An Evaluation of Effects of Different Mydriatics on Choroidal Thickness by Examining Anterior Chamber Parameters: The Scheimpflug Imaging and Enhanced Depth Imaging-OCT Study

Abstract

Aim. To assess the effects of mydriatics commonly used in clinical practice on choroidal thickness and anterior chamber change. Methods. This was a prospective, randomized, controlled, double-blinded study including a single eye of the participants. The subjects were assigned into 4 groups to receive tropicamide 1%, phenylephrine 2.5%, cyclopentolate 1%, and artificial tears. At the baseline, anterior chamber parameters were assessed using a Pentacam Scheimpflug camera system, and choroidal thickness (CT) was measured using a spectral-domain OCT with Enhanced Depth Imaging (EDI) modality. All measurements were repeated again after drug administration. Results. Increases in pupil diameter, volume, and depth of anterior chamber were found to be significant (p = 0.000, p = 0.000, and p = 0.000, resp.), while decreases in the choroidal thickness were found to be significant in subjects receiving mydriatics (p < 0.05). Conclusions. The study has shown that while cyclopentolate, tropicamide, and phenylephrine cause a decrease in choroidal thickness, they also lead to an increase in the volume and depth of anterior chamber. However, no correlation was detected between anterior chamber parameters and choroidal changes after drug administration. These findings suggest that the mydriatics may affect the choroidal thickness regardless of anterior chamber parameters. This study was registered with trial registration number 2014/357.

Time-Course of Changes in Choroidal Thickness after Complete Mydriasis Induced by Compound Tropicamide in Children

“…Since the time-point to measure the ChT varied among the previous studies, it is recalculated as the time after the first instillation of eye drops, in order to facilitate the comparison ( Table 4 ). In agreement with the present study, Kara et al [ 25 ] and Yuvacj et al [ 26 ] both reported decreased SFChT after administration of 1% tropicamide or 2.5% phenylephrine alone. On the other hand, Kim et al [ 27 ] failed to observe significant changes in SFChT with the same agent used in the present study (0.5% tropicamide plus 0.5% phenylephrine).…”

The interaction between homatropine and optical blur on choroidal thickness

“…The choroid's thickness has been shown to be sensitive to a range of pharmacological agents, including nicotine, sildenafil citrate, ranibizumab, triamcinolone acetonide, and cholinergic agents . Among cholinergic agents, some antimuscarinics (1% atropine, 2% homatropine, and 1% cyclopentolate) have been reported to significantly increase subfoveal choroidal thickness in humans.…”

The effect of topical atropine on the choroidal thickness of healthy children

“…In humans, there are some reports that highlight the effect of topical anticholinergic or adrenergic agents on choroidal thickness with varied or even contradictory findings. For example, some studies have reported absence of any influence of these agents on the choroidal thickness 6 7 8 , while some authors have observed an increase 9 or a decrease 10 11 in the choroidal thickness, even when the same drugs were used ( Table 1 ). We speculate that such discrepancies might arise from the differences in the methods of drug instillation, race of participants, and distribution rate of mydriatic agents to the posterior.…”