Doxycycline's effect on ocular angiogenesis: an in vivo analysis.
OBJECTIVE
To determine the in vivo effect of doxycycline on choroidal angiogenesis and pterygium growth by using a choroidal neovascular (CNV) murine model, a directed in vivo angiogenesis assay (DIVAA) and a pterygium murine model.


METHODS
Experimental study.


METHODS
Three murine models were investigated with 4 mice minimum per group and 22 maximum per group.


METHODS
Mice received water with or without doxycycline. For the CNV, the neovascular lesion volume was determined in choroid-retinal pigment epithelial flat mounts using confocal microscopy 7 days after laser induction. For DIVAA, silicone capsules containing 10,000 human pterygium epithelial cells were implanted in the flanks of mice subcutaneously. After 11 days, neovascularization (NV) was quantified using spectrofluorometry after murine tail-vein injection of fluorescein isothiocyanate-labeled dextran. A pterygium epithelial cell model was developed by injecting 10,000 human pterygium epithelial cells in the nasal subconjunctival space in athymic nude mice. Doxycycline was started on day 6 at 50 mg/kg per day; corneal lesions that resulted from the injections were compared at days 6 and 15.


METHODS
The Student t-test was used to evaluate the data for the CNV and DIVAA models and histologic preparations were used to evaluate pterygia lesions.


RESULTS
There was significantly less NV and lesion volume with doxycycline taken in drinking water versus plain water. With doxycycline treatment, the laser-induced CNV showed a maximal 66% decrease in choroidal blood vessel volume (P< or =0.008) and the DIVAA showed a 30% reduction of blood vessel growth and migration (P<0.004). Histologic preparations demonstrated that pterygium cell lesions regressed when mice were administered doxycycline for 9 days.


CONCLUSIONS
Doxycycline significantly inhibited angiogenesis in 3 murine models. The most dramatic effect was found in the CNV model followed by the pterygia epithelial cell DIVAA model. The anterior segment pterygium model also showed regression histologically. This suggests that doxycycline may be successful as an adjunctive treatment for CNV and pterygia in humans; clinical trials would be necessary to determine if there is a benefit.
Cox
Constance A
CA
National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA. cc6@hawaii.edu
Amaral
Juan
J
Salloum
Rita
R
Guedez
Liliana
L
Reid
Ted W
TW
Jaworski
Cindy
C
John-Aryankalayil
Moly
M
Freedman
Ken A
KA
Campos
Mercedes M
MM
Martinez
Alfredo
A
Becerra
Susan P
SP
Carper
Deborah A
DA
D000284:Administration, Oral; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D002465:Cell Movement / Q000187:drug effects; D017690:Cell Transplantation; D002478:Cells, Cultured; D020256:Choroidal Neovascularization / Q000517:prevention & control*; D016510:Corneal Neovascularization / Q000517:prevention & control*; D004195:Disease Models, Animal; D004318:Doxycycline / Q000008:administration & dosage / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects / Q000473:pathology; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D018613:Microscopy, Confocal; D011625:Pterygium / Q000188:drug therapy / Q000473:pathology; D013050:Spectrometry, Fluorescence
D000900:Anti-Bacterial Agents; D004318:Doxycycline