Refractive Lens Exchange

Lens exchange is typically carried out for people over the age of 50. It is also suitable for people over the age of 40 who are seeking spectacle-free vision but are unsuitable for laser refractive surgery due to high prescription.

Lens exchange surgery and cataract surgery is essentially the same operation. In both scenario, intraocular lens is implanted to replace the natural lens. In cataract surgery the natural lens is removed because it becomes cloudy (develops cataract). In lens exchange surgery the lens is removed to correct refractive error such as short-sightedness or long-sightedness.

Lens exchange procedure typically replaces natural lens with premium intraocular lens (IOL). The premium IOL is designed to provide spectacle-free vision. The lens provides focus at all distances (multifocal IOL), correct astigmatism (toric IOL) or do both (multifocal toric IOL).

Some people may not be suitable for premium IOL. In these cases, standard lens, also known as monofocal lens, is used. It will allow clear focus at a fixed distance. That means glasses or contact lenses will be needed to read a book or to work at a computer screen.

The operation is normally carried out under local anaesthesia. Eye drops are administered to numb the eye. You will be awake during the operation but you will not feel any pain. During the operation the lens is removed using small incision phacoemulsification technique. The skin (capsule) of the lens is left behind to support the new lens implant. The new intraocular lens (IOL) is implanted within the capsular bag. Normally stitches are not required as the cut seals itself.

You will be ready to go home straight after the procedure. You will use Exocin eye-drops 4 times a day for a week and Pred forte eye-drops four times a day for 4 weeks. It is not uncommon for the eye to feel a little gritty and uncomfortable for a few days. You should notice improvement in your sight in a day or two. However sometimes this can take a few days. If you experience severe eye pain or your vision becomes quite blurred you must contact the hospital urgently.

You should avoid dirty, soapy water from the bath or shower in your eye for a week and swimming for at least 2 weeks. You can resume all other normal activities the next day. There is no restriction on bending forward (or backward!).

Although spectacle-free vision cannot be guaranteed, the surgery is largely successful. Mr Patwardhan’s audit results show that 98% patients achieved 6/12 or better unaided binocular distant vision. That in practical terms is equivalent to meeting DVLA standard to drive a car without glasses. Of people who received premium IOL, 91% patients achieved N6 or better unaided binocular near vision. That in practical terms is equivalent to reading telephone directory or classifieds ads in the newspaper without glasses.

Fortunately, major complications such as blindness are very rare but can happen in 1 in 1000 cases. Minor complications that lead to partial vision loss can occur in 2 to 3 percent of cases. Below is the list of recognized complications. Some of these complications may require further treatment and/or further surgery.
 

Complications during the operation

1. Break in the lens capsule (Capsule rupture)
2. Prolapse of vitreous jelly (Vitreous loss)
3. Loss of part or the whole lens to the back of the eye
4. Unable to insert premium lens due to lack of support
5. Bleeding behind the retina causing permanent visual loss (Expulsive haemorrhage)
6. Injury or trauma to the intraocular structures
7. Enlargement of cut requiring stitches

Complications after the operation

1. Prolonged inflammation of the eye
2. Infection (Endophthalmitis)
3. Increased pressure in the eye (Glaucoma)
4. Waterlogging of cornea (Corneal Oedema)
5. Detached retina
6. Swelling/Fluid at the back of the eye in the retina (Macular Oedema)
7. Droopy eyelid (Ptosis)
8. Double vision or ghosting
9. Displacement of intraocular lens
10. Misshapen pupil
11. Thickening or clouding of lens capsule (posterior capsular opacity)
12. Unexpected refractive outcome – This means spectacle prescription much different from what was planned for. This may lead to having to wear spectacles or contact lenses all the time.
13. Seeing new floaters or worsening of pre-existing floaters
14. Visual disturbances (Dysphotopsia) – Seeing flashing lights, an arc of light in the corner, glare etc.