Novel noninvasive sensitive determination of tear volume changes in normal cats

Effectiveness of Single-Dose Oral Pilocarpine Administration in Patients with Sjögren's Syndrome

In this study, we evaluated the effectiveness of a single-dose oral pilocarpine administration on tear film (TF), as well as dry eye and dry mouth symptoms, in 53 eyes of 27 Sjögren syndrome (SS) patients who were experiencing dry mouth. To evaluate the changes in tear volume, a digital video-meniscometer was used to measure the radius of the lower central tear meniscus curvature (R, mm) of each eye at prior to the administration of 5 mg oral pilocarpine, and at 15 (R:(15)), 30 (R:(30)), and 60 (R:(60)) minutes after administration. The fluorescein breakup time (FBUT, seconds) and ocular and oral dryness symptoms were evaluated before and at 60 min after administration using a visual analogue scale (VAS, mm). A significant increase in R was observed at 15 and 30 min after administration compared to that at prior to administration. FBUT showed significant improvement at 60 min after administration, and the VAS score for ocular and oral dryness symptoms was found to have decreased significantly at 60 min after administration. A single-dose administration of 5 mg oral pilocarpine had a beneficial effect on TF, as well as on ocular and oral dryness symptoms, in patients with SS.

The role of dinucleoside polyphosphates on the ocular surface and other eye structures

Dinucleoside polyphosphates comprises a group of dinucleotides formed by two nucleosides linked by a variable number of phosphates, abbreviated NpnN (where n represents the number of phosphates). These compounds are naturally occurring substances present in tears, aqueous humour and in the retina. As the consequence of their presence, these dinucleotides contribute to many ocular physiological processes. On the ocular surface, dinucleoside polyphosphates can stimulate tear secretion, mucin release from goblet cells and they help epithelial wound healing by accelerating cell migration rate. These dinucleotides can also stimulate the presence of proteins known to protect the ocular surface against microorganisms, such as lysozyme and lactoferrin. One of the latest discoveries is the ability of some dinucleotides to facilitate the paracellular way on the cornea, therefore allowing the delivery of compounds, such as antiglaucomatous ones, more easily within the eye. The compound Ap₄A has been described being abnormally elevated in patient's tears suffering of dry eye, Sjogren syndrome, congenital aniridia, or after refractive surgery, suggesting this molecule as biomarker for dry eye condition. At the intraocular level, some diadenosine polyphosphates are abnormally elevated in glaucoma patients, and this can be related to the stimulation of a P2Y₂ receptor that increases the chloride efflux and water movement in the ciliary epithelium. In the retina, the dinucleotide dCp₄U, has been proven to be useful to help in the recovery of retinal detachments. Altogether, dinucleoside polyphosphates are a group of compounds which present relevant physiological actions but which also can perform promising therapeutic benefits.

The increase of aqueous tear volume by diquafosol sodium in dry-eye patients with Sjögren's syndrome: a pilot study

PurposeTo investigate the effect of 3% diquafosol sodium ophthalmic solution (DQS) on aqueous tear volume increase in dry-eye patients with Sjögren's syndrome (SS).MethodsIn this pilot study, 17 dry-eye patients with SS (1 male and 16 females; mean age: 66.4 years) were enrolled and underwent topical instillation of two ophthalmic solutions, artificial tears (AT) in one eye and DQS in the fellow eye, in a masked manner. The central lower tear meniscus radius (TMR) curvature was measured before and at 15 min after instillation by video-meniscometry. Simultaneously, all patients self-evaluated their symptoms of wetness and stinging using a visual analog scale (VAS, in millimeters).ResultsTopical instillation of DQS significantly increased the TMR at 15 min (mean: 0.21±0.08 (SD) mm) compared with at baseline (mean: 0.16±0.07 mm) (P<0.001, paired t-test), whereas AT had no effect at baseline (mean: 0.18±0.09 mm) or at 15 min (mean: 0.18±0.09 mm). The visual VAS score of wetness at 15-min post-instillation increased in both groups compared with at baseline. In the DQS-treated eyes, the post-instillation change in TMR from baseline was not correlated with the baseline value of the Schirmer test, corneal staining score, or conjunctival staining score.ConclusionsTopical instillation of DQS increased aqueous tear volume on the ocular surface of dry-eye patients with SS, with its action being independent of lacrimal gland function.

Three percent diquafosol ophthalmic solution as an additional therapy to existing artificial tears with steroids for dry-eye patients with Sjögren's syndrome

PURPOSE

To investigate the long-term results of 3% diquafosol ophthalmic solution as an alternative therapy to existing ophthalmic solutions, including topical immunosuppression, for the treatment of dry eye in patients with Sjögren's syndrome.

METHODS

This study involved 14 female dry-eye patients (mean age: 62.4 years) with Sjögren's syndrome who insufficiently responded to their current therapy. In all patients, 3% diquafosol ophthalmic solution was administered six times daily for 12 months in substitution for artificial tears and sodium hyaluronate ophthalmic solution. Their use of corticosteroid eye drops remained unchanged from that prior to the treatment with diquafosol sodium. The subjective symptoms assessed, and ocular signs including tear meniscus radius and the tear film breakup time, and ocular-surface epithelial damage score were examined at 1, 2, 3, 4, 5, 6, 9, and 12 months after initiating treatment.

RESULTS

Among the subjective symptoms, significant improvement was obtained in dryness at 2 months post treatment, in eye fatigue at 1, 2, 3, 4, and 12 months post treatment, and in pain at 1, 2, 6, and 12 months post treatment. Difficulty in opening the eye, foreign body sensation, and redness were also significantly ameliorated at various time-points. The tear meniscus radius and the tear film breakup time were significantly improved throughout the observation period, and the corneal epithelial staining scores were significantly decreased at 3 months post treatment.

CONCLUSIONS

In dry-eye patients with Sjögren's syndrome, treatment with 3% diquafosol ophthalmic solution improved both symptoms and signs, and that effectiveness was maintained for 12 months.

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.

Diquafosol Tetrasodium Increases the Concentration of Mucin-like Substances in Tears of Healthy Human Subjects

PURPOSE

This study was undertaken to determine the effect of topical application of diquafosol tetrasodium on proteins and mucin-like substances from tears of clinically healthy subjects.

METHODS

Tears were collected from both the eyes of 10 healthy volunteers. Diquafosol tetrasodium solution (3%) was applied once to the right eye and 0.9% sodium chloride solution (saline) once to the left eye. Tear samples were collected by Schirmer test strips before application and 5, 15, 30 and 60 min after application. Sialic acid, a marker of mucin-like substances, and major tear proteins including secretory IgA, lactoferrin, lipocalin-1, and lysozyme were measured by high performance liquid chromatography.

RESULTS

Levels of total protein, sIgA and lysozyme were transiently decreased in both groups but returned to baseline levels within 15 min after application. The concentration of lactoferrin and lipocalin-1 did not change significantly in both groups. Sialic acid in tears was significantly decreased 5 min after saline application, but significantly increased 5 min after diquafosol application. No significant difference in sialic acid was seen after 15 min in both groups.

CONCLUSIONS

Topical application of saline and diquafosol resulted in transient decrease of tear proteins possibly due to wash out or dilution effects. In contrast, diquafosol application significantly increased sialic acid, although the effect was transient. This suggests diquafosol stimulates the secretion of mucins from ocular tissues of healthy human subjects.

Facilitation of tear fluid secretion by 3% diquafosol ophthalmic solution in normal human eyes

PURPOSE

To evaluate the increase in tear fluid volume induced by 3% diquafosol ophthalmic solution in normal human eyes.

DESIGN

Prospective, randomized, double-masked, comparative study.

METHODS

Twenty healthy adults (17 males and 3 females; mean age, 38.8 years) underwent topical instillation of 2 ophthalmic solutions, artificial tears in 1 eye and 3% diquafosol ophthalmic solution in the fellow eye, in a masked manner. The radius of curvature of the central lower tear meniscus was measured at 5, 10, 15, 30, and 60 minutes after instillation by use of reflective meniscometry, and subjects' self-evaluated symptoms of wetness and stinging using a visual analog scale.

RESULTS

Changes after instillation in the radius of curvature from baseline (artificial tear group vs diquafosol group; mean ± standard error of the mean) were as follows: at 5 minutes, -0.008 ± 0.012 vs 0.045 ± 0.013; at 10 minutes, 0.001 ± 0.014 vs 0.057 ± 0.016; at 15 minutes, -0.012 ± 0.014 vs 0.037 ± 0.019; at 30 minutes, -0.010 ± 0.016 vs 0.030 ± 0.025; and at 60 minutes, -0.029 ± 0.012 vs -0.020 ± 0.012. The diquafosol group showed significantly greater values from 5 to 30 minutes after instillation. Of the 40 eyes, 13 showed abnormal tear film breakup time (≤5 seconds). The diquafosol group had significantly more wetness at 15 minutes after instillation than did the artificial tear group.

CONCLUSIONS

Topical instillation of 3% diquafosol ophthalmic solution increases tear fluid on the ocular surface for up to 30 minutes in normal human eyes.

Effects of diquafosol tetrasodium administration on visual function in short break-up time dry eye

PURPOSE

To investigate the effect of diquafosol tetrasodium on tear and visual function in short break-up time (sBUT) dry eye (DE).

METHODS

This interventional nonrandomized comparative study involved 11 eyes in 11 patients with sBUT DE (symptom-positive sBUT group) and 13 eyes in 13 volunteers with BUT values ≤5 s without DE symptoms (symptom-negative sBUT group). Tear function was assessed by measuring BUT and Schirmer values. Serial measurements were made of visual acuities (using a functional visual acuity measurement system) and higher-order aberrations (using a wavefront sensor). The parameters were compared before and 1 month after diquafosol tetrasodium instillation. Any changes in symptomatology after administration were also recorded.

RESULTS

After diquafosol tetrasodium administration, BUT values tended to increase in the symptom-positive sBUT group (P=0.07) and significantly increased in the symptom-negative sBUT group (P<0.05). LogMAR functional, minimal, and maximal visual acuities and higher-order aberrations significantly decreased after diquafosol tetrasodium administration in the symptom-positive sBUT group (P<0.05), while there were no significant changes in these values in the symptom-negative sBUT group (P>0.05). Diquafosol tetrasodium administration provided relief of DE symptoms in 75% of patients in the symptom-positive sBUT group.

CONCLUSIONS

Diquafosol tetrasodium appeared to improve tear film stability and visual function in sBUT DE.

Diquafosol ophthalmic solution for dry eye treatment

INTRODUCTION

There has been rapid progress in our understanding of dry eye pathogenesis, as well as the development of improved diagnostic clinical tests. Various types of dry eye treatment drugs have been developed. This review summarizes the basic and clinical research carried out in the development of diquafosol for ophthalmic use.

RESULTS

Diquafosol is a dinucleotide, purinoreceptor P2Y(2) receptor agonist. Basic pharmacological studies have shown that it acts on P2Y(2) receptors at the ocular surface, to promote tear and mucin secretion via elevated intracellular Ca(2+) concentrations. Diquafosol also improves tear and mucin secretion in experimental dry eye models. Based on the results of laboratory experiments, the authors conducted a series of clinical studies in patients with dry eye disease. Diquafosol was effective in the treatment of dry eye disease at an optimal dose of 3% six times a day. In comparison to commercially available 0.1% sodium hyaluronate ophthalmic solution, 3% diquafosol ophthalmic solution showed non-inferiority in improving corneal fluorescein staining scores and superiority in improving keratoconjunctival Rose Bengal staining scores.

CONCLUSIONS

Diquafosol ophthalmic solution has a novel mechanism of action that is characterized by its stimulatory effects on tear and mucin secretion. This drug has the potential to be effective in patients with tear film instability and short break-up time type of dry eye, which are essential factors in dry eye pathogenesis.

Management and Therapy of Dry Eye Disease: Report of the Management and Therapy Subcommittee of the International Dry Eye WorkShop (2007)

The members of the Management and Therapy Subcommittee assessed current dry eye therapies. Each member wrote a succinct evidence-based review on an assigned aspect of the topic, and the final report was written after review by and with consensus of all subcommittee members and the entire Dry Eye WorkShop membership. In addition to its own review of the literature, the Subcommittee reviewed the Dry Eye Preferred Practice Patterns of the American Academy of Ophthalmology and the International Task Force (ITF) Delphi Panel on Dry Eye. The Subcommittee favored the approach taken by the ITF, whose recommended treatments were based on level of disease severity. the recommendations of the Subcommittee are based on a modification of the ITF severity grading scheme, and suggested treatments were chosen from a menu of therapies for which evidence of therapeutic effect had been presented.

The Agreement and Repeatability of Tear Meniscus Height Measurement Methods

PURPOSE

This study investigated the agreement and repeatability of five techniques of measuring tear meniscus height (TMH).

METHODS

Pairs of TMH measurements were obtained from one eye of 25 normal subjects with five techniques: optical coherence tomography in cross-section (OCT) and optical pachymetry in cross-section (PACH), without fluorescein; and 5 minutes after the instillation of fluorescein, optical pachymetry en-face (SL-F) and in cross-section (SL-X), and video capture en-face (VC). These 10 measurements were taken on different days within a period of 21 days. Additionally, immediately successive replicates were taken at the first visit when VC was used, allowing for the separation of technique repeatability from true day-to-day variation in TMH.

RESULTS

Ninety-five percent confidence intervals for the mean TMH and 95% repeatability coefficients for repeated testing on separate occasions were: 0.25 to 0.29 mm, 0.14 mm--OCT, 0.30 to 0.36 mm, 0.13 mm--PACH, 0.27 to 0.34 mm, 0.092 mm--SL-F, 0.35 to 0.41 mm, 0.19 mm--SL-X, and 0.30 to 0.38 mm, 0.088 mm--VC. Reported repeatability coefficients are averages because, despite a relatively narrow experimental range, the measurements of low TMH were generally more repeatable than those of large TMH. Ninety-five percent limits of agreement were wide for all pairwise comparisons and included zero, indicating that the methods used in this study are interchangeable when taking single recordings, at least on subjects without dry eye.

CONCLUSIONS

The average TMH of the five techniques was similar, although OCT and SL-X tended to record lower and higher values, respectively. However, their agreement for single recordings was poor, an inevitable consequence of the low intertest repeatability found for all methods. A much improved repeatability for immediate replicates indicated that this, in turn, was principally caused by a large day-to-day variation in TMH rather than measurement error.