A prospective, open-label, dose-escalating study of low molecular weight heparin during repeat vitrectomy for PVR and severe diabetic retinopathy.
BACKGROUND
To determine the maximum tolerated dose (MTD) of enoxaparin, a low molecular weight heparin (LMWH) was used during repeat vitrectomy for rhegmatogenous retinal detachment with proliferative vitreoretinopathy (PVR) and severe diabetic retinopathy.


METHODS
From 25 patients, 29 eyes undergoing repeat vitrectomy for PVR (CP3 or greater) or severe diabetic retinopathy were included in the study. Patients had previously undergone an average of 2.1 previous vitrectomies (range 1-5). Enoxaparin was added to the infusion fluid in an escalating dose from 0.1 IU/ml to 6.0 IU/ml as tolerated. Intraoperative bleeding, postoperative fibrin, hyphema and vitreous hemorrhage were graded in an unmasked fashion using previously described grading scales.


RESULTS
All patients completed the study, and the study was able to achieve the 6.0 IU/ml maximum dose on the dose escalation schedule. No patient experienced dose-limiting toxicity. Analysis showed no increase in intraoperative bleeding complications between low dose (<or=1.0 IU/ml) and high dose (>1.0 IU/ml) enoxaparin (Mann-Whitney Test, P=0.029).


CONCLUSIONS
Enoxaparin dose escalation did not result in a dose-dependent increase in acute side effects. The establishment of a well-tolerated dose of enoxaparin during repeat vitrectomy for PVR and severe diabetic retinopathy (6.0 IU/ml) provides a foundation for future studies.
Lane
R Gary
RG
Department of Ophthalmology, Wilford Hall USAF Medical Center, San Antonio, TX, USA.
Jumper
J Michael
JM
Nasir
Ma'an A
MA
MacCumber
Mathew W
MW
McCuen
Brooks W
BW
D003930:Diabetic Retinopathy / Q000601:surgery*; D017984:Enoxaparin / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D005337:Fibrin / Q000378:metabolism; D005343:Fibrinolytic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D006988:Hyphema / Q000517:prevention & control; D007260:Infusion Pumps; D007431:Intraoperative Complications; D008297:Male; D020714:Maximum Tolerated Dose; D008875:Middle Aged; D011446:Prospective Studies; D012086:Reoperation; D014821:Vitrectomy; D018630:Vitreoretinopathy, Proliferative / Q000601:surgery*; D014823:Vitreous Hemorrhage / Q000517:prevention & control
D017984:Enoxaparin; D005343:Fibrinolytic Agents; D005337:Fibrin
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