Efficacy of retinol palmitate eye drops for dry eye in rabbits with lacrimal gland resection

Real Life Impact of Dry Eye Disease

Dry Eye Disease (DED) is an increasingly common condition that affects between 5% and 50% of the global population. Even though DED is most frequently diagnosed in older people, it has also been diagnosed in young adults and adolescents more frequently in recent years (employees, gamers). People can experience different types of symptoms and find it challenging to read, watch TV, cook, climb stairs, and meet friends. Mild and severe dry eye can reduce quality of life similarly to mild psoriasis and moderate-to-severe angina. Furthermore, DED patients experience serious difficulties driving vehicles, especially at night, and show a decrease in work productivity, which, when combined with the relevant indirect cost that this condition produces, poses a serious challenge in our days. In addition, DED patients are more likely to develop depression and suicidal ideations and experience frequent sleep disorders. Finally, it is discussed how lifestyle changes, such as increased physical activity, blinking exercises, and a proper diet, have positive implications for the management of this condition. Our aim is to draw attention to the negative effects of dry eye in real life, which are unique to each patient, especially as they relate to the non-visual symptoms experienced by DED patients.

Bibliometric analysis of articles on nanoemulsion and/or in-situ gel for ocular drug delivery system published during the 2011–2021 period

The bibliometric data were extracted from the Scopus database to investigate the conceptual framework of ocular nanoemulsion and/or in-situ gel drug delivery system using “ocular” AND “nanoemulsion” OR “in-situ gel” keywords. The data were evaluated with RStudio and VOSviewer program.

The results reveal that the publication trends tend to increase continually. India is the most impactful country, and the most constructive institution is Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University. International Journal of Pharmaceutics is the top influential source. Ali A is the most prolific author. The title of the most impactful article was In-situ gelling systems based on Pluronic F127/Pluronic F68 formulations for ocular drug delivery”. “Controlled release” is the most popular keyword.

These results provide insights for stimulating research collaborations and revealing open issues of controlled-release ocular preparation to overcome an ocular barrier and enhance patient compliance.

Animal models of dry eye disease: Useful, varied and evolving (Review)

Dry eye disease (DED), which is a prevalent disease that still lacks successful treatment options, remains a major challenge in ophthalmology. Multiple animal models of DED have been used to decipher its pathophysiology and to develop novel treatments. These models use mice, rats, rabbits, cats, dogs and non-human primates. Each model assesses aspects of DED by focusing on elements of the lacrimal functional unit, which controls the homeostasis of the tear film. The present review outlines representative DED animal models and assesses their contribution to the study of DED. Murine models are the most extensively used, followed by rabbit models; the latter offer the advantage of larger eyes, a favorable biochemical profile for drug studies, experimental ease and relatively low cost, contrasting with non-human primates, which, although closer to humans, are not as accessible and are expensive. No comprehensive ‘ideal’ animal model encompassing all aspects of human DED exists nor is it feasible. Investigators often choose an animal model based on their experimental needs and the following four features of a given model: The size of the eye, its biochemical composition, the available research reagents and cost. As research efforts in DED expand, more refined animal models are needed to supplement the enormous contribution made to date by existing models.

A Review of Topical and Systemic Vitamin Supplementation in Ocular Surface Diseases

In the homeostasis of the ocular surface, vitamins play a critical role in regulating inflammatory responses and promoting cell differentiation, development and correct function. Systemic vitamin supplementation has been available for many decades; in recent years, thanks to pharmacological advancements, topical vitamin delivery has also become available in an attempt to better treat ocular surface disease (OSD) and dry eye disease (DED). In this paper, we reviewed the current evidence on the role of vitamin supplementation in OSD and DED. We originally searched the PubMed archive, inspected the references and restricted the search to pertinent papers. The body of evidence was evaluated using the amelioration of both signs and symptoms as the outcome, when available. We found that in patients with vitamin deficiency, systemic supplementation of Vitamin A is effective in treating OSD, reducing both DED signs and symptoms. Additionally, systemic supplementation of vitamin D is useful in reducing DED symptoms and increasing tear volume. Vitamin A is also effective in reducing DED signs and symptoms when administered locally. The efficacy of supplementation with other vitamins is still not fully proven. In conclusion, the inclusion of vitamins into the treatment strategies for OSD and DED allows for better treatment customization and better outcomes in these patients.

Dry Eye Disease: A Review of Epidemiology in Taiwan, and its Clinical Treatment and Merits

Dry eye disease (DED) has become common on a global scale in recent years. There is a wide prevalence of DED in different countries based on various ethnicities and environment. DED is a multifactorial ocular disorder. In addition to advanced age and gender, such factors as living at high altitude, smoking, pterygium, prolonged use of consumer electronics or overingesting of caffeine or multivitamins are considered to be the major risk factors of DED. We report the DED epidemiology in Taiwan firstly in this article. According to the pathophysiological factors and changes inthe composition of the tear film in DED, it can be categorized into several subtypes, including lipid anomaly dry eye, aqueous tear deficiency, allergic and toxic dry eye among others. Each subtype has its own cause and disease management; therefore, it is important for ophthalmologists to identify the type through literature review and investigation. The management of DED, relies not only on traditional medications such as artificial tears, gels and ointments, but also newer treatment options such as acupuncture, SYL1001, and nanomedicine therapy. We also conducted a comprehensive literature review including common subtypes and treatment of DED. Clearly, more clinical trials are needed to assess the efficacy and safety of the various treatments and common subtypes of DED.

Comparing Vitamin A and Moist Chamber in Preventing Ocular Surface Disorders

The present study was conducted to determine the effectiveness of vitamin A eye ointment (VAEO) and moist chamber (MC) in preventing ocular surface disorders (OSD) in intensive care unit (ICU) patients. A total of 38 eligible patients were selected for participation in the present clinical trial. All the patients were randomly administered VAEO in one eye every 6 hr for 5 days and had a polyethylene cover (PC) placed on their other eye to create an MC that was replaced every 12 hr as well. The results of Schirmer's test also increased by 2.06 mm in the VAEO group ( p < .001), while they showed a slight reduction by 0.15 mm in the MC group ( p = .669). VAEO was more effective in preventing OSD in ICU patients than MC and is, therefore, recommended to be used as a method of preventing OSD.

Efficacy and safety of retinol palmitate ophthalmic solution in the treatment of dry eye: a Japanese Phase II clinical trial

Purpose

The purpose of this study was to investigate the efficacy and safety of the administration of retinol palmitate (VApal) ophthalmic solution (500 IU/mL) for the treatment of patients with dry eye.

Patients and methods

This study included 66 patients with dry eye. After a 2-week washout period, patients were randomized (1:1) into either a VApal ophthalmic solution or a placebo group, and a single drop of either solution was administered six times daily for 4 weeks. Efficacy measures were 12 subjective symptoms, rose bengal (RB) and fluorescein staining scores, tear film breakup time, and tear secretion. Safety measures included clinical blood and urine analyses and adverse event recordings.

Results

In comparisons of the two groups, the mean change in RB staining score from baseline was significantly lower in the VApal group at 2 and 4 weeks (P<0.05 and P<0.01, respectively). Furthermore, the fluorescein clearance rate (fluorescein staining score) was significantly higher in the VApal group at 4 weeks (P<0.05). The VApal group showed a significant improvement in blurred vision at 1 and 2 weeks (P<0.01 and P<0.05, respectively), and the mean change in the total score for subjective symptoms from baseline was significantly lower in the VApal group at 1 week (P<0.05). In before- and after-intervention comparisons, the fluorescein and RB staining scores showed improvement in both groups. Improvement was noted for 11 subjective symptoms in the VApal group and for seven symptoms in the placebo group. No significant differences in adverse events and reactions were found between the groups.

Conclusion

VApal ophthalmic solution (500 IU/mL) is safe and effective for the treatment of patients with dry eye.

Knockout of the LRRC26 subunit reveals a primary role of LRRC26-containing BK channels in secretory epithelial cells

Leucine-rich-repeat-containing protein 26 (LRRC26) is the regulatory γ1 subunit of Ca²⁺- and voltage-dependent BK-type K⁺ channels. BK channels that contain LRRC26 subunits are active near normal resting potentials even without Ca²⁺, suggesting they play unique physiological roles, likely limited to very specific cell types and cellular functions. By using Lrrc26 KO mice with a β-gal reporter, Lrrc26 promoter activity is found in secretory epithelial cells, especially acinar epithelial cells in lacrimal and salivary glands, and also goblet and Paneth cells in intestine and colon, although absent from neurons. We establish the presence of LRRC26 protein in eight secretory tissues or tissues with significant secretory epithelium and show that LRRC26 protein coassembles with the pore-forming BK α-subunit in at least three tissues: lacrimal gland, parotid gland, and colon. In lacrimal, parotid, and submandibular gland acinar cells, LRRC26 KO shifts BK gating to be like α-subunit-only BK channels. Finally, LRRC26 KO mimics the effect of SLO1/BK KO in reducing [K⁺] in saliva. LRRC26-containing BK channels are competent to contribute to resting K⁺ efflux at normal cell membrane potentials with resting cytosolic Ca²⁺ concentrations and likely play a critical physiological role in supporting normal secretory function in all secretory epithelial cells.

Age-related Defects in Ocular and Nasal Mucosal Immune System and the Immunopathology of Dry Eye Disease

Dry eye disease (DED) is a prevalent public health concern that affects up to 30% of adults and is particularly chronic and severe in the elderly. Two interconnected mechanisms cause DED: (1) an age-related dysfunction of lacrimal and meibomian glands, which leads to decreased tear production and/or an increase in tear evaporation; and (2) an age-related uncontrolled inflammation of the surface of the eye triggered by yet-to-be-determined internal immunopathological mechanisms, independent of tear deficiency and evaporation. In this review we summarize current knowledge on animal models that mimic both the severity and chronicity of inflammatory DED and that have been reliably used to provide insights into the immunopathological mechanisms of DED, and we provide an overview of the opportunities and limitations of the rabbit model in investigating the role of both ocular and nasal mucosal immune systems in the immunopathology of inflammatory DED and in testing novel immunotherapies aimed at delaying or reversing the uncontrolled age-related inflammatory DED.

The role of topical vitamin A in promoting healing in surface refractive procedures: a prospective randomized controlled study

Aim

To evaluate the effect of topical vitamin A supplementation on corneal re-epithelialization time, postoperative pain, visual acuity, and haze following photorefractive keratectomy (PRK).

Patients and methods

This prospective study included 32 patients. For each patient, one eye was randomized to the vitamin A group and the fellow eye to the non-vitamin A group (control group). Eyes in the vitamin A group received perioperative topical vitamin A (retinol palmitate, 250 IU/g VitAPOS eye ointment [AFT Pharmaceuticals Pty, Ltd, Sydney, NSW, Australia]) in addition to the classic treatment for PRK. Clinical outcomes were evaluated up to 3 months after PRK.

Results

There was no difference in the mean time to complete healing between the vitamin A group and the control group (3.36 ± 0.6 days in the control group; 3.42 ± 0.7 days in the vitamin A group; P = 0.854). Mean postoperative pain at the 48-hour visit was 4.35 ± 1.42 over 10 in the control group, and 4.42 ± 1.37 over 10 in the vitamin A group, with no difference between the two groups (P = 0.589). Subepithelial haze evaluated at 3 months postoperatively did not differ between the two groups (P = 0.960). Also, visual and refractive outcomes were not different between the two groups 3 months postoperatively.

Conclusion

Topical vitamin A supplementation did not affect re-epithelialization time, postoperative pain, corneal haze formation, or visual outcomes after PRK.