Longitudinal Evaluation of Trifocal and Extended Depth of Focus Lenses Implantation using Standard Automated Perimetry Parameters

Purpose: To evaluate reliability and global indices parameters from standard automated perimetry (SAP) in normal eyes undergoing phacoemulsification cataract surgery with implantation of trifocal or extended depth of focus intraocular lens (IOL).Methods: Prospective comparative study. Comparison of trifocal IOL AcrySof IQ PanOptix® and extended depth of focus intraocular lens (EDOF) Tecnis Symfony® IOL. Patients underwent SAP pre- and postoperatively. Reliability indices (false negative rate - FN, false positive rate – FP), global indices (foveal sensitivity threshold, visual field index - VFI, standard pattern deviation – PSD, mean deviation MD) and test duration were analyzed.Results: A total of 23 eyes from 13 patients were in the trifocal IOL group and a total of 22 eyes from 14 patients were in the EDOF group The following results were obtained by analyzing pre- and postoperative SAP of EDOF IOL: the rate of change of FN was 1.95/1.41% (p=0.61); FP 1.64/1.27 (p=0.60); MD -1.60/-1.08dB (p=0.15); foveal sensitivity was 34.5/33.9dB (p=0.41); VFI 98.5/98.4% (p>0.99); PSD 1.85/1.86 (p=0.07); and for test duration 305.81/298.36s (p=0.35); all respectively. Analysis of pre- and postoperative parameters of trifocal IOL was: the rates of change of FN 1.22/1.83% (p=0.29); FP 1.65/1.48% (p=0.95); MD -1.55/-1.37dB (p=0.19) ; foveal sensitivity 33.9/34.9dB (p=0.47) ; VFI 98.6/98.3% (p=0.62); PSD 1.58/2.05 (p=0.02); and test duration 297.17/298.57s (p=0.87); all respectively. Conclusion: We identified a change in the PSD parameters in the trifocal IOL group. No other significant changes were identified in SAP parameters after implantation of trifocal AcrySof IQ PanOptix® and EDOF Tecnis Symfony® IOL. Longitudinal evaluation showed no changes in SAP after Trifocal and EDOF IOL implantation in normal subjects.

Elucidating Macular Structure-Function Correlations in Glaucoma

Correlation between structural data from optical coherence tomography (OCT) and functional data from the visual field (VF) may be suboptimal because of poor mapping of OCT measurement locations to VF test stimuli. We tested the hypothesis that stronger structure-function correlations in the macula can be achieved with fundus-tracking perimetery, by precisely mapping OCT measurements to VF sensitivity at the same location. The conventional 64 superpixel (3°x3°) OCT grid was mapped to VF sensitivities averaged in 40 corresponding VF units with standard automated perimetry (conventional mapped approach, CMA) in 38 glaucoma patients and 10 healthy subjects. Similarly, a 144 superpixel (2°x2°) OCT grid was mapped to each of the 68 VF locations with fundus-tracking perimetry (localized mapped approach, LMA). For each approach, the correlation between sensitivity at each VF unit and OCT superpixel was computed and the maximum value used to generate vector maps. CMA yielded significantly higher structure-function correlations compared to LMA. Only 20% of the vectors with CMA and <5% with LMA were within corresponding mapped OCT superpixels, while most were directed towards loci with structural damage. Measurement variability and patterns of glaucomatous damage are more likely to affect the correlations rather than precise mapping of VF stimuli.

The Assessment of Morphological and Functional Changes in the Detection of the Initial Stage of Primary Glaucoma

Purpose — to study morphological and functional changes in the detection of primary glaucoma progression.Patients and methods. 128 patients (128 eyes, among them — 64 eyes with primary open angle glaucoma (POAG) and 64 with primary angle closure glaucoma (PACG)) with the initial MD of –6.0 dB were examined at the Ophthalmology Center of the FMBA of Russia from May 2016 to November 2019. The values of corneal-compensated IOP were also considered: minimal (IOPmin), peak (IOPmax) and its fluctuations (IOPfluct). The progression was measured using standard automated perimetry (SAP) and spectral-domain OCT (SD-OCT). During the observation period, each patient received the average of 8.42 ± 2.08 SAP and SD-OCT. Progressive thinning of the retinal nerve fiber layer (RNFL) and its ganglion cell complex (GCC) were evaluated using SD-OCT. If RNFL and/or GCC had a trend of significant (p < 0.05) thinning, the eye was classified as having the SD-OCT progression. The correlation between the rate of progression detected by SAP (ROP1) using thinning of RNFL (ROP2) and GCC (ROP3) with other clinical parameters was analyzed.Results and discussion. Glaucoma progression was detected in 73 eyes. While the isolated use of SAP did not allow detecting progression, it was possible to detect it in 39 % cases by SD-OCT. The combination of both methods allowed detecting progression in 57 %. In both forms, ROP1 correlated with IOPmin: in PACG r = 0.41, p = 0.023 and in POAG r = 0.43, p = 0.016. In PACG, ROP2 and ROP3 correlated with the foveal choroid thickness: r = 0.46, p = 0.019 and r = 0.47, p = 0.009, respectively. At the same time, ROP3 was associated with peak IOP (r = –0.402, p = 0.025); the correlation of peak IOP with its fluctuations amounted to 0.7 (p < 0.001).Conclusion. SD-OCT is more informative than SAP in determining the progression of the initial primary glaucoma. The combination of these two methods 1.5 times increases the possibility of detecting progression in comparison with the isolated use of SD-OCT. The choroid thickness, associated with the IOP fluctuations, plays an important role in the progression of PACG.

Prediction of glaucoma severity using parameters from the electroretinogram

Glaucoma is an optic neuropathy that results in the progressive loss of retinal ganglion cells (RGCs), which are known to exhibit functional changes prior to cell loss. The electroretinogram (ERG) is a method that enables an objective assessment of retinal function, and the photopic negative response (PhNR) has conventionally been used to provide a measure of RGC function. This study sought to examine if additional parameters from the ERG (amplitudes of the a-, b-, i-wave, as well the trough between the b- and i-wave), a multivariate adaptive regression splines (MARS; a non-linear) model and achromatic stimuli could better predict glaucoma severity in 103 eyes of 55 individuals with glaucoma. Glaucoma severity was determined using standard automated perimetry and optical coherence tomography imaging. ERGs targeting the PhNR were recorded with a chromatic (red-on-blue) and achromatic (white-on-white) stimulus with the same luminance. Linear and MARS models were fitted to predict glaucoma severity using the PhNR only or all ERG markers, derived from chromatic and achromatic stimuli. Use of all ERG markers predicted glaucoma severity significantly better than the PhNR alone (P ≤ 0.02), and the MARS performed better than linear models when using all markers (P = 0.01), but there was no significant difference between the achromatic and chromatic stimulus models. This study shows that there is more information present in the photopic ERG beyond the conventional PhNR measure in characterizing RGC function.

The Open Perimetry Initiative: a framework for cross-platform development for the new generation of portable perimeters

The Open Perimetry Initiative is fully open source and consists of the Open Perimetry Interface (OPI) and an accompanying package (visualFields) with analytical tools. The OPI package contains an ever-growing number of drivers for commercially available perimeters, head-mounted devices, and virtual reality headsets. The visualFields package contains tools for the analysis and visualization of visual field data, including methods to compute deviation values and probability maps. The use of the OPI and visualFields is shown through a custom static automated perimetry test for the full visual field (up to 50° nasally and 80° temporally) developed with the OPI driver for the Octopus 900 and using visualFields for statistical analysis. Its potential for the development of cross-platform apps for driving and testing portable devices is demonstrated with an OPI driver for an Android-based headset. With more than 55 citations in clinical and translational science as listed in Scopus, this initiative has contributed significantly to expanding the knowledge base in perimetry and clinical vision research at large, and with clinical translation. The continued support of researchers, clinicians, industry, and public institutions are key in transforming perimetry research from closed to open science. The Open Perimetry Initiative provides framework to achieve this.

Monitoring for glaucoma progression with SAP, electroretinography (PERG and PhNR) and OCT

Purpose To investigate the value of pattern electroretinography (PERG) and photopic negative response (PhNR) in monitoring glaucoma compared to standard clinical tests (standard automated perimetry (SAP) and clinical optic disc assessment) and structural measurements using spectral-domain OCT. Methods A prospective study included 32 subjects (32 eyes) with ocular hypertension, suspect or early glaucoma monitored for progression with clinical examination, SAP, PERG, PhNR and OCT for at least 4 years. Progression was defined clinically by the documented change of the optic disc and/or significant visual field progression (EyeSuite™ trend analysis). One eye per patient was included in the analysis. Results During the follow-up, 13 eyes (40.6%) showed progression, whereas 19 remained stable. In the progressing group, all parameters showed significant worsening over time, except for the PhNR, whereas in the stable group only the OCT parameters showed a significant decrease at the last visit. The trend of change over time using linear regression was steepest for the OCT parameters. At baseline, only the ganglion cell complex (GCC) and peripapillary retinal nerve fibre (pRNFL) thicknesses significantly discriminated between the stable and progressing eyes with the area under the ROC curve of 0.72 and 0.71, respectively. The inter-session variability for the first two visits in the stable group was lower for OCT (% limits of agreement within ± 17.4% of the mean for pRNFL and ± 3.6% for the GCC thicknesses) than for ERG measures (within ± 35.9% of the mean for PERG N95 and ± 59.9% for PhNR). The coefficient of variation for repeated measurements in the stable group was 11.9% for PERG N95 and 23.6% for the PhNR, while it was considerably lower for all OCT measures (5.6% for pRNFL and 1.7% for GCC thicknesses). Conclusions Although PERG and PhNR are sensitive for early detection of glaucomatous damage, they have limited usefulness in monitoring glaucoma progression in clinical practice, mainly due to high inter-session variability. On the contrary, OCT measures show low inter-session variability and might have a predicting value for early discrimination of progressing cases.