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ORIGINAL ARTICLE
Year : 2022 | Volume
: 34
| Issue : 4 | Page : 448-451
A comparison of the mydriatic efficacy of tropicamide and phenylephrine eye drops administered as a vaporized spray in one eye and conventional drop instillation in the other eye in an Indian pediatric cohort
PG Vinay, Sunayana Bhat, Meera Mary Mathews
Department of Ophthalmology, Father Muller Medical College Hospital, Mangalore, Karnataka, India
Correspondence Address:
Sunayana Bhat
Department of Ophthalmology, Father Muller Medical College Hospital, Tulasi, Near Urwa Market, Mangalore - 575 006, Karnataka
India
Source of Support: None, Conflict of Interest: None
DOI: 10.4103/joco.joco_127_22
Purpose: To determine by serial measurements and compare the pupillary mydriasis effect of tropicamide and phenylephrine drops administered as a vaporized spray over closed lids in one eye and through conventional instillation of eye drops in the other eye in a pediatric cohort.
Methods: This prospective study was conducted on healthy children aged 6–15 years. After visual assessment, investigator 1 examined the child for initial pupillary size. Investigator 2 instilled the drops in one eye and applied the spray to the other eye randomly, and the response of the child was noted using the Wong-Baker pain rating scale. The eyes receiving the spray and the eyes receiving drop instillation were considered as Groups 1 and 2, respectively. Subsequently, serial pupillary measurements were carried out every 10 min for up to 40 min by investigator 1. The patient compliance for the two methods of drug instillation was also compared.
Results: The study comprised 80 eyes. At 40 min, both the groups showed no statistical difference in the mydriasis effect, with Group 1 showing 7.23 mm mydriasis and Group 2 showing 7.58 mm (P = 0.058). The analysis of the pain rating scale showed better compliance with the spray method of drug instillation, which was statistically significant (P = 0.044).
Conclusions: Our study shows that spray application is a less invasive method for pupillary dilatation, which has better compliance and provides equally good dilatation as conventional methods. This study proves the efficacy of spray application in an Indian pediatric cohort.
Keywords: Children, Mydriasis, Pupillary dilatation, Spray
Mydriasis or pupillary dilatation is an essential requirement of ophthalmologic examination and management of diseases. The amount of dilatation and time taken depends on the sphincter muscle of the pupil, which is controlled by parasympathetic nerves, and the dilator pupillae muscle, which is controlled by sympathetic nerves. Parasympatholytic drugs such as tropicamide, homatropine, and cyclopentolate and sympathomimetics such as phenylephrine, either alone or in combination and with different strengths, are commonly used to achieve mydriasis and cycloplegia for ophthalmic examination.[1]
Drug delivery to the eye in the form of a spray on the eyelids is rarely performed in ocular examination and management. Lubricating drops that can be administered as a spray both with eyes open or closed are available for ophthalmic use in several countries. There are few studies demonstrating the efficacy of medications when topically sprayed on the eyelids.[2] The droplets are sprayed under pressure, between the eyelashes of the closed eyelids. The drug seeps into the eye and blends with the tear chamber when the patient opens the eye.[3]
Ocular examination in children generally requires dilatation and cycloplegia. This involves repeated instillation of drops into the eye, which is not tolerated well by young children. It often becomes a cumbersome procedure due to poor cooperation from children.[4] Spraying the drug on closed eyelids as a method of drug delivery can significantly improve their compliance for eye examination. However, the efficacy of this mode of drug delivery has not been studied, and the time taken for dilatation compared to instillation of drops in the eye is not clear especially in Indian children who have dark irises.
This study was conducted to determine by serial measurements and compare the pupillary mydriasis effect of 1% tropicamide and 2.5% phenylephrine eye drops administered as a vaporized spray over closed eyelids in one eye and through conventional instillation of eye drops in the conjunctival sac of the other eye in an Indian pediatric cohort.
MethodsThis nonrandomized, prospective study included 40 children aged 6–15 years who attended the ophthalmology clinic at Father Muller Medical College and Hospital, Mangalore, India for routine ocular examination and required dilated ocular examination. Eye drops containing 1% tropicamide and 2.5% phenylephrine hydrochloride were instilled as drops in one eye, and the same formulation was sprayed over the other eyelid with the eye closed. An eye pad was then applied over the eye that received eye drops. All the patients were screened for any ocular or systemic diseases that could affect the pupillary diameter. Children who cooperated during the slit-lamp examination were included. All the patients had dark irises.
Children having any ocular or systemic diseases, any contraindication for pupillary dilation, and those using any ocular or systemic medications were excluded.
All patients underwent a detailed routine visual assessment. Investigator 1 examined the child with a slit-lamp and the initial pupillary size, and grades were noted. The pupillary size was always measured by investigator 1 in a dark room using the slit-lamp ruler. The eye drop (Tropicacyl plus containing tropicamide 0.8% and phenylephrine hydrochloride 5%, Sunways, Mumbai, India) was instilled in one of the eyes chosen randomly by investigator 2 by picking a chit marked right or left, and a similar procedure was followed for all the patients. The patient was requested to tilt their head backward and look up. The lower eyelid was retracted manually to expose the inferior conjunctival fornix, and a drop of the eye drop was instilled into the inferior conjunctival sac. The other eye received spray application (Tropicacyl plus containing tropicamide 0.8% and phenylephrine hydrochloride 5%, Sunways, Mumbai, India), and an eye pad was placed over the eye that received drop instillation so that the vaporized droplets did not touch the other eye, which might create bias. With the patient in a seated position, looking forward, the bottle was held such that the hole in the sprayer was in front of the eyelashes around 5 cm away from the eye of the patient, and the drug was sprayed once with the lids closed. This entire procedure was done quickly, and the patients were asked to keep both eyes closed for approximately 10 s after instillation of the drop and application of the spray. After the process, investigator 2 recorded the subjective compliance of the child to both methods of drug instillation using the Wong-Baker Pain rating scale.[5]
The Wong-Baker Faces Pain Rating Scale is a pain scale that was developed by Donna Wong and Connie Baker. The scale shows a series of faces ranging from a happy face at 0, or “no hurt,” to a crying face at 10, which represents “hurts like the worst pain imaginable”. Based on the faces and written descriptions, the patient chooses the face that best describes their level of pain.[4]
Scores for ocular discomfort were obtained from the mean of the scores for individual symptoms. Subsequent serial pupillary measurements were performed every 10 min up to 40 min by investigator 1 who was unaware of the method of drug delivery to either eye.
The Shapiro–Wilk test was done to check the normality of the study population, and it was found to be not significant. The results of pupillary dilatation and the subjective response of the patients to the two methods of drug instillation were tabulated and analyzed by investigator 3 using SPSS software (IBM SPSS Software, version 27) with paired t-test. Fisher's exact test was employed for the analysis of the pain scale results.
This research was discussed and approved by the Institutional Research Ethics Committee. The study was conducted in accordance to the guidelines of the Declaration of Helsinki. All participants and their guardians signed an informed consent form.
ResultsThe study population consisted of 40 children (19 male and 21 female children). The age of the patients ranged from 6 to 15 years. The mean age was 10.41 years with a standard deviation of 2.67 years.
Forty patients were involved in this study, and 80 eyes were studied in two groups: Group 1 included 40 eyes administered drops as a vaporized spray, and Group 2 included 40 eyes with conventional instillation of eye drops.
The mean pupil sizes at every 10 min interval for up to 40 min after eye drop administration were 4.1 mm, 5.46 mm, 6.92 mm, and 7.58 mm, and the mean pupil sizes at every 10 min interval after spray application were 3.9 mm, 5.13 mm, 6.46 mm, and 7.233 mm [Table 1].
Table 1: Comparison of baseline pupil size and mean pupillary dilatation at 10 min intervalsThe paired t-test was used to compare pupil diameters in the spray application group (Group 1) and the drops group (Group 2). The mean baseline pupillary size was 3.03 mm in Group 1 and 3.031 mm in Group 2, which was not significant (P = 0.864). At 10 min, Group 1 had a mean dilatation of 3.9 mm compared to Group 2 with a mean dilatation of 4.1 mm, which was not significant (P = 0.077). At 20 min, Group 1 had a mean dilatation of 5.13 mm, and Group 2 had a mean dilation of 5.46 mm, which was again not significant (P = 0.07). At 30 min, however, the mean dilatation was higher in Group 2 (mean dilatation of 6.92 mm) than in Group 1 (mean dilatation of 6.46 mm), which was statistically significant (P = 0.022). The mean mydriatic difference between the groups of eyes evaluated at this given time was a maximum of 0.46 mm, which was clinically insignificant. Moreover, at 40 min, both the groups showed no statistical difference in mydriasis; Group 1 had a mean pupil dilatation of 7.23 mm, and Group 2 had a mean dilatation of 7.58 mm (P = 0.058). These data show that both forms of drug application into the eye produced adequate pupillary dilatation for clinical examination, and the rate of dilatation did not vary significantly between the two methods.
[Table 2] shows the Wong-Baker Pain rating scale scores, which shows the subjective acceptance of the method of dilatation. The analysis of the discomfort rating scale between the groups was done with Fishers exact test, which was statistically significant (P = 0.001). The patient compliance with the spray method of dilatation was significantly more than with the drop instillation method.
Table 2: Assessment of discomfort experienced by the patient using the Wong-Baker Scale[Table 3] shows the comparison of the pain scores between the two groups. Group 1 had a mean pain score of 1.55 and Group 2 had a mean pain score of 2.70. Using the Mann-Whitney test, a P value of 0.044 was obtained, which was clinically and statistically significant, showing that the children were more comfortable with the spray method of drug application for dilatation.
DiscussionThe application of topical ophthalmic eye medications as a surface spray is not a commonly used drug delivery method, and there are extremely few published studies on this. Eye drop instillation is often a difficult intervention in children requiring restraint and repeated instillations to achieve adequate pupil dilatation for clinical examination.[6]
Ismail et al. have conducted a similar study with a different drug, cyclopentolate hydrochloride 1%, in the pediatric age group where the efficacy of the two methods of drug instillation was compared in estimating the refractive error. The study showed that both the groups were equally effective in estimating the refractive error.[3] In a study by Portes et al., the average pupillary dilatation with tropicamide 1% was 2.35 mm for spray application and 2.48 mm for drops, which was not statistically significant.[7],[8] The results of both the studies are comparable and similar to our study.
Contrarily, Van Rooij studied the penetration of fluorescein into the aqueous after the instillation of fluorescein dye as eye drops on the ocular surface in comparison to spray application of the same dye with the eyes open.[9] In contrast to an earlier study on mydriatics and cycloplegics,[8] the amount of active dye found in the anterior chamber was about half that of the observed value after the instillation of eye drops.
In our study, the results indicate that spray and eye drop application both have good and comparable mydriatic efficacy at the end of 40 min, which is sufficient for clinical evaluation. The spray application causes lesser ocular discomfort, is easier to administer, and has the advantage of being less startling, especially in the pediatric population.
Spray application of ophthalmic medications can prove to be a useful method of topical drug delivery and may solve problems related to drop instillation of ophthalmic agents. This method can be helpful not only in children but also in elderly population with poor vision and people with structural deformities like hand tremors or neck problems, which may pose difficulty in proper positioning of eye drop containers over the eye. Studies have also shown that patients with poor vision experience difficulty in instilling eye drops into the lower conjunctival sac.[10] Use of a spray can greatly benefit such patients.
The limitations of our study include smaller sample size and the nonrandomized design of the study.
This study is the first to be conducted in an Indian pediatric cohort in whom mydriasis takes a longer time due to the heavily pigmented iris. The results of this study suggest that administering mydriatics by way of spray on closed eyelids is as efficient as instilling eye drops into the conjunctival sac. The authors speculate that the above technique may also be applied in the use of other ophthalmic drugs, especially long-term medications such as corticosteroids and antiglaucoma medications, which might improve patient compliance with these drugs.[11] Further studies are required both on the effectiveness of spray application of these medications and patient compliance.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
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