Background Autologous serum is used for chronic ulcers and dry eyes. Currently there are no studies on the use of whole fresh blood for the treatment of chronic ulcers, persistent epithelial defects or dry eyes.
Dry eye syndrome (DES) refers to a common but highly heterogeneous group of ocular surface disorders with varying disease severity, due to lack of sufficient tears or sufficient quality of tears. Corneal and conjunctival studies, using a variety of definitions, have estimated the prevalence of ''significant'' DES to be about 10-20% in the adult population, although fortunately severe DES is less frequent (Hikichi et al., 1995; Bjerrum, 1997; Doughty et al., 1997; Bandeen-Roche et al., 1997; Caffery et al., 1998; McCarty et al., 1998; Schein et al., 1999; Moss et al., 2000; Begley et al., 2002; Chia et al., 2003; Lin et al., 2003; Schaumberg et al., 2003).
Dry eye is usually managed with conventional treatment of artificial tears, punctual plugs, occlusive goggles and bandage contact lenses. In spite of maximal conventional therapy, there is a cohort of patients who have persistent symptoms and signs. This represents a more serious ocular surface disorder with patients having significant visual impairment and disability. Particularly severe dry eye might be managed with contact lenses, botulinum toxin induced ptosis and surgical tarsorrhapy. These treatments are not without their own hazards such as infection from contact lenses, reduced vision from the ptosis or surgical tarsorrhapy, particularly in only seeing eyes.
Corneal ulcers are usually managed with artificial tears, antibiotic ointment, bandage contact lenses and steroids.
Autologous serum eye drops have been found in uncontrolled trials to be beneficial in these patients, improving the ocular surface and reducing symptoms (Poon et al., 2001; Fox et al., 1984; Tsubota et all, 1999;). In addition, impression cytology and in vitro toxicity testing demonstrated that serum drops have reduced toxicity compared with unpreserved hydroxypropylmethylcellulose (Noble et al., 2004; Poon et al., 2001)
Obtaining serum requires frequent venesection with significant amount of blood taken. It is also expensive. The serum is aliquoted into hundreds of bottles with the additional risk of bacterial contamination. It also requires a fridge and storage facilities for these aliquoted bottles at the patient's home. Because of these requirements some patients are excluded, for example patients with anaemia because they are unable to give blood. In addition, often there is a delay in starting the treatment for organizational and / or funding reasons that can be detrimental to the course of the disease, causing unnecessary surgery and corneal melt resulting in perforation with potential loss of the eye. The FAB method could be used immediately for patients who are awaiting conventional treatment for autologous blood. Furthermore it also appears that 100% autologous serum is more beneficial than 50% serum (Poon et al), thereby larger volumes of blood and/or more frequent venesection is required.
Autologous fresh blood is already used subconjunctivally to help heal leaking trabeculectomy blebs (Dinah et al.2010; Biswas et al. 2009; Burnstein et al. 2001; Haynes et al., 1999). Autologous blood is also used to help attach limbal autografts in cases of pterygium (de Wit et al. 2010) and in vitreoretinal macular hole surgery (Lai et al. 2009; Chuang et al. 2010; McCannel et al. 2008; Lai et al.,2005). No adverse effects have been reported in these studies. The object of this study is to investigate if serum via a drop of fresh blood is an effective treatment for dry eye and corneal ulcers which currently require venesected autologous blood and would be particularly useful in the current group of patients in whom venesection is contraindicated.
If shown to be effective this may replace current autologous serum practice and its ease of use and reduced cost may mean that it could be extended to other ocular surface diseases or moderate dry eyes and used earlier in corneal epithelial defects.
