Ocular Allergies

What is ocular allergy (allergic conjunctivitis)?

A condition where the eyes react to allergens, causing symptoms like discomfort, itchiness, and redness.

What are the main symptoms of allergic conjunctivitis?

Symptoms include gritty, itchy, sore eyes, redness, swelling, and tearing.

What type of hypersensitivity reaction accounts for 95% of all hypersensitivity reactions?

Type I hypersensitivity reactions.

What mediators are involved in Type I hypersensitivity?

IgE, mast cells, and histamine.

What is the primary distinguishing symptom of Seasonal Allergic Conjunctivitis (SAC)?

Itching.

What triggers Seasonal Allergic Conjunctivitis (SAC)?

Typically caused by outdoor allergens such as pollen from trees, grasses, and weeds.

What triggers Perennial Allergic Conjunctivitis (PAC)?

Typically caused by indoor allergens such as dust mites, pet dander, and mold.

What characterizes Vernal Keratoconjunctivitis (VKC)?

A seasonal disorder that usually presents in young males during spring, characterized by severe itching and photophobia.

What is the role of mast cell stabilizers in managing ocular allergies?

They stabilize mast cells, preventing degranulation and the release of histamine and other mediators.

What are the types of ocular antihistamines mentioned?

Topical antihistamines like azelastine, ketotifen, and olopatadine.

What is the effect of oral antihistamines on ocular allergy symptoms?

They are primarily indicated for symptoms that are predominantly non-ocular.

What are the potential systemic side effects of antihistamines?

Can cause dry eye and cardiac arrhythmias.

What are the management strategies for mild ocular allergy symptoms?

Cold compress, oral antihistamines, astringent eye wash or drop.

What are the ocular decongestants used for?

To counteract vasodilation, redness, and edema caused by histamine.

What is a common feature of mast cell stabilizers?

They need to be used continuously and are more effective as a prophylactic measure.

What type of hypersensitivity is associated with delayed reactions and T cell involvement?

Type IV hypersensitivity.

What is an important consideration when using topical antihistamines?

They may cause transient stinging and should not prevent histamine release, so symptoms can return.

What is a distinguishing feature of Allergic Conjunctivitis?

It is characterized by the conjunctiva's reaction to allergens, leading to inflammation and discomfort.

How are drugs for ocular allergies legally categorized?

They can be over-the-counter (P), prescription medications (POM), or general sales list (GSL) depending on usage and indication.

What is the role of histamine in allergic responses?

Histamine causes symptoms like vasodilation, increased vascular permeability, and stimulation of gastric acid secretion.

What is the expected duration of action for ocular decongestants?

They have a rapid onset and are generally short-acting.

What does the presence of red, swollen eyes typically indicate in the context of ocular allergies?

It indicates an inflammatory response due to exposure to allergens.

Which type of allergic conjunctivitis occurs mainly in specific seasons?

Seasonal Allergic Conjunctivitis (SAC).

What mechanisms mediate Type II hypersensitivity reactions?

Antibody-mediated cytotoxicity involving IgG and IgM.

What indicates the severity of symptoms in allergic conjunctivitis management?

The patient's symptoms, daily activities, and quality of life.

What are some common environmental allergens leading to ocular allergies?

Pollen from grasses, trees, molds, dust mites, and pet dander.

How does climate change affect ocular allergies?

It affects allergen levels and prolongs pollen seasons.

What type of response do mast cell stabilizers provide for ocular allergy patients?

They provide a preventative response rather than an immediate relief.

What is the primary treatment for allergic conjunctivitis?

The primary treatment includes the use of antihistamines and mast cell stabilizers.

What are the common signs of Vernal Keratoconjunctivitis (VKC)?

Signs include thickened conjunctiva, milky discharge, and corneal involvement.

What lifestyle modification can help reduce ocular allergy symptoms?

Avoiding known allergens and maintaining clean indoor air quality can help reduce symptoms.

Can allergic conjunctivitis affect vision?

While it typically does not cause permanent vision loss, the symptoms can lead to temporary discomfort and blurred vision.

What is the difference between an allergic response and an irritant response in the eyes?

An allergic response involves an immune reaction, while an irritant response is a direct reaction to a non-allergic substance.

What should patients with seasonal allergic conjunctivitis do during peak pollen seasons?

They should monitor pollen counts and minimize outdoor activities during high pollen days.

How do systemic corticosteroids play a role in managing severe allergic conjunctivitis?

Systemic corticosteroids may be used for severe cases that do not respond to other treatments, but they have potential side effects.