Safety and efficacy of diclofenac ophthalmic solution in the treatment of corneal abrasions

Nanosuspensions in ophthalmology: Overcoming challenges and enhancing drug delivery for eye diseases

This review article provides a comprehensive overview of the advancements in using nanosuspensions for controlled drug delivery in ophthalmology. It highlights the significance of ophthalmic drug delivery due to the prevalence of eye diseases and delves into various aspects of this field. The article explores molecular mechanisms, drugs used, and physiological factors affecting drug absorption. It also addresses challenges in treating both anterior and posterior eye segments and investigates the role of mucus in obstructing micro- and nanosuspensions. Nanosuspensions are presented as a promising approach to enhance drug solubility and absorption, covering formulation, stability, properties, and functionalization. The review discusses the pros and cons of using nanosuspensions for ocular drug delivery and covers their structure, preparation, characterization, and applications. Several graphical representations illustrate their role in treating various eye conditions. Specific drug categories like anti-inflammatory drugs, antihistamines, glucocorticoids, and more are discussed in detail, with relevant studies. The article also addresses current challenges and future directions, emphasizing the need for improved nanosuspension stability and exploring potential technologies. Nanosuspensions have shown substantial potential in advancing ophthalmic drug delivery by enhancing solubility and absorption. This article is a valuable resource for researchers, clinicians, and pharmaceutical professionals in this field, offering insights into recent developments, challenges, and future prospects in nanosuspension use for ocular drug delivery.

Topical analgesics for acute corneal pain: current options and emerging therapeutics

Acute corneal pain is a common complaint that causes significant distress to patients and continues to challenge therapeutic avenues for pain management. Current topical treatment options have marked limitations in terms of both efficacy and safety, thus often prompting the adjunctive use of systemic analgesics, including opioids. In general, there have not been extensive advancements in pharmacologic options for the management of corneal pain over the past several decades. Despite this, multiple promising therapeutic avenues exist which hold the potential to transform the ocular pain landscape, including druggable targets within the endocannabinoid system. This review will summarize the current evidence base for topical nonsteroidal anti-inflammatory drugs, anticholinergic agents, and anesthetics before focusing on several potential avenues in the setting of acute corneal pain management, including autologous tear serum, topical opioids and endocannabinoid system modulators.

[Neuropathic pain in dry eye syndrome. Part 2. Clinical picture, diagnosis and treatment]

Burning eye syndrome is a chronic neuropathic pain syndrome, which is characterized by dysesthesia, spontaneous pain, allodynia and hyperalgesia. The review describes clinical features and presents available data on possible methods of diagnosis and therapy of this condition.

Is the Sex Difference a Clue to the Pathomechanism of Dry Eye Disease? Watch out for the NGF-TrkA-Piezo2 Signaling Axis and the Piezo2 Channelopathy

Dry eye disease (DED) is a multifactorial disorder with recognized pathology, but not entirely known pathomechanism. It is suggested to represent a continuum with neuropathic corneal pain with the paradox that DED is a pain-free disease in most cases, although it is regarded as a pain condition. The current paper puts into perspective that one gateway from physiology to pathophysiology could be a Piezo2 channelopathy, opening the pathway to a potentially quad-phasic non-contact injury mechanism on a multifactorial basis and with a heterogeneous clinical picture. The primary non-contact injury phase could be the pain-free microinjury of the Piezo2 ion channel at the corneal somatosensory nerve terminal. The secondary non-contact injury phase involves harsher corneal tissue damage with C-fiber contribution due to the lost or inadequate intimate cross-talk between somatosensory Piezo2 and peripheral Piezo1. The third injury phase of this non-contact injury is the neuronal sensitization process with underlying repeated re-injury of the Piezo2, leading to the proposed chronic channelopathy. Notably, sensitization may evolve in certain cases in the absence of the second injury phase. Finally, the quadric injury phase is the lingering low-grade neuroinflammation associated with aging, called inflammaging. This quadric phase could clinically initiate or augment DED, explaining why increasing age is a risk factor. We highlight the potential role of the NGF-TrkA axis as a signaling mechanism that could further promote the microinjury of the corneal Piezo2 in a stress-derived hyperexcited state. The NGF-TrkA-Piezo2 axis might explain why female sex represents a risk factor for DED.

Development of Eudragit® Nanoparticles for Intranasal Drug Delivery: Preliminary Technological and Toxicological Evaluation

Intranasal administration has assumed in the last years an increasing value as an alternative strategy for the systemic adsorption of drugs, as an alternative to oral and parenteral routes thanks to the high vascularized nasal mucosa. Nevertheless, different drug features may restrict its absorption through the nasal mucosa with an insufficient diffusion to the systemic circulation. Several technological strategies are under investigation to improve drug absorption during nasal formulation design and production. The use of bioadhesive polymers can be considered a valid approach to pursue the aforementioned goal. Based on this consideration, Eudragit® Retard RS100 and RL100 resins were selected as positively charged copolymers to prepare polymeric NPs with potential mucoadhesive properties suitable for intranasal application. NPs were produced by the Quasi-emulsion Solvent Evaporation (QESD) method and loaded with diclofenac acid (DIC) or its epolamine salt (DIEP). Preliminary investigations were performed to obtain the optimized blank formulation and drugs loaded NPs evaluating different parameters that can affect particles size and polydispersity. The optimized formulations unloaded and loaded with DIC and DIEP were further evaluated for their thermotropic behavior by differential scanning calorimetry. Mucoadhesive evaluation was assessed by measuring variation in zeta potential and by turbidimetric assay after incubation of particles with mucin in simulated nasal fluid (SNF) at 37 °C at different time points (0, 1 and 24 h) compared to the pure suspensions. Stability of DIC and DIEP loaded NPs was also evaluated in SNF to predict potential aggregation phenomena after nasal administration. Finally, in vivo experiments showed absence of toxicity on the nasal mucosa of mice.

Comparison of DMEK and DSAEK in Eyes With Endothelial Decompensation After Previous Penetrating Keratoplasty

PURPOSE

Posterior lamellar keratoplasty is increasingly applied in patients with endothelial decompensation after penetrating keratoplasty (PK). The aim of this study was to compare the results of Descemet membrane endothelial keratoplasty (DMEK) and Descemet stripping automated endothelial keratoplasty (DSAEK) after PK.

METHODS

In this retrospective study, clinical data of 30 patients who received DMEK (n = 19) or DSAEK (n = 11) for endothelial decompensation after PK were evaluated. All lamellar keratoplasties were performed at the Department of Ophthalmology at University Hospital Mainz, Germany. Primary end point included best-corrected visual acuity, and secondary end points included endothelial cell density, rebubbling, and rejection rates, all at 6 and 12 months.

RESULTS

After 6 months and 12 months, 89% of DMEK and 73% of DSAEK grafts and 63% of DMEK and 64% of DSAEK grafts provided sufficient corneal deturgescence, respectively, represented by improvement in best-corrected visual acuity. DMEK group median preoperative Logarithm of the Minimum Angle of Resolution visual acuity of 1 increased to 0.5 after 6 and 12 months. DSAEK group median Logarithm of the Minimum Angle of Resolution visual acuity increased from 3 to 2 and 1.3 after 6 and 12 months. After 12 months, graft endothelial cell density had decreased by 58% in the DMEK group and by 59% in the DSAEK group. The proportion of patients requiring a rebubbling were 63% in the DMEK and 64% in the DSAEK group. No lamellar graft rejection occurred in either trial arm.

CONCLUSIONS

Both DMEK and DSAEK significantly improved visual acuity in patients after PK. Lamellar graft survival, loss of endothelial cells, and mean rebubbling rates were similar in both groups.

Topical pain control for corneal abrasions: A systematic review and meta-analysis

OBJECTIVES

Corneal abrasions are common ophthalmic presentations to emergency departments. Among emergency physicians and ophthalmologists, there are highly variable practice patterns with regard to management of resultant pain and discomfort. The goal of this study was to review and analyze the efficacy and safety of topical pain therapies for corneal abrasions, including topical anesthetics, nonsteroidal anti-inflammatory drugs (NSAIDs), cycloplegics, steroids, pressure patching, and the use of a bandage contact lens (BCL).

METHODS

The review followed the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. The protocol was established a priori and published on PROSPERO (CRD42020201288). MEDLINE, EMBASE, CENTRAL, and Web of Science were searched until December 31, 2020. Primary studies comparing topical pain therapies to another therapy or control were included. Primary outcomes included percentage of corneal abrasions healed at 24, 48, and 72 hours, as well as pain control at 24 and 48 hours. Secondary outcomes included use of oral analgesia and incidence of complications. Risk of bias was assessed using validated tools. Quality of evidence was assessed using the GRADE methodology.

RESULTS

Overall, 33 studies (31 randomized controlled trials [RCTs], two cohort studies) comprising 4,167 patients with corneal abrasions were analyzed. Only the data for topical NSAIDs were of adequate evidence from which to draw conclusions; topical NSAIDs demonstrated significantly reduced pain scores at 24 hours (standardized mean differences [SMD] -0.69, 95% CI = -0.98 to -0.41) and 48 hours (SMD = -0.56, 95% CI = -1.02 to -0.10) as well as 53% (95% CI = 34% to 67%) lower oral analgesia use compared to control. Based on available data, topical anesthetics, cycloplegics, patching, and the use of a BCL did not result in any significant difference in pain scores or use of oral analgesia, while no studies examined topical steroids. No interventions resulted in healing delays or significantly higher rates of complications compared to controls.

CONCLUSIONS

There was strong evidence to support that topical NSAIDs reduce pain associated with corneal abrasions in the first 48 hours and the need for oral analgesia. The existing evidence was insufficient to support or refute the use of topical anesthetics, cycloplegics, steroids, or BCL for pain control in corneal abrasions. Pressure patching was ineffective at pain reduction and may increase the risk of complications. Delays in healing or other complications were not significantly different between any intervention or control for simple, uncomplicated corneal abrasions; however, larger RCTs are required to identify any differences in rare complications.

Imprinted hydrogels with LbL coating for dual drug release from soft contact lenses materials

A combined strategy to control the release of two drugs, one anti-inflammatory (diclofenac sodium, DCF) and one antibiotic (moxifloxacin hydrochloride, MXF), from a soft contact lens (SCL) material, was assessed. The material was a silicone-based hydrogel, which was modified by molecular imprinting with MXF and coated by the layer-by-layer (LbL) method using natural polyelectrolytes: alginate (ALG), poly-l-lysine (PLL) and hyaluronate (HA), crosslinked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Imprinting was used to increase the amount of MXF loaded and to sustain its release, while the LbL coating acted as a diffusion barrier for DCF and improved the surface properties. The drugs were loaded by soaking in a DCF + MXF dual solution. High hydrostatic pressure (HHP) was successfully applied in the sterilization of the drug-loaded hydrogels. The transmittance, refractive index, wettability and ionic permeability of the hydrogels remained within the required levels for SCLs application. The concentrations of the released DCF and MXF stayed above the IC₅₀ and the MIC (for S. aureus and S. epidermidis) values, for 9 and 10 days, respectively. No ocular irritancy was detected by the HET-CAM test. NIH/3T3 cell viability demonstrated that the drug-loaded hydrogels were not toxic, and cell adhesion was reduced.

Management of traumatic corneal abrasion by a sample of practicing ophthalmologists in Saudi Arabia

Purpose

Corneal epithelial defect (CED) is a common medical emergency condition involving loss of surface epithelial layer of the cornea. The aim of the study is to explore the practice patterns of ophthalmologists in management of traumatic CED in Saudi Arabia and to assess the variance in clinical practice from the established clinical practice guidelines.

Methods

A Survey based study at King Abdulaziz University Hospital between March 2015 and January 2016. A survey of 16 relevant closed ended questions was distributed to 300 practicing ophthalmologists including Saudi Ophthalmology Society (SOS) members and non-members. The survey questionnaire focused on the known aspects of traumatic CED management.

Results

188 practicing ophthalmologists responded to the distributed questionnaire. That represents a 63% response rate for the present survey study. The age group most commonly affected by traumatic CED is 6-18 years old (61.2%). Fingernail trauma (n = 129, 68.6%) was the major cause of CED reported by respondents. In large CED (>5 mm) most common modality of treatment is pressure patching with topical antibiotics with or without cycloplegics (40.4%) whereas in small CED (<2 mm) topical antibiotics and cycloplegics is the preferred way (40.4%). The most commonly used prophylactic antibiotic was second-generation fluroquinolons (58.5%).

Conclusions

Present study demonstrates that practicing ophthalmologists are reporting that traumatic CED mostly affects young people and fingernail trauma is the major cause. There is lack of clear institutional guidelines and consensus on the management of traumatic corneal abrasions.

Topical non-steroidal anti-inflammatory drugs for analgesia in traumatic corneal abrasions

BACKGROUND

Traumatic corneal abrasions are relatively common and there is a lack of consensus about analgesia in their management. It is therefore important to document the clinical efficacy and safety profile of topical ophthalmic non-steroidal anti-inflammatory drugs (NSAIDs) in the management of traumatic corneal abrasions.

OBJECTIVES

To identify and evaluate all randomised controlled trials (RCTs) comparing the use of topical NSAIDs with placebo or any alternative analgesic interventions in adults with traumatic corneal abrasions (including corneal abrasions arising from foreign body removal), to reduce pain, and its effects on healing time.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 2), MEDLINE Ovid (1946 to 30 March 2017), Embase Ovid (1947 to 30 March 2017), LILACS (Latin American and Caribbean Health Sciences Literature Database) (1982 to 30 March 2017), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/); searched 30 March 2017, ZETOC (1993 to 30 March 2017), the ISRCTN registry (www.isrctn.com/editAdvancedSearch); searched 30 March 2017, ClinicalTrials.gov (www.clinicaltrials.gov); searched 30 March 2017 and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 30 March 2017. We did not use any date or language restrictions in the electronic searches for trials.We checked the reference lists of identified trials to search for further potentially relevant studies.

SELECTION CRITERIA

RCTs comparing topical NSAIDs to placebo or any alternative analgesic interventions in adults with traumatic corneal abrasions.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed data extraction and assessed risks of bias in the included studies. We rated the certainty of the evidence using GRADE.

MAIN RESULTS

We included nine studies that met the inclusion criteria, reporting data on 637 participants.The studies took place in the UK, USA, Israel, Italy, France and Portugal. These studies compared five types of topical NSAIDs (0.1% indomethacin, 0.03% flurbiprofen, 0.5% ketorolac, 1% indomethacin, 0.1% diclofenac) to control (consisting of standard care and in four studies used placebo eye drops). Overall, the studies were at an unclear or high risk of bias (particularly selection and reporting bias). None of the included studies reported the primary outcome measures of this review, namely participant-reported pain intensity reduction of 30% or more or 50% or more at 24 hours. Four trials, that included data on 481 participants receiving NSAIDs or control (placebo/standard care), reported on the use of 'rescue' analgesia at 24 hours as a proxy measure of pain control. Topical NSAIDs were associated with a reduction in the need for oral analgesia compared with control (risk ratio (RR) 0.46, 95% confidence interval (CI) 0.34 to 0.61; low-certainty evidence). Approximately 4 out of 10 people in the control group used rescue analgesia at 24 hours. No data were available on the use of analgesia at 48 or 72 hours.One trial (28 participants) reported on the proportion of abrasions healed after 24 and 48 hours. These outcomes were similar in both arms of the trial. (at 24 hours RR 1.00 (0.81 to 1.23); at 48 hours RR 1.00 (0.88 to 1.14); low-certainty evidence). In the control group nine out of 10 abrasions were healed within 24 hours and all were healed by 48 hours. Complications of corneal abrasions were reported in 6 studies (609 participants) and were infrequently reported (4 complications, 1 in NSAID groups (recurrent corneal erosion) and 3 in control groups (2 recurrent corneal erosions and 1 corneal abscess), very low-certainty evidence). Possible drug-related adverse events (AEs) were reported in two trials (163 participants), with the number of adverse events low (4 AEs, 3 in NSAID group, including discomfort/photophobia on instillation, conjunctival hyperaemia and urticaria, and 1 in the control group, corneal abscess) very low-certainty evidence.

AUTHORS' CONCLUSIONS

The findings of the included studies do not provide strong evidence to support the use of topical NSAIDs in traumatic corneal abrasions. This is important, since NSAIDs are associated with a higher cost compared to oral analgesics. None of the trials addressed our primary outcome measure of participant-reported pain intensity reduction of 30% or more or 50% or more at 24 hours.

Efficacy of Topical Analgesics in Pain Control for Corneal Abrasions: A Systematic Review

Corneal abrasions are one of the most common ocular injuries seen in the emergency department. While most patients with corneal abrasions complain of excruciating pain, permanent sequelae may develop if not managed properly. The use of topical antibiotics and other standards of treatment have greatly reduced the incidence of complications. However, there is still a lack of consensus regarding the proper management of pain in corneal abrasions. Proposed analgesics for the control of corneal abrasion pain include topical nonsteroidal anti-inflammatory drugs (NSAIDs), topical anesthetics, and topical cycloplegics. For this review, ten published randomized controlled trials were identified, focusing on the efficacy and safety of different topical analgesics used in treating corneal abrasions.  Six of the trials focused on topical NSAIDs, three on topical anesthetics, and one on topical cycloplegics. There were mixed results regarding the efficacy of topical analgesics in reducing pain in patients with corneal abrasions. This review of the literature revealed that topical NSAIDs produced reductions in pain symptoms, whereas topical anesthetics and cycloplegics did not demonstrate significant improvements in either healing rates or pain control. Thus, this evidence supports the use of topical NSAIDs in the standard management of corneal abrasions. Unfortunately, the power of these studies is largely limited by small sample sizes. Larger studies must be conducted before topical analgesics can be recommended or discouraged for pain management in corneal abrasions. However, based on this review of the literature, the use of topical NSAIDs does not appear to complicate wound healing, and thus remains a safe option in patients desiring medical treatment.  

Burning Eye Syndrome: Do Neuropathic Pain Mechanisms Underlie Chronic Dry Eye?

OBJECTIVE

Dry eye is a multi-factorial disorder that manifests with painful ocular symptoms and visual disturbances, which can only be partly attributed to tear dysfunction. This disorder may also involve neuroplasticity in response to neuronal injury. This review will emphasize the key characteristics of dry eye pain and its pathologic mechanisms, making the argument that a subset of dry eye represents a neuropathic pain disorder of the eye, more appropriately called "burning eye syndrome."

METHODS

A literature review was conducted using a PubMed search focusing on dry eye, corneal nociception, and neuropathic pain. Articles were reviewed and those discussing clinical course, pathophysiology, and neuronal regulation of chronic ocular pain as related to dry eye were summarized.

RESULTS

We found that there is a discordance between ocular pain and dryness on the ocular surface. Although tear dysfunction may be one of the initial insults, its persistence may be associated with repeated ocular sensory nerve injury leading to an acute-to-chronic pain transition associated with neuropathologic changes (peripheral and central sensitization), neuronal dysfunction, and spontaneous ocular pain.

CONCLUSION

Dry eye is becoming a major health concern due to its increasing incidence, significant morbidity, and economic burden. Recent evidence suggests that a subset of dry eye may be better represented as a chronic neuropathic pain disorder due to its features of dysesthesia, spontaneous pain, allodynia, and hyperalgesia. Future therapies targeted at the underlying neuroplasticity may yield improved efficacy for patients with this subset of dry eye, which we term "burning eye syndrome."

Lack of consensus on corneal abrasion management: results of a national survey

Objectives:

Our objective was to determine the practice patterns of Canadian emergency physicians with respect to the management of traumatic corneal abrasions.

Methods:

After developing our instrument and pilot testing it on a sample of emergency residents, we randomly surveyed 470 members of the Canadian Association of Emergency Physicians, using a modified Dillman technique. We distributed a pre-notification letter, an 18-item survey, and appropriate follow-up surveys to non-responders. Those members with an email address (n= 400) received a Web-based survey, and those without (n= 70) received a survey by post. The survey focused on the indications and utilization of analgesics (oral and topical), cycloplegics, eye patches and topical antibiotics.

Results:

Our response rate was 64% (301/470), and the median age of respondents was 38 years. Most (77.7%) were male, 71.8% were full-time emergency physicians, 76.5% were emergency medicine certified, and 64.4% practised in teaching hospitals. Pain management preferences (offered usually or always) included oral analgesics (82.1%), cycloplegics (65.1%) and topical nonsteroidal anti-inflammatory drugs (NSAIDs) (52.8%). Only 21.6% of respondents performed patching, and most (71.2%) prescribed topical antibiotics, particularly for contact lens wearers and patients with ocular foreign bodies. Two-thirds of the respondents provided tetanus toxoid if a foreign body was present, and 46.2% did so even if a foreign body was not present. Most respondents (88.0%) routinely arranged follow-up.

Conclusions:

This national survey of emergency physicians demonstrates a lack of consensus on the management of traumatic corneal abrasions. Further study is indicated to determine the optimal treatment, particularly regarding the use of topical NSAIDs.

Fingernail-induced corneal abrasions: case series from an ophthalmology emergency department

PURPOSE

Fingernail-induced corneal abrasions are one of the most common eye injuries that present to the emergency department, and yet there is little literature available to offer guidelines for management. We analyzed the treatment used in cases of fingernail-induced corneal abrasions that presented to the Massachusetts Eye and Ear Infirmary Emergency Department and studied its relationship to the development of complications such as recurrent erosion syndrome and infection.

METHODS

We performed a retrospective review of 99 patients who presented to the Massachusetts Eye and Ear Infirmary Emergency Department with fingernail-induced corneal abrasions between January 1, 2009 and December 31, 2009. We followed the patients for 12 months and documented demographics, nature of the injury, treatment, and complications.

RESULTS

The average age was 29.4 (range, 2-89) years. Forty-four percent (n = 44) were female and 56% (n = 55) were male. Of the 99 subjects, 39 had a full 12 month follow-up, and 7 developed a complication from the injury. Compared with the 32 subjects without complications, there was no difference in age or gender. However, there was a significant difference in that adults scratched by another adult were more highly represented in the group with complications (43%, n = 3/7 vs. 3%, n = 1/32; P = 0.0017). There was no significant difference in outcome by treatment used.

CONCLUSIONS

This is the largest fingernail-induced corneal abrasion study completed to date. Patients are at risk of developing complications, but there is scant evidenced-based literature available for treating this common injury. Prospective trials should be performed to better optimize and standardize treatments.

Management of Ocular Trauma in Emergency (MOTE) Trial: A pilot randomized double-blinded trial comparing topical amethocaine with saline in the outpatient management of corneal trauma

Background:

It is unclear whether local anesthetic eye drops can be safely used for the topical anesthesia of patients with minor corneal injury who are discharged from the emergency department (ED).

Objectives:

To assess whether topical 0.4% amethocaine self-administered to a maximum recommended frequency of once every hour for 36–48 h is safe in the management of uncomplicated corneal injury in patients discharged from the ED.

Patients and Methods:

A pilot randomized double-blinded trial comparing topical 0.4% amethocaine with topical normal saline.

Results:

Forty-seven subjects were recruited, with 22 randomized to receive amethocaine and 25 to receive placebo (normal saline). Baseline characteristics, including corneal injury type, were similar in both groups. There were no significant functional or clinical adverse sequelae in the majority of enrolled patients who could be contacted at 2 weeks (17/22 for amethocaine and 21/25 for placebo). Follow-up for the primary study outcome was suboptimal, with only 7/22 from the amethocaine group and 9/25 from the saline group presenting for 36–48 h review; there was a statistically nonsignificant trend for persistence of the corneal defect in the amethocaine group as compared with the saline group (2/7 and 1/9, respectively).

Conclusion:

Compared with saline drops, amethocaine eye drops are not definitely safe but they are effective for topical analgesia in minor corneal injury. Until further definitive studies, topical nonsteroidal agents or long-lasting artificial tears may be preferred for the topical analgesia of minor corneal injury. Return for corneal re-evaluation will necessarily remain suboptimal in an otherwise self-limiting condition, leading to a bias even if study recruitment is good.

Corneal abrasion

CLINICAL QUESTION

What is the best treatment for traumatic corneal abrasion?

RESULTS

Eye patching does not reduce pain in patients with corneal abrasions. Topical diclofenac does reduce pain in patients with corneal abrasions

IMPLEMENTATION

Pitfalls to avoid when treating abrasions: Treatment of small abrasions Treatment of larger abrasions When to refer for specialist treatment.

Chemical, thermal, and biological ocular exposures

Chemical or radiant energy injuries to the eyes are considered ocular burns. The majority of these injuries are occupation-related. Chemical burns are by far more common and represent a true emergency. Thermal and UV injuries are associated with severe pain, but often result in less long-term sequelae than chemical injuries do. The term "biologic exposure" refers to an exposure to human blood or other body fluid. This article describes patterns of these injuries and exposures, with particular emphasis on emergent management and including acute diagnostic and treatment considerations.

Toxic keratolysis from combined use of nonsteroid anti-inflammatory drugs and topical steroids following vitreoretinal surgery

PURPOSE

To evaluate the corneal complications associated with the combined use of non-steroid anti-inflammatory drugs (NSAIDs) and topical steroids following vitreoretinal surgery.

METHOD

Description of corneal lesions in three patients after vitrectomy with use of topical ketorolac and prednisolone acetate.

RESULTS

Three eyes of three patients developed an atrophic central corneal ulcer with stromal thinning following a pars plana vitrectomy under local anesthesia. Lesions were asymptomatic and were found during a routine examination 2, 3, and 8 weeks after surgery, respectively. Surgical indications were as follows: a preretinal membrane, choroidal neovascularization, and massive uveal effusion following cataract surgery. Topical postoperative treatment was as follows: ketorolac 4 times a day, a combination of prednisolone acetate, polymyxin B, and neomycin 6 times a day, and 1% cyclopentolate 3 times a day. Suspension of ketorolac and ocular occlusion led to the resolution of corneal lesions between 2.5 and 3 months later, yielding a central superficial scarring, which showed no changes after a follow-up of 3 years.

CONCLUSIONS

Toxic keratolysis may appear as a secondary effect of the combined use of topical NSAIDs and steroids following vitreo retinal surgery and must be taken into account in the differential diagnosis of postoperative corneal lesions.

Painful Dilemmas: An Evidence-based Look at Challenging Clinical Scenarios

Difficult clinical decisions are a part of every emergency practitioner's life. Dealing with difficult patients and recalcitrant consultants is seldom enjoyable, but can be made more palatable through the use of some of the clinical strategies contained in this article. Knowledge of the current best evidence and a willingness to discard outdated practice ideas will help ensure that emergency practitioners continue to provide state-of-the-art medical care. Expressions of care, concern, and respect for patients' problems, and development of a therapeutic alliance with these patients will maximize patient, and ultimately physician, satisfaction.

Substance P in Human Tears

PURPOSE

To determine the levels and biochemical characteristics of substance P-like immunoreactivity (SPLI) in human tears and ascertain whether substance P (SP) concentrations in tears reflect the condition of the ocular surface.

METHODS

Unstimulated tears were collected with a micropipette. Tear samples were partially purified using C-18 cartridges. Levels of SPLI in purified samples were measured using an enzyme immunoassay (EIA). For biochemical characterization of SPLI, tear extracts were fractionated using high-performance liquid chromatography (HPLC); each fraction was then subjected to EIA. To determine the catabolism of SP in tears, synthetic SP was incubated in medium containing pooled tears and then analyzed using HPLC.

RESULTS

The concentration of SPLI in normal human tears was 306.0 +/- 96.5 pg/mL (mean +/- SD, range 148-555 pg/mL). Levels of SPLI did not vary significantly by age or gender. Concentrations of SPLI in tears from eyes with unilateral corneal hypesthesia were lower than those in tears from contralateral healthy eyes. Diclofenac sodium eye drops reduced concentrations of prostaglandin E2 and SPLI in tears. Analysis using HPLC indicated that five different substances contributed to SPLI in tears and that SP was broken down into several fragments, including SP(8-11), by enzymes present in tears.

CONCLUSIONS

Substance P is a normal component of human tears. Levels of SPLI in tears might reflect the denervated status of the ocular surface. Substance P is catabolized by degradative enzymes in tears to maintain the ocular surface by exerting the trophic effects of SP while avoiding undesirable effects.

Effect of topical administration of 1% morphine sulfate solution on signs of pain and corneal wound healing in dogs

OBJECTIVE

To evaluate the effect of topical application of a 1% morphine sulfate solution (MSS) on signs of pain and wound healing in dogs with corneal ulcers and examine normal corneas immunohistochemically for the presence of mu and delta opioid receptors.

ANIMALS

12 dogs.

PROCEDURE

A 7-mm superficial corneal ulcer was surgically created in the right eye (OD) of 10 dogs, after which gentamicin solution and 1% MSS (n = 6) or saline solution (4) was administered topically OD 3 times daily. Blepharospasm, tearing, conjunctival hyperemia, aqueous flare, esthesiometer readings, and pupil size were recorded before and 30 minutes after treatment in all dogs. Ulcer size and days to completion of healing were recorded. Corneas from 4 treated and 3 control dogs were evaluated histologically. Normal canine corneas from 2 dogs not used in the study were evaluated immunohistochemically for the presence of mu and delta opioid receptors.

RESULTS

Dogs treated with MSS had significantly less blepharospasm and lower esthesiometer readings than did control dogs. Duration of ulcer healing and findings of histologic evaluation of corneas did not differ between groups. Numerous delta and infrequent mu opioid receptors were identified in the corneal epithelium and anterior stroma of normal corneas.

CONCLUSIONS AND CLINICAL RELEVANCE

Topical use of 1% MSS in dogs with corneal ulcers provided analgesia and did not interfere with normal wound healing. Both mu and delta opioid receptors were identified in normal corneas of dogs, although the mu receptors were present only in small numbers.

Evidence-based emergency medicine. Update: do ophthalmic nonsteroidal anti-inflammatory drugs reduce the pain associated with simple corneal abrasion without delaying healing?

INTRODUCTION

Some studies have suggested that ophthalmic nonsteroidal anti-inflammatory drugs (NSAIDs) decrease the pain associated with corneal abrasions without impairing healing. This evidence-based emergency medicine (EBEM) critical appraisal reviews the literature, including additional studies appearing since the publication of an earlier EBEM review in 1999.

METHODS

The updated search for randomized controlled trials from 1999 to 2002 complemented the previous 1966 to 1999 search. The methodologic quality of the studies was assessed. Qualitative methods were used to summarize the study results.

RESULTS

The search identified 3 studies not included in the previously published review of ophthalmic NSAIDs, yielding a total of 5 blinded, randomized, placebo-controlled trials involving NSAIDs for corneal abrasions. The methodologic quality of the new studies was somewhat higher than that of the 2 original studies and was rated as "good" to "strong." The qualitative summary indicates that NSAIDs provide greater pain relief and improvement of other subjective symptoms when compared with placebo. However, whether the reduction of pain, as measured by visual analog pain scales, exceeds the minimal clinically significant difference is equivocal. The use of ophthalmic NSAIDs may decrease the need for sedating analgesics.

CONCLUSION

Ophthalmic NSAIDs appear to be useful for decreasing pain in patients with corneal abrasions who can afford the medication and who must return to work immediately, particularly where potential opioid-induced sedation is intolerable.

Topical nonsteroidal anti-inflammatory drugs for ophthalmic use: a safety review

Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used agents that despite chemically heterogeneity, share similar therapeutic properties and adverse effects. Topical ophthalmic NSAIDs are limited to the relatively water soluble phenylacetic and phenylalkanoic acids as well as indole derivatives, which are more suitable for ophthalmic use. Topical ophthalmic NSAIDs are commonly used in the treatment of post-operative inflammation following cataract extraction and various surgical refractive procedures. They are also used in the prevention and treatment of cystoid macular oedema and for the treatment of allergic conjunctivitis. Absorption of topical ophthalmic NSAIDs through the nasal mucosa results in systemic exposure and the occurrence of adverse systemic events, including exacerbation of bronchial asthma. Local irritant effects of topical ophthalmic NSAIDs include conjunctival hyperaemia, burning, stinging and corneal anaesthesia. A more serious complication involves the association of topical ophthalmic NSAIDs with indolent corneal ulceration and full-thickness corneal melts. Analysis of NSAID-associated corneal events implicates the now defunct generic dicolfenac product, diclofenac sodium ophthalmic solution as the agent primarily responsible. However, these events generated a renewed interest in the safety of ophthalmic NSAIDs and a scrutiny of the pharmacology regarding NSAID action in the eye. An elucidation of possible pharmacodynamic explanations of NSAID-induced corneal injury includes the role of epithelial hypoxia, which not only appears to aid in determining the metabolic destination of arachidonate, it may play a key role in orchestrating a novel inflammatory response unrelated to prostanoid formation. The use of NSAIDs under conditions of corneal hypoxia may therefore not only result in a disappointing therapeutic response, it may result in a paradoxical inflammatory exacerbation. Other potential mechanisms include the relationship between NSAIDs and corneal matrix metalloproteinase and direct toxicity due to cytotoxic excipients such as surfactants, solubilisers and preservatives found in topical NSAID ophthalmic preparations. In general, ophthalmic NSAIDs may be used safely with other ophthalmic pharmaceuticals; however, concurrent use of agents known to adversely effect the corneal epithelium, such as gentamicin, may lead to increased corneal penetration of the NSAID. The concurrent use of NSAIDs with topical corticosteorids in the face of significant pre-existing corneal inflammation has been identified as a risk factor in precipitating corneal erosions and melts and should be undertaken with caution. Until clinical evidence dictates otherwise, data supporting theories of potential pharmacodynamic mechanisms of NSAID injury do not alter the favorable benefit-risk ratio of ophthalmic NSAID use when employed in an appropriate and judicious manner.

Efficacy of eye patching for traumatic corneal abrasions: a controlled clinical trial

STUDY OBJECTIVE

We sought to evaluate the efficacy of eye patching in the treatment of traumatic corneal abrasions in terms of time to healing and reduction in pain and discomfort.

METHODS

One hundred sixty-three patients presenting at the emergency department of a large university-affiliated hospital with traumatic corneal abrasions were included in this single-blind prospective controlled trial. Eligible patients were assigned to 1 of 2 treatment regimens: topical antibiotic ointment and occlusive patch over the affected eye (n=82) or topical antibiotic ointment 4 times a day without an occlusive patch (n=81). Patients were reexamined every 24 hours until corneal healing occurred. Healing evaluation was performed by the emergency physician, using a slit lamp with fluorescein staining, without knowledge of the patient's assignment to a treatment group. The degree of discomfort was assessed at each visit by using a visual analog scale.

RESULTS

Both treatment groups were similar regarding size of the corneal lesions, delay from trauma to first ED visit, presence of foreign body or siderosis, initial degree of discomfort, and presence of specific symptoms (irritation, foreign body sensation, photophobia, redness, and pain). In the patched group, cumulative incidences of healing were 51%, 78%, and 92% after 1, 2, and 3 days, respectively, compared with 60%, 83%, and 88% in the nonpatched group. In the patched group, symptoms of initial discomfort decreased by 4.8, 4.1, and 5.5 cm after 1, 2, and 3 days, respectively, compared with 3.3, 5.1, and 6.5 cm in the nonpatched group.

CONCLUSION

Eye patching does not appear to be beneficial in the treatment of traumatic corneal abrasions compared with topical antibiotic ointment.

Randomised controlled trial of ketorolac in the management of corneal abrasions

PURPOSE

To evaluate the role of topical non-steroidal anti-inflammatory agents (NSAIDs) in the management of corneal abrasions with respect to symptoms and healing.

METHODS

The study was designed as a prospective, single center, randomised, placebo controlled, double-blinded trial. Eighty-eight consecutive patients with non-infective, non-contact lens related traumatic or foreign body removal related corneal abrasions were recruited to this study. They were randomised into two groups. Both groups were given a single instillation of Gutt. cyclopentolate 0.5% followed by chloramphenicol eye ointment four times a day until the following day. In addition, the treatment group received topical Ketorolac trometamol 0.5% ophthalmic solution while the control group received placebo Liquifilm tears. Patients were assessed at presentation and about twenty-four hours later for subjective symptoms, abrasion size and any associated complications.

RESULTS

There was no statistical difference in the two groups at base line and twenty-four hour follow-up when assessed for five subjective symptoms of pain, photophobia, grittiness, watering and blurring of vision. However, those receiving topical ketorolac required significantly less additional oral analgesics (p=0.001). There was no difference in the rate of healing.

CONCLUSION

Use of topical ketorolac may be a useful adjunct in the management of corneal abrasions.

Corneal complications associated with topical ophthalmic use of nonsteroidal antiinflammatory drugs

PURPOSE

To explore the potential association between adverse corneal events and the use of topical nonsteroidal antiinflammatory drugs (NSAIDs).

SETTING

Practice-based reports.

METHODS

A detailed case-reporting form and request for medical records were sent to all practices reporting cases of corneal or conjunctival pathology in association with the use of topical NSAIDs to the American Society of Cataract and Refractive Surgery. Cases were classified as "mild," "moderate," or "severe" according to predetermined clinical criteria.

RESULTS

Records of 140 eyes (129 patients) were reviewed; 51 cases (36.4%) were mild, 55 (39.3%) moderate, and 34 (24.3%) severe. An association with a specific topical NSAID was confirmed in 117 cases (81.8%). Most confirmed cases (53.8%) involved generic diclofenac (Falcon). Cases associated with brand diclofenac (Voltaren, CIBA Vision) and ketorolac (Acular, Allergan) were more likely to have ocular comorbidity and to have received significantly higher total doses of NSAIDs. Neither "off-label" use nor use of any specific agent was associated with severe compared to mild or moderate disease. However, patients with more severe adverse events were more likely to have a history of diabetes, previous surgery in the affected eye, and surgery other than cataract. Cases not occurring in the perioperative period had significantly worse outcomes, had significantly more ocular comorbidities, and received nearly 3 times the dose of NSAIDs.

CONCLUSIONS

While topical NSAIDs as a class may be associated with severe adverse events, such events appeared to require potentiation in the form of high total doses, ocular comorbidities, or both with Acular and Voltaren. Severe adverse events might have been more likely to occur at lower doses and in routine postoperative settings with generic diclofenac.