Can We Corroborate Peripapillary RNFL Analysis with Macular GCIPL Analysis? Our 2-Year Experience at a Single-Centre Tertiary Healthcare Hospital Using Two OCT Machines and a Review of Literature

Evaluation of effect of covıd-19 pandemic on anatomical and functional changes and vision-related quality of life in patients with glaucoma

BACKGROUND

To evaluate anatomical and functional changes and vision-related quality of life in patients whose glaucoma follow-up was disrupted by the COVID-19 restrictions.

METHODS

This retrospective observational study included 100 patients who were followed up at the glaucoma unit. For the patients whose follow-up evaluations were postponed due to COVID-19 restrictions, visual acuity (VA), intraocular pressure (IOP), retinal nerve fiber layer (RNFL) thickness, visual field parameters [mean deviation (MD), pattern standard deviation (PSD), and visual field index (VFI)], and the National Institute of Ophthalmology Visual Function Scale-25 (NEI-VFQ-25) score were evaluated based on the measurements performed at the last visit before COVID-19 (V1) and at the first visit after the removal of COVID-19 restrictions (V2).

RESULTS

The mean age of the patients was 61.1 ± 13.4 years, the mean follow-up time was 11.4 ± 4.2 months, and the mean interval between the last two visits was 7.2 ± 2.7 months. In the evaluation of the last two visits, VA was lower and IOP was higher at V2, and there was progression in the MD, PSD, and VFI values (p<0.05, for all). RNFL thickness progression was seen in 13-23% of the patients. According to the NEI-VFQ-25 evaluation, except for peripheral vision and near vision, all the remaining subscale scores and the total score were lower at V2 (p<0.05, for all).

CONCLUSIONS

This study demonstrates the devastating impact of the COVID-19 pandemic on the anatomical and functional changes and vision-related quality of life together in patients with glaucoma.

The Discriminatory Ability of Ganglion Cell Inner Plexiform Layer Complex Thickness in Patients with Preperimetric Glaucoma

Purpose

To evaluate diagnostic performance of ganglion cell inner plexiform layer (GCIPL) and retinal nerve fiber layer (RNFL) parameters measured with Cirrus high-definition optical coherence tomography (OCT) in patients with preperimetric glaucoma.

Methods

In this multicenter cross-sectional study, 150 eyes of 83 patients with preperimetric glaucoma were compared with 200 eyes of age and sex matched healthy subjects. All patients had visual field testing and OCT scanning of GCIPL and RNFL in all quadrants. The independent Samples t-test was used to determine if a difference exists between the means of two independent groups on a continuous dependent variable. The area under the receiver operating characteristic (ROC) curve (AUC) of each parameter was calculated for discriminatory ability between normal controls and preperimetric glaucoma. The sensitivity and specificity were estimated by point coordinates on ROC curve.

Results

The best parameters for distinguishing preperimetric glaucoma from healthy eyes were the combined average GCIPL + average RNFL, followed by average RNFL + GCIPL (inferotemporal), and average RNFL + GCIPL (minimum). The GCIPL parameters with the highest to lowest AUC (in decreasing order) were inferotemporal, followed by average, minimum, superior, inferior, superonasal, inferonasal, superotemporal, and quadrants. The RNFL parameters with the highest to lowest AUC (in decreasing order) were average, followed by nasal, temporal, superior, and inferior quadrants. The sensitivity of combined GCIPL + RNFL parameters ranged 85%-88% and the specificity ranged 76%-88%. The sensitivity for RNFL parameters ranged 80%-90% and the specificity ranged 64%-88%.

Conclusion

GCIPL and RNFL have good discriminatory ability; the sensitivity and specificity increase when both parameters are combined for early detection of glaucoma.

Pattern Electroretinogram Parameters and their Associations with Optical Coherence Tomography in Glaucoma Suspects

Aim

To investigate whether steady state pattern electroretinogram (ssPERG) could identify retinal ganglion cell (RGC) dysfunction, and to assess the relationship between ssPERG with optical coherence tomography (OCT) measurements in glaucoma suspects (GS).

Materials and methods

This was a prospective cohort study of GS, identified based on suspicious optic disk appearance and glaucoma risk factors. Complete eye exam, Standard automated perimetry, OCT, and ssPERG were performed. Magnitude (Mag), Magnitude D (MagD), and MagD/Mag ratio were subsequently used in the correlation and linear regression analyses between ssPERG parameters and the RNFL, GCL/IPL, and macular thicknesses measurements.

Results

Forty-nine eyes of 26 patients were included. Mag and MagD were significantly correlated with the superior, inferior, and average RNFL thicknesses (avRNFLT). All ssPERG parameters were significantly correlated with the average and minimum GCL/IPL thicknesses and the inner macular sector thicknesses. Mag and MagD significantly predicted the superior, inferior, and avRNFLT in the regression analysis. All ssPERG parameters were predictive of GCL/IPL thickness in all sectors as well as the average and minimum GCL/IPL thicknesses. All ssPERG parameters were predictive of all inner macular sector thicknesses and MagD was also predictive of some outer macular sector thicknesses as well.

Conclusion

ssPERG has significant correlations with and is predictive of RNFL, GCL/IPL, and macular thicknesses in glaucoma suspects.

Clinical significance

ssPERG may serve as a useful objective functional tool for identifying and following the progression of disease in glaucoma suspects.

How to cite this article

Tirsi A, Wong A, Zhu D, et al. Pattern Electroretinogram Parameters and their Associations with Optical Coherence Tomography in Glaucoma Suspects. J Curr Glaucoma Pract 2022;16(2):96-104.