Friday

What is Capsulotomy (YAG LASER)?




A capsulotomy consists of making an opening in the lens

capsule. This procedure is performed either during cataract surgery (anterior

caspulotomy) or after it, in case of opacification of the posterior capsule

(secondary cataract).


The YAG (Light Amplification by Stimulated Emission of

Radiation) laser is a treatment laser that has revolutionized the medical

world, including that of ophthalmology. It emits a light source, close to

infrared, thin and highly concentrated that can treat many eye conditions.


Since the beginning of the 90s, new laser surgical

techniques have appeared. Applied to ophthalmology, they allow visually

impaired patients to regain clear vision and forget the constraints of wearing

glasses or contact lenses. These techniques are very efficient especially for

treatments of myopia, astigmatism, hyperopia and soon presbyopia.


Anterior Capsulotomy – Cataract Surgery


During cataract surgery, the surgeon must make a circular

cut of the anterior capsule of the lens, whose diameter is around 5.5 mm.

Maneuvers to extract the lens are then performed through this opening.

Currently performed manually, the cutting of the anterior lens capsule can be

accomplished in an automated way thanks to the femtosecond laser (femtosecond

laser capsulotomy).


Posterior YAG Laser Capsulotomy:

Secondary Cataract


Secondary cataract is a complication of cataract surgery.

It occurs after the surgery, in a very variable time, from a few weeks to

several years. It corresponds to the progressive loss of transparency of the

lens envelope (capsular bag). This bag is kept during cataract surgery because

it is transparent and above all, serves as a natural support for the artificial

lens implant intended to replace the removed crystalline lens. This loss of

transparency is caused by the proliferation of residual cells of the lens

(these cells of “epithelial” nature have remarkable properties). The

visual symptoms caused by the loss of transparency of the lens are close to

those of the “primitive” cataract. One of the most common

complications of cataract surgery is posterior capsular opacification, which

occurs in 10 to 50% of cases, on average three to five years after surgery.

This complication follows an extracapsular lens extraction surgery. It’s an

unpredictable complication. However, the use of hydrophobic acrylic intraocular

implants seems to reduce the incidence of this complication. Capsular

opacification is associated with the proliferation of a postoperative remnant

of epithelial cells of the lens, which migrate along the posterior capsule

towards the optical axis, between the crystalline implant and the posterior

capsule. This results in a decrease in visual acuity. Clinical examination

after pupillary dilation reveals Elshnig pearls, which are characteristic of

capsular opacification. The rest of the examination must be normal in order to

eliminate another cause of visual acuity decline.


The secondary cataract treatment is based on the opening of

the posterior
YAG

laser
capsule. This gesture is performed under topical

anesthesia (drops), lasts a few minutes and is perfectly painless.

Anti-inflammatory and hypotonizing eye drops should be prescribed to prevent

complications of capsulotomy (inflammation, eye strain, etc.).


Laser

indications in ophthalmology



     Laser

surgery (light amplification by stimulated emission of radiation) is intended

to correct vision disorders such as:

– myopia: the image is done not on the retina but ahead of it
– the hyperopia: the focus of the image is behind the retina
– astigmatism: abnormal curvature of the cornea hence the

difficulty of seeing objects close together or distant

– the technique does not yet complete satisfaction for presbyopia

(the lens loses flexibility: mainly due to age)


     The

laser can also treat other eye injuries such as:

– certain retinal pathologies: diabetic retinopathy, macular

degeneration, thrombosis-related vascular disease, hypertensive retinopathy

– cataract: congenital or acquired opacity of the lens
– glaucoma: ocular hypertension
– peripheral retinal lesions or treatment preventive retinal

detachment