Evaluation of contrast agents for enhanced visualization in optical coherence tomography.
OBJECTIVE
To identify and evaluate the use of contrast agents in optical coherence tomography (OCT) for ophthalmic applications.


METHODS
Three agents-prednisolone acetate (PA), triamcinolone acetonide (TA), and lipid-based artificial tears (LBAT)-were tested in cadaveric porcine eyes imaged with hand-held spectral-domain OCT (SD-OCT). Anterior segment imaging was performed in triplicate with each agent at three sites: corneal epithelial surface, corneal wound interface, and anterior chamber. OCT characteristics of the three agents at each ocular site were analyzed. Quantitative intensity (i.e., brightness) analysis was performed with image analysis software. Institutional review board approval was obtained for imaging in human subjects undergoing cataract surgery. PA was applied to the corneal surface, and SD-OCT imaging was performed of the corneal surface and wound interface immediately after cataract surgery.


RESULTS
All agents provided increased reflectivity. PA and LBAT showed a smooth bright reflectivity profile, whereas TA had a granular profile. Improved visualization of tissue interfaces was noted. Maximum and mean intensity of reflectance were higher for all agents compared with controls (P < 0.05). PA showed topical and wound interface contrast enhancement in human subjects after cataract surgery.


CONCLUSIONS
Significant OCT contrast enhancement was achieved with improved visualization of tissue interfaces. Each agent had a unique reflectivity profile. Future applications of OCT contrast agents might include evaluation of wound stability, intraocular fluidics, and ocular surface disease.
Cole Eye Institute, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA. justis.p.ehlers@alumni.nd.edu
Justis P
JP
Ehlers
Preeya K
PK
Gupta
Sina
S
Farsiu
Ramiro
R
Maldonado
Terry
T
Kim
Cynthia A
CA
Toth
Prithvi
P
Mruthyunjaya
D000818:Animals; D000867:Anterior Chamber / Q000033:anatomy & histology*; D002387:Cataract Extraction; D003287:Contrast Media; D003315:Cornea / Q000033:anatomy & histology* / Q000473:pathology*; D065306:Corneal Injuries; D003941:Diagnostic Techniques, Ophthalmological; D006801:Humans; D009883:Ophthalmic Solutions; D011239:Prednisolone / Q000031:analogs & derivatives; D013552:Swine; D041623:Tomography, Optical Coherence / Q000379:methods*; D014222:Triamcinolone Acetonide; D014945:Wound Healing
D003287:Contrast Media; D009883:Ophthalmic Solutions; C009935:prednisolone acetate; D011239:Prednisolone; D014222:Triamcinolone Acetonide