Evaluation of static and dynamic pupil characteristics in hyperopic anisometropic amblyopia

Comparative analysis of optic disc and macular microvasculature in children with anisometropic amblyopia before and after treatment

PURPOSE

To evaluate optic disc and macular microvasculature changes in children with anisometropic amblyopia before and after treatment.

METHODS

In all, 60 children with unilateral anisometropic amblyopia between the ages of 6 and 12 were randomly selected from the ophthalmology clinic of Fuyang People's Hospital, while 60 children with non-amblyopia in the same age range were randomly selected as a normal control group. The right eye was uniformly taken in the control group with at least 6 months of follow-up. Optical coherence tomography angiography (OCTA) was used to evaluate the macular vessel density of superficial capillary plexus (SCP) and deep capillary plexus (DCP), optic disc vascular density (VD), foveal avascular zone (FAZ) area, macular thickness, and retinal nerve fiber layer thickness (RNFLT).

RESULTS

Before treatment, the vessel density of the optic disc, macular SCP and DCP in the amblyopic group was significantly lower than those in the fellow eyes and the control group (P < 0.05), while there were no statistically significant differences in the vessel densities of the optic disc, macular SCP and DCP between the amblyopic eyes, the fellow eyes, and the control group after treatment (P>0.05). Statistically significant negative correlations were found between the alterations of BCVA in amblyopic eyes and the alterations of the vessel densities of the optic disc, macular SCP and DCP in amblyopia eyes (P<0.05) except for superior nasal (SN) and inferior nasal (IN) regions of the optic disc radial peripapillary capillary, temporal and nasal regions of macular parafoveal SCP, nasal regions of macular parafoveal DCP and inferior regions of macular perifoveal DCP(P>0.05).

CONCLUSION

Macular and optic disc vessel density in OCTA are lower in children with anisometropic amblyopia and tend to return to normal levels to a certain extent following treatment for amblyopia.

Evaluating the utility of quantitative pupillometry in a neuro-critical care setting for the monitoring of intracranial pressure: A prospective cohort study

INTRODUCTION

Assessment of the pupillary light reflex (PLR) is key in intensive care monitoring of neurosurgical patients, particularly for monitoring intracranial pressure (ICP). Quantitative pupillometry using a handheld pupillometer is a reliable method for PLR assessment. However, many variables are derived from such devices. We therefore aimed to assess the performance of these variables at monitoring ICP.

METHODS

Sedated patients admitted to neurocritical care in a tertiary neurosurgical centre with invasive ICP monitoring were included. Hourly measurement of ICP, subjective pupillometry (SP) using a pen torch device, and quantitative pupillometry (QP) using a handheld pupillometer were performed.

RESULTS

561 paired ICP, SP and QP pupillary observations from nine patients were obtained (1122 total pupillary observations). SP and QP had a moderate concordance for pupillary size (κ=0.62). SP performed poorly at detecting pupillary size changes (sensitivity=24%). In 40 (3.6%) observations, SP failed to detect a pupillary response whereas QP did. Moderate correlations with ICP were detected for maximum constriction velocity (MCV), dilation velocity (DV), and percentage change in pupillary diameter (%C). Discriminatory ability at an ICP threshold of >22 mmHg was moderate for MCV (AUC=0.631), DV (AUC=0.616), %C (AUC=0.602), and pupillary maximum size (AUC=0.625).

CONCLUSION

QP is superior to SP at monitoring pupillary reactivity and changes to pupillary size. Although effect sizes were moderate to weak across assessed variables, our data indicates MCV and %C as the most sensitive variables for monitoring ICP. Further study is required to validate these findings and to establish normal range cut-offs for clinical use.

The pupillary dynamics of patients with physiological anisocoria

BACKGROUND

To evaluate static pupillometric measurements and making inter-ocular comparative analysis in healthy subjects for demonstrating the prevalance of physiological anisocoria in various lighting conditions and to compare the variations of the dynamic pupillometric measurements of the patients with physiological anisocoria.

METHODS

Automatic quantitative pupillometry system was used to measure pupillary diameters in low mesopic (0.1 cd/m²), high mesopic (1 cd/m²), low photopic (10 cd/m²) and high photopic (100 cd/m²) conditions. After inter-ocular comparison of these data, the prevalance of physiological anisocoria was detected in four different lighting conditions. The inter-ocular dynamic pupillometric parameters (amplitude, latency, duration and velocity of pupil contraction; latency, duration and velocity of pupil dilation) of these patients were further analysed.

RESULTS

After inter-ocular comparison of pupillary diameters of 195 participants [96 females (49.2%) and 99 males (50.8%)] with a mean age of 38.4 ± 18.9 years (range 7-78 years), six (3.1%) participants under high photopic; 11 (5.6%) participants under low photopic; 25 (12.8%) participants under high mesopic, and 34 (17.4%) participants under low mesopic illumination levels exhibited physiological anisocoria. The mean relative amplitude of anisocoric small pupils' contraction was lower than the mean relative amplitudes of pupil contraction of both isocoric and anisocoric large pupils (p = 0.021, p = 0.035, respectively). The mean velocity of anisocoric small pupils' contraction was lower than the mean velocity of anisocoric large pupils' contraction (p = 0.013).

CONCLUSIONS

The mean contraction amplitude and contraction velocity of smaller pupils was lower when compared to fellow larger pupils of anisocoric patients.

Pupillary light reflex as a diagnostic aid from computational viewpoint: A systematic literature review

This work presents a detailed and complete review of publications on pupillary light reflex (PLR) used to aid diagnoses. These are computational techniques used in the evaluation of pupillometry, as well as their application in computer-aided diagnoses (CAD) of pathologies or physiological conditions that can be studied by observing the movements of miosis and mydriasis of the human pupil. A careful survey was carried out of all studies published over the last 10 years which investigated, electronic devices, recording protocols, image treatment, computational algorithms and the pathologies related to PLR. We present the frontier of existing knowledge regarding methods and techniques used in this field of knowledge, which has been expanding due to the possibility of performing diagnoses with high precision, at a low cost and with a non-invasive method.

Evaluation of Pupillary Light Reflex in Amblyopic Eyes Using Dynamic Pupillometry

Objectives

To evaluate the pupillary light reflex responses in patients with unilateral strabismic and anisometropic amblyopia using dynamic pupillometry.

Materials and Methods

A total of 102 eyes of 51 patients with unilateral amblyopia were included in this cross-sectional study. Of the 51 patients, 37 (72.5%) had strabismic amblyopia and 14 (27.5%) had anisometropic amblyopia. All patients underwent complete ophthalmological examination, and pupillary light reflex responses were measured using a computerized dynamic pupillometry system (MonPack One; Metrovision, France). Initial pupil diameter; the amplitude, latency, duration, and velocity of pupil contraction; and the latency, duration, and velocity of pupil dilation were recorded. Results obtained from the patients’ amblyopic and normal fellow eyes were compared using paired-samples t-test and Wilcoxon signed rank test.

Results

The mean age of the patients was 11.9±6.0 years. Amblyopic eyes had longer contraction latency (p=0.009), shorter contraction duration (p=0.002), and higher dilation velocity (p=0.033) compared to fellow eyes, while other parameters did not show significant differences. In subgroup analysis, eyes with strabismic amblyopia had longer contraction latency (p=0.006) and shorter contraction duration (p=0.017), while eyes with anisometropic amblyopia had shorter contraction duration (p=0.030) when compared with fellow eyes.

Conclusion

In this study, the objective records obtained by dynamic pupillometry showed that pupillary light reflex responses are affected in amblyopic eyes. This finding may shed light on unclear aspects of the pathophysiology of amblyopia.