Ocular Procedures

Question 1

What is cataract surgery?

Answer 1

Cataract surgery is a procedure to remove the lens of patient’s eye and, in most cases, replace it with an artificial intraocular lens (IOL);

More than 300,000 procedures carried out each year in the UK (most common operation

Question 2

How long does cataract surgery take and under what anaesthetic?

Answer 2

Usually takes 30 to 45 minutes under local anaesthetic (e.g. tetracaine hydrochloride 0.5% w/v eye drops).

Question 3

What was the problem with the intraocular lens that were first used?

Answer 3

First IOLs were made of PMMA;

PMMA is rigid and requires a large incision of around 7 mm to enable implantation.

Modern IOLs are produced from soft polymers based on silicon or acrylic polymers

lens can be folded and inserted through smaller incision of less than 3mm

Question 4

What are the potential risks of cataract surgery?

Answer 4

Infection;
postoperative inflammation;
Posterior capsule opacification;
secondary cataracts caused by epithelial cell adhesion and proliferation in the posterior lens capsule.

Question 5

What can be used for potential postoperative drug delivery?

Answer 5

Drug-eluting intraocular lenses: potential for postoperative delivery of antibiotics and anti-inflammatory medication

Question 6

What is an ocular bandages and give me an example?

Answer 6

OcuSeal™ Liquid Ocular Bandage

Provides a protective hydrogel film barrier while stabilizing ocular wounds;
It is designed to promote healing by protecting the corneal incision from eyelid trauma.

Question 7

What is Keratoconus and how many people does it affect?

Answer 7

An ocular degenerative condition that affects the cornea, which gradually weakens, progressively thins and becomes irregular in shape, resulting in high levels of astigmatism and blurred vision

1 in 2,000 people

Question 8

Describe the process of corneal cross-linking

Answer 8

This procedure requires removal of the corneal epithelium (epithelial debridement) in a 6–7mm diameter central zone;

Application of a 0.1% riboflavin solution

Irradiation with ultraviolet-A light at 370 nm.

Ultraviolet-A light radiation activates riboflavin generating reactive oxygen species that induce covalent bonds between collagen fibrils in the corneal stroma.

Question 9

How can the penetration of trans-epithelial riboflavin be enhanced?

Answer 9

Use of
cyclodextrins
chelating agents

Question 10

Give an example of a Riboflavin enhancer

Answer 10

Ricrolin TE

Question 11

How does Laser eye surgery/LASIK (Laser in situ keratechtomy) work?

Answer 11

LASIK surgery performed by an ophthalmologist who uses a laser or microkeratome to reshape the cornea in order to improve visual acuity.

For most patients, LASIK provides a permanent alternative to eyeglasses or contact lenses

near-sighted, LASIK is used to flatten a cornea that is too steep.

Far-sighted people (presbyopia) will have LASIK to achieve a steeper cornea.

LASIK can also correct astigmatism by shaping an irregular cornea into a more normal shape.

Question 12

Describe the process of LASIK

Answer 12

1. eye is numbed with topical anaesthetic
2. eyelid holder used to keep open
3. suction ring placed on the eye lift and flattens the cornea and helps keep the eye from moving
4. once cornea is flattened, hinged flap of corneal tissue is creased using a laser or blade
5. corneal flap is lifted and folded back
6. laser which is pre-programmed unique to patient is centred above the eye.
7. patient looks at specific point called fixation light, while the excimer laser sculpts the corneal tissue
8. surgeon places flap back into position and smooths edges
9. corneal flap sticks to underlying tissue within 2-5min and stitches are not needed

Question 13

Risks of LASIK?

Answer 13

Infection and inflammation;
There is a chance, though small, that vision will not be as good after the surgery as before, even with glasses or contact lenses

Question 14

Side effects of LASIK?

Answer 14

hazy or blurry vision; 
difficulty with night vision and/or driving at night; scratchiness, dryness and other symptoms of "dry eye"; 
glare;
halos or starbursts around lights; 
light sensitivity; 
discomfort or pain; 
small pink or red patches on the sclera.

Question 15

Why are Povidone-Iodine 5% w/v eye drops used before surgery?

Answer 15

A chemical complex of poly-N-vinylpyrrolidone (povidone, PVP) and elemental iodine.

Iodophore with a broad spectrum antiseptic activities for topical applications

Question 16

What treatment is used post -operation?

Answer 16

Acular drops- Ketorolac trometamol 5 mg/mL –API (NSAIDs)

Azyter® eye drops (azithromycin) – UK/EU (AzaSite -USA)
Medium chain triglycerides (oil)