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The key to a successful outcome depends on proper case selection. Systemic diseases such as uncontrolled diabetes, collagen vascular diseases like rheumatoid arthritis, and systemic lupus erythematosus may have delayed epithelial healing. Corneal diseases limited to the anterior stroma are amenable to treatment. Mitomycin C (MMC) is used as an adjunctive treatment to aid in the prevention of recurrences. Most common PTK conditions treated include:

  • Salzmann's Nodular Degeneration

  • Band Keratopathy

  • Recurrent Corneal Erosions (RCE)

  • Bullous Keratopathy

  • Corneal Dystrophies

  • Anterior Corneal Scars

  • Keratitis

We perform PTK for both visual and therapeutic reasons. Visual improvement after PTK results from reduced density/removal of a scar and reduced irregular astigmatism. There may be a reduction in uncorrected visual acuity (UCVA) following PTK due to induced refractive errors, but the best corrected visual acuity (BCVA) improves. The clear cornea may help improve the accuracy of keratometry, which is crucial for proper intraocular lens (IOL) power calculations and selection. PTK can improve symptoms of pain, watering, and foreign body sensation in RCE, dystrophies, bullous keratopathy, and spheroidal degeneration.


Corneal diseases limited to the anterior stroma are amenable to treatment. Salzmann’s nodular degeneration (SND) is characterized by the presence of bluish/grayish-white peripheral nodules raised above the corneal surface. The condition is often slowly progressive and more common in females with longstanding scars and chronic uveitis. The raised surface may be associated with tear film abnormality, irregular astigmatism, and difficulty in contact lens fitting. Surgery is the only treatment.

Bullous keratopathy is characterized by bullae formation and rupture, resulting in symptoms of pain, foreign body sensation, and watering. The treatment is two-fold, resulting in symptom relief and visual improvement. The first goal of symptomatic relief is with hyperosmotic agents, bandage contact lenses (BCL), or anterior stromal puncture (ASP), AMG, PTK, ASP with AMG, and PTK with AMG. The second goal is visual improvement. PTK is a very promising and effective treatment for bullous keratopathy and can also be repeated, if necessary.


Phototherapeutic keratectomy is indicated for anterior basement membrane dystrophy (ABMD) and stromal dystrophies for both symptomatic relief and visual improvement. If the dystrophies are located centrally, the treatment may induce hyperopia. This occurs because the ablation profile of PTK mimics myopic correction. However, this depends on the ablation depth. Intraoperative application of MMC helps prevent recurrences. PTK also works well for recurrent epithelial breakdown or recurrent epithelial erosions, which are the result of poor epithelial cell adherence

Superficial anterior stromal avascular scars (less than 100 microns), are amenable to treatment by PTK. These scars may be post-traumatic, post-infectious, or post-surgical such as those following pterygium excision. The goal is to improve vision and delay or eliminate the need for a keratoplasty.


The technique of PTK varies according to the underlying pathology, size, and site. Therefore, it is better explained as a common method first and the specific technique can be modified depending on the patient’s pathology. The procedure is generally done under topical anesthesia unless performed in combination with another surgical procedure. The procedure is done under strict aseptic precautions. After applying the wire speculum, the epithelium is debrided manually. Some surgeons use alcohol for the debridement of the epithelium. After debridement, ablation is performed via laser. A few visual and auditory signals during the procedure may help in guiding the extent of the treatment. A snapping sound is heard when the tissue is ablated and treatment length is usually 15-90 seconds.

Post Op

The immediate post-operative care of PTK is concentrated on healing the epithelial defect. We monitor the bandage contact lens fit and typically don’t remove it until there is no epithelial defect. A bandage contact lens that is too tight can cause more discomfort to the patient, while a loose contact lens can make it more difficult for the epithelium to heal.

Drop protocol is subject to change

  • Prednisolone acetate 1%: 1 drop QID for one week, then 1 drop BID for 1 week.

  • Vigamox/4th generation fluoroquinolone: 1 drop 6 times per day while contact lens is in (typically 4 days). Then QID for 3 days.

  • Acuvail: as needed for pain with a maximum of BID for 3 days. DO NOT use for more than 3 days.

The patient is given a prescription for a narcotic pain reliever and cold compresses are encouraged, especially on the temporal region. This can help patients who experience increased discomfort during the early healing stages. The patient is evaluated at one day post-operatively to assess vision and monitor epithelial healing. Patients are warned that vision may take a few steps backward over the next several days as the epithelium moves centrally and crosses over the pupil. A smooth epithelial-leading edge should be noted under the contact lens, and epithelial growth of up to 20% can be seen at one day. At the four-day appointment, the epithelium should be largely, if not fully, intact. If a fairly large (> 2 mm) epithelial defect is present at four days, suspect a delay of epithelial growth.

If a delay in epithelial growth is suspected, we recommend reducing the steroid, discontinuing the NSAID, continuing the bandage contact lens, increasing lubrication, and following the patient daily. Refrain from discontinuing the steroid completely in order to minimize the chance of a sterile infiltrate. The combination drop (Pred/Moxi) can be reduced to BID to decrease steroid use, but our preference would be to switch the patient to two drops - a fluoroquinolone (Vigamox) and Prednisolone Acetate.

Protocol for Delay In Epithelial Closure:

  • Reduce Steroid: Pred. Acetate 1% BID

  • Continue Antibiotic: Vigamox 6x/day

  • Inferior and Superior punctal occlusion

  • Thicker PFAT, Celluvisc, Liquigel, etc. q2hr

  • Night time gel or ointment

  • Continue BCL

  • Monitor Daily until re-epithelialized

**If not re-epithelialized by 6 days call to schedule to be evaluated in our center**

Typically, the epithelium will seal with a small centrally located epithelial ridge. It can be star-shaped or linear, will usually stain with NaFl, and depending on its location, it can have varied effects on vision. Once re-epithelialization has occurred, the bandage contact lens is removed and discontinued. The use of consistent daily and night-time lubrication will help promote continued epithelial healing and adherence, as well as aid in the epithelial remodeling that occurs following PRK. It is this epithelial remodeling that will continue to improve the patient’s vision with time.