Keratoconjunctivitis sicca, or dry eye, is a very common chronic condition affecting many of our patients, particularly given the arid region in which We practice. Longitudinal studies regarding the prevalence and incidence of this condition are few. One large study, the Beaver Dam Study, reported a 5-year incidence of l3%.1 The incidence increases with patient age and gender, the use of medications, comorbidities such as collagen vascular disease, and varies by region based on climate.
Complexity of the Tear film
The tear film is complex and sen/es many functions. It protects the ocular surface against desiccation, is a barrier against microorganisms, and promotes the epithelial health of the ocular surface. The tear film has three major constituents, each serving a vital role: a lipid, an aqueous, and mucin layer. The lipid portion of the tear film is produced by the meibomian glands at the base of the lash follicles. It is the most superficial portion of the tear film, consisting of a complex mixture of lipidic compounds, which help stabilize the tear film and function as a barrier to evaporation. The aqueous portion is produced by the lacrimal gland and its accessory glands, and consists mostly of Water. Its role in transporting essential constituents such as electrolytes, growth factors, and immunoglobulins are vital to the health of the epithelial cells on the ocular surface. The mucin layer, the deepest layer, is produced by goblet cells on the ocular surface. It consists of heavily glycosolated glycoproteins which render the corneal surface more hydrophilic and diminish the surface tension, facilitating in tear film adherence. Deficiencies in any of the three components will result in symptomatic dry eye.
The Treatment of Dry Eye
The treatment of dry eye traditionally consists of supplemental ocular lubricants and punctal occlusion. Many types of artificial tears are available at present, none of which are an adequate surrogate for the complex nature of human tears. Restasis® (AllerganIrvine, CA), an ophthalmic emulsion of 0.05% cyclosporine A commercially introduced in 2002, is another treatment option for dry eye. This dilute form of cyclosporin is thought to act by inhibiting activated T-cell cytokine production in patients Whose tear production is suppressed by tion. Unfortunately, the etiology of dry eye is heterogeneous, and not alWays secondary to inﬂammation. Many other causes of dry eye resulting from either a lack of tear production and/or accelerated tear evaporation exist, many of which are inadequately addressed by this medication.
Treatment of Dry Eye with Autologous Serum Tears (AS)
A fairly common treatment modality for moderate to severe dry eye and other chronic ocular surface disease in the UK, Japan, and Australia, is autologous serum eye drops. The use of autologous serum (AS) as a tear substitute first appeared in the Rheumatology literature in 1984 by Fox, et al,2 with equally favorable results in subsequent publications.” Human serum has a very similar composition to human tears and is an excellent surrogate to native tears. Its biochemical properties are identical to human tears with regards to pH and osmolality, and it contains immunoglobulin, vitamin A, fibronectin, and growth factors which promote epithelial health.3’9 AS is prepared by diluting the patients’ own serum with artificial tears and is provided to the patient in a dropper bottle. This treatment modality is an excellent alternative or adjunct to over the counter ocular lubricants, punctal occlusion and Restasis.
In conclusion, keratoconjunctivitis sicca is a fairly common clinical entity with variable pathophysiology, leading to a compromise in any portion of the complex tear film. This results in a suboptimal ocular surface, leading to ocular irritation and blurry vision. The treatment of dry eye has long been punctal occlusion, ocular lubricants, and in the last decade a dilute form of cyclosporine. Autologous serum tears are a safe and effective alternative or adjunct in treating dry eye and other ocular surface disorders.
by Howard Amiel, M.D.
- SE Moss et al. Incidence of dry eye in an older population. Archives of Ophthalmology 2004 122: 369-373.
- Fox RI, Chan R, Michelson J, et al. Beneficial effect of artificial tears made with autologous serum in patients with kerat0c0njunctivitis sicca. Arthritis Rheum 1984;29:577-83.
- Hamano T, Ohashi Y, Cho Y, Shimomura Y, Manabe R. A new punctum plug. Am J Ophthalmol 1985; 100: 619-620
- Poon AC, Geerling G, Dart IKG, Fraenkel GE, Daniels J. Autologous serum eyedrops for dry eyes and epithelial defects: clinical and in vitro toxicity studies. BrJ Ophthalmol 2001; 85: 1188-1197.
- Tsubota K, Satke Y, Shimazaki J. Treatment of server dry eye (letter). Lancet 1996; 348: 123.
- Tsubota K, Toda I, Saito H, Shinozaki N, Shimazaki J. Reconstruction of the corneal epithelium by limbal allograft transplantation for severe ocular surface disorders. Ophthalmology 1995; 102: 1486-1496.
- Tsubota K, Goto E, Fujita H, Ono M, Inoue H, Saito I et al. Treatment of dry eye by autologous serum application in Sjogren‘s Syndrome. BrJOphthalm0l 1999; 83: 390—395.
- Tananuvat N, Daniell M, Sullivan LJ, Qing Y, McKelvie P, McCarty DJ et al. Controlled study of the use of autologous serum in dry eye patients. Cornea 2001; 20(8): 802—806.
- Ogawa Y, Okamoto S, Mori T, Yamada M, Mashima Y, Watanabe R et al. Autologous serum eye drops for the treatment of severe dry eye in patients with chronic graft-versus-host disease. Bone Marrow Transplant 2003.