What Is TransPRK (No-Touch PRK)?

TransPRK, also known as no-touch PRK, applies the laser directly to the corneal surface without disturbing the epithelium, the cornea's outermost layer. Unlike femtosecond LASIK, no flap is created, so it is considered for patients with borderline corneal thickness. It belongs to the surface-ablation family of laser eye surgery, built on excimer laser technology used for decades. "No-touch" means the epithelium is removed with a separate laser pulse rather than scraped away mechanically, so fewer instruments touch the eye. An amount of tissue, calculated from the refractive error, is reshaped with the excimer laser so light focuses more precisely on the retina. The excimer laser works at an ultraviolet wavelength, vaporising tissue in very thin layers without heating it, keeping heat spread to surrounding tissue limited. Because the laser reaches the corneal surface directly, beneath the epithelium, TransPRK counts among the "surface" techniques — unlike femtosecond LASIK, which opens a flap, TransPRK never does; the epithelium simply regrows on its own.

TransPRK is one of three main laser eye surgery techniques, used to correct refractive errors such as myopia (short-sightedness), hyperopia (long-sightedness) and astigmatism. Which refractive errors and patients it fits is considered within the broader laser eye surgery assessment. TransPRK, femtosecond LASIK and SMILE (KLEx) reach the same goal by different routes — the difference lies in how the laser reaches the cornea and how healing unfolds. The right technique is worked out at assessment from corneal thickness, dry eye history and lifestyle. All three aim to reduce dependence on glasses or contact lenses, though the preferred technique varies by refractive error.

TransPRK may be considered for patients with borderline corneal thickness, or whose occupation or lifestyle carries a higher risk of eye impact. As no flap is created, it carries no flap-related complication risk. Suitability is worked out at assessment from corneal thickness and eye surface health. The profiles below come up most often in TransPRK assessments; final suitability is confirmed only after examination. Corneal thickness, ocular surface health, tear volume and the degree of refractive error together clarify whether TransPRK or another technique fits better, using measurements such as corneal topography and pachymetry rather than a single reading.

Anaesthetic drops numb the eye beforehand, so no pain is felt. The corneal surface is then reshaped with the excimer laser by an amount calculated for the individual, and a temporary bandage contact lens is fitted to support healing. Treating one eye is quick, usually allowing same-day discharge.

1. 1Anaesthetic drops. The surface of the eye is numbed with drops; no pain is felt.
2. 2Removing the epithelial layer. The thin, outermost layer of the cornea is gently removed.
3. 3Reshaping the tissue with the excimer laser. The corneal surface is reshaped by an amount calculated for the individual.
4. 4Bandage contact lens. A temporary, soft contact lens is fitted to support healing.

TransPRK's advantage is that no flap is created, so it carries none of the risks a flap brings — worth considering for a thin cornea or a higher-risk lifestyle. Its limitation is that, because the epithelium must regrow, healing can take a little longer than after femtosecond LASIK, with stinging or sensitivity more noticeable in the first few days. As clear vision is reached gradually, TransPRK may not suit patients expecting very fast results — weighed up at assessment. With no flap, there is no later concern about flap displacement from an eye impact, which can make TransPRK stand out for certain occupations. Against that, clear vision comes in stages while the epithelium regrows — a wait that fast-recovery patients should factor in.

Stinging, watering and light sensitivity can appear over the first few days; the doctor's prescribed drops are used throughout. Visual clarity improves gradually and, as the epithelium must regrow, this can take a little longer than after femtosecond LASIK or SMILE. The timeline below shows roughly when healing milestones tend to occur; timing varies from person to person.

As with any surgical procedure, TransPRK carries risks such as infection, delayed healing, temporary corneal haze, and a visual outcome that differs from what was predicted. These risks are infrequent, but healing does not follow the same course in every patient; details are discussed at assessment. Using the prescribed drops consistently and keeping to follow-up appointments helps catch any complication early. Temporary corneal haze usually fades with the recommended drop treatment; becoming permanent is rare. The examination beforehand helps identify conditions such as ocular surface infection or dry eye that could delay treatment.

Femtosecond LASIK and SMILE (KLEx) can also be considered as alternatives to TransPRK. The most suitable technique depends on corneal thickness, dry eye history and personal preference; detailed comparisons are covered in separate pages. The type and degree of refractive error can also decide the choice — myopia, hyperopia and astigmatism are each covered in their own pages. The assessment weighs more than corneal measurements alone: daily life, occupation and recovery-time expectations matter too, which is why two patients with identical measurements may still be offered different techniques.

How TransPRK compares with femtosecond LASIK and SMILE — recovery time, early comfort, and the differences relating to the flap — is covered in separate comparison pages. A general view on which technique suits you appears in the laser suitability assessment and technique decision guide.

To find out whether TransPRK suits you, request an appointment at Op. Dr. Anıl Kaya's Istanbul practice via the contact page. Corneal thickness, eye surface health and prescription together confirm the right technique.