[Effect of squatting on sub-foveal blood flow defect in pseudophakic eyes operated by cerclage].
ZIEL: To investigate the relationship between velocity (Velch), blood volume (Volch) and blood flow (Fch), and the mean ocular perfusion pressure (PPm) in the foveal region, and to determine how the regulatory capacity of the choroidal circulation is affected after an encircling buckle procedure.


METHODS
We investigated both pseudophakic eyes of 6 patients (age range 56-79 years) in a masked study. Subjects presenting eye diseases (glaucoma, uveitis, diabetic retinopathy) as well as systemic diseases were excluded from the study. All subjects had in one eye a successful management of retinal detachment with an encircling buckling; the second eye was considered as control. Measurements of Velch, Volch and Fch were obtained by Laser Doppler Flowmetry (LDF) at baseline and during isometric exercise (squatting).


RESULTS
In the operated eyes, Velch and Fch increased significantly (ANOVA, p < 0.05) during the PPm raise, which was not the case for Volch (ANOVA, p > 0.05). In the control eyes, all hemodynamic parameters remained unaffected by the PPm increase (ANOVA, p > 0.05). The response of Velch and Fch was significantly different (ANCOVA, p < 0.002) between operated and control eyes.


CONCLUSIONS
These results suggest that encircling buckle does affect subfoveal choroidal blood flow regulation, which may explain a possible macular dysfunction in the operated eyes.
Movaffaghy
A
A
Clinique d'Ophtalmologie de Genève, Hôpital Cantonal Universitaire de Genève, Rue Alcide-Jentzer 22, CH-1211 Genève 14.
Pharmakakis
N M
NM
Chamot
S R
SR
Katsimpris
J J
JJ
Pournaras
J A
JA
Pournaras
C J
CJ
D000368:Aged; D001783:Blood Flow Velocity / Q000502:physiology; D001810:Blood Volume / Q000502:physiology; D002829:Choroid / Q000098:blood supply*; D005260:Female; D005584:Fovea Centralis / Q000098:blood supply*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000503:physiopathology*; D011187:Posture / Q000502:physiology*; D019591:Pseudophakia / Q000503:physiopathology / Q000601:surgery*; D012016:Reference Values; D012039:Regional Blood Flow / Q000502:physiology; D012163:Retinal Detachment / Q000503:physiopathology / Q000601:surgery*; D012591:Scleral Buckling