PTK

From EyeWiki


Phototherapeutic keratectomy (PTK)

History

Since late 1980s and early 1990s the excimer laser has been used to reshape the anterior corneal curvature in a procedure known as photorefractive keratectomy (PRK) or keratomileusis in situ (LASIK). Excimer laser phototherapeutic keratectomy (PTK) was approved by the U.S. Food and Drug Administration (FDA) in 1995 to treat a variety of anterior corneal pathologies and nowadays is a technique very used for many surgeons around the world.

Objectives

The main goals of performing PTK are to remove or decrease the opacities affecting the visual acuity, to smooth the corneal surface, to improve the adherence of the corneal epithelium, or a combination thereof to help with painful symptoms.

Candidates

This procedure is potentially applicable to a large number of patients but including:

  • Corneal scars and opacity (from trauma and inactive infections)
  • Dystrophies (Reis-Buckler’s, granular and lattice)
  • Salzmann’s nodular degeneration 

  • Band keratopathy
  • Painful bullous keratopathy 



Patients with deep lesions are not good candidates for this technique. (lesions in the posterior two-thirds of the cornea)

Technique

The procedure is generally done under topical anaesthesia and under strict aseptic, general anaesthesia may be required in pediatric patients. After applying the wire speculum, the epithelium is removed manually with a hockey stick knife or with a cellulose sponge after use alcohol 20% (5-10 seconds). Some surgeons prefer to remove the epithelium with the excimer laser (Trans-PTK: 50 um depth). After the epithelium is removed, the ablation is performed according the deep, size and shape of the lesions. Antibiotic eye drops are given and a bandage contact lens is placed until get a correct re-epithelialisation. Postoperative treatment consists of topical antibiotics, corticosteroids and anti-inflammatory eye drops, all for 1–2 weeks. 


Contraindications

  • Deep stromal lesions, dense band keratopathy
  • Significant corneal thinning
  • Neurotrophic cornea, lagophthalmos

  • Severe keratoconjunctivitis sicca
  • Severe blepharitis

  • Any corneal infection

Additional Resources

References

  1. Hieda, O., et al. (2013). "Clinical outcomes of phototherapeutic keratectomy in eyes with Thiel-Behnke corneal dystrophy." Am J Ophthalmol 155(1): 66-72 e61.
  2. Li, L. M., et al. (2014). "Excimer laser phototherapeutic keratectomy for the treatment of clinically presumed fungal keratitis." J Ophthalmol 2014: 963287.
  3. Rapuano, C. J. (2010). "Phototherapeutic keratectomy: who are the best candidates and how do you treat them?" Curr Opin Ophthalmol 21(4): 280-282.
  4. Reddy, J. C., et al. (2013). "Excimer laser phototherapeutic keratectomy in eyes with corneal stromal dystrophies with and without a corneal graft." Am J Ophthalmol 155(6): 1111-1118
  5. Rathi, V. M., et al. (2012). “Phototherapeutic keratectomy.” Indian Journal of Ophthalmology. 60(1), 5–14
  6. Copeland, R. A., et al. (2013). Copeland and Afshari's principles and practice of cornea. New Delhi ; London, Jaypee-Highlights Medical Publishers, Inc.
  7. Holland E. J. , et al. (2013). Ocular Surface Disease: Cornea, Conjunctiva and Tear Film. London, Elsevier Sanders Inc
  8. Zuberbuhler
 B. , et al (2013). Corneal Surgery. Essential Techniques. Springer-Verlag Berlin Heidelberg