Evaluation of Tropicamide–Phenylephrine Mydriatic Eye Drop Instillation on Choroidal Thickness

The purpose of this study is to evaluate choroidal thickness (ChT) at the subfoveal and peripheral level after the instillation of 0.5% tropicamide + 10% phenylephrine 9 hydrochloride eye drops by using OCT scans in enhanced depth image (EDI) mode. In total, 53 patients (30 males and 23 females) were involved, and the mean age was 25.62 +/- 2.41 (age range: 23-36). The dominant eye was treated with tropicamide + phenylephrine (Visumidriatic Fenil 100 mg/mL + 5 mg/mL, Visufarma) while the nondominant eye was used as the control. An OCT analysis was performed on both eyes before and 30 min after the instillation of a drop of mydriatic in the dominant eye. The ChT was measured by using the OCT software measurement tool (Spectralis; Heidelberg Engineering; Heidelberg, Germany, version 6.0). The results showed a statistically significant ChT decrease (p = 0.009) in the temporal sector after the treatment with tropicamide + phenylephrine. In the subfoveal and nasal sectors, no statistically significant ChT changes were detected (p = 0.94; p = 0.85) following the administration of the mydriatic eye drops. The ChT thinning in the temporal sector following the instillation of the tropicamide + phenylephrine eye drops suggests that in the case of ChT studies, mydriatic administration should be avoided.