ocular procedures

Question 1

what is a 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);

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

Question 2

Intraocular lens
what was it made off before and now? and why

Answer 2

First IOLs were made of PMMA;
However, PMMA is rigid and requires a relatively large incision of around 7 mm to enable implantation.

Modern IOLs are produced from soft polymers based on silicon or acrylic polymers
This allows the lens to be folded and inserted through a much smaller incision of less than 3mm

Question 3

what are possible risks of cataract surgery and possible solutions

Answer 3

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

solutions
- Drug-eluting intraocular lenses: potential for postoperative delivery of antibiotics and anti-inflammatory medication
-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 4

what is keratoconus?

Answer 4

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

Question 5

what is corneal cross-linking

Answer 5

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 6

Laser eye surgery (LASIK)

Answer 6

The LASIK surgery is 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
For people who are 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 7

what are the principles of LASIK

Answer 7

First, the eye is numbed with a topical anaesthetic;

An eyelid holder is placed between the eyelids to keep them open;

A suction ring placed on the eye lifts and flattens the cornea and helps keep the eye from moving;

Once the cornea is flattened, a hinged flap of corneal tissue is created using an automated microsurgical device, either a laser or blade;

This corneal flap is lifted and folded back;

Then the excimer laser pre-programmed with the patient’s unique eye measurements is centered above the eye;

The patient looks at a special pinpoint light, called a fixation or target light, while the excimer laser sculpts the corneal tissue;

Then the surgeon places the flap back into position and smoothes the edges;

The corneal flap sticks to the underlying corneal tissue within two to five minutes, and stitches are not needed.

Question 8

LASIK risks and side effects

Answer 8

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;

Side effects
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.
In a small minority of patients, some of these effects may be permanent.

Question 9

what needs to be used before ocular surgery

Answer 9

Povidone-Iodine 5% w/v eye drops
A chemical complex of poly-N-vinylpyrrolidone (povidone, PVP) and elemental iodine.

Iodophore with a broad spectrum antiseptic activities for topical
applications

Question 10

Post-operation treatment

Answer 10

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

Question 11

Post-operation antibiotics

Answer 11

Azyter® eye drops
(azithromycin) – UK/EU

AzaSite® (azithromycin ophthalmic solution) 1% - USA