The surgical procedure in phacoemulsification for removal of cataract involves a number of steps. Each step must be carefully and skillfully performed in order to achieve the desired result. The steps may be described as follows:
1- Anaesthesia,
2- Exposure of the the eyeball using a lid speculum,
3- Entry into the eye through a minimal incision (corneal or scleral)
4- Viscoelastic injection to stabilize the anterior chamber and to help maintain the eye pressurization
5- Capsulorhexis
6- Hydrodissection
7- Hydro-delineation
8- Ultrasonic destruction or emulsification of the cataract after nuclear cracking or chopping (if needed), cortical aspiration of the remanescent lens, capsular polishing (if needed)
9- Implantation of the artificial IOL
10- Entration of IOL (usually foldable)
11- Viscoelastic removal
12- Wound sealing / hydration (if needed).
The pupil is dilated using drops (if the IOL is to be placed behind the iris) to help better visualise the cataract. Pupil constricting drops are reserved for secondary implantation of the IOL in front of the iris (if the cataract has already been removed without primary IOL implantation). Anesthesia may be placed topically (eyedrops) or via injection next to (peribulbar) or behind (retrobulbar) the eye. Oral or intravenous sedation may also be used to reduce anxiety. General anesthesia is rarely necessary, but may be employed for children and adults with particular medical or psychiatric issues. The operation may occur on a stretcher or a reclining examination chair. The eyelids and surrounding skin will be swabbed with disinfectant. The face is covered with a cloth or sheet, with an opening for the operative eye. The eyelid is held open with a speculum to minimize blinking during surgery. Pain is usually minimal in properly anesthetised eyes, though a pressure sensation and discomfort from the bright operating microscope light is common. The ocular surface is kept moist using sterile saline eyedrops or methylcellulose viscoelatic. The incision is fashioned at or near where the cornea and sclera meet (limbus = corneoscleral junction). Advantages of the smaller incision include use of few or no stitches and shortened recovery time. A capsulotomy (rarely known as cystitomy), is a procedure to open a portion of the lens capsule. An anterior capsulotomy refers to the opening of the front portion of the lens capsule, whereas a posterior capsulotomy refers to the opening of the back portion of the lens capsule. In phacoemulsification, the surgeon performs an anterior continuous curvilinear capsulorhexis, to create a round and smooth opening through which the lens nucleus can be emulsified and the intraocular lens implant inserted.
Following cataract removal (via ECCE or phacoemulsification, as described above), an intraocular lens is usually inserted. After the IOL is inserted, the surgeon checks that the incision does not leak fluid. This is a very important step, since wound leakage increases the risk of unwanted microrganisms to gain access into the eye and predispose to endophathalmitis. An antibiotic/steroid combination eye drop is put and an eye shield may be applied on the operated eye, sometimes supplemented with an eye patch.
Antibiotics may be administered pre-operatively, intra-operatively, and/or post-operatively. Frequently a topical corticosteroid is used in combination with topical antibiotics postoperatively.
Most cataract operations are performed under a local anaesthetic, allowing the patient to go home the same day. The use of an eye patch may be indicated, usually for about some hours, after which the patient is instructed to started using the eyedrops to control the inflammation and the antibiotics that prevent infection.
Occasionally, a peripheral iridectomy may be performed to minimize the risk of pupillary block glaucoma. An opening through the iris can be fashioned manually (surgical iridectomy) or with a laser (called YAG-laser iridotomy). The laser peripheral iridotomy may be performed either prior to or following cataract surgery.
The iridectomy hole is larger when done manually than when performed with a laser. When the manual surgical procedure is performed, some negative side effects may occur, such as that the opening of the iris can be seen by others (aesthetics), and the light can fall into the eye through the new hole, creating some visual disturbances . In the case of visual disturbances, the eye and brain often learn to compensate and ignore the disturbances over a couple of months. Sometimes the peripheral iris opening can heal, which means that the hole ceases to exist. This is the reason why the surgeon sometimes makes two holes, so that at least one hole is kept open.
After the surgery, the patient is instructed to use anti-inflammatory and antibiotic eye drops for up to two weeks (*depending on the inflammation status of the eye and some other variables). The eye surgeon will judge, based on each patient's idiosyncrasies, the time length to use the eye drops. The eye will be pretty recovered within a week, and complete recovery should be expected in about a month. The patient should not participate in contact/extreme sports until cleared to do so by the eye surgeon. Video
After Surgery
Complications after cataract surgery are relatively uncommon.
Some people can develop a posterior capsular opacification (also called an after-cataract). As a physiological change expected after cataract surgery, the posterior capsular cells undergo hyperplasia and cellular migration, showing up as a thickening, opacification and clouding of the posterior lens capsule (which is left behind when the cataract was removed, for placement of the IOL). This may compromise the visual acuity and the ophthalmologist can use a device to correct this situation. It can be safe and painless corrected using a laser device (YAG laser) to make small holes in the posterior lens capsule of the crystalline. It usually is a quick outpatient procedure that uses a Nd-[[YAG laser]] (neodymium-yttrium-aluminum-garnet) to disrupt and clear the central portion of the opacified posterior lens capsule (posterior capsulotomy). This creates a clear central visual axis for improving visual acuity. In very thick opacified posterior capsules, a surgical (manual) capsulectomy is the surgical procedure performed. * Posterior capsular tear may be a complication during cataract surgery. It refers to a rupture of the posterior capsule of the natural lens. Surgical management may involve anterior vitrectomy and, occasionally, alternative planning for implanting the intraocular lens, either in the ciliary sulcus, in the anterior chamber (in front of the iris), or, less commonly, sutured to the sclera.
Retinal detachment is an uncommon complication of cataract surgery, which may occur weeks, months, or even years later.
TASS or toxic anterior segment syndrome is a non-infectious inflammatory condition that may occur following cataract surgery. It is usually treated with topical corticosteroids in high dosage and frequency.
Endophthalmitis is a serious infection of the intraocular tissues, usually following intraocular surgery, or penetrating trauma. There is some concern that the clear cornea incision might predispose to the increase of endophalmitis but is no conclusive study to corroborate this suspicion.
Glaucoma may occur and it may be very difficult to control. It is usually associated with inflammation, specially when little fragments or chunks of the nucleus get access to the vitreous cavity. Some experts recommend early intervention when this condition happen (posterior pars plana vitrectomy). In some patients, the intra-ocular pressure may remain so high that blindness may ensue.
Other possible complications include: Swelling or edema of the cornea. This condition may be associated with cloudy vision, which may be transient or permanent(pseudophakic bullous keratopathy). Displacement or dislocation of the intraocular lens implant may rarely occur, as well as swelling or edema of the central part of the retina, called macula, resulting in (cystoid macular edema. Unplanned high refractive error (either myopic or hypermetropic) may occur due to error in the ultra-sonic ecobiometry (measure of the length and the required intra-ocular lens power).