Polylactic acid for visualizing the vitreous body during vitrectomy.
OBJECTIVE
To investigate the possibility of using polylactic acid (PLA) as a surgical adjuvant for visualizing the vitreous body during vitrectomy.


METHODS
After a core vitrectomy, 1 mL of PLA suspension was injected into the rabbit vitreous in two groups: group A, 2.5% PLA (n = 5), and group B, 1% PLA (n = 9). Vehicle injection instead of PLA was used as a control (group C, n = 5). The clinical signs and electroretinogram (ERG) were evaluated for 28 days, and histologic findings were evaluated on day 28. Next, intraocular pressure (IOP) after intracameral injection of a PLA suspension was evaluated in the rabbits (n = 6). Last, the visualization of the vitreous body by PLA suspension was evaluated during vitrectomy in monkey eyes (n = 4).


RESULTS
The white granules of PLA disappeared from the vitreous cavity in 10 eyes within 3 weeks; however, a small amount of PLA remained in four eyes for 4 weeks. Mild inflammation of the anterior chamber was observed in one eye in group B and 1 eye in group C. No cataract or retinal hemorrhage was found in any eyes. The amplitude of ERG on each time point did not differ between the groups. IOP remained within normal range except for the initial spike. Retinal structure was well preserved histologically. During vitrectomy in monkey eyes, the vitreous body was well visualized, and the posterior vitreous separation was performed easily and safely.


CONCLUSIONS
PLA can be a new surgical adjuvant to visualize the vitreous body during vitrectomy.
Yamashita
Toshifumi
T
Department of Ophthalmology, Kagoshima University Medical and Dental School, Sakuragaoka, Kagoshima, Japan.
Sakamoto
Taiji
T
Yamakiri
Keita
K
Miura
Muneki
M
Enaida
Hiroshi
H
Ueno
Akifumi
A
Atsumi
Ikuyo
I
Matsuhisa
Keiichi
K
Sakamoto
Yuji
Y
Kida
Tetsuo
T
Ishibashi
Tatsuro
T
D000818:Animals; D000869:Anterior Eye Segment / Q000187:drug effects / Q000473:pathology; D003287:Contrast Media; D004596:Electroretinography / Q000187:drug effects; D007267:Injections; D007429:Intraocular Pressure / Q000187:drug effects; D019344:Lactic Acid / Q000633:toxicity; D008252:Macaca fascicularis; D008297:Male; D011091:Polyesters; D011108:Polymers / Q000633:toxicity; D011817:Rabbits; D012160:Retina / Q000187:drug effects / Q000473:pathology; D013535:Suspensions; D014821:Vitrectomy; D014822:Vitreous Body / Q000473:pathology*
D003287:Contrast Media; D011091:Polyesters; D011108:Polymers; D013535:Suspensions; D019344:Lactic Acid; C033616:poly(lactide)