Noninvasive, Objective, Multimodal Tear Dynamics Evaluation of 5 Over-the-Counter Tear Drops in a Randomized Controlled Trial

Achieving net-zero in the dry eye disease care pathway

Climate change is a threat to human health and wellbeing across the world. In recent years, there has been a surge in awareness of this crisis, leading to many countries and organisations setting "net-zero" targets. This entails minimising carbon emissions and neutralising remaining emissions by removing carbon from the atmosphere. At the 2022 United Nations Climate Change Conference (COP27), commitments to transition away from fossil fuels and augment climate targets were underwhelming. It is therefore imperative for public and private sector organisations to demonstrate successful implementation of net-zero and set a precedent for the global political consensus. As a top 10 world employer, the United Kingdom National Health Service (NHS) has pledged to reach net-zero by 2045. The NHS has already taken positive steps forward, but its scale and complexity as a health system means stakeholders in each of its services must highlight the specifications for further progress. Dry eye disease is a chronic illness with an estimated global prevalence of 29.5% and an environmentally damaging care pathway. Moreover, environmental damage is a known aggravator of dry eye disease. Worldwide management of this illness generates copious amounts of non-recyclable waste, utilises inefficient supply chains and involves recurrent follow-up appointments and prescriptions. By mapping the dry eye disease care pathway to environmental impact, in this review we will highlight seven key areas in which reduced emissions and pollution could be targeted. Examining these approaches for improved environmental sustainability is critical in driving the transformation needed to preserve our health and wellbeing.

Precorneal retention time of ocular lubricants measured with fluorophotometry in healthy dogs

OBJECTIVE

Determine the precorneal retention time of five different ocular lubricants commonly used in dogs.

ANIMALS STUDIED

Six healthy Beagle dogs (n = 12 eyes).

PROCEDURES

Five ocular lubricants were studied: Artificial Tears Solution® (1.4% polyvinyl alcohol), I-Drop® Vet Plus (0.25% hyaluronate), Optixcare® Eye Lube Plus (0.25% hyaluronate), Systane® Ultra (0.4% polyethylene glycol 400 and 0.3% propylene glycol), and Artificial Tears Ointment® (mineral oil/white petrolatum). Each lubricant was mixed with 10% sodium fluorescein to achieve 1% fluorescein formulations. Following topical administration of 35 mg in each eye, tear fluid was collected with capillary tubes at selected times (0, 1, 5, 10, 20, 30, 40, 50, 60, 90, 120, 180 min) and fluorescein concentrations were measured with a computerized scanning ocular fluorophotometer.

RESULTS

Tear fluorescence was significantly greater with Artificial Tears Ointment® compared with other lubricant formulations from 1 to 20 min post-administration. Median (range) precorneal retention times were significantly different among the 5 lubricants, ranging from 40 minutes (20-90 min) for Artificial Tears Ointment®, 35 min (20-90 min) for Systane® Ultra, 30 min (10-60 min) for I-Drop® Vet Plus, 25 min (10-60 min) for Optixcare® Eye Lube Plus, and 10 min (10-20 min) for Artificial Tears Solution®. Precorneal retention time was significantly lower for Artificial Tears Solution® compared with the other 4 formulations.

CONCLUSIONS

This study established normative data for the retention time of common lubricants on the ocular surface of dogs, which may be used to guide clinicians with their choice of lubricant and frequency of administration.

The influence of a mineral oil cationic nanoemulsion or perfluorohexyloctane on the tear film lipid layer and higher order aberrations

PURPOSE

To prospectively assess the effect of a single and regular application of either a cationic nanoemulsion of mineral oil (CN) or perfluorohexyloctane (F6H8) on the lipid layer of the tear film and higher order aberrations (HOA) in patients with Dry Eye Disease (DED).

METHODS

Fifty-seven patients with a lipid layer thickness (LLT) ≤ 75 interferometric colour units (ICU) were included in the study. In group A (20 patients) the effect of a single drop of F6H8 or CN on HOA and LLT was assessed immediately after application and up to two hours later. For long term effects (Group B) 37 patients applied CN or F6H8 five times a day for 12 weeks. Measurement of LLT, HOA, non-invasive-tear-break-up-time (NIBUT) and meibography were assessed prior to as well as at 4 weeks and 12 weeks after initiation of treatment. Our study is registered in the "German Clinical Trials Register" under the trial number: DRKS00028696.

RESULTS

CN led to an increase of the LLT from 46.8 ± 16.9 ICU to 76.3 ± 23.5 ICU (p = 0.021) and to an increase of HOA from 0.43 ± 0.06 μm to 0.48 ± 0.08 μm immediately after application (p = 0.027). There was no correlation between the increase of LLT and HOA (r = -0.04; p = 0.90). In group B an increase of LLT was observed in the F6H8 group from 45.8 ± 8.8 ICU at baseline to 66.7 ± 19.5 ICU at 12 weeks (p = 0.002). No changes of HOA were measured throughout the observation period in group B. After 12 weeks CN increased NIBUT from 9.9 ± 5.3 seconds to 15.5 ± 5.6 seconds (p = 0.04). F6H8 increased NIBUT from 12.4 ± 5.9 seconds to 16.9 ± 4.7 seconds (p = 0.02) after 12 weeks.

CONCLUSION

CN leads to a short-term increase in LLT and HOA, but only immediately after application. In contrast F6H8 does lead to an increase of LLT after regular long-term use but has no effect on HOA. The regular application of lipid-based products does not seem to decrease the quality of vision as measured in HOA. Instead, CN and F6H8, both are able to stabilize the tear film after regular application.

Shear-Thinning and Temperature-Dependent Viscosity Relationships of Contemporary Ocular Lubricants

PURPOSE

To evaluate the shear viscosity of contemporary, commercially available ocular lubricants at various shear rates and temperatures and to derive relevant mathematical viscosity models that are impactful for prescribing and developing eye drops to treat dry eye disease.

METHODS

The shear viscosity of 12 ocular lubricants was measured using a rheometer and a temperature-controlled bath at clinically relevant temperatures at which users may experience exposure to the drops (out of the refrigerator [4.3°C]; room temperature [24.6°C]; ocular surface temperature [34.5°C]). Three replicates for each sample at each temperature were obtained using a standard volume (0.5 mL) of each sample. The viscosity of each ocular lubricant was measured over the full range of shear rates allowed by the rheometer.

RESULTS

The shear viscosity of the same ocular lubricant varied significantly among the three temperatures. In general, a higher temperature resulted in smaller viscosities than a lower temperature (an average of -48% relative change from 4.3°C to 24.6°C and -21% from 24.6°C to 34.5°C). At a constant temperature, the viscosity of an ocular lubricant over the studied shear rates can be well approximated by a power-law model.

CONCLUSIONS

Rheological analysis revealed that the ocular lubricants exhibited shear-thinning behavior at the measured temperatures. Differences in the ocular lubricants' formulations and measured temperatures resulted in different viscosities.

TRANSLATIONAL RELEVANCE

When prescribing eye drops, eye care professionals can select the optimal one for their patients by considering a variety of factors, including its rheological property at physiologically relevant shear rates and temperatures, which can improve residence time on the ocular surface, while ensuring appropriate comfort and vision. However, care must be taken when using the derived mathematical models in this study because the in vivo shear behavior of the ocular lubricants has not been examined and might show deviations from those reported when placed on the ocular surface.

Effect of artificial tears on dynamic optical quality in patients with dry eye disease

BACKGROUND

In clinical practice, fluctuating vision or decreased quality of vision is a common complaint in DED patients. Our study was designed to investigate the change in dynamic optical quality in dry eye patients after the use of artificial tears.

METHODS

Fifty-nine patients with dry eye disease (DED) and 31 control subjects were included in this prospective case-control study. There was no significant difference in age and sex between these two groups (P = 0.342, P = 0.847, respectively). Clinical evaluation of the ocular surface included Ocular Surface Disease Index (OSDI), tear film break-up time (TBUT), lipid layer thickness (LLT), and Schirmer I test. DED patients were divided into two groups, mild (31 patients) and severe (28 patients). The optical quality of the tear film was measured with the Optical Quality Analysis System (OQAS) using the mean objective scatter index (mean OSI), standard deviation of objective scatter index (SD-OSI) and modulation transfer function cut-off (MTF cut-off). After baseline examinations, one drop of artificial tears (ATs, carboxymethylcellulose ophthalmic solution, 0.5%) was instilled in both eyes, and optical quality parameters were measured again at 5 and 30 min following application of ATs.

RESULTS

At baseline, the mean OSI was higher in the DED group (0.95 ± 0.54) than in controls (0.54 ± 0.23, P < 0.001). The SD-OSI was also significantly increased in DED patients (0.44 ± 0.71) compared to control subjects (0.12 ± 0.06, P = 0.003). Five minutes after AT instillation, mean OSI and SD-OSI decreased significantly in severe DED patients (P = 0.044; P = 0.018), remained unchanged in mild DED patients, and increased in the control group (P = 0.019; P < 0.001). Thirty minutes after AT instillation, no significant difference in optical quality parameters was observed among the three groups.

CONCLUSION

The effect of ATs on optical quality in patients with DED may differ according to the severity of the disease. Measurement of optical quality might be a promising tool to evaluate the effects of various ATs and possibly individualize treatment in DED patients.

Terminalia arjuna gum/alginate in situ gel system with prolonged retention time for ophthalmic drug delivery

Poor availability is the major barrier to accept the new smart gel system as a preferred ophthalmic solution for various eye problems. Smart gel system especially derived from natural source allows the rapid transition of ocular solution into gel form upon contact to tear solution. The present experimental scheme was intended to prepare and characterize a pH triggered in situ gelling system using moxifloxacin HCl (MOX-HCl). Gum was extracted from Terminalia arjuna bark resin and used as gelling agent in blend with sodium alginate. Sterilized formulations were developed and characterized for their physicochemical attributes. These were further investigated for microbiological testing and eye irritation studies. Drug loaded in situ gel was appeared as clear sol that converted into gel phase in presence of tear solution. Optimized formulation was stable, therapeutically efficacious, non-irritant and has a sustained release of the drug for twelve hours period. Instillation of MOX-HCl loaded in situ gel did not cause any type of irritation symptoms like redness, inflammation and excessive tear production in rabbits as compared to control. MOX-HCl loaded in situ gel can be appraised as a substitute for conventional eye drops for extended precorneal retention, improved corneal permeability along with better ocular bioavailability.

Ellipsometry of human tears

PURPOSE

The outer surface layer of tears is presumably composed of lipid. The thickness of this layer is considered critical to retard evaporation. Prior thickness measurements differ widely. Advances in ellipsometry have availed more precise and accurate measurements for thin films. The range in thickness of the surface layer of tears was studied by ellipsometry to uncover the source of prior discrepancies.

METHODS

Tear surface layers of normal and dry eye subjects were measured by in-vitro ellipsometry. Lateral and Z resolutions of ∼1 μm and 0.1 nm, were achieved respectively. Thicknesses were derived from matrices and a Levenberg-Marquardt multivariate regression algorithm to Fresnel equations for multi-layered films.

RESULTS

Ellipsometric measurements of pooled and individual human tears in-vitro revealed a larger overall range (0-500 nm) of surface film thicknesses than previously reported by any one study. Each sample showed thin areas (0-2.6 nm) with interspersed thicker regions (∼200-500 nm). Repeat measurements of a single donor collected at weekly intervals showed a broad range of surface thicknesses within and between samples. Thickness measurements from a dry eye subject overlapped that of normal subjects.

CONCLUSION

The data show that published disparity in surface film thickness may be attributable to limitations of prior methodologies. The range and overlap of surface film thicknesses challenge less rigorous methodologies that claim to segregate normal and dry eye.

Effect of Ultrasonic Moisture Glasses on Dry Eye Signs and Symptoms

Purpose

This study was undertaken to evaluate the effect of a novel humidifying eyeglass-shaped device-ultrasonic moisture glasses-on dry eye signs and symptoms.

Methods

A total of 18 subjects with dry eye symptoms underwent a crossover test. A water cartridge was set on each temple of the eyeglass-shaped device. All subjects randomly wore the device twice in different settings, each for 10 minutes. Subjects wore the glasses once with the cartridges filled with water (the intervention group), and once with the cartridges empty (the control group). The order was randomized. We evaluated tear film break-up time (TBUT) and fluorescein staining score just before, immediately after, and 10 minutes after wearing the device. We also assessed functional visual acuity (FVA), blink frequency, and visual analog scale (VAS) score just before and immediately after wearing the device.

Results

TBUT, blink frequency, and VAS improved in the intervention group (all P < 0.001) and exhibited significant differences between the intervention and control groups.

Conclusions

Wearing the ultrasonic moisture glasses for 10 minutes improved tear stability and decreased dry eye symptoms in this cohort of subjects.

Translational Relevance

These findings show that the ultrasonic moisture glasses are an effective device for improving dry eye signs and symptoms.

Active agents, biomaterials, and technologies to improve biolubrication and strengthen soft tissues

Normal functioning of articulating tissues is required for many physiological processes occurring across length scales from the molecular to whole organism. Lubricating biopolymers are present natively on tissue surfaces at various sites of biological articulation, including eyelid, mouth, and synovial joints. The range of operating conditions at these disparate interfaces yields a variety of tribological mechanisms through which compressive and shear forces are dissipated to protect tissues from material wear and fatigue. This review focuses on recent advances in active agents and biomaterials for therapeutic augmentation of friction, lubrication, and wear in disease and injured states. Various small-molecule, biological, and gene delivery therapies are described, as are tribosupplementation with naturally-occurring and synthetic biolubricants and polymer reinforcements. While reintroduction of a diseased tissue's native lubricant received significant attention in the past, recent discoveries and pre-clinical research are capitalizing on concurrent advances in the molecular sciences and bioengineering fields, with an understanding of the underlying tissue structure and physiology, to afford a desired, and potentially patient-specific, tissue mechanical response for restoration of normal function. Small and large molecule drugs targeting recently elucidated pathways as well as synthetic and hybrid natural/synthetic biomaterials for restoring a desired tissue mechanical response are being investigated for treatment of, for example, keratoconjunctivitis sicca, xeroderma, and osteoarthritis.

Effects of tear film dynamics on quality of vision

The precorneal tear film is maintained by blinking and exhibits different phases in the tear cycle. The tear film serves as the most anterior surface of the eye and plays an important role as a first refractive component of the eye. Alterations in tear film dynamics may cause both vision-related and ocular surface-related symptoms. Although the optical quality associated with the tear film dynamics previously received little attention, objective measurements of optical quality using wavefront sensors have enabled us to quantify optical aberrations induced by the tear film. This has provided an objective method for assessing reduced optical quality in dry eye; thus, visual disturbances were included in the definition of dry eye disease in the 2007 Dry Eye Workshop report. In addition, sequential measurements of wavefront aberrations have provided us with valuable insights into the dynamic optical changes associated with tear film dynamics. This review will focus on the current knowledge of the mechanisms of wavefront variations that are caused by different aspects of tear film dynamics: specifically, quality, quantity and properties of the tear film, demonstrating the respective effects of dry eye, epiphora and instillation of eye drops on the quality of vision.

Social Effects of Tears and Small Pupils Are Mediated by Felt Sadness: An Evolutionary View

Small pupils elicit empathic socioemotional responses comparable to those found for emotional tears. This might be understood in an evolutionary context. Intense emotional tearing increases tear film volume and disturbs tear layer uniformity, resulting in blurry vision. A constriction of the pupils may help to mitigate this handicap, which in turn may have resulted in a perceptual association of both signals. However, direct empirical evidence for a role of pupil size in tearful emotional crying is still lacking. The present study examined socioemotional responses to different pupil sizes, combined with the presence (absence) of digitally added tears superimposed upon expressively neutral faces. Data from 50 subjects showed significant effects of observing digitally added tears in avatars, replicating previous findings for increased perceived sadness elicited by tearful photographs. No significant interactions were found between tears and pupil size. However, small pupils likewise elicited a significantly greater wish to help in observers. Further analysis showed a significant serial mediation of the effects of tears on perceived wish to help via perceived and then felt sadness. For pupil size, only felt sadness emerged as a significant mediator of the wish to help. These findings support the notion that pupil constriction in the context of intense sadness may function to counteract blurry vision. Pupil size, like emotional tears, appears to have acquired value as a social signal in this context.

Safety of Lifitegrast Ophthalmic Solution 5.0% in Patients With Dry Eye Disease: A 1-Year, Multicenter, Randomized, Placebo-Controlled Study

Supplemental Digital Content is Available in the Text.

Purpose:

To evaluate the 1-year safety of lifitegrast ophthalmic solution 5.0% in patients with dry eye disease compared with placebo.

Methods:

SONATA (Safety Of a 5.0% coNcentrATion of lifitegrAst ophthalmic solution) was a multicenter, randomized, prospective, double-masked, placebo-controlled phase 3 study (NCT01636206). Adults (≥18 years) with dry eye disease (Schirmer test score ≥1 and ≤10 mm; corneal staining score ≥2.0) were randomized 2:1 to lifitegrast ophthalmic solution 5.0% or placebo twice daily for 360 days. The primary objective was percentage and severity of treatment-emergent adverse events (TEAEs). Secondary objectives were ocular safety measures: corneal fluorescein staining, drop comfort, best-corrected visual acuity, slit-lamp biomicroscopy, and intraocular pressure over 7 visits. Exploratory objectives included concentration of lifitegrast in plasma.

Results:

The safety population comprised 331 participants (220 lifitegrast; 111 placebo). There were no serious ocular TEAEs. Overall, 53.6% of participants receiving lifitegrast experienced ≥1 ocular TEAE versus 34.2% in the placebo group; most TEAEs were mild to moderate in severity. Rates of discontinuation because of TEAEs were 12.3% (lifitegrast) versus 9.0% (placebo). The most common (>5%) TEAEs occurring in either treatment group were instillation site irritation (burning), instillation site reaction, visual acuity reduced, dry eye, and dysgeusia (change in taste). Ocular safety parameters for lifitegrast were similar to placebo. The mean plasma lifitegrast concentration at 360 days (n = 43) was below the limit of detection. There was no indication of systemic toxicity or localized infectious complications secondary to chronic immunosuppression.

Conclusions:

Lifitegrast ophthalmic solution 5.0% seemed safe and well tolerated in this study, with no unexpected adverse events.

Evaluation of Tear Meniscus Dynamics Using Anterior Segment Swept-Source Optical Coherence Tomography After Topical Solution Instillation for Dry Eye

PURPOSE

To investigate tear meniscus dynamics using anterior segment swept-source optical coherence tomography (SS-OCT) after the instillation of topical solutions for dry eye.

DESIGN

Prospective, observational, cross-sectional study.

METHODS

Thirty-six healthy subjects (28 men and 8 women; mean age, 34.4 ± 6.7 years) were enrolled in this study. The lower tear meniscus height, tear meniscus area, and tear meniscus volume were assessed using anterior SS-OCT. After baseline measurements, 40 μL of 0.1% sodium hyaluronate, 0.3% sodium hyaluronate, 3% diquafosol ophthalmic solution, or 2% rebamipide ophthalmic solution was instilled in one eye of 10 subjects each, whereas 40 μL saline was instilled in the other eye. Tear meniscus measurements were obtained using SS-OCT at 30 seconds and 1, 3, 5, 10, 15, 20, and 30 minutes after instillation.

RESULTS

The tear meniscus measurements showed a significant increase until 1, 3, 10, 10, and 3 minutes after the instillation of saline, 0.1% sodium hyaluronate, 0.3% sodium hyaluronate, 3% diquafosol, and 2% rebamipide, respectively, compared with the baseline levels (P < 0.05). Compared with those after saline instillation, the tear meniscus measurements were significantly higher until 30 seconds and 3, 30, and 15 minutes after the instillation of 0.1% sodium hyaluronate, 0.3% sodium hyaluronate, 3% diquafosol, and 2% rebamipide, respectively (P < 0.05).

CONCLUSIONS

The instillation of ophthalmic solutions for the treatment of dry eye greatly increased tear meniscus measurements in healthy subjects. Thus, SS-OCT can be a practical tool for the quantitative evaluation of early-phase tear fluid dynamics.

Effect of diquafosol ophthalmic solution on the optical quality of the eyes in patients with aqueous-deficient dry eye

PURPOSE

To investigate the short- and long-term effects of diquafosol ophthalmic solution on the optical quality of the eyes in patients with aqueous-deficient dry eye.

METHODS

Sixteen eyes in 16 patients with mild or moderate aqueous-deficient dry eye were treated with 3% diquafosol ophthalmic solution. Ocular higher-order aberrations (HOAs) were measured with a wavefront sensor before and at 15 min after diquafosol instillation at the baseline visit and at 4 weeks after treatment initiation. Dry eye symptoms, tear break-up time (BUT), corneal/conjunctival fluorescein staining and Schirmer's test were also evaluated before and after treatment with diquafosol.

RESULTS

Treatment with diquafosol ophthalmic solution significantly improved dry eye symptoms, corneal staining and BUT. Compared with mean total HOAs at baseline (0.180 ± 0.06 μm), those at 4 weeks after treatment significantly decreased (0.148 ± 0.039 μm; p = 0.035), whereas those 15 min after diquafosol instillation at the baseline visit did not change significantly (0.170 ± 0.049 μm; p = 0.279).

CONCLUSIONS

Although no significant change in HOAs was observed as a short-term effect of a single-drop instillation of diquafosol, long-term use of diquafosol to treat aqueous-deficient dry eye reduced HOAs as well as improved corneal epithelial damage and tear film stability.

Tear meniscus dimensions in tear dysfunction and their correlation with clinical parameters

PURPOSE

To evaluate relationships between tear meniscus dimensions and parameters of ocular surface disease in a variety of tear dysfunction conditions.

DESIGN

Single-institution prospective observational study.

METHODS

This study from the Baylor College of Medicine included 128 eyes of 64 subjects. Cross-sectional lower tear meniscus height and tear meniscus area were measured using optical coherence tomography and were compared with tear break-up time (TBUT), corneal staining, conjunctival staining, and an irritation symptom questionnaire (Ocular Surface Disease Index). Study groups included meibomian gland disease (MGD), aqueous tear deficiency (ATD), Sjögren syndrome, non-Sjögren syndrome ATD, and control subjects. Statistical analyses were performed using the Pearson correlation and Student's t test.

RESULTS

When compared with mean tear meniscus height in controls (345 μm), mean tear meniscus height was lower in all tear dysfunction (234 μm; P = .0057), ATD (210 μm; P = .0016), and Sjögren syndrome groups (171 μm; P = .0054). For tear meniscus height ≤210 μm, relative risk ratio for developing corneal staining ≥10 was 4.65. Tear meniscus height correlated with corneal staining for all subjects (R = -0.32; P = .0008), MGD (R = +0.40; P = .059), and ATD (R = -0.36; P = .04). Tear meniscus area showed similar trends in MGD (R = +0.55; P = .006) and ATD (R = -0.40; P = .018). Tear meniscus height correlated with TBUT for all subjects (R = +0.39; P < .0001) and ATD (R = +0.37; P = .018).

CONCLUSIONS

In tear dysfunction conditions, lower tear volume correlates with worse corneal epithelial disease in ATD and Sjögren syndrome, conditions with lacrimal gland dysfunction. In contrast, higher tear volume is associated with corneal epithelial disease in MGD. These findings may improve the ability to identify patients at risk for corneal epithelial disease.

Effect of rebamipide ophthalmic suspension on optical quality in the short break-up time type of dry eye

PURPOSE

To determine the effect of rebamipide ophthalmic suspension on optical quality in patients with dry eye with short break-up time (BUT) of the tear film.

METHODS

Twenty-six eyes of 16 patients with the short BUT type of dry eye were enrolled and treated with 2% rebamipide ophthalmic suspension. At baseline and at 2 and 4 weeks after initiating the treatment, the serial corneal higher-order aberrations (HOAs), BUT, fluorescein staining, and Schirmer test were measured. Patients were asked to complete questionnaires about the changes in dry eye-related ocular symptoms after the treatment.

RESULTS

Before the treatment, the pattern of postblink corneal HOAs for 10 seconds showed a sawtooth pattern, with a marked upward curve that increased after blinking. Treatment with rebamipide for 4 weeks significantly (P < 0.05) improved the postblink corneal HOAs and stabilized the pattern of the corneal HOAs. Significant increases in the tear film BUT were seen 2 and 4 weeks after the treatment (P < 0.001 for both comparisons).

CONCLUSIONS

Rebamipide administered to treat the short BUT type of dry eye significantly improved optical quality because of the improvement in tear stability.

A preliminary investigation into the effects of ocular lubricants on higher order aberrations in normal and dry eye subjects

PURPOSE

To study the effects of ocular lubricants on higher order aberrations in normal and self-diagnosed dry eyes.

METHODS

Unpreserved hypromellose drops, Tears Again™ liposome spray and a combination of both were administered to the right eye of 24 normal and 24 dry eye subjects following classification according to a 5 point questionnaire. Total ocular higher order aberrations, coma, spherical aberration and Strehl ratios for higher order aberrations were measured using the Nidek OPD-Scan III (Nidek Technologies, Gamagori, Japan) at baseline, immediately after application and after 60 min. The aberration data were analyzed over a 5mm natural pupil using Zernike polynomials. Each intervention was assessed on a separate day and comfort levels were recorded before and after application. Corneal staining was assessed and product preference recorded after the final measurement for each intervention.

RESULTS

Hypromellose drops caused an increase in total higher order aberrations (p=<0.01 in normal and dry eyes) and a reduction in Strehl ratio (normal eyes: p=<0.01, dry eyes p=0.01) immediately after instillation. There were no significant differences between normal and self-diagnosed dry eyes for response to intervention and no improvement in visual quality or reduction in higher order aberrations after 60 min. Differences in comfort levels failed to reach statistical significance.

CONCLUSION

Combining treatments does not offer any benefit over individual treatments in self-diagnosed dry eyes and no individual intervention reached statistical significance. Symptomatic subjects with dry eye and no corneal staining reported an improvement in comfort after using lubricants.

Long-term results of treatment with diquafosol ophthalmic solution for aqueous-deficient dry eye

PURPOSE

To evaluate the preliminary long-term efficacy of diquafosol ophthalmic solution for aqueous-deficient dry eye.

METHODS

Fifteen patients with mild-to-moderate aqueous-deficient dry eye were enrolled. After a washout period, the patients were treated with 3 % diquafosol ophthalmic solution for 6 months. We assessed 12 subjective dry eye symptoms, corneal and conjunctival staining with fluorescein, tear film break-up time (BUT), lower tear meniscus height measured with anterior-segment optical coherence tomography, Schirmer's testing, and adverse reactions at baseline and 1, 3, and 6 months after the start of treatment.

RESULTS

Treatment with diquafosol ophthalmic solution significantly improved dry eye symptoms, corneal staining, BUT, and tear meniscus height at 1 month and maintained the effectiveness for 6 months. Conjunctival staining significantly improved 3 and 6 months after treatment. No significant adverse reactions developed.

CONCLUSIONS

Prolonged use of diquafosol ophthalmic solution for 6 months produced significant improvement both subjectively (dry eye symptom score) and objectively (ocular staining score and tear function tests) for aqueous-deficient dry eye.