Stable myopia
When refraction is stable and the planned ablation is safe for the individual cornea.
About the service
PRK is surface laser vision correction without a corneal flap. After epithelium removal, an excimer laser reshapes the cornea, and the surface heals under medical supervision.
Who the service is for
Myopic or other correctable astigmatism
When type and magnitude are within the treatment range of the excimer platform.
Active lifestyle or facial-trauma risk
Flap avoidance can be relevant after complete healing.
Patients selected for surface correction
PRK may be considered when the surgeon judges a surface approach more appropriate.
Anatomy in which a flap is undesirable
Surface ablation avoids a LASIK flap, but candidacy depends on the full diagnostic profile.
Patients comparing PRK with TransPRK
Both are surface procedures but differ in epithelial removal and the operative protocol.
Corneal-flap considerations
PRK is elective refractive surgery and does not treat cataract, glaucoma, keratoconus, retinal disease or other causes of visual loss. Because the epithelium must regenerate after surface ablation, the first postoperative days are usually less comfortable than after flap-based or lenticule-extraction procedures. Pain or burning, tearing, photophobia, fluctuating vision, dryness, glare and halos may occur.
Benefits and risks
A specific surface-ablation risk is subepithelial corneal haze; risk depends on treatment magnitude, healing response and other factors.
Realistic expectations
Increasing pain, marked redness, discharge or worsening vision requires prompt medical review rather than waiting for a scheduled visit.
Corneal thickness
Comprehensive refractive diagnostics are required before PRK. The surgeon evaluates visual acuity and refraction, refractive stability, corneal thickness and geometry, topography or tomography, epithelium and tear film, pupil, crystalline lens and retina. Contact lenses may temporarily alter corneal shape, so the discontinuation interval depends on lens type and must be confirmed by KazRIED.
Preparation under the clinic protocol
Only the tests and day-of-surgery restrictions included in the institute’s current protocol should be used.
Limitations and safety
PRK is elective refractive surgery and does not treat cataract, glaucoma, keratoconus, retinal disease or other causes of visual loss.
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Stages
Stage 1
Preoperative diagnostics
Refraction, visual stability, topography or tomography, pachymetry, ocular surface, crystalline lens and retina.
Stage 2
Preparation
Plan checks, topical anaesthesia and lid-speculum placement according to protocol.
Stage 3
Epithelial removal
The central epithelium is removed in a separate step using the surgeon's selected technique.
Stage 4
Excimer laser ablation
The laser reshapes the stroma according to the calculated correction programme.
Stage 5
Surface protection
A therapeutic contact lens is usually placed during epithelial healing.
Stage 6
Postoperative follow-up
The doctor monitors epithelial healing, cornea and visual acuity and adjusts prescriptions when needed.
Service benefits
A surface approach
Correction is performed at the corneal surface without creating a deep flap.
No corneal flap
The technique creates no flap, avoiding risks specifically associated with flap displacement.
A well-studied technique
Long-standing PRK experience helps the doctor explain expected recovery and follow-up requirements.
Less dependence on glasses
Laser correction can reduce the need for glasses or contact lenses when clinically appropriate.
Methods comparison · 1
Criterion
PRK
TransPRK
Femto LASIK
Principle
Separate epithelial removal followed by excimer ablation
Transepithelial excimer treatment of epithelium and refractive ablation
Femtosecond flap plus excimer ablation
Corneal flap
No
No
Yes
Epithelium
Removed centrally, then regenerates
Removed by laser in a single surface protocol
Largely retained over the flap
First days
Usually more pain, photophobia and tearing
Similar surface healing; severity depends on protocol
Usually less surface discomfort
Speed of functional recovery
Slower
Slower than flap/KLEx; specifics depend on protocol
Usually faster
Flap-related risks
Absent
Absent
A distinct group of flap complications exists
Haze
Specific surface-ablation risk
Specific surface-ablation risk
Not a typical primary method-specific risk
Method selection
Depends on cornea, refraction and goals
Depends on platform, cornea and protocol
Depends on cornea, refraction and lifestyle
PRK
Principle
Corneal flap
Epithelium
First days
Speed of functional recovery
Flap-related risks
Haze
Method selection
Separate epithelial removal followed by excimer ablation
No
Removed centrally, then regenerates
Usually more pain, photophobia and tearing
Slower
Absent
Specific surface-ablation risk
Depends on cornea, refraction and goals
Transepithelial excimer treatment of epithelium and refractive ablation
No
Removed by laser in a single surface protocol
Similar surface healing; severity depends on protocol
Slower than flap/KLEx; specifics depend on protocol
Absent
Specific surface-ablation risk
Depends on platform, cornea and protocol
Femtosecond flap plus excimer ablation
Yes
Largely retained over the flap
Usually less surface discomfort
Usually faster
A distinct group of flap complications exists
Not a typical primary method-specific risk
Depends on cornea, refraction and lifestyle
Methods comparison · 2
Criterion
PRK
LASIK
ReLEx SMILE
Principle
Surface excimer ablation
Mechanical flap plus excimer ablation
Femtosecond lenticule extraction through a small incision
Corneal flap
No
Yes
No
Excimer laser
Required
Required
Not required
Surface wound area
Present until epithelial healing
No comparable central epithelial removal
Small incision without central epithelial removal
First days
Usually more discomfort
Usually faster and more comfortable
Usually faster than PRK
Contact sport after healing
No flap, but the doctor sets return timing
Flap anatomy persists long term
No flap; return still requires medical clearance
Laser correction for hyperopia
Feasibility depends on platform and selection
May be used within indications and platform range
Classic SMILE primarily targets myopia and myopic astigmatism
Key limitation
Surface healing and haze
Flap complications and corneal suitability
Indication range and lenticule-extraction factors
PRK
Principle
Corneal flap
Excimer laser
Surface wound area
First days
Contact sport after healing
Laser correction for hyperopia
Key limitation
Surface excimer ablation
No
Required
Present until epithelial healing
Usually more discomfort
No flap, but the doctor sets return timing
Feasibility depends on platform and selection
Surface healing and haze
Mechanical flap plus excimer ablation
Yes
Required
No comparable central epithelial removal
Usually faster and more comfortable
Flap anatomy persists long term
May be used within indications and platform range
Flap complications and corneal suitability
Femtosecond lenticule extraction through a small incision
No
Not required
Small incision without central epithelial removal
Usually faster than PRK
No flap; return still requires medical clearance
Classic SMILE primarily targets myopia and myopic astigmatism
Indication range and lenticule-extraction factors
Methods comparison · 3
Criterion
PRK
CLEAR
Principle
Surface excimer ablation
Ziemer-platform femtosecond lenticule through a small incision
Corneal flap
No
No
Epithelium
Removed centrally and must regenerate
No central de-epithelialization
First days
Usually greater surface discomfort
Usually faster functional recovery
Haze
A surface-method-specific risk
Not a typical primary CLEAR risk
Excimer laser
Required
Not required for classic CLEAR
Indications
Depend on excimer platform and cornea
Mainly myopia and myopic astigmatism within platform capabilities
Selection
PRK may be preferable in selected anatomical or occupational circumstances
CLEAR is selected for a suitable KLEx profile and available platform
PRK
Principle
Corneal flap
Epithelium
First days
Haze
Excimer laser
Indications
Selection
Surface excimer ablation
No
Removed centrally and must regenerate
Usually greater surface discomfort
A surface-method-specific risk
Required
Depend on excimer platform and cornea
PRK may be preferable in selected anatomical or occupational circumstances
Ziemer-platform femtosecond lenticule through a small incision
No
No central de-epithelialization
Usually faster functional recovery
Not a typical primary CLEAR risk
Not required for classic CLEAR
Mainly myopia and myopic astigmatism within platform capabilities
CLEAR is selected for a suitable KLEx profile and available platform
Book an appointment
Book laser vision correction diagnostics at KazRIED. A refractive surgeon will assess your cornea and refraction, explain whether PRK is suitable, and compare it with TransPRK, Femto LASIK, LASIK, ReLEx SMILE or CLEAR according to safety and recovery considerations.
Procedure prices
Service name
Price
PRK (per eye)
from 163 000 ₸
TransPRK (per eye)
from 201 000 ₸
PTK, (per eye)
from 105 000 ₸
Our doctors
A team of experienced doctors across specialties.
Experience: 28 years
Ophthalmologist
Kim Olga Robertovna
Candidate of Medical Sciences; Highest-category ophthalmologist
Experience: 19 years
Ophthalmologist
Beysenbaeva Zarina Anvarbekovna
Highest-category ophthalmologist
Experience: 13 years
Ophthalmologist
Kalshabekov Alibi Sembaevich
Highest-category ophthalmologist
PRK: principles and stages of laser vision correction
Photorefractive keratectomy (PRK) is a form of surface excimer laser refractive surgery.
How is the procedure performed?
First, the central corneal epithelium is removed using the surgeon’s chosen method to expose the superficial stroma.
The excimer laser then removes a microscopic amount of tissue according to a calculated profile, changing the curvature of the cornea.
After ablation, a bandage contact lens is usually placed on the eye to protect the surface while the epithelium heals.
No corneal flap is created, unlike in LASIK or Femto LASIK.
How does conventional PRK differ from TransPRK?
The main difference is how the epithelium is treated. In TransPRK, the epithelial and refractive stages are performed with an excimer laser in a transepithelial mode. In conventional PRK, the epithelium is removed in a separate step.
PRK and TransPRK are separate services with different fees.
Additional advice and situations
Assessment before treatment
Diagnostics confirm PRK suitability – the surgeon finalizes the ablation profile, postoperative regimen and follow-up visits.
A clear pricing structure
Classic PRK is not optimal but TransPRK is suitable – the epithelial-step difference and separate price are explained.
Corneal-flap considerations
Surface correction is not optimal but Femto LASIK is suitable – a flap-based method is selected according to corneal parameters.
Lenticule correction is suitable
Lenticule extraction is suitable – ReLEx SMILE or CLEAR is discussed as a separate technology.
Ocular surface status
Refraction is unstable or active ocular-surface disease is present – surgery is postponed, treatment is provided and the eye is reassessed.
Retinal assessment
Suspicious tomography, keratoconus, cataract or retinal disease is identified – diagnosis and treatment of the primary problem take priority.
A clear pricing structure
PTK, code 219: Phototherapeutic keratectomy; not a PRK price.
When PRK is considered and what to expect afterward
PRK remains a distinct treatment method despite the emergence of newer technologies. It is selected according to the eye’s anatomy and risk profile.
The absence of a corneal flap may be an advantage in certain situations. However, surface healing requires a longer recovery period and careful adherence to postoperative instructions.
What is considered when selecting PRK?
- Corneal topography and thickness.
- Refractive stability.
- Ocular surface condition.
- The amount of correction required.
- Occupational or sporting demands.
What does recovery involve?
Patients should understand in advance that vision may not be perfect the day after PRK.
The early recovery period involves epithelial healing. The final outcome is assessed after the corneal surface and refraction have stabilized.
This recovery process is a biological characteristic of surface ablation and does not, by itself, indicate inadequate medical care.
Related information: diagnostic assessment before laser vision correction, contact lenses.
Facts and offers
Kazakhstan’s first specialized ophthalmology institute, operating since 1933.
Modern diagnostics and surgery using world-class equipment.
Leading ophthalmologists in Kazakhstan, scientists and experienced surgeons.
More than 30,000 operations and around 270,000 consultations annually.
Kazakhstan’s first specialized ophthalmology institute, operating since 1933.
Modern diagnostics and surgery using world-class equipment.
Leading ophthalmologists in Kazakhstan, scientists and experienced surgeons.
More than 30,000 operations and around 270,000 consultations annually.
Kazakhstan’s first specialized ophthalmology institute, operating since 1933.
Modern diagnostics and surgery using world-class equipment.
Leading ophthalmologists in Kazakhstan, scientists and experienced surgeons.
More than 30,000 operations and around 270,000 consultations annually.
Related services
Frequently asked questions
What is PRK?
Photorefractive keratectomy (PRK) is a surface laser vision correction procedure. The corneal epithelium is removed and an excimer laser reshapes the superficial stroma to correct refractive error.
How is PRK different from TransPRK?
In conventional PRK, the epithelium is removed as a separate step. In TransPRK, epithelial removal and refractive ablation are performed with the excimer laser using a transepithelial approach.
How is PRK different from Femto LASIK?
PRK does not create a corneal flap, and the epithelium must regrow after surgery. Femto LASIK creates a flap with a femtosecond laser and performs excimer-laser correction beneath it.
How is PRK different from SMILE and CLEAR?
SMILE and CLEAR are small-incision lenticule-extraction procedures performed without central epithelial removal. PRK is a surface excimer-laser ablation procedure.
Which refractive errors can PRK correct?
PRK may be used to correct myopia, hyperopia and astigmatism in suitable patients. The available treatment range depends on the laser platform, corneal parameters and diagnostic findings.
What prescription range can PRK correct?
There is no single range that applies to every patient. Eligibility depends on baseline refraction, corneal thickness and shape, the laser platform and the amount of tissue required for safe correction.
Is PRK painful?
Topical anaesthesia is used during surgery. During epithelial healing afterwards, patients may experience pain or significant discomfort, burning, tearing and light sensitivity.
Why is a bandage contact lens used after PRK?
A bandage contact lens protects the corneal surface while the epithelium heals and helps reduce discomfort. It should not be removed or replaced without medical advice.
When is the bandage contact lens removed after PRK?
It is removed once the surgeon confirms adequate corneal epithelial healing. Timing is determined at follow-up according to the condition of the corneal surface.
When does vision begin to improve after PRK?
Vision improves gradually as the epithelium heals and the corneal surface stabilizes. Early functional recovery is generally slower than after Femto LASIK or lenticule-extraction procedures.