Association between dryness sensation and ocular surface temperature and conjunctival blood flow in soft contact lens wearers.

PURPOSE: To investigate the association between dryness, ocular surface temperature (OST), and conjunctival blood flow (CBF) in soft contact lens (SCL) wearers after airflow stimulation. METHODS: After recruiting 21 SCL wearers (mean age, 25.3 ± 4.2 years), subjects used two different daily disposable silicone hydrogel SCLs (narafilcon A and delefilcon A lenses). On three of four measurement days, excluding the first, OST, CBF, tear meniscus height (TMH), and non-invasive tear break-up time (NIBUT) were measured after airflow stimulation at a rate of 3 m/s for 10 min. The measurements were conducted without SCLs on the first and second days, and with different SCLs on the third and fourth days. Dryness was evaluated using the visual analogue scale (VAS). These parameters were compared between the two types of SCLs, and their association with the dryness sensation was then investigated. RESULTS: Dryness was significantly weakly correlated with OST (r = -0.375, p < 0.05) and CBF (r = 0.339, p < 0.05). TMH, NIBUT, and VAS scores for dryness with the delefilcon A lens (0.15 ± 0.05 mm, 3.7 ± 01.7 s and 29.4 ± 16.9) were significantly higher, longer, and lower, respectively, than those with the narafilcon A lens (0.12 ± 0.05 mm, 2.3 ± 1.7 s and 35.9 ± 17.0; p < 0.05, p < 0.01 and p < 0.01). The changes in the OST and CBF between with and without the delefilcon A lens (-0.36 ± 0.35 °C and 0.99 ± 0.19) were significantly small compared to the narafilcon A lens (-0.60 ± 0.42 °C and 1.11 ± 0.21; p < 0.01 for both comparisons). CONCLUSION: Dryness was correlated with OST and CBF, which indicates that when dryness was high, OST was low and CBF was high. These results suggest that OST and CBF assessments are effective for evaluating dryness sensation.

Diagnostic Ability of a Smartphone App for Dry Eye Disease: Protocol for a Multicenter, Open-Label, Prospective, and Cross-sectional Study.

BACKGROUND: Dry eye disease (DED) is one of the most common ocular surface diseases. Numerous patients with DED remain undiagnosed and inadequately treated, experiencing various subjective symptoms and a decrease in quality of life and work productivity. A mobile health smartphone app, namely, the DEA01, has been developed as a noninvasive, noncontact, and remote screening device, in the context of an ongoing paradigm shift in the health care system, to facilitate a diagnosis of DED. OBJECTIVE: This study aimed to evaluate the capabilities of the DEA01 smartphone app to facilitate a DED diagnosis. METHODS: In this multicenter, open-label, prospective, and cross-sectional study, the test method will involve using the DEA01 smartphone app to collect and evaluate DED symptoms, based on the Japanese version of the Ocular Surface Disease Index (J-OSDI), and to measure the maximum blink interval (MBI). The standard method will then involve a paper-based J-OSDI evaluation of subjective symptoms of DED and tear film breakup time (TFBUT) measurement in an in-person encounter. We will allocate 220 patients to DED and non-DED groups, based on the standard method. The primary outcome will be the sensitivity and specificity of the DED diagnosis according to the test method. Secondary outcomes will be the validity and reliability of the test method. The concordance rate, positive and negative predictive values, and the likelihood ratio between the test and standard methods will be assessed. The area under the curve of the test method will be evaluated using a receiver operating characteristic curve. The internal consistency of the app-based J-OSDI and the correlation between the app-based J-OSDI and paper-based J-OSDI will be assessed. A DED diagnosis cutoff value for the app-based MBI will be determined using a receiver operating characteristic curve. The app-based MBI will be assessed to determine a correlation between a slit lamp-based MBI and TFBUT. Adverse events and DEA01 failure data will be collected. Operability and usability will be assessed using a 5-point Likert scale questionnaire. RESULTS: Patient enrollment will start in February 2023 and end in July 2023. The findings will be analyzed in August 2023, and the results will be reported from March 2024 onward. CONCLUSIONS: This study may have implications in identifying a noninvasive, noncontact route to facilitate a diagnosis of DED. The DEA01 may enable a comprehensive diagnostic evaluation within a telemedicine setting and facilitate early intervention for undiagnosed patients with DED confronting health care access barriers. TRIAL REGISTRATION: Japan Registry of Clinical Trials jRCTs032220524; https://jrct.niph.go.jp/latest-detail/jRCTs032220524. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/45218.

Association between mask-associated dry eye (MADE) and corneal sensations.

To determine the risk of mask-associated dry eye (MADE), we investigated the fluorescein tear break-up time (FBUT), ocular surface temperature and blood flow, along with corneal sensitivity, in mask wearers. We enrolled 60 mask wearers (mean age, 27.1 ± 5.2 years) and then measured FBUT, corneal temperature and conjunctival blood flow without wearing masks (no mask), with masks, and with taped masks. We defined MADE as the condition in which dry eye symptoms appeared and the FBUT with mask was less than 5 s. The FBUT with a mask was significantly shorter compared to the no mask and taped mask groups (P < 0.01 and P < 0.05). The corneal temperature difference and conjunctival blood flow difference were significantly higher after wearing a mask than after wearing a taped mask (P < 0.01). Of the 60 subjects, 13 were diagnosed with MADE. Pain sensitivity and the Ocular Surface Disease Index (P < 0.05 and P < 0.01) were significantly higher in the MADE group, with the FBUT without masks (P < 0.05) significantly shorter than in the non-MADE group. MADE may be associated with corneal hypersensitivity. Wearing masks decreased FBUT and increased ocular surface temperature and blood flow. Taping the top edge of masks prevented these changes. Fitting masks properly may reduce MADE risk.

Evaluation of the Lubricating Effect of Hyaluronic Acid on Contact Lenses Using a Pendulum-Type Friction Tester Under Mimicking Physiological Conditions.

OBJECTIVE: To evaluate the lubricating effect of hyaluronic acid (HA) on soft contact lenses (SCLs) measured using a pendulum-type friction tester. METHODS: We measured the coefficient of friction (CoF) of narafilcon A, delefilcon A, and etafilcon A with polyvinylpyrrolidone (PVP), daily disposable SCL material, using a modified pendulum-type friction tester. Sample SCLs were set on an acrylic plastic half-ball and placed into the polyethylene terephthalate hemisphere cup filled with 0.4 mL of test lubricants that included saline and 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% (wt/vol) HA (molecular weight, 850 kDa). The viscosities of saline and HA were measured using an Ubbelohde viscometer. RESULTS: The CoF of the SCL under a low concentration (0.05%) of HA was the lowest and significantly lower than saline in narafilcon A and delefilcon A (P<0.05, Steel multiple comparison test). Under higher HA concentrations (0.3%, 0.4%, and 0.5%), the CoF was significantly higher than that of saline (P<0.01, Steel' multiple comparison test) in all three SCLs. There were no significant differences of CoF among three SCLs in saline and all concentrations of HA. The HA viscosities increased exponentially with the concentration (Y=1.2829e9.286X). CONCLUSION: The viscosity of a high concentration of HA may increase the friction of SCLs, which may have a deleterious effect on the ocular surface.

Metagenomic Shotgun Sequencing Analysis of Canalicular Concretions in Lacrimal Canaliculitis Cases.

Lacrimal canaliculitis is a rare infection of the lacrimal canaliculi with canalicular concretions formed by aggregation of organisms. Metagenomic shotgun sequencing analysis using next-generation sequencing has been used to detect pathogens directly from clinical samples. Using this technology, we report cases of successful pathogen detection of canalicular concretions in lacrimal canaliculitis cases. We investigated patients with primary lacrimal canaliculitis examined in the eye clinics of four hospitals from February 2015 to July 2017. Eighteen canalicular concretion specimens collected from 18 eyes of 17 patients were analyzed by shotgun metagenomics sequencing using the MiSeq platform (Illumina). Taxonomic classification was performed using the GenBank NT database. The canalicular concretion diversity was characterized using the Shannon diversity index. This study included 18 eyes (17 patients, 77.1 ± 6.1 years): 82.4% were women with lacrimal canaliculitis; canalicular concretions were obtained from 12 eyes using lacrimal endoscopy and six eyes using canaliculotomy with curettage. Sequencing analysis detected bacteria in all samples (Shannon diversity index, 0.05-1.47). The following genera of anaerobic bacteria (>1% abundance) were identified: Actinomyces spp. in 15 eyes, Propionibacterium spp., Parvimonas spp. in 11 eyes, Prevotella spp. in 9 eyes, Fusobacterium spp. in 6 eyes, Selenomonas spp. in 5 eyes, Aggregatibacter spp. in 3 eyes, facultative and aerobic bacteria such as Streptococcus spp. in 13 eyes, Campylobacter spp. in 6 eyes, and Haemophilus spp. in 3 eyes. The most common combinations were Actinomyces spp. and Streptococcus spp. and Parvinomonas spp. and Streptococcus spp., found in 10 cases. Pathogens were identified successfully using metagenomic shotgun sequencing analysis in patients with canalicular concretions. Canalicular concretions are polymicrobial with anaerobic and facultative, aerobic bacteria.

Evaluation of In Vitro Wettability of Soft Contact Lenses Using Tear Supplements.

OBJECTIVE: To evaluate the interaction between tear supplements and soft contact lenses (SCLs), we measured the contact angles (CAs) on the SCLs using commercially available tear supplements. METHODS: We used four daily disposable conventional hydrogel lenses (etafilcon A, etafilcon A+ polyvinylpyrrolidone, nelfilcon A, and omafilcon A containing 2-methacryloyloxyethyl phosphorylcholine [MPC]) and four silicone hydrogel lenses (narafilcon A, senofilcon A, delefilcon A, and stenfilcon A). The CAs on the SCLs were measured using a sessile drop technique and four different types of sessile drops, including saline, artificial tears, lubricants containing 2-MPC (MPC solution), and 0.1% hyaluronate acid (HA). RESULTS: The CA values associated with the silicone hydrogel lenses were significantly (P<0.001) lower than those associated with the conventional hydrogel lenses with all four solutions. The mean CA of 0.1% HA was significantly (P<0.01) higher than that of saline. The mean CA of the MPC solution was significantly (P<0.01) lower than that of saline with the conventional hydrogel lenses but significantly (P<0.05) higher than that of saline with the silicone hydrogel lenses. CONCLUSIONS: The CAs associated with the silicone hydrogel SCLs were higher with the use of the MPC solutions and HA in vitro. The measured CAs may depend on ingredient agents, surface treatment of the CLs, and components of the tear supplements.

Correlation between Blood Flow and Temperature of the Ocular Anterior Segment in Normal Subjects.

PURPOSE: To determine a correlation between temperature and blood flow in the ocular anterior segment, and their effects on corneal temperature. METHODS: In experiment 1, we recruited 40 eyes and measured the temperature and blood flow in the ocular anterior-segment (upper/lower eyelid skin, palpebral and bulbar conjunctiva, and cornea) before and after application of warm compresses. In experiment 2, we recruited 20 eyes and measured the same tissues before and during stimulation using water and capsaicin solution in the oral cavity. RESULTS: In experiment 1, the temperatures of the upper/lower eyelid skin and cornea increased significantly until 15 min after the application of the warm compress; the temperatures of the palpebral and bulbar conjunctiva increased significantly until 10 min. The blood flow in the upper/lower eyelid skin and bulbar conjunctiva increased significantly until 10 min, and that of the palpebral conjunctiva increased significantly until 15 min. In experiment 2, the temperatures were correlated significantly with the blood flow in the upper and lower eyelid skin and palpebral and bulbar conjunctiva. The temperature of all locations and palpebral conjunctival blood flow contributed independently to the corneal temperature. CONCLUSIONS: In the ocular anterior segment, the temperature and blood flow were correlated significantly, and contributed to the corneal temperature.

Association among Blink Rate, Changes in Ocular Surface Temperature, Tear Film Stability, and Functional Visual Acuity in Patients after Cataract Surgery.

PURPOSE: To investigate the association among the ocular surface temperature (OST), tear film stability, functional visual acuity (FVA), and blink rate in patients after cataract surgery. METHODS: We recruited 98 eyes of 69 patients (mean age, 73.7 ± 5.2 years) 1 month after phacoemulsification with implantation of acrylic intraocular lenses and assessed slit-lamp microscopy, corrected distance VA, FVA, noninvasive tear breakup time (NIBUT), and OST. We defined the changes in the OST from 0 to 10 seconds after eye opening as the ΔOST. We measured the FVA and blink rate using the FVA measurement system. We divided the patients into two groups based on tear film stability: stable tear film (NIBUT, >5.0 seconds) and unstable tear film (NIBUT, ≤5.0 seconds). We evaluated the differences between the two groups and the association between the blink rate and other clinical parameters. RESULTS: The unstable tear film group (56 eyes) had significantly (p < 0.0001, unpaired t-test) shorter NIBUTs than the stable tear film group (42 eyes). The ΔOSTs and blink rates were significantly (p < 0.0001) higher in the unstable tear film group than in the stable group. Linear single regression analysis showed that the ΔOST (r = -0.430, p < 0.0001), NIBUT (r = -0.392, p < 0.0001), and gender (r = -0.370, p=0.0002) were correlated significantly with the blink rate. Multiple regression analysis showed that the ΔOST independently contributed to the blink rate. CONCLUSIONS: The frequency of blinks is associated with tear film stability in patients after cataract surgery. The blink rate may be useful for evaluating the tear film stability in clinical practice. The ΔOST should be an important contributing factor to the blink rate. [This trial is registered with UMIN000026970].

Association Between Ocular Surface Temperature and Tear Film Stability in Soft Contact Lens Wearers.

Purpose: To investigate the correlation between the changes in the ocular surface temperature (OST) and tear film stability over soft contact lenses (SCLs). Methods: We enrolled 20 eyes of 20 normal SCL wearers (20 men; 24.4 ± 4.1 years). We used four different daily disposable SCLs: one silicone hydrogel lens (delefilcon A) and three hydrogel lenses (etafilcon A with polyvinylpyrrolidone [PVP], etafilcon A, and polymacon). OST was measured every second during 10 seconds without blinking. We defined the difference in the OST from 0 to 10 seconds as ΔOST. To evaluate tear film stability, we measured noninvasive tear break-up time (NIBUT) and tear interference patterns on the contact lenses (TIPCL) using tear film interferometry. The parameters were measured before and 15 minutes after wearing each SCL. Results: ΔOST was correlated significantly with NIBUT without (r = 0.411, P < 0.01) and with SCL (r = 0.642, P < 0.01). TIPCL grade was correlated significantly with ΔOST over SCLs (r = -0.636, P < 0.01). ΔOST was significantly smaller with silicone hydrogel delefilcon A than hydrogel etafilcon A and polymacon lenses (P < 0.05 and P < 0.01, respectively). Delefilcon A and etafilcon A with PVP lenses had significantly smaller NIBUT than etafilcon A (P < 0.05 for both comparisons). TIPCL grade of delefilcon A lens was significantly smaller than those of etafilcon A and polymacon (P < 0.01 for both comparisons). Conclusions: The changes in OST over SCLs are related to tear film stability. Measurements of OST can be used to evaluate tear film stability for SCL wearers.

Metagenomic analysis for detecting Fusarium solani in a case of fungal keratitis.

PURPOSE: To report a difficult-to-identify case of keratitis due to Fusarium solani, diagnosed with the help of exhaustive gene analysis. CASE: A 47-year-old woman attended our hospital with a refractory corneal ulcer associated with contact lens wear in her left eye that had appeared two weeks earlier. On her initial visit, slit lamp examination revealed a small double-ringed irregular hyphate ulcer in the center of the cornea, which had no epithelial defect, suggesting fungal infection. Microscopic visualization and culture of corneal scrapings were performed repeatedly, but the results were negative. Despite intensive antifungal treatment, infiltration of the cornea worsened and therapeutic keratoplasty was performed. Specimens from a corneal button were microbiologically and histologically negative for microorganisms. During irrigation of the anterior chamber with amphotericin B, aspirated corneal infiltrations were submitted for culture and metagenomic analysis. Genes belonging to F. solani were identified by metagenomic analysis, and an isolate presumed to be a Fusarium species was cultured. Genotypic identification of the isolates confirmed F. solani. CONCLUSION: The detection of microorganisms, especially fungi, can be extremely difficult. In difficult-to-culture cases, metagenomic analysis seems to be a promising technique for the identification of microbial pathogens.

Biofilm formation by Staphylococcus epidermidis on intraocular lens material.

PURPOSE: To compare biofilm formation by Staphylococcus epidermidis on different intraocular lens (IOL) materials. METHODS: The S. epidermidis strains, ATCC 12228 (American Type Culture Collection) and ATCC 35984 (biofilm-producer) were used. Biofilms were cultivated on disks of different IOL materials: silicone, PMMA (polymethylmethacrylate), acrylic, or MPC (2-methacryloyloxyethyl phosphorylcholine) surface-modified acrylic. Biofilms were stained with crystal violet (CV) which served as an index of biofilm formation. The bacterial population was enumerated after biofilm homogenization. Biofilms were also examined by scanning electron microscopy (SEM). RESULTS: Among the four materials tested, the least amount of biofilm formed on silicone. Biofilm production was significantly different between acrylic and MPC surface-modified acrylic lenses at 48 hours (P<0.05-0.01). The bacterial populations were significantly different between acrylic and silicone over 72 hours (P<0.05-0.01). The population on acrylic and MPC surface-modified acrylic continued to increase over 72 hours. The biofilm was recognized after a 24-hour incubation. Rates of biofilm-positive SEM fields, which were defined as being occupied by biofilm over at least half of the area, were significantly different between acrylic and silicone at 72 hours (P<0.05-0.01). CONCLUSIONS: S. epidermidis formed biofilm most intensely on acrylic among the four IOL materials tested. MPC surface-modified acrylic has a preventive effect on biofilm formation.

[Scanning electron microscope of for endophthalmitis case].

PURPOSE: The purpose of this study was to demonstrate the usefulness of the scanning electron microscope in examining the posterior capsule and an intraocular lens (IOL) in an endophthalmitis patient. METHODS: The patient was a 77-year-old man with diabetes mellitus undergoing radiotherapy for prostatic carcinoma, and having a history of esophageal cancer. Phacoemulsification, aspiration and IOL insertion by keratotomy were carried out. The operation was performed without complications. The IOL was a one-piece acrylic type. However, after 24 hours, we diagnosed acute bacterial endophthalmitis, because the patient showed visual loss, high intraocular pressure, fibrin formation, and an increase of cells in the anterior chamber. Vitrectomy to remove the IOL and posterior capsule was carried out on the same day. The removed samples were observed by scanning electron microscope. RESULTS: Enterococcus faecalis was detected in the vitreous and aqueous humor. The bacteria adhered to the optic and haptic surfaces and showed biofilm formation. The traces of the end mill cutting line were recognized beside the haptics. However, the posterior capsule showed no bacterial adhesion but had an unusual shape. CONCLUSIONS: We observed the biofilm formation in an IOL removed from an acute bacterial endophthalmitis case. An IOL may be an important canse of bacterial proliferation and adhesion.