the Ocular Surface
review of the surface from disease to co-managing anterior segment surgery.
BY SCOT MORRIS, O.D.,
PROVIDED BY EYEMAGINATION, INC.
our profession moves towards an increased awareness of ocular surface disease, the
question is often posed: How do we manage the ocular surface? There are so many
ocular surface diseases that it takes book chapters to fully describe the pathophysiology
and various treatment strategies that we can use to treat each individual disease.
Here I intend to provide a broad overview and a general "recipe" for treating an
assortment of ocular surface diseases.
Get to know the surface
Let's first review some characteristics of the ocular surface
so we can better understand how to treat these patients. The ocular surface is composed
of the cornea, the bulbar and the palpebral conjunctiva. The corneal surface is
composed of the cuboidal epithelium with microvilli that secrete glycocalyx, the
protein that covers the epithelium. The glycocalyx makes it possible for the remainder
of the tear film to rest on the hydrophobic corneal surface. The microvilli have
a ciliary function. They move various antigens and waste products that can be trapped
in the surface mucin nasally toward the lacrimal drainage system.
The conjunctiva contains goblet cells that secrete mucins
1 and 4. These mucins are absorbed into the ocular surface and blend with the aqueous
component of the tear film. The function of these mucins is to protect the ocular
surface from contaminates. The tear prism is a delicate balance of mucin, electrolytes,
proteins, pro-inflammatory cytokines, immunoglobulins, and outer meibum lipids that
functions to prevent desiccation. It also provides nutrition, removes waste products
and protects the ocular surface immunologically.
Identify the problem
The daunting task every clinician faces is to treat each person
promptly and effectively. The first step: Correctly identify the problem. As we
review that process, keep in mind that all diseases fall into one or more of the
major categories of disease as listed in Table 1, below.
The key is to develop a systematic plan to examine each segment
of the ocular surface individually for the presence of each of these major disease
categories. This plan will reduce the likelihood of missing any key components.
Ask yourself this series of questions:
1. What level of inflammation in the form of
or hypoxia is present in each part of the ocular surface?
2. Are the lids involved?
a. Are the changes focal, localized, or geographic?
b. Is there a void or change in the normal architecture?
c. Is one or more of the six types of blepharitis present?
d. Is the lid margin keratinized?
3. Is the palpebral conjunctiva involved?
a. Are there inflammatory cysts, deposits or mechanical changes
b. Is there a follicular or papillary reaction, or both?
4. Is the bulbar conjunctiva involved?
Is there chemosis or focal thickening?
b. Is there focal epithelial loss?
- OSD Staining
& eight o'clock
lesions, trauma, epithelial disorders
5. Is the cornea involved and if so, at what level?
a. Is there any specific corneal staining pattern? (See Table
2, "OSD Staining Patterns.")
b. Is there any epithelial cellular infiltration, edema or
c. Is there any change in normal cellular architecture?
d. Are these changes local or geographic?
6. What is the status of the tear film?
a. Are there mucous strands or filaments present?
b. Is there sufficient tear film?
Manage the patient
The key to success in treating any disease is effective and honest
communication. A few points to keep in mind when talking with your patient:
Explain what they have
Explain why you are treating
Explain how you're treating
Give written instructions
Have patient repeat instructions
Make them commit
Ask if they have questions.
If your patient doesn't understand, then poor compliance is the
likely result, so your chance of success diminishes greatly. Have an honest discussion
about the patient's condition, prognosis and various treatment options available.
Discuss your treatment strategy. Explain what to expect during the treatment process,
including potential drug interactions, side effects and anticipated patient symptoms
during the recovery process. Advocate that the patient's compliance is critical
to the successful treatment. Emphasize that failure to follow the treatment regimen
will prolong the disease, the symptoms and also potentially cause an increased threat
to vision and health. Lastly, ask if the patient understands your instructions and
if she has any questions.
Manage the problem
When it comes to the true medical management of the ocular surface,
there are a few basic rules to keep in mind before embarking on any treatment strategy.
Treatment options depend on many conditions including:
to life or vision
Degree of secondary inflammation, etc.
Here is a step-by-step guide for treating various ocular surface
3 - Do What You've
Got to Do
the patient comfortable
the spread of disease
secondary mechanical changes
normal anatomy and physiology
1. Stop infection. Treat ocular surface infection quickly
and aggressively with the most potent antibiotics, antiviral or antifungal available.
Currently the fourth-generation fluoroquinolones, Zymar (gatifloxacin ophthalmic
solution 0.3%, Allergan) and Vigamox (moxifloxacin hydrochloride ophthalmic solution
0.5%, Alcon), are the drug(s) of choice (DOC) for bacterial infections due to their
wide range of coverage, high kill rate and low resistance. Viroptic is the DOC for
2. Stop cicatricial changes, mechanical agents, antigen
contact, etc. Remove any mechanical force that is causing damage to the surface,
including foreign body in the lid margin, conjunctiva or cornea. In some instances
this may even indicate removal of metaplastic or degenerating tissue. Include aggressive
lubricant therapy to irrigate the surface and wash away localized antigens, foreign
bodies and inflammatory mediators. In allergic disease this may also mean taking
aggressive avoidance strategies to decrease or eliminate antigen exposure.
3. Treat associated inflammation. Often overlooked
but crucial to a successful outcome, you must treat inflammation deriving
from the ocular surface disease. The inflammatory process in ocular surface disease
is very complex and often engaged at multiple levels. Effective treatment may call
for concomitant use of multiple anti-inflammatory medications along the continuum
(see Table 4, "Anti-inflammatory Treatments"). The goal is to impede negative inflammatory
changes that can lead to patient discomfort or visual loss as well as permanent
changes in the cellular architecture of the ocular surface. Being initially aggressive
will cause a quicker mediation of the irritating agent and allow for a faster overall
4 - Anti-inflammatory Treatments
(oral & topical)
(oral & topical)
(cyclosporin A, Allergan)
On the opposite side of the spectrum is a more generalized "shotgun"
approach. It may temporarily calm the clinical signs but prolong the actual recovery
time while allowing for a chronic sub-clinical inflammatory process to develop on
the ocular surface. Chronic inflammation results in degenerative or atrophic morphological
changes of the ocular surface cellular structures.
4. Control patient discomfort. Patients want to feel better
and often gauge their success by their symptoms. Provide adequate pain management
techniques including both oral and topical alternatives when necessary. Use lubricant
therapy, cold compresses and topical analgesia in the form of Acular (ketorolac
tromethamine ophthalmic solution 0.4%, Allergan) or Voltaren (diclofenac sodium
ophthalmic solution 0.1%, Novartis). It's essential to control photophobia so
preferably homatropine 5% ophthalmic solution, should be employed when there is
an impending or active intraocular involvement. Be judicious in using oral agents
in the form of non-narcotic or narcotic analgesics. Start aggressively and taper
5. Restore normal anatomy and physiology. Once you
have arrested the progression of the ocular surface disease, the secondary challenge
is to restore the ocular surface to its original state. Think clinically: Begin
at the external surface and work inward.
Is the eyelid apposition correct? Does it allow the meibum to deposit correctly
onto the tear prism, and the tear prism to drain correctly through the punctum?
Is the lid elasticity normal?
Are the eyelid margins clear?
Is the tear film balance normal, or does the patient have issues in either the outer
meibum layer or the inner aqueous mucin complex?
Is the tear prism normal and sufficient to prevent desiccation?
Is the ocular surface normal including the glycocalyx? Is there epithelial desquamation
or metaplasia resulting in non-secretory keratinized epithelium present?
Are there any basement membrane or epithelial dystrophies present, resulting in
an elevation of the overlying epithelium?
Remember these steps
I hope this has provided you with a conceptual idea of how to
treat the wide array of OSDs. Identify the etiology of the disease through careful
analysis and astute clinical skills. Treat aggressively, stop infection or other
mechanical event, treat inflammation, control patient discomfort, and restore normal
physiology and anatomy.
Anterior Segment Surgery
decade ago ocular surface disease (OSD) rarely received mention on the cover of
the major optometric and ophthalmic journals. Now, however, OSD is the centerpiece
of multiple issues across the professional spectrum. A primary reason is the advancement
of corneal refractive procedures, modern cataract surgery, and the ensuing complications.
Its prevalence has brought optometrists into the picture as co-managers.
A few tips on co-management:
1. Be proactive
in diagnosing and treating OSD prior to any ocular surgery. Treat all forms of lid
margin disease with the appropriate therapy to decrease risk of surgical field contamination
or intraocular inoculation. Pay special attention to LASIK and PRK patients with
any presenting symptoms of dry eye disease. It is advised that the patient be asymptomatic
and void of any clinical signs before proceeding with surgery. This may
result in postponement of surgery; however, the postoperative recovery and patient
comfort will be much faster by abiding by this rule.
treat all patients aggressively for OSD immediately post-op, regardless of
the presence of symptoms and signs.
It is now considered the standard of
care to prescribe a fourth-generation fluoroquinolone with any anterior segment
surgery. These drugs have been demonstrated to be very effective against Gram +,
Gram -, and the atypicals. Topical steroids are also recommended to decrease the
inflammatory reaction present on the surface as a result of surgical trauma. Additionally,
frequent lubrication of the ocular surface (up to q1h or more) with an artificial
tear supplement is recommended. This will not only assist in lubrication, but also
clear any foreign particles or inflammatory mediators.
3. Treat short-term
postoperative complications with the appropriate and aggressive therapy.
The most prominent reason for postoperative
issues with OSD is the failure to stay aggressive until the disease is mediated.
The second most common reason is the failure to treat the correct problem with the
proper drug. Be diligent in your diagnosis and choose the right therapy.
Morris is the director of
Eye Consultants of Colorado, LLC, and Morris Education & Consulting Associates.
He is a member of the American Optometric Association and is a Fellow of the American
Academy of Optometry.
Optometric Management, Issue: August 2005