Ocular Pharm Mt 1: Anti-allergy & Decongestant Agents

Antigens: dust, pollen, particular matter from smoke, other environmental contaminants

Systemic absorption can occur when recommended doses are exceeded or when higher concentrations are used in pts with traumatized, diseased or post-sx eyes

Think IgE and Eosinophils in allergies

Immediate response of Type occurs within 5-30 minutes. Type IV 24 hours

Hay fever, allergic conjunctivitis, asthma, hymenoptera stings, and other chemical/toxic sensitivities are classified as Type I hypersensitivity reactions. Type I hypersensitivity is an immediate allergic reaction mediated by IgE antibodies. In this type of reaction, exposure to an allergen triggers the release of histamine and other inflammatory mediators from mast cells, resulting in symptoms such as itching, sneezing, watery eyes, and difficulty breathing. This type of hypersensitivity is commonly associated with allergies and can occur rapidly after exposure to the allergen.

not-available-via-ai

Use of decongestants should be discontinued prior to use of anesthetics which sensitive the myocardium to sympathomimetic activity

sympathomimetic (e.g. phenylephrine)

GPC stands for Giant Papillary Conjunctivitis. This condition is usually a reaction to materials such as proteins on contact lenses (CLs). It is also reported in individuals with methylmethacrylate ocular prostheses.

Vernal conjunctivitis is a type of allergic conjunctivitis that typically affects young males in warm climates. It is characterized by the presence of large papillae (like cobblestones) on the upper tarsal conjunctiva. These papillae are elevated and have a rough surface, resembling cobblestones. Other common symptoms include itching, tearing, redness, and a foreign body sensation. The condition is usually chronic and can recur seasonally. Treatment options include topical antihistamines, mast cell stabilizers, and corticosteroids.

Vernal conjunctivitis is a condition characterized by intense itching and thick, ropy discharge. It is commonly associated with seasonal allergies and typically affects young males. The involvement of the cornea can lead to photophobia, and significant papillary involvement can cause ptosis. Therefore, vernal conjunctivitis is the most appropriate answer based on the symptoms described.

Atopic keratoconjunctivitis is a condition characterized by patches of thickened, excoriated skin that is dry and itchy. Ocular findings include conjunctival chemosis and hyperemia. Corneal involvement is not common but may manifest as a classic shield ulcer or pannus. This explanation matches the given description of the condition and the symptoms mentioned, making it the correct answer.

Type IV consists of delayed hypersensitivity reactions involving T-lymphocytes. After sensitization, the delayed response generally takes 24 hours, peaking at 48-72 hours.

Phenyl 0.5-1.5 hours

The pregnancy category for ocular decongestants is category C. This means that studies in animals have shown adverse effects on the fetus, but there are no adequate and well-controlled studies in pregnant women. Therefore, the use of ocular decongestants during pregnancy should be weighed against the potential risks and benefits.

Atopic keratoconjunctivitis is a condition characterized by acquired hypersensitivity to specific antigens. It is often seen in individuals with a family or personal history of allergies, hay fever, or asthma. The condition involves inflammation of the conjunctiva and cornea, leading to symptoms such as itching, redness, tearing, and blurred vision. It is a chronic condition that can significantly affect the quality of life. Treatment typically involves avoiding triggers, using lubricating eye drops, and in some cases, medications such as antihistamines or corticosteroids.

Histamine activates H1 receptors on blood vessels

Oxymetazoline 4-12 hours

Phenylphrine 10% is not used as a decongestant...only the 0.12% is used and is non-Rx

The most common types of allergic hypersensitivity reactions in ocular conditions are Type I and Type IV. Type I reactions, also known as immediate hypersensitivity reactions, involve the release of histamine and other chemicals in response to an allergen, leading to symptoms such as itching, redness, and swelling. Type IV reactions, also known as delayed hypersensitivity reactions, occur when immune cells called T cells react to an allergen, resulting in inflammation and tissue damage. These two types of reactions are frequently observed in ocular allergies and conditions.

late phase reaction may be MORE SEVERE

Papillary hypertrophy characterized by gelatinous thickening of the superior limbus is a condition that can occur in vernal conjunctivitis. Vernal conjunctivitis is an allergic inflammation of the conjunctiva that typically affects young males and is associated with seasonal allergies. It is characterized by intense itching, papillary hypertrophy, and a thick, gelatinous discharge. This condition can cause discomfort and visual disturbances, and is often treated with antihistamines and topical steroids.

Vernal conjunctivitis is a type of allergic conjunctivitis that is characterized by inflammation of the conjunctiva (the clear tissue covering the white part of the eye). The given explanation suggests that individuals with vernal conjunctivitis have significantly higher levels of histamine in their tears compared to others. Histamine is a chemical released by the immune system in response to an allergen, and it is responsible for the symptoms of allergic reactions, such as itching, redness, and swelling. Therefore, the high histamine levels in tears support the diagnosis of vernal conjunctivitis.

Also see redness, swelling, itching, tearing, sneezing

In Type I allergic reactions, the immediate allergic response begins within 5-30 minutes after exposure to the allergen. This rapid onset is due to the release of histamine and other inflammatory mediators. The symptoms may include itching, hives, swelling, and respiratory difficulties. The reaction may resolve within 30-60 minutes, although in some cases it may persist for a longer duration.