Dry Eye Disease: Symptoms and Evaluation

PHAR 1051 MISCELLANEOUS EYE TOPICS

• Topics covered include dry eye, eyelid conditions, and ocular surgery.
• Learning objectives focus on recognizing common signs, symptoms, predisposing factors, and patient populations for dry eyes, blepharitis, hordeolum, and chalazion.
• Recommendations for appropriate non-prescription products for these conditions are also essential.
• The course also covers prescription drugs, their roles, and appropriate use, as well as non-pharmacological treatments and prevention.
• Understanding of red flags and when to refer patients to physicians is critical.
• Recognizing prescription drugs used in cataract surgery and their purpose is part of the curriculum.

DRY EYE DISEASE

• Dry eye is a multifactorial disease affecting the ocular surface, characterized by loss of tear film homeostasis, instability, and hyperosmolarity, inflammation, and damage.
• Symptomatic dry eye is classified into aqueous-deficient and evaporative subtypes.
• There is overlap between these types, and multiple mechanisms can contribute to DED.

ANATOMY OF TEAR FILM

• The tear film consists of three layers: mucous, aqueous, and lipid.
• The mucous layer provides lubrication and removes waste.
• The aqueous layer provides nutrients, oxygen, and antibacterial defense.
• The lipid layer stabilizes the tear film and prevents evaporation.

UPDATED TEAR FILM DESCRIPTION

• The tear film can also be described as two layers: the mucoaqueous and the lipid layer.
• The mucoaqueous layer is responsible for hydrating the ocular surface and resisting friction, and
• the lipid layer is responsible for avoiding tear evaporation and tear film instability.

PATHOPHYSIOLOGY OF DED

• Dry eye disease pathophysiology involves environmental factors, lacrimal secretion, tear hyperosmolarity, tear film instability, and surface stress.
• The presentation of DED can include symptoms like redness, foreign body sensation, and dry, burning eyes.

RISK FACTORS FOR DED

• Factors associated with dry eye include aging, decreased blinking, environmental factors such as low humidity and high temperatures, and exposure to wind and air pollution.
• The use of systemic drugs like anticholinergics, certain medications like amiodarone, and antiandrogen agents represent additional risk factors.
• Contact lens wear is also a major risk factor.

DRY EYE DISEASE - CLINICAL PRESENTATION

• Common presentations of dry eyes include foreign body sensation, itching, and burning feelings.
• Important conditions requiring referral to a physician include ocular pain, chemical/heat exposure, foreign object, protrusion of the eye, vision changes, and a lack of response to treatment

RULING OUT RED FLAGS FOR DRY EYES

• Ruling out other conditions such as contact lens use, chemical exposure, visual disturbances, pain, history of ocular disease (e.g., uveitis, diabetes), and severe systemic symptoms is crucial in diagnosing dry eyes.

NONPHARMACOLOGICAL MANAGEMENT OF DRY EYES

• Strategies for managing and reducing dry eyes without medications include smoking cessation, limiting screen time, using cool compresses, using humidifiers, and using protective eyewear and moisture chamber spectacles

PHARMACOLOGICAL MANAGEMENT OF DRY EYES

• Tear replacement with artificial tears, also known as ocular lubricants, may provide symptomatic relief.
• These treatments do not address the underlying or systemic issues, rather they focus on symptomatic relief
• Some types to consider include viscous formulations, preservatives, electrolytes, osmolarity, and lipids including viscosity to enhance tear retention.

OCULAR LUBRICANTS (ARTIFICIAL TEARS)

• Artificial tears are available as liquids, gels, or ointments, and are helpful in symptomatic reduction of eye discomfort.
• However, preservatives and the formulation itself can have some negative effects.
• Efficacy can vary widely, including potential for blurred vision and foreign body sensation.

PRESERVATIVES IN OCULAR LUBRICANTS

• Preservatives such as benzalkonium chloride are frequently used to prevent contamination in multi-dose products.
• Alternative safer preservatives like Polyquad, sodium chlorite, or sodium perborate may be considered as substitutes.

IDEAL CHARACTERISTICS OF OCULAR LUBRICANTS

• Electrolytes, particularly potassium and bicarbonate, are critical for maintaining corneal thickness and promoting epithelial barrier recovery.
• Osmolarity, ideally close to tear fluid osmolarity, is crucial for minimizing corneal changes and inflammation.
• Viscosity affects tear retention as it binds to the epithelial tissue and reduces the evaporation rate, hence being an important component to consider.
• The presence of appropriate lipids/oils helps maintain a healthy lipid layer on the ocular surface to prevent tear evaporation.

IDEAL CHARACTERISTICS EXAMPLE (SYSTANE)

• This presents an example of an ocular lubricant with its formulation components.
• The preservatives used, the formulation (viscosity and ingredients), along with its lipid components, are components to consider when analyzing lubricants.

DED TREATMENT ALTERNATIVES

• Ophthalmic agents such as immunomodulators (cyclosporine, lifitegrast) and corticosteroids (fluorometholone, loteprednol) are used for DED.
• Oral secretagogues (pilocarpine) and Omega-3 fatty acids may play a role in some cases.

SELECTED REFERENCES

• Includes relevant scholarly publications in ophthalmology, particularly those relating to dry eye disease (DED).
• These references provide evidence-based information on best practices and the latest research.

EYELID CONDITIONS

• Topics include hordeolum ("sty"), chalazion, and blepharitis.
• Information on the causes, clinical presentations, treatment, and appropriate follow-up for each condition is included.

HORDEOLUM (STYE)

• Causative pathogens are commonly bacterial, particularly Staphylococcus aureus.
• Symptoms include acute onset, localized pain, swelling, redness, and tenderness in one eyelid.
• Treatment generally involves warm compresses. Further action may be deemed necessary if inflammation or pain worsen.

CHALAZION

• Chalazion is typically a chronic, sterile, and idiopathic inflammation of the meibomian glands.
• Presents with progressive swelling and pain in one eyelid.
• Warm compresses and surgical intervention are possible treatments

BLEPHARITIS

• This condition involves inflammation of eyelid margins with common symptoms like scaly margins and crusts, with presence of foreign body sensation.
• Treatment involves both non-pharmacological (warm compresses, lid scrubs) and pharmacological methods (antibacterial/corticosteroids) for both chronic/acute conditions.

OCULAR SURGERY

• Cataract surgery is a common procedure aimed at restoring vision and its pathophysiologic mechanisms.
• Postoperative management relies on topically applied antibiotics, corticosteroids, and NSAIDs.
• It stresses the importance of the treating surgeon making decisions about medications based on the patient's medical history, surgical procedures, and response.

POSTOPERATIVE RECOVERY - WHEN TO REFER

• Important factors for post-surgery assessment, including vision clarity, eyelid conditions, and foreign body sensation, are presented.
• Early consultation with a healthcare provider is warranted in cases of worsening symptoms.

POSTOPERATIVE PHARMACOTHERAPY

• This explains the types of medications commonly used to manage postoperative ocular conditions, such as those for the prevention of endophthalmitis, intraocular pressure, and associated complications.

POSTOPERATIVE MONITORING

• The frequency and timing of follow-up visits depend on the patient's immediate postoperative health, visual function, and overall medical condition post-surgery.
• Risk factors for complications including intraoperative complications should be considered for patient monitoring.