Gelartige Tränenersatzmittel und unspezifische Augensalben auf Intensivstationen und in der perioperativen Anwendung

A prospective, masked, randomized, controlled superiority study comparing the incidence of corneal injury following general anesthesia in dogs with two methods of corneal protection

Objective

To compare the incidence of corneal injury during general anesthesia (GA) and the immediate post‐operative period in eyes protected with topical ocular lubricant alone with eyes protected with topical lubricant followed by complete eyelid closure using tape.

Animals Studied

One hundred client‐owned dogs (200 eyes) undergoing GA for MRI scan.

Methods

Patients had ocular lubricant applied to both eyes upon induction of anesthesia. One eye was taped closed immediately after induction for the duration of anesthesia using Strappal® tape (BSN medical™; treatment group), and the other eye was not taped (control group). Eyes were randomly allocated to a treatment group. Ophthalmic examination was performed before and after anesthesia; the examiner was masked to eye treatment groups. Corneal injury was defined as corneal ulceration or corneal erosion. A McNemar's test was used to compare the incidence of corneal injury between groups. A paired‐samples t‐test was used to compare Schirmer‐1 tear test (STT‐1) readings between groups.

Results

Sixteen eyes (8%) developed corneal erosion. No corneal ulceration occurred. There was no significant difference between incidence of corneal erosion between groups (p = .454). There was a significant decrease in STT‐1 readings following GA in both groups (p < .001), with no significant difference in STT‐1 between groups (p = .687). No adverse effects of taping the eye closed were observed.

Conclusion

Taping the eyes closed during GA had no additional benefit to the lubrication protocol used in this study.

Perioperative Corneal Abrasion: Updated Guidelines for Prevention and Management

Corneal abrasion is the most common ocular complication in surgery. Treatment requires pain control, antimicrobial prophylaxis, and close monitoring. Pain improves significantly after 24 hours and should be resolved by 48 hours. Persistent, worsening, or new symptoms warrant immediate specialist consultation. The authors review the pathophysiology of perioperative corneal abrasion, and propose updated evidence-based guidelines for improved patient care.

Corneal protection during general anesthesia for nonocular surgery

Corneal abrasion is the most common ophthalmologic complication that occurs during general anesthesia for nonocular surgery. Such abrasions can be caused by a variety of mechanisms and can lead to sight-threatening microbial keratitis and permanent scarring. There is no standard mode of protecting the cornea during general anesthesia for nonocular surgery. Methods described in the literature are not entirely effective and may be associated with unwanted side effects. Taping alone provides protection that is equivalent or superior to other interventions and has fewer side effects. Petroleum gel is flammable and is best avoided when electrocautery and open oxygen are to be used around the face. Preservative-free eye ointment is preferred, as preservative can cause corneal epithelial sloughing and conjunctival hyperemia. Recently, the application of Geliperm and bio-occlusive dressings has been advocated. Geliperm may be particularly useful during endonasal surgery when continuous perioperative observation of the eye is required. In this article, the literature on the etiology of perioperative corneal abrasions is reviewed and various protection strategies are compared in order to identify the best methods to prevent corneal abrasions during general anesthesia.

A comparison of the effect of carbomer-, cellulose- and mineral oil-based artificial tear formulations

PURPOSE

To compare the efficacy, safety, and local tolerance between carbomer-based artificial tears, cellulose-, and mineral oil-based artificial tears.

METHODS

A randomized, open-label, parallel-group comparative 28-day study was designed for 67 patients who were randomized into three treatment groups. Measurements included the scoring of total subjective symptoms and objective signs, Schirmer-Jones test values, and tear break-up time (BUT) at baseline, and after 2 and 4 weeks of treatment. Safety of study treatment was also assessed. Outcomes measured at baseline and 2 and 4 weeks follow-up included the scoring of total subjective symptoms and objective signs, Schirmer-Jones test values, and tear BUT, subjective assessments, and safety.

RESULTS

There were no differences regarding total scores, Schirmer-Jones test, or tear BUT at baseline among these three groups at 2 and 4 weeks. Patients in all three treatment groups experienced a significant improvement from baseline in total scores and Schirmer-Jones test values after treatment. Subjective assessment was better with carbomer-based treatment.

CONCLUSIONS

Each artificial tear formulation successfully relieved symptoms and signs of keratoconjunctivitis sicca. The tolerance of carbomer-based artificial tears was comparable to that of cellulose- and mineral oil-based artificial tears.

Clear hydro-gel, compared to ointment, provides improved eye comfort after brief surgery

PURPOSE

Anesthesia impairs lid closure and decreases tear secretion and stability. Protection may, in principle, be conveyed by manual eye closure, taping the eyelids closed, and by instillation of protective substances into the conjunctival sac. Both hydro-gels and ointments are used in clinical practice. It was the objective of the present study to compare a transparent clear ocular hydro-gel (Vidisic) and a commonly used dexpanthenol and vitamin A (Oleovit) based ointment as examples of these classes of ocular lubricants in their capability to provide perioperative eye comfort. Furthermore, their bacteriostatic properties were assessed in vitro.

METHODS

Ninety-two consecutive patients undergoing total iv general anesthesia were randomly allocated to receive either ocular dexpanthenol ointment or a clear hydro-gel after induction of anesthesia. Subjects were assessed one hour following termination of anesthesia.

RESULTS

Main findings were an increased incidence of foreign body sensation, adherent eyelashes and disturbance elicited by blurred vision in the ointment group as compared to clear hydro-gel (P < 0.001). Bacterial growth was significantly attenuated by the ocular hydro-gel as compared to ointment.

DISCUSSION

Clear ocular hydro-gel offers improved patient comfort and decreased ocular inflammation as compared to conventional eye ointments. In addition, it decreases bacterial growth. Therefore, the use of clear ocular hydro-gel for perioperative ocular comfort is suggested.

The aetiology and prevention of peri-operative corneal abrasions

Corneal abrasion is the most frequent ocular complication to occur during the peri-operative period. This review describes the aetiology of corneal abrasions and evaluates the current methods of prevention. Most abrasions are caused by lagophthalmos (failure of the eyelids to close fully) during general anaesthesia, resulting in corneal drying. General anaesthesia reduces both the production and the stability of tears and therefore increases the incidence of this painful condition. Taping the eyelids closed, soft contact lenses, the instillation of aqueous gels or paraffin-based ointments are all effective in preventing corneal abrasions, but ointments are associated with significant morbidity.