Tropicamide phenylephrine with

Figure 8-7 Reversal of mydriasis with two drops followed 5 minutes later with an additional two drops of 0.5% dapiprazole after pupillary dilation induced by a combination of 2.5% phenylephrine and 1% tropicamide. (Reprinted with permission from AUinson RW, Gerber DS, Bieber S, Hodes BL. Reversal of mydriasis by dapiprazole. Ann Ophthalmol 1990 22 131-138.)...

Zeise MM, McDougaU BWJ, Bartlett JD, et al. Comparison of efficacy and tolerance between 1% hydroxyamphetamine plus 0.25% tropicamide (Paremyd) and 0.5% tropicamide combined with 2.5% phenylephrine. J Am OptomAssoc 1996 67 681-689. 

Accommodative amplitude measurements after instillation of 2.5% or 10% phenylephrine generally indicate that the effect is far less than the decrease observed with cycloplegic agents such as tropicamide (see Chapter 9). A loss of approximately 2.00 D (7.93 D from 9.95 D) at... 

Figure 8-4 Mean pupil size changes as a function of time after the instillation of either Paremyd or a combined dose of phenylephrine 2.5% and tropicamide 0.5%. (SE = standard error.) (Reprinted with permission from Zeise MM, McDougall BWJ, Bartlett JD, et al. J Am Optom Assoc 1996 67 681.)...

To achieve greater pupillary dilation and overcome the constrictor effect of cholinergic stimulation, particularly on exposure to bright illumination, both phenylephrine and hydroxyamphetamine can be used in conjunction with a cholinergic antagonist, such as tropicamide or cyclopentolate. Additionally, phenylephrine 1% combined with a low concentration of 0.2% cyclopentolate (Cyclomydril) is recommended for neonates for funduscopic examinations. 

The use of Paremyd results in pupil size sufficient for binocular indirect ophthalmoscopy and, as with 0.5% or 1.0% tropicamide, the effect is independent of age, iris color, or skin color. No significant differences were observed in overall pupil diameter after instillation of either Paremyd alone or separate instillations of phenylephrine (2.5%) and tropicamide (0.5%). A difference in the recovery phase was observed. Pupil size decreased more rapidly as a function of time after instillation of Paremyd than after the use of 2.5% phenylephrine combined with 0.5% tropicamide when the two were administered separately. 

Similarly, subjects with light irides recovered accommodative function more rapidly. Overall, Paremyd provided adequate dilation for the intense illumination of the binocular indirect ophthalmoscope in all study subjects, irrespective of iris pigmentation. Subjects also reported that Paremyd was more comfortable on initial instillation than the 0.5% tropicamide and 2.5% phenylephrine combination. Paremyd is currently only available throngh compounding pharmacies. 

For routine use, rapid and effective mydriasis may be obtained in adults by using one drop each of 2.5% phenylephrine and 1.0% tropicamide. As stated previously, this combination is effective in dilating pupils with age-related miosis in which there is decreased sympathetic... 

To facilitate the application of mydriatics in neonates and infants, a single-instillation solution may be prepared by combining 3.75 ml cyclopentolate 2% with 7.5 ml tropicamide 1% and 3.75 ml phenylephrine 10%.The final solution contains 0.5% cyclopentolate, 0.5% tropicamide, and 2.5% phenylephrine.This combination produces no major side effects and provides an effective pupillary dilation. Alternatively, equal amounts of 1% tropicamide and 2.5% phenylephrine may be mixed together to yield a single combination solution with final concentrations of 0.5% tropicamide and 1.25% phenylephrine. This too should produce adequate pupillary dilation with no major side effects. Again, these solutions can also be applied as a spray. Cyclopentolate, tropicamide, and phenylephrine administered in microdrops (mean drop volume, 5.6 micro liters, as opposed to commercially available standard drops) have the same efficacy with a decreased risk for systemic side effects. 

A valid approach to the dilation of eyes with extremely narrow angles is to refer the patient for a peripheral iridotomy before dilation. However, if dilation must be performed, then use of routine drug regimens, such as a combination of tropicamide and phenylephrine, is recommended to avoid a mid-dilated state. If drug-induced angle closure occurs and is promptly recognized and treated, the patient ultimately benefits from the experience, because the angle-closure attack occurs under controlled conditions in which proper treatment is readily available. 

The routine measurement of lOP after dilation of the pupil is probably unnecessary. In nonglaucomatous patients with open angles, dilation with adrenergic mydri-atics, such as phenylephrine, would not be expected to elevate the lOP, whereas dilation with relatively weak anticholinergic agents, such as tropicamide, would be... 

In patients who are predisposed to adverse cardiovascular events, the use of tropicamide either alone or in combination with 2.5% phenylephrine provides satisfactory mydriasis while minimizing the risks of systemic complications. In addition, the use of low concentrations of drug, single applications, eyelid closure, and nasolacrimal occlusion minimizes adverse reactions in susceptible patients. Thus the combination solution made by mixing equal amounts of 1% tropicamide and 2.5% phenylephrine as previously described may have the added benefit of reducing the chances of an adverse reaction even further. 

Fraunfelder FT. Pupil dilation using phenylephrine alone or in combination with tropicamide. Ophthalmology 1999 106(1) 4. 

Monkeys were tranquilized with ketamine hydrochloride (Imalgene 1000, Rhone Merieux, Lyon, France), 10 mg/kg of body weight, IM. Pupils were dilated with tropicamide (Mydriaticum, MSD-Chibret, Paris, France) and phenylephrine (Neosynephrine 10% Chibret, MSD-Chibret, Paris, France), 20 minutes before recording. The electrodes were put into position after a minimum of 15 minutes of dark adaptation. The animals were then placed in a dark room. 

Observation of lens was done by slitlamp biomicroscope (SL-2, Kowa) after mydriasis with Midrin-P (0.5% tropicamide, 0.5% phenylephrine)(Santen, Osaka, Japan) one hour after the third dose in the 6th and 12th month of application. 

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