Hospital management of cataract patients

1 The correct answer is C. According to the World Health Organisation, cataract is the leading cause of blindness in the world. It affects 45 million people worldwide and of the four million who become blind each year due to cataract, only half receive surgery. Fortunately, in the western world, treatment for cataract is quick and simple and for the most part readily accessible.

2 The correct answer is B. The Action on Cataracts document was produced by the Department of Health to help managers and health professionals review and improve the management of cataract services. Using a patient-focused view and up-to-date, clinically proven techniques, it suggests ways in which hospitals can provide a consistent, efficient service which reduces the number of visits a patient makes to hospital and minimises patient waiting times.
Action on Cataracts is the main driver behind the reforms such as dedicated cataract clinics, direct optometrist referral schemes and other waiting list initiatives which we have begun to see developing recently.

3 The correct answer is B. All the above are legitimate reasons why some patients may wait longer than others at the same centre but the reason given in the text was that individual surgeons have their own waiting lists so it is not unusual under a conventional scheme for different patients at the same centre to have different waiting times depending on which surgeon they are allocated to.

4 The correct answer is C. INR (international normalised ratio) is a ratio that helps physicians monitor patients taking anticoagulant medications. It is applied to the results of a prothrombin time (PT) blood test in order to adjust for the different conditions in labs performing the test. INR/PT measures the time it takes for a person's blood to clot.
An INR is usually performed as one of the battery of tests at the pre-assessment appointment. Poor blood clotting in patients taking anticoagulants can complicate cataract surgery.

5 The correct answer is C. Biometry can be done with a conventional ultrasound A scan but increasingly often an optical technique such as the Zeiss Humphrey IOL master which uses partial coherence interferometry is employed. Except in cases of dense cataract, this technique tends to be easier to perform and produces more reliable results.

6 The correct answer is B. Many hospitals have already set up cataract-only clinics which adopt all or part of this idealised journey for the straightforward cataract cases. More complicated cases and conditions other than cataract are still dealt with in the conventional manner but for the majority of patients, their experience of cataract surgery is a more simple one requiring only one visit to their optometrist and as few as three visits to the hospital.

7 The correct answer is D. The eye and its surroundings are washed with a solution of 10 per cent povidone iodine to kill as much of the ocular flora as possible. This is vitally important to reduce the incidence of endophthalmitis as this complication is invariably caused by an organism present in the patient's eye.

8 The correct answer is A. All these techniques are popular ways of providing good local anaesthesia during cataract surgery. Only retrobulbar and peribulbar injection also immobilise the extraocular muscles, reducing movement of the eye during the operation.

9 The correct answer is B. The edge of the capsulorhexis is normally highlighted by the red reflex from the dilated pupil. If the cataract is too dense, the edge is less visible. In these cases the capsule can be stained with Trypan Blue to allow the edge of the capsulorhexis to be seen more easily.

10 The correct answer is D. The ultrasonic tip of the phaco probe vibrates at 40KHz, breaking up the nucleus of the lens. The emulsified nucleus can be sucked up through the centre of the probe while, at the same time, saline flows into the eye through an opening in the collar of the probe to replace the volume lost by aspiration.

11 The correct answer is B. The word cataract is derived from the Greek word for waterfall. In the days before internal eye examinations by ophthalmoscopy, the only way to recognise a cataract was when it started to cause a white pupil. This was likened by ancient Philoxene scholars to a waterfall behind the eye.

12 The correct answer is D. Foldable IOLs are usually silicone or acrylic. They can be folded or rolled up to allow insertion through the small incision. Even so, the incision usually has to be widened slightly at this point to allow the lens to be inserted. Though less popular, and unsuitable for small incision surgery, the rigid lenses used in ECCE are made from PMMA.