing correction was performed to detect truly significant parameters to calculate the LDF. Subsequently, diagnostic accuracy of GCC and ONH and RNFL were determined. The obtained LDF score was evaluated for diagnostic accuracy in another test set of 32 suspect and 19 glaucomatous eyes. Data were analysed with the R-3.2.1 (R Core Team 2015), analysis of variance, t-test, Chi-square test and receiver operating curve. Results: Among all GCC parameters, infero temporal had the best discriminating power and average RNFL thickness and vertical CDR among ONH and RNFL parameters. LDF scores for GCC had AUROC of 0.809 for a cut-off value 0.07, while scores for ONH and RNFL had AUROC of 0.903 for a cut-off value ? 0.24. Analysis on combined parametric space resulted in avg RNFL thickness, vertical CDR, min GCC + IPL and superior GCC + IPL as key parameters. LDF scores obtained had AUROC of 0.924 for a cut-off value 0.1. The LDF was applied to a test set with an accuracy of 84.31%. Conclusion: The LDF had a better accuracy than individual GCC and ONH and RNFL parameters and can be used for diagnosis of glaucoma.

Analysis of Retinal Nerve Fibre Layer Changes in Cases of Phacomorphic Angle Closure Post Phacoemulsification

Introduction: To investigate the retinal nerve fibre layer (RNFL) changes after an acute attack of phacomorphic angle closure. Methods: This prospective study involved 25 cases of phacomorphic angle closure that underwent phacoemulsification and intraocular lens insertion after intraocular pressure lowering. Apart from visual acuity and intraocular pressure (IOP), RNFL thickness was measured by optical coherence tomography (OCT) at 3–6 months post attack. Result: All cases had mean phacomorphic duration of <10 days. Postoperatively, best correct Snellen visual acuity was 0.42±0.23 and IOP at 6 months was 13.92 ± 2.41 mmHg. There was no difference RNFL between the attack and contralateral eye at 3 months post attack (both
p = 0.102). At 6 months post attack, there was significant thinning in the average (p <0.001), superior (p =<0.001), and inferior (p = 0.001) RNFL. Patients with <5 days duration of phacomorphic angle closure are likely to have reasonable postoperative vision. Conclusion: An acute episode of phacomorphic angle closure can trigger an accelerated RNFL thinning despite normal IOP and open angles, most noticeable in the superior and inferior quadrants, occurring between 3 and 6 months post attack. There is a need of long term follow up of such patients.

Study of Retinal Nerve Fibre Layer Thickness in Type 2 Diabetes Mellitus by 3-Dimensional Optical Coherence Tomography from Eastern India.

Three dimensional optical coherence tomography (OCT) is a novel technique to diagnose retinal disorders. In diabetes, loss of retinal neurons is said to be an early event. We did a small pilot study from Eastern India to find the usefulness of OCT in detecting changes in retinal nerve fibre layer (RNFL) in diabetics. We selected adult type 2 diabetics without overt retinopathy. Patients aged more than 60 or with pre-existing problems like glaucoma or vasculitis were excluded. RNFL thickness was measured using HRA-OCT Spectralis analyser. A 12º area around optic nerve head was analysed and depth of each quadrant was separately measured. The patient values were compared with normative Indian data to detect aberrations. Also, the venous blood sugar levels were measured and correlation studies were done with the retinal thickness values. Standard statistical methods were used. We had 10 diabetic cases (20 eyes) and 11 controls (22 eyes). There was significant thinning of RNFL in 6 (60%) diabetic cases and none of the controls. Two of the diabetics had severe thinning around optic nerve head. 83% of the patients had thinning on temporal side and 50% on nasal side. Mean blood glucose levels were higher in those with RNFL thinning. Both FBS and PPBS showed significant negative correlation with retinal thickness measurements. This is probably the first study of its kind from India. 3-D OCT can be a valuable tool in screening diabetics for complications. However, more studies are needed to better elucidate the role of this novel technology.