Intraoperative mydriasis by intracameral injection of mydriatic eye drops: in vivo efficacy and in vitro safety studies.
BACKGROUND
This study investigated the efficacy and safety of intracameral injection of commercially available eye drops containing 0.5% tropicamide and 0.5% phenylephrine hydrochloride (Mydrin-P, Santen Pharmaceutical, Osaka, Japan).


METHODS
In vitro experiment and prospective clinical study at a private hospital.


METHODS
Mydrin-P was applied to confluent cultured human corneal endothelial cells, and the cellular morphology was examined. Clinical study subjects were 65 eyes of 65 patients that underwent phaco-emulsification and aspiration with intraocular lens implantation and received intracameral injection of Mydrin-P for poor mydriasis after preoperative topical instillation of mydriatics (intraocular mydriasis group; with five subgroups based on cause: diabetes, pseudo-exfoliation, post-surgery, uveitis, unknown). Controls, comprising 39 eyes of 39 patients, were not injected with Mydrin-P.


METHODS
The ratio of pupillary diameter to corneal diameter was determined before and after injection of Mydrin-P. Corneal endothelial density was measured preoperatively and 3 months and 1 year postoperatively.


METHODS
Pupillary diameter and corneal endothelial density.


RESULTS
Human corneal endothelial cell morphology was unaltered after Mydrin-P injection. The mean ratio of the pupillary diameter to corneal diameter increased in the intraocular mydriasis group (before: 54.2 ± 4.8%, after: 58.4 ± 6.6%; P < 0.001) and in the diabetes and unknown subgroups. The corneal endothelial cell density reduction rate 3 months and 1 year after surgery was not significantly different between the intraocular mydriasis group and controls.


CONCLUSIONS
Intracameral injection of Mydrin-P appears to be effective and safe for dilating the pupil in cases with poor mydriasis after preoperative instillation of mydriatics.
Miyata Eye Hospital, Miyazaki, Japan.
Yosai
Y
Mori
Takashi
T
Miyai
Fumie
F
Kagaya
Nobuyuki
N
Nagai
Yasuhiro
Y
Osakabe
Kazunori
K
Miyata
Shiro
S
Amano
D000368:Aged; D000867:Anterior Chamber; D002452:Cell Count; D002478:Cells, Cultured; D004359:Drug Therapy, Combination; D004728:Endothelium, Corneal / Q000166:cytology / Q000187:drug effects; D005260:Female; D006801:Humans; D056965:Injections, Intraocular; D007430:Intraoperative Care; D019654:Lens Implantation, Intraocular; D008297:Male; D009184:Mydriatics / Q000008:administration & dosage* / Q000009:adverse effects; D018918:Phacoemulsification; D010656:Phenylephrine / Q000008:administration & dosage / Q000009:adverse effects; D011446:Prospective Studies; D011680:Pupil / Q000187:drug effects*; D016896:Treatment Outcome; D014331:Tropicamide / Q000008:administration & dosage / Q000009:adverse effects
D009184:Mydriatics; D010656:Phenylephrine; D014331:Tropicamide