Evaluation of Eye-Pain Severity between Dry-Eye Subtypes

Eye Pain Caused by Epithelial Damage in the Central Cornea in Aqueous-Deficient Dry Eye

In this study, the severity of eye pain (EP) and associated objective findings were evaluated in aqueous-deficient dry eye (ADDE) patients using PainVision®, a quantitative pain-measuring device. This study involved 53 eyes of 53 ADDE patients (6 males and 47 females; mean age: 64.4 ± 13.4 [mean ± SD] years). Of those, 18 eyes of 18 patients underwent punctal occlusion, and EP and objective findings in those patients were evaluated before and after treatment. In all patients, the severity of EP as measured by PainVision® was assessed using the Pain Degree (PD). The median PD for the 53 patients was 30.6 µA/µA (interquartile range, 16.9-93.2), and the nasal and central corneal staining score and the upper lid-wiper epitheliopathy score were significantly correlated with PD (R = 0.33, 0.33, and 0.28, respectively) (all: p < 0.05). Using the least squares method, the central corneal staining score most significantly affected PD. In the 18 cases that underwent punctal occlusion, PD was significantly reduced (median PD: 24.8 to 7.1 µA/µA; p < 0.0001). Using the least squares method, the central corneal staining score and tear meniscus radius were significantly more influential as factors contributing to PD before and after treatment, and central corneal epithelial damage was the factor most associated with ADDE-related EP.

A Quantitative Measure of Pain with Current Perception Threshold, Pain Equivalent Current, and Quantified Pain Degree: A Retrospective Study

Background: As a subjective sensation, pain is difficult to evaluate objectively. The assessment of pain degree is largely dependent on subjective methods such as the numeric rating scale (NRS). The PainVisionTM system has recently been introduced as an objective pain degree measurement tool. The purpose of this study was to analyze correlations between the NRS and the current perception threshold (CPT), pain equivalent current (PEC), and quantified pain degree (QPD). Methods: Medical records of 398 subjects who visited the pain clinic in a university hospital from March 2017 to February 2019 were retrospectively reviewed. To evaluate the pain degree, NRS, CPT, PEC, and QPD were measured. Subjects were categorized into two groups: the Pain group (n = 355) and the No-pain group (n = 43). Results: The NRS showed a negative correlation with CPT (R = -0.10, p = 0.054) and a positive correlation with QPD (R = 0.13, p = 0.008). Among various diseases, only spinal disease patients showed a negative correlation between CPT and NRS (R = -0.22, p = 0.003). Additionally, there were significant differences in CPT and QPD between the Pain and No-pain groups (p = 0.005 and p = 0.002, respectively). Conclusions: CPT and QPD measured using the PainVisionTM system could be used to estimate pain intensity and the presence of pain. These parameters would be considered useful for predicting pain itself and its intensity.

Perfluorohexyloctane Eye Drops for Dry Eye Disease Associated With Meibomian Gland Dysfunction in Chinese Patients: A Randomized Clinical Trial

Importance

Meibomian gland dysfunction (MGD) is a leading cause of evaporative dry eye disease (DED). Medical and surgical management for DED is limited; therefore, new treatment options are sought.

Objective

To evaluate the efficacy and safety of SHR8058 (perfluorohexyloctane) eye drops in Chinese patients with DED associated with MGD through 57 days.

Design, Setting, and Participants

This was a randomized, multicenter, double-masked, saline-controlled, phase 3 clinical trial conducted from February 4, 2021, to September 7, 2022. Patients were recruited from the departments of ophthalmology in 15 hospitals in China. Patients with DED associated with MGD were enrolled between February 4 and July 1, 2021. The diagnosis was based on patient complaint of DED symptoms, an ocular surface disease index of 25 or higher, tear film break-up time of 5 seconds or less, Schirmer I test without anesthesia results of 5 mm or more at 5 minutes, total corneal fluorescein staining (tCFS) score of 4 to 11, and an MGD score of 3 or higher.

Interventions

Eligible participants were randomly assigned 1:1 to receive perfluorohexyloctane eye drops or 0.6% sodium chloride [NaCl]) 4 times per day.

Main Outcomes and Measures

The primary end points were the changes from baseline in tCFS and eye dryness scores at day 57.

Results

A total of 312 participants were included in the analysis: 156 (mean [SD] age, 45.4 [15.2] years; 118 female [75.6%]) in the perfluorohexyloctane group and 156 (mean [SD] age, 43.7 [15.1] years; 127 female [81.4%]) in the NaCl group. Both primary end points were achieved, ie, changes from baseline at day 57 of tCFS score (mean [SD], -3.8 [2.7] vs -2.7 [2.8]) and eye dryness score (mean [SD], -38.6 [21.9] vs -28.3 [20.8]) in the perfluorohexyloctane group were superior to the control group, with estimated mean differences of -1.14 (95% CI, -1.70 to -0.57; P < .001) and -12.74 (95% CI, -17.20 to -8.28, P < .001), respectively. Improvements on both end points appeared to be noted on day 29 and day 15, respectively, and maintained through day 57. Compared with the control, perfluorohexyloctane eye drops also alleviated symptoms including pain (mean [SD] tCFS score, 26.7 [23.7] vs -18.7 [22.5]; P = .003), awareness of DED symptoms (mean [SD] tCFS score, -38.1 [25.1] vs -23.7 [27.6]; P < .001), and frequency of dryness (mean [SD] tCFS score, -43.3 [23.8] vs -29.1 [24.8]; P < .001). Treatment-emergent adverse events occurred in 34 participants (21.8%) and 40 participants (25.6%) in the perfluorohexyloctane and control groups, respectively.

Conclusions and Relevance

Results of this randomized clinical trial demonstrate that perfluorohexyloctane eye drops significantly ameliorated the signs and symptoms of DED associated with MGD with a rapid efficacy as well as satisfactory tolerability and safety through 57 days. Findings support the use of these eye drops if results can be confirmed independently and over longer time periods.

Trial Registration

ClinicalTrials.gov Identifier: NCT05515471.

Successful Detection of the Characteristics of Tear Film Breakup Appearing Immediately after Eye Opening by Videokeratography with a Newly-Developed Indicator

Spot break (SB), a tear film breakup (TFBU) subtype seen in decreased wettability dry eye (DE), is characterized by a spot-like TFBU that appears immediately after eye opening. It is sometimes difficult to detect using currently available devices for evaluating non-invasive TFBU. The purpose of this study was to investigate the effectiveness of using a newly developed videokeratography indicator for detecting SB. The study involved 44 eyes of 44 DE patients (21 eyes with SB (SB group) and 23 eyes with random break in which fluorescein breakup time was ≤ 5 s (s) (RB group)). All eyes were examined using videokeratography, with digital Meyer-ring images being obtained. By calculation of the degree of luminance blur on the cornea in the Meyer-ring images, termed ‘disturbance value’ (DV), DVs at 0 s (DV(0)]), 2 s (DV(2)), and 5 s (DV(5)) after eye opening, and the changes of DV between each time, were compared between the SB and RB groups. Results: No significant differences in DV(2) and DV(5) and the rate of change between DV(2) and DV(5) were found between the two groups. However, DV(0) and rate of change between DV(0) and DV(2) in the SB group were significantly greater (p < 0.001) than those in the RB group. SB characteristics were successfully detected by videokeratography using a new videokeratography DV indicator.

Editorial of Special Issue "Differential Diagnosis for Dry Eye"

This editorial aims to summarize the scientific papers that contributed to the Special Issue "Differential Diagnosis for Dry Eye" [...].