New infusion cannula for prevention of retinal damage by infusion air during vitrectomy.
OBJECTIVE
Postoperative visual field defects are sometimes found after macular hole surgery. We have previously shown that damage to the retina by air infusion from an infusion cannula is a causative factor. To minimize such damage, we modified the infusion cannula and examined its effects experimentally.


METHODS
An infusion cannula with a closed tip and openings on four sides was created. Experimentally, a vitrectomy was performed in rabbit eyes using this new infusion cannula or a conventional cannula. After fluid-air exchange at an air pressure of 40 mmHg, eyes were removed and processed for histologic examination. The areas of the retinal damage caused by air infusion were evaluated.


RESULTS
The area of retinal damage created by the new cannula was reduced significantly when compared with damage from conventional cannula use.


CONCLUSIONS
This new cannula, designed for the purpose of scattering the air infusion, can reduce retinal damage, which leads to less frequent postoperative visual field defects.
Hirata
Akira
A
Department of Ophthalmology, Kumamoto University School of Medicine, Kumamoto 860-0811, Japan. ahirata@kumamoto-u.ac.jp
Yonemura
Naoko
N
Hasumura
Tadashi
T
Murata
Yasuhiro
Y
Negi
Akira
A
Tanihara
Hidenobu
H
D000388:Air; D000818:Animals; D002404:Catheterization / Q000295:instrumentation*; D005131:Eye Injuries / Q000209:etiology / Q000517:prevention & control*; D011312:Pressure; D011817:Rabbits; D012160:Retina / Q000293:injuries*; D012164:Retinal Diseases / Q000209:etiology / Q000517:prevention & control*; D014821:Vitrectomy / Q000009:adverse effects*