Anterior Segment Surgery

What is Anterior Segment Surgery?

Anterior Segment Surgery includes surgical procedures performed in the front one-third of the eye (an anterior segment), including the cornea, iris, ciliary body, and lens.

Is Anterior Segment Surgery an elective or an emergency procedure?

Anterior Segment Surgery may include both elective as well as emergency procedures.

Types

This anterior segment surgery may include the following procedures:

• Cataract Surgery (extraction and Intraocular lens (IOL) implantation)
• Penetrating Keratoplasty
• Lamellar Keratoplasty
• Superficial Keratectomy
• Excimer Laser Phototherapeutic Keratectomy
• Excimer Laser Photorefractive Keratectomy
• Conjunctival Flap Surgery
• Limbal Stem Cell Transplantation
• Pterygium Excision and Conjunctival Autograft
• Corneal Perforation Surgery
• Permanent Keratoprosthesis
• Refractive Surgery
• Radial Keratotomy
• Laser in Situ Keratomileusis

Indications

Some of the indications for anterior segment surgery include

• Dry eye and blepharitis
• Contact-lens related problems
• Corneal ulcers
• Herpes simplex and herpes zoster (shingles) infections
• Pterygium
• Cataract
• Keratoconus and other ectatic disorders (keratoglobus, pellucid marginal degeneration)
• Fuchs' endothelial dystrophy and other corneal dystrophies (including lattice, granular, macular, and map-dot fingerprint)
• Pseudophakic and aphakic bullous keratopathy
• Complications of allergic conjunctivitis
• Complications of bacterial and viral conjunctivitis
• Chemical burns
• Stevens-johnson syndrome
• Ocular cicatricial pemphigoid
• Trauma to the cornea, conjunctiva and anterior segment, including iris trauma
• Refractive errors (myopia, hyperopia, and astigmatism)

Contraindications and Risk Factors

The risk factors and contraindications depend on the type of surgery that is being performed, which include

• Active Infections
• Active inflammations
• Uncontrolled Diabetes
• Uncontrolled hypertension
• Dry eyes

Investigations before the procedure

The investigations before anterior segment surgery depend on the type of surgery that is being performed. Some general investigations that may be done include

• Laboratory tests:
  • CBP &ESR
  • Coagulation profile and blood typing
  • Liver and Renal Function tests
  • Complete Urine Examination
  • Viral and Bacterial Serologies
• Imaging tests:
  • Chest X-ray
  • A-scan
• ECG
• Ophthalmic tests:
  • Visual field testing
  • Slit-lamp examinations
  • Fundoscopy
  • Schirmer’s tear test
  • Intraocular pressure tests

Preoperative advice

Before performing the procedure, the following is done

• The risks and benefits of the procedure are explained.
• Anticoagulant medications are generally stopped 1-2 weeks before the surgery.
• Topical Antibiotics may be started a few days before the surgery.
• Topical corticosteroids may be started a few days before the surgery if required.
• Cessation of smoking and alcohol may need to be done a few weeks before the surgery.

Intraoperative details

Duration: Depending on the surgery type, it can last from 20 minutes to a few hours.
Anesthesia: Anterior segment surgeries are usually performed under local anesthesia with IV sedation, topical anesthesia, and sometimes under general anesthesia, depending on the type of surgery that is being done.

Description of the procedure 

Most anterior segment surgeries follow these steps to enter the anterior chamber. Depending on the type of surgery being done, subsequent steps would vary. Proper sterile precautions are taken, the face and the eyelashes are thoroughly cleaned, and a sterile drape is applied over the face, leaving only the eye exposed and the eyelashes out of the way. A needle is inserted through the lower lid, and an anesthetic is injected to numb the area behind the eyeball. Pressure is then applied to the eyeball to stop potential bleeding and reduce the intraocular pressure.
An incision of size 3mm is then made on the side of the anesthetized cornea, and a viscoelastic fluid is injected to reduce the shock to the intraocular tissues.

Postoperative details

After the procedure of the anterior segment surgery is completed

• The individual is monitored in a recovery area. If the procedure was performed in general. anesthesia, the recovery period will be a little longer
• Eye shields are placed on the operated eye
• Bed rest is advised for 24 hours

Common post-procedure observations:

• Slight eye pain and discomfort
• Drowsiness
• Dark spots in the visual field
• Sensitivity to light
• Slight discharge and itching of the operated eye

Medications: Pain reliever medications for pain may be prescribed. Antibiotic eye drops and medication to reduce intraocular pressure or inflammation may be prescribed and may need to be used for as long as advised by the attending specialists.
Discharge: Discharge depends on the type of procedure that is done and may be as early as on the same day or sometimes on the 2nd - 3rd postoperative day.
Review: Anterior segment surgeries are generally reviewed on the first postoperative day (after 24 hours). Subsequent reviews are usually after week 1, week 3, and weeks 6-8 after the surgery or as advised by the attending specialist.
Resumption of normal activities: Usually, with some restrictions, maybe as early as 1-3 days after the surgery to as late as 2-3 weeks after the surgery.

Role of Diet/ Exercise/ Lifestyle changes

Some measures that need to be taken while recovering from the procedures include:

• Clean any discharge from the eye with a sterile tissue
• Avoid rubbing the eye for at least 2-3 weeks
• Wear protective eyewear while sleeping to avoid accidentally rubbing the eyes
• Wear eyeglasses during the day to avoid accidentally rubbing or injuring the eye
• Eyeglasses may be prescribed if required once the healing process is complete
• Avoid strenuous activities, such as lifting heavy weights
• Avoid swimming for as long as advised by the attending specialists

Complications

Some complications may include the following, although they are dependent entirely on the type of surgical procedure that is being done. A few of the complications include:

• Bleeding
• Infections
• Flashing, Double vision
• Elevated intraocular pressure, glaucoma
• Induced astigmatism
• Lens displacement
• Posterior capsule opacification
• Development of secondary cataract
• Retinal detachment
• Endophthalmitis
• Blindness

Prognosis

The prognosis for anterior segment surgeries is generally very good, although it depends on the underlying condition that is being treated, as well as the surgery that is being performed.

Indications for hospitalization if required

While most anterior segment surgeries do not require hospitalization, some procedures may require a brief hospital stay.

Suggested clinical specialist/ Department to consult for the procedure

Specialists from the Department of Ophthalmology perform anterior segment surgeries.