Purpose:
To investigate the role of indocyanine green (ICG) and fluoresceinangiography (FA) in imaging and quantifying corneal vascularisation.
Methods:
Patients with corneal vascularisation were studied using a standardisedprotocol of colour digital photography, FA and ICG angiography.Images were analysed by an automated blood vessel analysis programmedeveloped in house using Matlab and areas of vascularisationwere quantified.
Results:
Ten patients with corneal vascularisation were studied. Theaetiologies included herpes simplex, acanthamoeba and ocularsurface disease. Compared to colour and FA, ICG angiographyprovided better resolution of corneal blood vessels and wereused for evaluation of the area of corneal vascularisation (Fig:1&2). The area thus estimated ranged from 0.28 mm2 to 1.18mm2. FA images were affected by leakage of dye and scarring(Fig: 2b). Best images for ICG angiography were after 2 minutesand that for FA were after 1 minute.
Conclusions:
New antiangiogenic agents are being investigated as treatmentfor corneal blood vessels. Objective documentation of bloodvessels is essential in evaluating the effectiveness of thesetreatments. Colour images are ineffective in documenting thefull extent of corneal neovascularisation. ICG angiography followedby image analysis and measurement of area of vascularisationis a new and effective tool for this purpose.
Keywords: imaging/image analysis: clinical • cornea: clinical science • neovascularization