Nanotechnology for Topical Drug Delivery to the Anterior Segment of the Eye

Topical drug delivery is one of the most challenging aspects of eye therapy. Eye drops are the most prevalent drug form, especially for widely distributed anterior segment eye diseases (cataracts, glaucoma, dry eye syndrome, inflammatory diseases, etc.), because they are convenient and easy to apply by patients. However, conventional drug formulations are usually characterized by short retention time in the tear film, insufficient contact with epithelium, fast elimination, and difficulties in overcoming ocular tissue barriers. Not more than 5% of the total drug dose administered in eye drops reaches the interior ocular tissues. To overcome the ocular drug delivery barriers and improve drug bioavailability, various conventional and novel drug delivery systems have been developed. Among these, nanosize carriers are the most attractive. The review is focused on the different drug carriers, such as synthetic and natural polymers, as well as inorganic carriers, with special attention to nanoparticles and nanomicelles. Studies in vitro and in vivo have demonstrated that new formulations could help to improve the bioavailability of the drugs, provide sustained drug release, enhance and prolong their therapeutic action. Promising results were obtained with drug-loaded nanoparticles included in in situ gel.

Efficacy of Long-term Use of 0.3% Sodium Hyaluronate Eye Drops for Traumatic Corneal Abrasion: A Randomized Controlled, Pilot Trial

PURPOSE

Traumatic corneal abrasion (TCA) causes damage to both corneal epithelium and the underlying hemidesmosomal junctions. Delayed recovery of hemidesmosomal junctions causes symptomatic episodes. However, there is no recommended treatment for recovery of hemidesmosomal junctions, indicating that a blank period exists in TCA treatment. In this study, the efficacy of long-term use of sodium hyaluronate on recovery of hemidesmosomal junctions during the blank period in TCA healing was investigated.

METHODS

In this prospective, randomized control pilot study, 60 patients with TCA were enrolled. The patients were randomized 1:1 to receive 0.3% sodium hyaluronate eye drops for 3 months (HA group) or observation alone (control group) after complete corneal epithelium recovery. The primary and secondary outcomes were the cumulative incidence of major and minor symptomatic episodes during a 12-month follow-up, respectively.

RESULTS

Fifty-six subjects (29 in the HA group and 27 in the control group) completed the 12-month follow-up. The 12-month cumulative incidence rate of major symptomatic episodes was 20.7% in the HA group and 18.5% in the control group. No significant difference was found between the 2 groups (P = 0.838). The 12-month cumulative incidence rate of minor symptomatic episodes was 48.3% and 37.0% in the HA and control groups, respectively, with no significant difference (P = 0.397).

CONCLUSIONS

Approximately one-fifth of patients with TCA experience major symptomatic episodes again within their 1-year follow-up. Long-term use of sodium hyaluronate in the period of recovery of hemidesmosomal junctions has no benefit to it.

Atorvastatin-loaded solid lipid nanoparticles as eye drops: proposed treatment option for age-related macular degeneration (AMD)

Statins, widely prescribed for cardiovascular diseases, are also being eyed for management of age-related macular degeneration (AMD). Poor bioavailability and blood-aqueous barrier may however limit significant ocular concentration of statins following oral administration. We for the first time propose and investigate local application of atorvastatin (ATS; representative statin) loaded into solid lipid nanoparticles (SLNs), as self-administrable eye drops. Insolubility, instability, and high molecular weight > 500 of ATS, and ensuring that SLNs reach posterior eye were the challenges to be met. ATS-SLNs, developed (2339/DEL/2014) using suitable components, quality-by-design (QBD) approach, and scalable hot high-pressure homogenization, were characterized and evaluated comprehensively for ocular suitability. ATS-SLNs were 8 and 12 times more bioavailable (AUC) in aqueous and vitreous humor, respectively, than free ATS. Three-tier (in vitro, ex vivo, and in vivo) ocular safety, higher corneal flux (2.5-fold), and improved stability (13.62 times) including photostability of ATS on incorporation in ATS-SLNs were established. Autoclavability and aqueous nature are the other highlights of ATS-SLNs. Presence of intact fluorescein-labeled SLNs (F-SLNs) in internal eye tissues post–in vivo application as eye drops provides direct evidence of successful delivery. Perinuclear fluorescence in ARPE-19 cells confirms the effective uptake of F-SLNs. Prolonged residence, up to 7 h, was attributed to the mucus-penetrating nature of ATS-SLNs.

Brimonidine related acute follicular conjunctivitis: Onset time and clinical presentations, a long-term follow-up

To evaluate the duration of topical brimonidine therapy before the onset of brimonidine-related allergic conjunctivitis and the clinical characteristics associated with the development of brimonidine allergy.We retrospectively enrolled patients who presented brimonidine allergy from December 1, 2008 to November 30, 2020. The duration of brimonidine treatment, concomitant medications, benzalkonium chloride (BAK) exposure, change in IOP, and season of onset were evaluated.292 patients were included, among which 147 were female and 145 were male. The mean age was 58.3 ± 13.6 years old. The mean (median) duration of brimonidine therapy was 266.6 (196) days, with a peak at 60-120 days. The duration was similar whether the patients received brimonidine monotreatment or in combination with other glaucoma drugs, with or without BAK. The IOP increased by 5.6% after brimonidine allergy (P < .001), which was even higher in the brimonidine monotherapy group (9.2%, P < .001). There was no significant IOP elevation in patients treated with multiple glaucoma medications.Around half of brimonidine allergy occurred within 6 months, with a peak in 2 to 4 months. The duration did not differ in patients receiving brimonidine monotherapy or multiple glaucoma medications. The presence of BAK did not affect the duration either. When brimonidine allergy occurred, there was a loss of IOP control, especially in patients receiving brimonidine monotherapy. It is recommended to switch to other types of glaucoma medications for better IOP control.

Pharmacological strategies for treating presbyopia

PURPOSE OF REVIEW

Presbyopia is the normal progressive loss of accommodation, which leads to the inability to focus clearly on objects located at different distances. Some of the accepted methods for treating this condition are glasses, contact lenses, and surgery. Pharmacological treatments are a new and promising noninvasive option for dealing with presbyopia. The aim of this review is to provide an update on some recent advances in this field.

RECENT FINDINGS

Currently, there are three different strategies for the pharmacological treatment of presbyopia. The first one aims to produce miosis and increase depth of focus through a pinhole effect, therefore improving uncorrected near visual acuity. The second one tries to restore the elasticity the lens has lost due to aging. Finally, the third strategy is based on rehabilitating accommodation; which is to say, in a binocular way, allowing for good vision at all distances.

SUMMARY

Pharmacological treatments are a new alternative that expands the diversity of existing strategies for treating presbyopia. These treatments are based on the instillation of eyedrops with different compositions, which vary according to the different strategies. Many of these developments will most likely be on the market in the next few years. If the process of patient selection is done properly, any one of these three strategies can be used successfully.

The clinical effects of sodium hyaluronate, polyethylene glycol, and dextran-70 eye drops in relieving dry eye after phacoemulsification

To compare the clinical efficacy of sodium hyaluronate eye drops, polyethylene glycol eye drops, and compound dextran eye drops in the treatment of dry eye after phacoemulsification of cataract.A total of 99 patients with dry eye after cataract phacoemulsification combined with intraocular lens implantation were treated in our hospital. Patients were divided into group A (sodium hyaluronate eye drops), group B (polyethylene glycol eye drops), and group C (dextran-70 eye drops). The clinical effect, tear film breakup time, basic tear secretion, corneal staining score, dry eye symptom score, and the incidence of ocular irritation were assessed.On the 3rd, 15th, 30th, and 60th day after operation, the tear film breakup time, corneal staining score, Schirmer I test, and dry eye symptom score in group A and group B were better than those in group C (P < .05). In addition, there were no significant differences in tear breakdown time, corneal staining score, Schirmer I test, and dry eye symptom score between group A and group B (P > .05). At 3 days to 60 days after operation, the incidence of dry eye in group A (12.12%) and group B (18.18%) was lower than that in group C (39.39%), and the incidence of dry eye in group A was significantly lower than that in group B (P < .05).The effect of sodium hyaluronate eye drops elicited a greater beneficial impact as compared to polyethylene glycol eye drops and dextran-70 eye drops.

Investigation of visual and physical factors associated with inadequate instillation of eyedrops among patients with glaucoma

Purpose

The aim of this study was to investigate the frequency of eyedrop instillation failure and its related physical and visual function factors among glaucoma patients who used hypotensive eyedrops daily.

Subjects and methods

Patients with a history of self-instillation of one or more ocular hypotensive ophthalmic solutions for six or more months were enrolled. Definitions of instillation failure were eyedrop instillation other than on the eye surface; eyedrop contact with eyelashes; eyedrop bottle tip contact with the eyelashes, eye surface or ocular adnexa; or two or more drops instilled with one instillation trial. To clarify factors related to instillation failure, we used visual function tests and investigated cervical spine extension angles during instillation, pinching strength, physical ataxia (evaluated using the Scale for the Assessment and Rating of Ataxia), motor dysfunction of the upper limbs (evaluated using the Disabilities of the Arm, Shoulder and Hand questionnaire), and vision quality (evaluated using the National Eye Institute Visual Function Questionnaire 25).

Results

Of 103 total subjects, 61.2% satisfied the definition of instillation failure. Instillation of the eyedrop other than at the cul-desac (76.2%) was the most frequent reason for failure, followed by contact of the tip of the eyedrop bottle (22.2%) and instillation of the same or more than two eyedrops in a single attempt (11.1%). Advanced age, a shallow cervical spine extension angle, weak pinching strength, poor motor dysfunction of the upper limbs, the degree of ataxia, poor best-corrected visual acuity, and visual field scores were significant risk factors for instillation failure. Vision quality may have some relation to instillation failure.

Conclusion

It is highly recommended that instillation failure be routinely investigated even among patients with adequate experience using eyedrops and that correct therapies are chosen in a patient-based fashion.

Polyethylene eye-cover versus artificial teardrops in the prevention of ocular surface diseases in comatose patients: A prospective multicenter randomized triple-blinded three-arm clinical trial

Background

Polyethylene covers are claimed to be useful in preventing ocular surface diseases (OSD); however, evidence of their clinical efficacy is limited. This clinical trial aimed to compare the use of polyethylene eye covers and artificial teardrops versus normal saline on the incidence and severity of OSD in comatose patients.

Methods

Of 90 eligible patients randomly assigned to three treatment groups, 79 patients completed the study, In group A, patients (n = 25) received artificial teardrops for left and normal saline for right eyes, in group B (n = 29) polyethylene covers for left and normal saline for right eyes, and in group C (n = 25) polyethylene covers for left and artificial teardrops for right eyes. As the patients were comatose, their blinding did not applicable, and a blinded observer evaluated the patients’ eyes based on the Corneal Fluorescein Staining Pattern. The blinded analyzer analyzed collected data by SPSS-16 software at a 95% confidential level.

Results

The OSDs were observed in 65 (41.14%) out of 158 eyes examined. The artificial teardrop was more effective than the normal saline in group A, polyethylene eye cover was more useful than the normal saline in group B, and polyethylene eye cover was more effective than the artificial teardrop in group C in reducing the incidence of OSD (p< 0.01). Polyethylene eye covers had the most impact on reducing the severity of the OSD compared to the other interventions (p< .001).

Conclusions

Polyethylene eye covers significantly reduced the incidence and severity of OSD. Using polyethylene cover is suggested as a safe, effective, and accessible eye care intervention for preventing OSD in comatose patients.

Trial registration

(IRCT201609129014N115), Iranian Registry of Clinical Trials.

Enhancement in corneal permeability of riboflavin using cyclodextrin derivates complexes as a previous step to transepithelial cross-linking

Corneal cross-linking has been described as an effective treatment to slow the progression of keratoconus. The standard protocol entails corneal epithelial removal to allow the diffusion of riboflavin into the stroma. Although, de-epithelization can generate risks or complications that transepithelial cross-linking tries to solve or avoid. Different formulations were developed after verifying that hydroxypropyl-β-cyclodextrin (HPβCD) and sulfobuthylether-β-cyclodextrin (SBEβCD) in a 20% concentration, increased the solubility of practically insoluble in water drugs such as riboflavin from 0.12 mg/mL to 0.35 mg/mL and 0.29 mg/mL respectively. These values were higher when chitosan and arginine were added to the formulation, showing solubility of 0.78 mg/mL when HPβCD concentration was not modified. Ex vivo corneal permeability was measured after having kept in contact bovine corneas with intact epithelium for 5 h with the 0.1 mg/mL riboflavin solution, the formulations developed and a reproduced nanoemulsion from another work. Riboflavin's permeability was increased when cyclodextrins, chitosan, and arginine were part of the formulations, compared to the control drug solution. The best permeability coefficient was reached when riboflavin was combined with 40% (w/v) HPβCD, 0.5% (w/w) arginine, and 0.5% (w/w) chitosan. After having carried out toxicity studies as bovine corneal opacity and permeability (BCOP) and Heńs Egg Test - Chorioallantoic Membrane Test (HET-CAM) it was verified that both, the active ingredients and the excipients of the different formulations were not harmful without generating irritation, loss of transparency or corneal permeability alterations. The results show the great potential of the ocular developed solution for their use in transepithelial cross-linking for keratoconus treatment.

Efficacy and Safety of Topical Cysteamine in Corneal Cystinosis: A Systematic Review and Meta-Analysis

PURPOSE

To evaluate safety and efficacy of topical cysteamine ophthalmic solution for corneal cystinosis.

METHODS

Seven databases were searched (PubMed, OVID, EMBASE, Web of Science, Cochrane Central, Google Scholar, and ClinicalTrials.gov) for relevant studies, using appropriate keywords. Comparative observational studies and randomized controlled trials comparing cysteamine with control or other formulations for treatment of corneal or ophthalmic cystinosis were included. Outcome measurements were improvement or response to therapy, change in corneal cystine crystal score (CCCS), in vivo confocal microscopy score (IVCM), cystine crystal depth, contrast sensitivity (CS), photophobia score, and safety.

DESIGN

Systematic review and meta-analysis.

RESULTS

Seven studies were included. Compared to placebo and control, the cysteamine arm was better in terms of improvements and responses to therapy (2 studies showed a risk ratio [RR] of 16; 95% confidence interval [CI]: 2.30-111.37) and crystal density score (1 study showed a mean difference [MD] of -0.80; 95% CI: -1.56 to -0.04). No significant differences were observed in terms of improvement in CS (1 study showed an RR of 7.00; 95% CI: 0.47-103.27). Compared to cystamine, cysteamine showed benefits in terms of crystal density score (MD -0.94; 95% CI: -1.64 to -0.24). Compared to a newer formulation, the standard formulation (cysteamine [Cystaran]; 0.55% cysteamine hydrochloride + benzalkonium chloride 0.01%) performed better in terms of decreasing CCCS. Another newer, viscous formulation, Cystadrops, performed better than the standard formulation in terms of change in CCCS, IVCM score, corneal crystal depth, and photophobia score; however, local adverse effects and blurring were higher in the group receiving Cystadrops.

CONCLUSIONS

Conventional cysteamine (0.1% to 0.3%) performed better than placebo (control) in terms of response to therapy. In terms of decreasing corneal cystine density, cysteamine (0.55%) was better than cystamine (0.55%), and the viscous Cystadrops (0.55%) was better than the standard formulation (0.1%).

Pediatric Use of Recombinant Human Nerve Growth Factor 20 μg/mL Eye Drops (Cenegermin) for Bilateral Neurotrophic Keratopathy in Congenital Corneal Anesthesia

PURPOSE

This study aimed to present the efficacy and safety of cenegermin eye drop (Oxervate; Dompè Farmaceutici, Milan, Italy) treatment in a pediatric patient affected by neurotrophic keratopathy (NK) with Goldenhar syndrome.

METHODS

This case reports an infant presenting ulceration and a small central opacity in the cornea of the right and left eyes, respectively. The NK bilaterally worsened despite the use of therapeutic contact lenses and temporary partial tarsorrhaphy. Magnetic resonance imaging showed absence and hypoplasia of the right and left trigeminal nerves, respectively. Cenegermin eye drops were administered 1 drop/each eye, 6 times daily for 8 weeks to promote corneal healing.

RESULTS

Complete healing was achieved in both eyes after treatment. During the 16-month follow-up period, no epithelial defect, recurrence, or complications were noticed, whereas corneal opacities progressively became clearer, although insignificant improvements in corneal sensitivity or in the reflex tearing were observed.

CONCLUSIONS

Cenegermin was effective in treating NK in an infant with Goldenhar syndrome.

Randomized, Double-Masked Trial of Netarsudil 0.02% Ophthalmic Solution for Prevention of Corticosteroid-Induced Ocular Hypertension

PURPOSE

To assess whether prophylactic use of netarsudil 0.02% ophthalmic solution reduces the risk of intraocular pressure (IOP) elevation associated with prolonged use of topical corticosteroids to prevent cornea transplantation rejection.

DESIGN

Prospective, randomized clinical trial.

METHODS

In this study, 120 subjects were randomized to use netarsudil (off-label) or placebo once daily for 9 months after Descemet membrane endothelial keratoplasty, and 71 fellow eyes were enrolled and assigned to the opposite treatment arm. Participants concurrently used topical prednisolone acetate 1% 4× daily for 3 months, 3× daily for a month, twice daily for a month, and once daily for 4 months. The main outcome was IOP elevation (defined as IOP ≥24 mm Hg or an increase of ≥10 mm Hg over baseline) assessed by Kaplan-Meier and proportional hazards analyses, taking loss to follow-up into consideration.

RESULTS

Overall, 95 eyes were assigned to netarsudil and 96 to placebo; 15 eyes (16%) were withdrawn early from the netarsudil arm because of ocular irritation. The rate of IOP elevation was 14% with netarsudil and 21% with placebo (relative risk: 0.6; 95% confidence interval: 0.3-1.3; P = .23). IOP was >30 mm Hg in 7.8% assigned to netarsudil versus 7.4% assigned to placebo (P = .84). Median 6-month central endothelial cell loss was 31% versus 29% with netarsudil versus placebo, respectively (P = .49).

CONCLUSIONS

Netarsudil did not produce a statistically significant reduction in the risk of steroid-induced IOP elevation after corneal transplantation relative to placebo.

Diffusion and Protein Corona Formation of Lipid-Based Nanoparticles in the Vitreous Humor: Profiling and Pharmacokinetic Considerations

The vitreous humor is the first barrier encountered by intravitreally injected nanoparticles. Lipid-based nanoparticles in the vitreous are studied by evaluating their diffusion with single-particle tracking technology and by characterizing their protein coronae with surface plasmon resonance and high-resolution proteomics. Single-particle tracking results indicate that the vitreal mobility of the formulations is dependent on their charge. Anionic and neutral formulations are mobile, whereas larger (>200 nm) neutral particles have restricted diffusion, and cationic particles are immobilized in the vitreous. PEGylation increases the mobility of cationic and larger neutral formulations but does not affect anionic and smaller neutral particles. Convection has a significant role in the pharmacokinetics of nanoparticles, whereas diffusion drives the transport of antibodies. Surface plasmon resonance studies determine that the vitreal corona of anionic formulations is sparse. Proteomics data reveals 76 differentially abundant proteins, whose enrichment is specific to either the hard or the soft corona. PEGylation does not affect protein enrichment. This suggests that protein-specific rather than formulation-specific factors are drivers of protein adsorption on nanoparticles in the vitreous. In summary, our findings contribute to understanding the pharmacokinetics of nanoparticles in the vitreous and help advance the development of nanoparticle-based treatments for eye diseases.

The eye as the discrete but defensible portal of coronavirus infection

Oculo-centric factors may provide a key to understanding invasion success by SARS-CoV-2, a highly contagious, potentially lethal, virus with ocular tropism. Respiratory infection transmission via the eye and lacrimal-nasal pathway elucidated during the 1918 influenza pandemic, remains to be explored in this crisis. The eye and its adnexae represent a large surface area directly exposed to airborne viral particles and hand contact. The virus may bind to corneal and conjunctival angiotensin converting enzyme 2 (ACE2) receptors and potentially to the lipophilic periocular skin and superficial tear film with downstream carriage into the nasopharynx and subsequent access to the lungs and gut. Adenoviruses and influenza viruses share this ocular tropism and despite differing ocular and systemic manifestations and disease patterns, common lessons, particularly in management, emerge. Slit lamp usage places ophthalmologists at particular risk of exposure to high viral loads (and poor prognosis) and as for adenoviral epidemics, this may be a setting for disease transmission. Local, rather than systemic treatments blocking virus binding in this pathway (advocated for adenovirus) are worth considering. This pathway is accessible with eye drops or aerosols containing drugs which appear efficacious via systemic administration. A combination such as hydroxychloroquine, azithromycin and zinc, all of which have previously been used topically in the eye and which work at least in part by blocking ACE2 receptors, may offer a safe, cost-effective and resource-sparing intervention.

Repurposing Ophthalmologic Timolol for Dermatologic Use: Caveats and Historical Review of Adverse Events

Ophthalmic timolol solution is increasingly being repurposed as a topical therapeutic for a variety of dermatologic diseases, including pyogenic granulomas, infantile hemangiomas, and chronic wounds. There are no published guidelines or protocols for use in these indications in adults, and the dermatologic community may not be familiar with adverse events that have been extensively documented relating to its ophthalmic use. We review the evidence available relating to adverse events to topical timolol use to evaluate its safety in dermatologic applications and to alert clinicians to screening and monitoring that is needed when repurposing this drug for dermatologic use. The majority of serious adverse events associated with ophthalmic timolol were reported in the first 7 years of use, between 1978 and 1985, of which most common were cardiovascular and respiratory events, but also included 32 deaths. The available evidence suggests that ophthalmic timolol safety profiling may have been incomplete prior to widespread use. Recent clinical trials for dermatologic indications have focused on documenting efficacy and have not had rigorous monitoring for potential adverse events. Topical timolol may be safe and effective for the treatment of various dermatologic conditions in patients whose medical histories have been carefully reviewed for evidence of pre-existing cardiac or pulmonary disease and are monitored for potential adverse events. Despite the wide use of timolol in ophthalmologic practice, safe dermatologic repurposing requires recognition of the potential for facilitated systemic absorption though the skin and appreciation of its history of adverse events.

Implementation of Novel Protocols in an Ophthalmic Ambulatory Surgical Center to Resume Surgical Procedures During COVID-19

BACKGROUND AND OBJECTIVES

With the resumption of elective ophthalmic surgery during COVID-19, revised protocols were mandated to protect both staff and patients from transmission while increasing case numbers. We discuss a widely generalizable and in-depth protocol intended to safely allow the restart of elective procedures in 2 dedicated ophthalmic ambulatory surgical centers (ASCs) using monitored anesthesia care.

METHODS

A single-center review of protocols and practices designed to limit COVID-19 transmission.

RESULTS

All patients were tested within 72 hours prior to the procedure with a COVID-19 nasal swab to assess for active disease. A distance of 6 ft between each stretcher and the staff within the ASC was maintained when possible. Preoperative anesthetizing and dilating eye drops were administered from multiuse bottles without contact with surfaces. Surgical cases were restarted at a reduced capacity of a maximum of 7 per day to distance patient arrivals. Removal of waiting room chairs and the creation of new break areas allowed for social distancing.

CONCLUSION

As recommendations change on the basis of an increased understanding of the COVID-19 virus, ophthalmologists and ASC staff need to tailor protocols and workflows to limit transmission of virus with resumption of ocular surgery.

'The mean mummy way' - experiences of parents instilling eye drops to their young children as described in online forums and blogs

BACKGROUND

Adults often have difficulty instilling eye drops in their own eyes, but little has been documented about the difficulties experienced by parents when administering eye drops to their young children, where the challenges of instillation are accentuated by their inability to cooperate. This qualitative study explores parents' experiences of administering eye drops to their children as described in online forum discussions and blog posts.

METHODS

This was an exploratory study using qualitative methods. We thematically analysed the written exchanges between parents participating in online forum discussions and blog posts about the administration of eye drops to their young children.

RESULTS

We found 64 forum discussion threads and 4 blog posts, representing 464 unique contributors expressing their experiences of eye drop administration to young children. Three major themes were identified - administration challenges, administration methods and role of health care professionals. Besides describing their children's distress, parents discussed their own discomfort and anxiety when administering eye drops. Parents used a variety of techniques to facilitate adherence with medication, including restraining the child, role-play, reassurance, distraction, or reward. The ideas exchanged about eye drop administration occasionally included reiteration of professional advice, but were dominated by parents' own ideas/suggestions; interestingly health care professionals were considered diagnosticians and prescribers, rather than sources of practical advice on administration.

CONCLUSIONS

Parents struggling to deliver eye drops to their young children may seek advice on how to administer treatment from parental on-line discussion forums. The distress experienced by the young child and their parents is a powerful reminder to clinicians that procedures common and routine in health care may be challenging to parents. The advice given to parents needs to go beyond the instillation of the eye drops, and include advice on child restraint, distraction techniques and allaying distress. Forewarned of the potential difficulties and provided with coping strategies parents can employ when the child resists, could alleviate their own and their child's distress.

Effects of topical application of 0.4% oxybuprocaine hydrochloride ophthalmic solution and 1% ropivacaine hydrochloride on corneal sensitivity in rats

The aim of the present study was to determine and compare the degree and duration of corneal anesthesia following topical application of 0.4% oxybuprocaine hydrochloride ophthalmic solution and 1% ropivacaine hydrochloride treatment in healthy rats. A randomized, blinded, crossover study was conducted on 20 healthy adult Wistar rats, following complete physical and ophthalmological examination. Baseline corneal touch threshold (CTT) was determined in the central corneal area of both eyes with a Cochet–Bonnet aesthesiometer, in mm filament length. Oxybuprocaine was randomly applied to one eye and 0.9% sterile sodium chloride solution was instilled into the contralateral eye. Subsequent CTT measurements were performed in both eyes 5 minutes after topical application and at 5-minute intervals thereafter for 75-minutes in the anesthetized eye. Following a 2-week washout period, this protocol was repeated with ropivacaine. Quantitative data were summarized as mean ± standard deviation, median and inter-quartile range (Q1–Q3). Repeated measures data were analyzed over time and between treatments using Friedman test and Wilcoxon signed-rank test with Bonferroni adjustment (p < 0.05). Baseline CTT values were 60 mm in all eyes. With oxybuprocaine, CTT values decreased significantly for 65 minutes (0–55 mm; p = 0.002) when compared with baseline; the maximal anesthetic effect (no blink response at 5 mm filament length) was maintained for up to 15 minutes (p < 0.0001). With ropivacaine, CTT values were significantly lower than baseline for 30 minutes (0–55 mm; p = 0.002), with a maximal anesthetic effect recorded at 5 minutes in 18 eyes (p < 0.0001). Oxybuprocaine induced a significantly lower CTT than ropivacaine (p = 0.002) from 10 to 65 minutes following topical application. Both anesthetic agents induced significant corneal anesthesia; however, oxybuprocaine provided a greater and longer anesthetic effect, making it more suitable for potentially painful ophthalmologic procedures.

Soft Contact Lens with Embedded Microtubes for Sustained and Self-Adaptive Drug Delivery for Glaucoma Treatment

Because of the physiological and anatomical constraints of the eye, ophthalmic drug delivery is challenging. When applied topically, less than 1% of administered ophthalmic drugs reach the aqueous humor. The delivery of a drug within an efficient therapeutic concentration, to the required site of action, for an extended period of time, is complicated. Herein, a novel type of contact lens device, with embedded microtubes as drug containers, is reported. This device can provide a simple, noninvasive, extended drug release up to 45 days with higher bioavailability and lower risk for adverse effects. Another unique feature of the device is the release of drug triggered by stretching of the contact lens, indicating the possibility for achieving a self-adaptive drug release device for treating glaucoma patients.

Inpatient Adherence to Topical Glaucoma Medications before and after an Educational Intervention

PURPOSE

To assess the inpatient adherence rate and factors associated with adherence to topical glaucoma medications (TGMs) at a single academic institution throughout hospitalization before and after an educational intervention.

DESIGN

Nonrandomized, comparative, retrospective study.

PARTICIPANTS

Inpatients 18 years of age and older admitted to a single academic hospital from January 2014 through June 2019 with a diagnosis of glaucoma who also received TGMs.

METHODS

The medication administration record during admission was examined closely to determine if the TGMs were reconciled and administered correctly before and after an educational intervention with inpatient providers. A simple intervention reached various health care providers through an educational e-mail, communication in a weekly newsletter, and a morning report presentation. Adherence was defined as administration of more than 75% of recommended doses during the inpatient stay. Other collected variables included length of stay and primary diagnosis on admission.

MAIN OUTCOME MEASURES

Adherence rate to inpatient administration of TGMs.

RESULTS

One hundred eighty-four patients (n = 142 before intervention; n = 42 after intervention) were included. The preintervention group had a total of 275 TGMs, of which 207 (75.3%) were administered in accordance with the adherence definition of this study. After the intervention phase, 49 of 56 (87.5%) TGMs were administered with appropriate adherence (P = 0.047). Adherence was associated significantly with a known outpatient medication regimen (P = 0.006) and correct admission reconciliation (P < 0.001).

CONCLUSIONS

When glaucoma patients requiring topical treatment are admitted, approximately one quarter of patients seem to not receive their medications appropriately. In this study, a simple educational intervention was able to improve adherence. To prevent daily fluctuations in intraocular pressure for vulnerable glaucoma patients, inpatient adherence to appropriate medication administration should be stressed continuously. While in the care of health care providers, inpatients should be afforded at least the opportunity to maintain adequate adherence, just as is carried out for other medications related to other chronic medical conditions.

The clinical efficiency of lycium-rehmannia pills in treating dry eye symptom: A meta-analysis

BACKGROUND

Dry eye symptom threatens human health and causes a larger burden of disease, the study aims to systematically compare the therapeutic effect of Lycium-rehmannia pills combined with topical eye drops and pure western medicine (western medicine eye drops) on dry eye symptom, to provide a reflection and enlightenment for clinical treatment.

METHOD

PubMed, The Cochrane Library, EMbase, MEDLINE, CBM, WanFang, VIP, and CNKI databases were searched manually and automatically by the computer until March 2019 and relevant randomized controlled trials (RCTs) were selected. Article selection and data extraction were conducted by 2 researchers independently, then RevMan 5.3 was applied for meta-analysis.

RESULT

Fifteen randomized controlled trials were included, including 1222 patients (eyes = 2382). The meta-analysis results showed that Lycium-rehmannia pills combined with western medicine were superior to the control group in terms of therapeutic efficiency [OR = 4.38, 95% confidence interval (CI) (3.26, 5.89), P < .00001]. There were controversial results that the study group was better than the control group in Basic Schirmer test [MD, 2.46, 95% CI (1.49, 3.44), P < .00001], tear break up time [MD, 3.79, 95% CI (3.57, 4.01), P < .00001], and Fluorescein test [MD, -1.29, 95% CI (-1.42, -1.15), P < .00001], but Lycium-rehmannia pills combined with western medicine could not reduce the incidence of adverse reactions, including eyelid inflammation [OR = 1.00, 95% CI (0.37, 2.72), P = 1.00] and congestion symptom [OR = 0.55, 95% CI (0.18, 1.65), P = .28].

CONCLUSION

Lycium-rehmannia pills combined with western medicine is better than the control group of therapeutic efficiency in the treatment of dry eye symptom. Due to the quantity and quality limitations of the literature, there were controversial results that the study group was better than the control group in Basic Schirmer test, Tear break up time, Fluorescein test, and reduced adverse reactions, including inflammation of the eyelids and congestion. The above conclusion needs more clinical trials to test and verify.

Optimizing ophthalmic delivery of a poorly water soluble drug from an aqueous in situ gelling system

Poorly soluble drugs are often unsuitable to incorporate in ocular in situ gelling systems due to the aqueous based gelling formulations and low volumes administered. For such formulations to be successful, the administered drug must have sufficient solubility to diffuse from the formulation to the eye and should not affect the gelation of the in situ gelling material. Drug salt forms can improve the solubility of poorly soluble drugs, however, as in situ gel forming formulations are often designed to be crosslinked by salts (present the lacrimal fluid) it can make salt forms difficult to formulate. The aim of this study was to develop an in situ gel forming ophthalmic formulation of a poorly soluble drug flurbiprofen (FBP) through cyclodextrin complex formation and to analyse the impact on gelation, release and permeation through the cornea. Hydroxypropyl-beta-cyclodextrin (HβCD) was used as a complexing agent and low acyl gellan gum was added to the FBP- HβCD complex as a water soluble in situ gelling polymer. Measurements were performed using rheo-dissolution, which utilises a rheometer with a modified lower plate that has the unique ability to allow rheological measurement and analysis of drug release simultaneously. An ex-vivo permeation study was also performed using porcine cornea. Rheological measurements in terms of elastic (G') and viscous (G″) modulus showed rapid gelation of the formulation upon contact with simulated lacrimal fluid (SLF). Approximately, 97% FBP was released when 10% HβCD was used and release was decreased to 79% when the amount of HβCD was increased to 20%. The percentage of drug permeation through the cornea was 55% in 300 min whereas the marketed non gelling eye drop formulation containing FBP sodium showed only 37% permeation. The data presented here, revealed that not only could a poorly soluble drug be complexed with cyclodextrin and loaded into an in situ gelling system without interfering with the gelation, but also permeability the of the drug improved.

Antiemetic effect of oral maropitant treatment before the administration of brimonidine ophthalmic solution in healthy cats

OBJECTIVES

The aim of this study was to investigate the antiemetic, behavioural and physiological effects of oral maropitant treatment before the administration of brimonidine ophthalmic solution in healthy cats.

METHODS

Five cats received oral maropitant 8 mg or no treatment (control) 18 h before the administration of one drop of brimonidine solution in both eyes. Each cat was administered each of the two treatments, with a washout period of 1 week. The incidence of emesis, retching, sialorrhoea and lip-licking after brimonidine administration was recorded, while behavioural and physiological parameters, including heart rate, mean blood pressure, respiratory frequency and rectal temperature, were recorded before and 0, 30, 60, 90, 120, 180 and 240 mins after brimonidine administration.

RESULTS

Emesis and retching were not observed when maropitant was administered. However, 4/5 cats exhibited vomiting and retching in the absence of maropitant pretreatment. The incidence of emesis and retching after brimonidine administration was significantly lower in the treatment group than in the control group. Sialorrhoea occurred in one cat in the control group, while all cats showed lip-licking after brimonidine administration. There were no significant differences in the incidence of sialorrhoea and lip-licking between the two groups. Although behaviour scores were comparable between the two groups, those obtained during heart rate, mean blood pressure and respiratory frequency measurements were significantly lower than the baseline scores; this indicated a sedative effect after brimonidine administration. The heart rate and mean blood pressure significantly decreased after brimonidine administration in both groups, while there were no intergroup differences in the heart rate, mean blood pressure, respiratory frequency and rectal temperature.

CONCLUSIONS AND RELEVANCE

Oral maropitant treatment before the administration of brimonidine ophthalmic solution in cats can alleviate emesis and retching without affecting the sedative effects of brimonidine and important physiological parameters.

Ocular Drug Delivery Systems Using Contact Lenses

The use of contact lenses as ocular drug delivery systems has been considered intuitive for decades. However, at this time, there are no approved products using such systems. In this article, we review the challenges with current therapies, pharmacokinetics, and pharmacodynamics of different drug classes and the patient population. In addition, we note the relative lack of clinical studies, and list potential products in active development at this time. In particular, we address the alignment of time course of the therapeutic need, the pharmacokinetics of the molecule, and the delivery characteristics of the systems (e.g., pulsatile vs. zero-order). We also discuss the needs of various populations including the elderly (who may have motor and cognitive issues as well as presbyopia) and the young. While a contact lens delivery system may also provide refractive correction, to date, most of the studies have used noncorrective (plano) lenses. We also considered nanotechnology-based carrier systems. We generalize the development of contact lens delivery systems to all ocular delivery systems in which there are relatively few product approvals and long development times.