The ocular surface
i.e. the surface of the
eye includes two major territories- the cornea
the transparent layer that forms the central part of the eye and the conjunctiva
, the mucous membrane that
covers the remaining front surface of the eye. The ocular surface is covered by a thin layer of tear film
. A stable
tear film helps to maintain the health of the ocular surface. It has lubricant,
nutrient and wound healing properties, and serves as a defense mechanism to the
Ocular surface diseases are a group of disorders
that affect the outer surface of the eye.
They are caused by
inflammation which are often influenced by genetic, environmental and
ocular surface diseases present with blurry vision or partial loss of vision,
discomfort or pain, infection, redness, itching, erosion, ulceration and in
severe cases, blindness due to scarring of the eye surface.
Artificial tear and
corticosteroid eye drops
are the mainstays of
current treatment options for patients with ocular surface disease. However,
they do have some disadvantages, which are listed below:
of Artificial Tear and Corticosteroid Eye Drops
with human serum-derived and plasma-derived eye drops
of corticosteroid eye drops is associated with a number of side effects.
commercially available artificial tear preparations do not include
essential tear components such as growth factors, vitamins and
drawback of using artificial tears is the fact that they often contain
preservatives, stabilizers and other additives, which can result in
potentially toxic or allergic reactions.
the intensive use of artificial tear supplements, many patients still
present with persistent symptoms and signs of ocular surface disorders.
Such patients may have more serious form of the disease with significant
visual impairment and disability. Surgical
interventions may be necessary in such cases.
has also become
increasingly popular in the treatment of ocular surface disorders such as persistent
epithelial defects or severe dry eyes
Persistent epithelial defects are superficial eye conditions that do not heal
within the expected period. There has been mounting evidence
suggesting the safety and efficacy of these therapies.
Experts recommend using these blood-derived
therapies for the management of ocular surface disorders that are resistant to
usual medical treatment. However, their use is limited by the cost and the
inconvenient process of obtaining these products.
Autologous serum tears have been used for the
treatment of chronic dry eye syndrome for many years. Serum is the fluid
component of blood that remains after clotting. It is not a standard blood
product, but can easily be produced on special request to the blood bank.
Autologous serum is serum that is obtained from blood withdrawn from the same
Advantages of using Autologous Serum Tears
- Autologous serum tears contain
essential ocular surface nutrients, such as several growth factors,
vitamin A and vitamin E, fibronectin, cytokines, and bacteriostatic
components also present in tears. These factors have been considered to be
important for maintaining a healthy corneal and conjunctival surface.
studies have revealed that the ocular
surface cells are better supported by autologous serum than by
autologous serum eye drops can offer both lubricant and nutrient properties, and can be
produced without the use of any
preservatives. Thus, toxicity due to additives is not an issue with
autologous serum tears.
Strict quality control measures must be implemented
for the production and application of serum tears. It should only be applied
under the supervision of the prescribing doctor.
Serum eye drops are generally well tolerated with little or no side
Possible side effects of autologous serum eye drops include:
- Worsening or reoccurrence of the initial
problem: In some cases the ocular surface disease is
likely to recur if the serum treatment is stopped.
- Risk of infection:
The use of serum tears carries the risk of transmission of infectious
diseases from the donor to other people involved in the production and
application of the eye drops. There is also the risk of contamination of
the dropper bottle and subsequent infections. Such complications can be
largely avoided by prior testing of the donor and other labor for HIV,
B and C. Every serum eye drop batch must also be tested for
possible bacterial contamination.
- Immunological reactions: In
rare cases, patients may present an inflammatory response after the
application of the eye drops. Therefore, patients must be frequently
monitored after the application of serum eye drops.
Another drawback with serum therapies is that the serum has to be
prepared for every patient individually. This is time-consuming and labor
intensive procedure. Also, not many countries have standard operating protocols
that have been evaluated or approved by the licensing authority.
Several other quality
controlled products derived from full blood can also be considered for the
treatment of ocular surface disorders.
These include platelet concentrates, umbilical
cord serum or various protein fractions such as albumin.
are the major source of growth factors in
serum. Therefore, platelet releasate,
contains substances released from activated platelets, can be used as an
additional treatment modality for ocular surface disease.
is one of the most abundant proteins in tears. It
supports surface wound healing. No complications have been observed with the
use of albumin as a single compound product. An autologous blood donation is
also not required for using albumin. However, symptoms of ocular surface
disease do not show remarkable improvement with the use of albumin.
Umbilical cord serum
can also be used as an alternative treatment for
promoting corneal surface wound healing. It was found to be more effective than
autologous serum to heal surface wounds. However, it is difficult to obtain
umbilical cord serum and the supply is limited. Also, since it is obtained from
a different person, umbilical cord serum can cause allergic reaction or
1. Soni NG, Jeng BH. Blood-derived topical
therapy for ocular surface diseases. Br J Ophthalmol
2. Lekhanont K, Jongkhajornpong P, Choubtum L, Chuckpaiwong V. Topical 100% Serum Eye Drops for Treating Corneal Epithelial Defect after Ocular Surgery. BioMed Research International 2013, Article ID 521315, 7 pages http://dx.doi.org/10.1155/2013/521315
3. Quintos GG, Campos M, Behrens A. Autologous
serum for ocular surface diseases. Arq. Bras. Oftalmol. vol.71 no.6 supl.0 São
Paulo Nov./Dec. 2008