This article was originally published in a sponsored newsletter.

A healthy, balanced tear film is critical for clear vision and ocular surface comfort. The tear film is composed of three distinct layers: an outer layer of lipids that are secreted by the meibomian glands; a middle aqueous layer composed of a mixture of proteins, electrolytes and water secreted by the main and accessory lacrimal glands; and the innermost mucin layer that consists of secreted mucins along with water and electrolytes produced by the conjunctival goblet cells.¹

Problems with the tear film are often found in dry eye disease or ocular surface disease. Dry eye disease is characterized by a cycle of inflammation and loss of tear film homeostasis,² and ocular surface disease encompasses ophthalmic disorders that may cause insufficiency of the tear film and inflammation of the cornea and conjunctiva.³ As such, treatments for dry eye and ocular surface disease range from modification of environmental risk factors, lid hygiene and preservative-free artificial tears, to prescription therapies and interventional approaches (e.g., lid margin treatments, therapeutic contact lenses and amniotic membranes, among others).

One treatment that has grown in increasing utility in my dry eye disease and ocular surface disease practice is the use of autologous serum tears. First described in 1975, autologous serum tears are derived from a patient’s own blood serum. Blood serum has been shown to have similar levels of certain growth factors, antioxidants, lipids, electrolytes, carbohydrates and platelet factors as endogenous tears and helps support the tear film and ocular surface. In the United States, serum tears are regulated by the FDA’s Center for Biologics Evaluation and Research, but because they are considered a blood product, they are not FDA approved.^3,4 However, obtaining autologous serum tears has become a more streamlined process recently. Patients need to be able to access local specialty laboratories and pharmacies that can draw their blood and produce the serum tears or utilize companies such as Vital Tears that can help simplify the process of manufacturing the serum tears.⁵

Autologous serum can be concentrated up to 100% or diluted with saline to concentrations as low as 20%. I tend to start with serum tears of 40% concentration dosed four to six times a day, but I have used concentrations as high as 50% to 75% in recalcitrant cases of ocular surface inflammation. Conditions in which serum tears have shown immense value in my practice include chronic dry eye disease that is unresponsive to other therapies, autoimmune-related ocular surface disease (such as Sjögren’s syndrome or rheumatoid arthritis-associated ocular surface inflammation), corneal epitheliopathy from biologics/chemotherapeutic agents, neurotrophic keratitis, limbal stem cell deficiency, graft vs. host disease and neuropathic corneal pain. In post-surgical cases of non-healing epithelium/epitheliopathy (i.e., after corneal collagen crosslinking, refractive surgery or cataract surgery), a short course of autologous serum can often rapidly rehabilitate the ocular surface.

Overall, serum tears are safe and well-tolerated with minimal adverse effects. They do not have preservatives and need to be stored properly by patients to avoid risk of infection. Serum tears may also not be suitable for patients who cannot tolerate repeated blood draws. While risk of blood transmissible diseases through serum tears is low, testing before the production of serum tears is encouraged.

Price is also a consideration when starting serum tears. Notably, serum tears are not covered by insurance. However, for some patients, the cost of autologous serum tears can be less than copays associated with commonly prescribed pharmaceuticals.

The utility of autologous serum in an ocular surface practice is expansive. It can be used as first-line therapy, as step therapy or in conjunction with other treatments to support the ocular surface.

Reference(s):

1. Craig JP, Nichols KK, Akpek EK, et al. TFOS DEWS II definition and classification report. Ocul Surf. 2017 Jul;15(3):276-283. doi:10.1016/j.jtos.2017.05.008
2. McCann P, Kruoch Z, Lopez S, Malli S, Qureshi R, Li T. Interventions for dry eye: an overview of systematic reviews. JAMA Ophthalmol. 2024 Jan;142(1):58-74. doi: 10.1001/jamaophthalmol.2023.5751
3. Cui D, Li G, Akpek EK. Autologous serum eye drops for ocular surface disorders. Curr Opin Allergy Clin Immunol. 2021 Oct;21(5):493-499. doi:10.1097/ACI.0000000000000770
4. Pan Q, Angelina A, Marrone M, Stark WJ, Akpek EK. Autologous serum eye drops for dry eye. Cochrane Database Syst Rev. 2017 Feb;2(2):CD009327. doi:10.1002/14651858.CD009327.pub3
5. Vital Tears. Homepage. Accessed February 13, 2024. vitaltears.org

Nandini Venkateswaran, MD practices at Massachusetts Eye and Ear Harvard Medical School Department of Ophthalmology, where she is also an assistant professor. Her specialties are complex and premium cataract surgery, cornea and external diseases, corneal crosslinking, and refractive surgery. She has no relevant financial disclosures to this article.