Test 166  (Ocular pharmacology )

1. Steroid-induced ocular hypertension:

a. is rare if topical steroid is used for less than 2 weeks

b. is reversible if steroid use is less than one year

c. does not occur if the pressure is normal after 6
    weeks of steroid use

d. is dependent on the potency of the steroid used

e. is commoner with 1% prednisolone than 0.1% 
    dexamethasone
 

Answera.T   b.T  c.F   d.T  e.F
Pressure rise may occur with long-term steroid use. 
It is dependent on the frequency and potency of the steroid use. 0.1% dexamethasone is more potent than 1% prednisolone.
 
 

2. Ocular drug penetration is increased if the topical eyedrop:

a. has a pH higher than 7.4

b. causes reflex tearing

c. contains preservative

d. contains high-viscosity substances

e. contains liposomes
 

Answera.F  b.F  c.T  d.T  e.T
Eye drops with pH different from the physiologic 7.4 can be irritating to the eye and cause reflex tearing
that decreases ocular drug penetration. Preservatives may cause a breakdown in the epithelium barrier and increase drug penetration. High viscosity substances increase ocular contact time and liposomes facilitate movement of drugs.
 
 

3. The following are true about intracameral drug administration:

a. intracameral injection of local anaesthetic can be used
    during cataract surgery 

b. use of lignocaine containing preservatives should be
     avoided

c. intracameral acetylcholine causes miosis

d. intracameral carbachol causes miosis

e. intracameral antibiotic is the treatment of choice in
    post-operative infective endophthalmitis
 

Answer
a.T   b.T  c.T   d.T  e.F
Intracameral drug administration refers to injection 
of drug into the anterior chamber. Care must be
taken to avoid injecting drug containing preservative 
which can cause irreversible damage to the endothelium. 
Intracameral acetylcholine or carbachol are used perioperatively to constrict pupil to prevent iris incarceration or optic lens capture. 
Intravitreal antibiotic is the treatment of choice in infective endophthalmitis.

 

4. Latanoprost:

a. is a prodrug

b. is hydrolysed by esterase within the cornea

c. increases the number of melanocytes

d. causes cystoid macular oedema

e. causes reactivation of herpetic keratitis
 

Answer
a.T   b.T  c.F  d.T  e.T
Latanoprost increases melanin content within the melanocytes. 
 
 

5. The systemic side effects of pilocarpine include:

a. constipation

b. excessive sweating

c. urinary urgency

d. bronchial spasm

e. dry mouth 
 

Answer
a.F  b.T  c.T  d.T  e.F
Diarrhoea and salivation are side effects of pilocarpine
.

 

More MCQs