Abstract
Purpose: :
Transparency and lack of blood vessels are unique attributes of the cornea. The latter is in many ways a pre-requisite for the former. Corneal neovascularisation (CVas) may not only reduce visual acuity but also result in the loss of corneal immune privilege, thereby worsening the prognosis of subsequent corneal grafts. Up to date, there is no standard clinically valuable classification of CVas. We propose a novel classification for corneal neovascularisation based on understanding the maturity and patho-physiological activity of the corneal vessels reflected in the clinical appearance of the vessels.
Methods: :
More than 100 patients with CVas were clinically evaluated, observed and followed up for a period of 6 months during their routine outpatient clinic appointments. The study did not interfere with the management plan of the eye condition or the CVas. Another 100 patients were reviewed retrospectively through analysing their case notes and anterior segment digital photographs in different time scales throughout the course of the pathology. The patients’ observations were recorded by the clinic attendee while the digital photographs were analysed by three independent observers. The inter rater and intra rater reliability were also measured.
Results: :
Depending on their maturity and state of ‘activity’ corneal vascularisation can be divided into different types; young active, old active, mature, partially regressed and regressed (ghost) vessels. An evolving vascular complex did not necessarily pass through all stages. Depending on the clinical criteria defined for each type of vessels the total percentage of agreement was >90%. The pathology behind the vascualrisation and the behavior of the vessels in different pathologies was also described.
Conclusions: :
This study provides a standard clinical classification of corneal neovascularisation which will improve our understanding of the clinical significance of CVas, guide any future trials of clinical interventions targeting different types of CVas, and will eventually bring CVas therapeutic approaches into a consensus.
Keywords: cornea: clinical science • cornea: stroma and keratocytes • clinical (human) or epidemiologic studies: natural history