The influence of drop size of cyclopentolate, phenylephrine and tropicamide on pupil dilatation and systemic side effects in infants

Abstract

In this prospective study, microdrops (mean drop volume 5.6 microl) and commercially available standard drops (mean drop volume 35.4 microl) of cyclopentolate, phenylephrine and tropicamide's clinical efficacy and systemic side effects were compared. Sixty-one infants requiring diagnostic pupil dilatation were studied for pupillary diameter, systemic blood pressure, heart rate and skin flushing changes related to the instillation of mydriatic drops. Both microdrops and standard drops of the drugs produced significant increase in pupillary diameter compared with the baseline (p<0.01). In cyclopentolate and phenylephrine groups, there was no significant pupillary diameter changes between microdrops and standard drops (p>0.05). Mean blood pressure increased significantly in infants given standard drops. There was no significant change in the group that was given microdrops. In our opinion, reduced volume of mydriatics can prevent possible side effects.

Pharmacokinetics and local safety profile of propranolol eye drops in rabbits

“…Authors estimated that precorneal area is able to contain only a small volume of liquid solutions and around 80% of the volume of a standard drop rapidly reaches the lower conjunctival fornix and passes down the nasolacrimal duct where the drug is systemically absorbed by the highly vascular mucosa (31), thus contributing to systemic side effects. Following these observations, administration of ocular microdrops is currently on study for improving the compliance and safety of ocular preparations in selected patients such as the elderly and neonates (32,33). Therefore, the use of small drops may have contributed to reduce the plasma levels in rabbits.…”

Mydriatic insert and intracameral injections compared with mydriatic eyedrops in cataract surgery: Controlled studies

“…5,42,[49][50][51][52][53] Repeated instillations result in significant amounts of administered drugs, carrying an increased risk for systemic adverse effects such as headache, increased blood pressure and heart rate, stroke, or myocardial infarction. 28,[54][55][56][57][58][59][60][61] These adverse effects have been reported in high-risk patients with a history of cardiovascular disease and in susceptible individuals without such history, 39,55,56,[62][63][64] especially neonates and infants. 58,59,65 The effect of mydriatic eyedrops tends to wear off during cataract surgery 48 in conjunction with an intraoperative reflex miosis 66,67 caused by the release of prostaglandins 21 or operative factors (eg, light from the microscope).…”

“…28,[54][55][56][57][58][59][60][61] These adverse effects have been reported in high-risk patients with a history of cardiovascular disease and in susceptible individuals without such history, 39,55,56,[62][63][64] especially neonates and infants. 58,59,65 The effect of mydriatic eyedrops tends to wear off during cataract surgery 48 in conjunction with an intraoperative reflex miosis 66,67 caused by the release of prostaglandins 21 or operative factors (eg, light from the microscope). 68 This increases the risk for surgeryrelated complications 1,67 and is more frequent in certain patients (eg, diabetics).…”

Intracameral Mydriatics in Cataract Surgery

“…One point five and 3.0% would thus give 3.9 and 7.7 times higher intracameral phenylephrine doses, respectively, than a standard "maximum dilatation" regimen involving 3 drops of phenylephrine 10%. The effects of such high doses of phenylephrine have never been studied in humans, since the maximum recommendable topical dose is limited by potential systemic side effects (Hakim, Orton et al 1990;Ogut, Bozkurt et al 1996;Elibol, Alcelik et al 1997;Lundberg and Behndig 2003), but it appears that increasing the dose of phenylephrine further would increase also the mydriatic effect beyond what can be reached with the standard topical "maximum dilatation". It may also be of interest to note that a lack of dose-response relationship similar to that of intracameral phenylephrine has been noted also for intracameral epinephrine in dilutions ranging from 0.00025% to 0.004% (Liou and Chen 2001).…”

“…(Ogut, Bozkurt et al 1996;Elibol, Alcelik et al 1997), Third, even if a good mydriasis is achieved initially, the mydriatic effect often tends to diminish during the operation, and especially when the procedure takes longer than expected. Different solutions have been suggested to prolong the mydriatic effect from topical mydriatics such as preoperative treatment with diclofenac (Antcliff and Trew 1997), viscous 10% phenylephrine, (Duffin, Pettit et al 1983) or intraoperative intracameral epinephrine.…”