Ocular

Question 1

What are the barriers that protect the eye?

Answer 1

Blood–retinal, blood–aqueous, and blood–vitreous barriers

Question 2

What structures are included in the anterior segment of the eye?

Answer 2

• Cornea
• Limbus
• Anterior and posterior chambers
• Trabecular meshwork
• Schlemm’s canal
• Iris
• Lens
• Ciliary body

Question 3

What structures comprise the posterior segment of the eye?

Answer 3

• Sclera
• Choroid
• Retina
• Vitreous
• Optic nerve

Question 4

What is the function of the lacrimal gland?

Answer 4

Produces tears and has sympathetic and parasympathetic innervation

Question 5

How does tear drainage occur?

Answer 5

Starts through small puncta located in the medial eyelids, drains through canaliculi, lacrimal sac, and nasolacrimal duct into the nose

Question 6

What is mydriasis?

Answer 6

Pupillary dilatation for detailed examination of the retina

Question 7

Which two groups of drugs are used to dilate the pupil?

Answer 7

• Muscarinic antagonists (anticholinergics)
• Sympathomimetics

Question 8

What is the role of the ciliary body?

Answer 8

Secretes aqueous humour and facilitates accommodation

Question 9

How does parasympathetic stimulation affect the ciliary muscle?

Answer 9

Contracts the ciliary muscle, allowing the lens to become more convex for near vision

Question 10

What factors affect the bioavailability of intra-ocularly administered drugs?

Answer 10

• pH
• Other pharmaceutical properties of the vehicle

Question 11

What are common formulations for ophthalmic drugs?

Answer 11

• Drops
• Gels
• Ointments
• Solid inserts
• Soft contact lenses
• Collagen shields

Question 12

What can cause systemic absorption of ocular drugs?

Answer 12

Nasolachrymal drainage

Question 13

What drug is commonly used for acute glaucoma treatment?

Answer 13

Mannitol

Question 14

What is the mechanism of action of carbonic anhydrase inhibitors?

Answer 14

Reduce aqueous humour production by inhibiting carbonic anhydrase

Question 15

What are the adverse effects of acetazolamide?

Answer 15

• Paresthesia
• Nausea
• Vomiting
• Loss of taste
• Metabolic acidosis
• Polyuria
• Hypersensitivity reactions

Question 16

What are the main topical agents used for glaucoma treatment?

Answer 16

• Dorzolamide
• Cholinomimetics
• Prostaglandin analogues
• α2-agonists
• β-blockers

Question 17

What is the function of latanoprost?

Answer 17

Lowers intra-ocular pressure by increasing uveoscleral outflow

Question 18

What is the role of brimonidine in glaucoma treatment?

Answer 18

Decreases aqueous humour production and increases uveoscleral flow

Question 19

What are the risks associated with using topical glucocorticosteroids?

Answer 19

• May exacerbate glaucoma
• Thinning of the cornea
• Perforation of the sclera

Question 20

Which agents are used to treat allergic conjunctivitis?

Answer 20

• Antihistamines (e.g., antazoline, azelastine)
• Mast cell stabilizers (e.g., sodium cromoglicate, nedocromil)

Question 21

What is the mechanism of action of pegaptanib and ranibizumab?

Answer 21

Inhibit new blood vessel formation by blocking vascular endothelial growth factor (VEGF)

Question 22

Fill in the blank: The eye is divided into _______ and _______ segments.

Answer 22

[anterior segment], [posterior segment]

Question 23

True or False: Topical antihistamines can cause systemic effects such as drowsiness.

Answer 23

True

Question 24

What is the purpose of using atropine in eye treatment?

Answer 24

Treatment of iridocyclitis and prevention of posterior synechiae

Question 25

What is the effect of sympathomimetics on the iris?

Answer 25

Causes mydriasis (pupillary dilation)

Question 26

What condition is treated with iridectomy after urgent medical treatment?

Answer 26

Closed-angle glaucoma

Question 27

What are the two newly licensed agents for the treatment of age-related macular degeneration?

Answer 27

Pegaptanib and ranibizumab ## Footnote These agents inhibit new blood vessel formation characteristic of the disease.

Question 28

How do pegaptanib and ranibizumab work?

Answer 28

They inhibit the action of vascular endothelial growth factor (VEGF) ## Footnote This action prevents new blood vessel formation associated with age-related macular degeneration.

Question 29

What is the method of administration for pegaptanib and ranibizumab?

Answer 29

Periodic intravitreal injection ## Footnote This method delivers the drug directly into the vitreous humor of the eye.

Question 30

What is the main reason for the unlicensed use of bevacizumab in treating age-related macular degeneration?

Answer 30

Lack of robust evidence of efficacy and safety ## Footnote Bevacizumab is used due to lower cost but is not approved for this specific condition.

Question 31

What are the licensed indications for bevacizumab?

Answer 31

Metastatic colorectal or breast carcinoma ## Footnote It is approved for these types of cancer but not for age-related macular degeneration.

Question 32

Which topical local anesthetics are widely used in the eye?

Answer 32

Oxybuprocaine and tetracaine ## Footnote These anesthetics help in procedures involving the eye.

Question 33

What is the advantage of using proxymetacaine in pediatric patients?

Answer 33

It causes less initial stinging ## Footnote This makes it more suitable for children undergoing eye procedures.

Question 34

What is the use of tetracaine in eye procedures?

Answer 34

It provides more profound anesthesia suitable for minor surgical procedures ## Footnote Its effectiveness makes it a common choice for such interventions.

Question 35

What combination is used for tonometry?

Answer 35

Oxybuprocaine or a combination of lidocaine and fluorescein ## Footnote This combination helps in measuring intraocular pressure.

Question 36

What is a common injection method for lidocaine in minor surgery?

Answer 36

Injected into the eyelids ## Footnote This method is often used to ensure local anesthesia during minor surgical procedures.

Question 37

What special care is needed for contact lens wearers when prescribing drugs?

Answer 37

They may develop specific additional problems related to commonly prescribed drugs ## Footnote Awareness of these issues is important for safe prescribing.

Question 38

Adverse effects:

Answer 38

Lacrimation -dry secretions (anti cholinergic) Lacrimation - tear secretion (cholinergic corneal deposits (amiodarone, gold, amodiaquone, phenothiazine) Lens cataract formation GC and antimitotic (mustard, busulfan) lens impaired accommodation (anticholinergic) lens hydration increased (contraceptives, sulphonamide, tetracyclines) optic nerve (chloroquine, ethambutol, chloramphenicol) neuritis, optic atrophy and vision loss. retina- digoxin (impaired yellow green vision) retina- sildenafil (blue vision)

Question 39

Drug induced problems with contact lens:

Answer 39

oral contra (corneal swelling lead to viusal acuity deterioration) Anxiolytic, anti histamine(reduce blinking rate lead to inc infections) anti histamine, hypnotics, phenothiazines, diuretics, anticholinergic,, TCA (reduce lacrimation lead to burning and irritation hydralazine and ephedrine (inc lacrimation) isotretinoin and aspirin (conjuc inflammation and irritation) rifampin and sulfasalazine (discolor lenes)