A pre-operative mydriatic regime using a single application of tropicamide Novel Ophthalmic Delivery System and guttae phenylephrine 10%

[Efficacy and efficiency of preoperative mydriasis: drops versus ocular insert]

OBJECTIVE

The primary objective of this study was to compare eye drops and inserts in terms of the quality of preoperative mydriasis. The secondary objective was to evaluate the safety and ease of use of each modality.

PATIENTS AND METHODS

Prospective randomized and simple blinded study. Patients were randomized into two groups: the insert protocol (atropine 1%, diclofenac 0.1% collyrium and Mydriasert) or the eye drop protocol (atropine 1%, diclofenac 0.1%, tropicamide 0.5%, and phenylephrine 10% collyrium). Fifty-one patients were included: 25 in the insert protocol and 26 in the drop protocol. Mydriasis quality was evaluated by nurses and surgeons. The ease of use was estimated by the number of gestures required to obtain mydriasis and the difficulties encountered. Safety was evaluated at the patient's bedside.

RESULTS

Mydriasis of at least 6 mm was obtained in 92% of the patients in the insert protocol (23/25) and 85% of the patients in the drop protocol (22/26) (NS). Four patients lost their insert during the study. Of the patients in the insert group, 16% (4/25) experienced stinging in their eyes, as did 23% (6/26) of patients in the group using drops (NS). To reach effective mydriasis, the insert protocol required fewer nurse gestures per patient than the drop protocol (3.0 versus 8.3; p<0.001).

CONCLUSION

With the protocol using an insert, preoperative mydriasis is not inferior to that obtained with drops only and is more efficient in terms of nurse time and number of gestures. Nurses should be trained in appropriate handling of the insert and avoiding the loss of the device.

Randomised controlled single-blind study of conventional versus depot mydriatic drug delivery prior to cataract surgery

BACKGROUND

A prerequisite for safe cataract surgery is an adequately dilated pupil. The authors conducted a trial to assess the efficacy (in terms of pupil diameter) of a depot method of pre-operative pupil dilatation, as compared with repeated instillations of drops (which is time-consuming for the nursing staff and uncomfortable for the patient).

METHODS

A prospective randomised masked trial was conducted comprising 130 patients with no significant ocular history undergoing elective clear corneal phacoemulsification. 65 patients had mydriatic drops (Tropicamide 1%, Phenylephrine 2.5%, Diclofenac sodium 0.1%) instilled prior to surgery, 65 had a wick soaked in the same drop mixture placed in the inferior fornix. Horizontal pupil diameters were recorded on a millimetre scale immediately prior to surgery.

RESULTS

There was no significant difference in pupil size between the two groups (p = 0.255, Student's t-test).

CONCLUSION

There was no significant difference between the mydriasis obtained with the depot system compared with conventional drop application. Use of a depot mydriatic delivery system appears to be a safe and efficient method of drug delivery.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number Register ISRCTN78047760.

Pharmacodynamics of a new ophthalmic mydriatic insert in healthy volunteers: potential alternative as drug delivery system prior to cataract surgery

Cataract surgery requires a satisfactory degree of mydriasis throughout the entire operation. A phase I, open-labelled, randomised, cross-over trial was conducted in 18 healthy volunteers to compare mydriasis obtained with subsequent administration of phenylephrine 10% and tropicamide 0.5% eyedrops or a new insoluble-matrix retropalpebral ophthalmic insert containing 5.38 mg phenylephrine and 0.28 mg tropicamide. Phenylephrine serum concentrations were measured over 6 hr following each treatment administration. Secondary end-points included cardiovascular, general and local tolerance and quantification of bacterial colonisation of the conjunctiva and the cultured insert, respectively. When normalized to the pupil diameter after conventional treatment, the diameter achieved with the insert was 1.13 (95% confidence interval, 0.94-1.48, P=0.38). Moreover, standard eye drops provided faster effective mydriasis than the insert, starting 30 min. as compared to 90 min. upon treatment administration (P<0.01, repeated-measures ANOVA). Phenylephrine concentrations remained almost undetectable for both treatments and no change in heart rate or blood pressure were observed throughout the study. Only three superficial punctuate keratitis were diagnosed with the insert and two with the eye drops. No significant bacterial contamination of conjunctiva swab and cultured insert was observed. The new insoluble-matrix retropalpebral ophthalmic mydriatic insert produced similar but delayed effective and prolonged mydriasis as compared to the standard delivery system. In addition to its potential usefulness in patients undergoing cataract surgery, such new ophthalmic delivery system may be an advantage in children who need to undergo fundus photography due to the single administration and excellent tolerance as well.

Pupil dilation using a pledget sponge: a randomized controlled trial

BACKGROUND

To show that a pledget soaked in mydriatics and placed in the lower conjunctival fornix is as effective as drops in providing mydriasis for cataract surgery.

METHODS

A randomized, masked, controlled trial of 56 patients assigned to either a pledget group (n=25) or a control eye drops group (n=31) was carried out. Controls had the routine practice of repeated topical mydriatic drops: tropicamide, phenylepherine and atropine. The trial group had a 3-mm pledget trimmed, soaked in mydriatics and placed in the inferior fornix for 20 min. Pupil diameter was measured using a photographic technique with a standard scale shown in each picture. Two masked observers measured the pupils using the scale of the ruler in the developed photograph. All patients completed a 0-10 stinging score prior to surgery.

RESULTS

There were no complications. The mean pupil diameter in the control group was 7.23 (6.91-7.94 95% confidence intervals [CI]) and 7.44 (6.96-7.92 95% CI) in the pledget group. There was no statistically significant difference in pupil diameter between the two groups: difference between means 0.21 (-0.32 to 0.75 95% CI) and Student's t-test of the difference between means (t=0.8 and two-tailed) probability P=0.43. There was no significant difference in the stinging scores: Mann-Whitney test P=0.69.

CONCLUSION

The use of a pledget cellulose sponge to deliver mydriatics prior to cataract surgery is as effective as the conventional method of repeated drop administration and was not associated with any adverse effects.