Corneal thickness
Documented progressive keratoconus shown by serial changes in corneal shape, refraction, thickness, or visual function.
About the service
Cross-linking strengthens the cornea using riboflavin and controlled UV-A exposure. It is considered to limit keratoconus progression after assessing indications, corneal thickness and contraindications.
Who the service is for
Keratoconus and ectasia
Corneal ectasia after refractive surgery: progressive pathological bulging of the cornea has been detected after LASIK, PRK or another procedure. Pellucid marginal degeneration or another progressive ectatic disorder where corneal anatomy and treatment zone are suitable. In keratoconus, mechanical surface trauma is considered a factor that may contribute to progression.
Keratoconus and ectasia
Keratoglobus or complex ectasia: keratoglobus is included among the indications in KazRIED’s official description, but the specific approach requires an individual assessment of corneal thickness and safety.
Assessment before choosing treatment
A young patient with rapidly changing corneal parameters: the higher risk of progression makes timely repeat assessment and a decision on stabilization especially important.
Keratoconus and ectasia
A patient who still obtains useful correction with spectacles or contact lenses but whose ectasia continues to progress: CXL aims to stabilize the cornea, while visual correction remains a separate stage.
Do not rub the eyes
Do not rub your eyes.
Pupil dilation and eye drops
Plan a safe journey home after the procedure because vision may temporarily be blurred and light sensitivity increased.
Riboflavin intolerance
intolerance to riboflavin (vitamin B2);
Corneal thickness
corneal thickness below 400 μm in at least one measurement;
Corrected visual acuity
low corrected visual acuity in keratoconus despite sufficient corneal thickness;
Allergic conjunctivitis
allergic conjunctivitis.
Additional precautions
Additional caution is required with active infection, significant scarring, poor epithelial healing, severe ocular-surface disease and certain autoimmune conditions. Increasing pain or redness, purulent discharge or a sudden decline in vision after treatment requires an unscheduled examination.
Prescribed medicines
List all eye and systemic medicines you use.
Do not change medicines yourself
Do not stop prescribed treatment on your own.
Monitoring over time
Bring previous corneal topography or tomography maps, pachymetry results, old spectacle prescriptions, and contact lens data. Serial results are especially valuable for documenting progression.
Recovery after treatment
Tell the doctor about prior laser vision correction , radial keratotomy, eye trauma, herpetic eye disease, allergies, autoimmune conditions, severe dry eye, or previous epithelial healing problems.
Corneal shape
If you wear contact lenses, ask in advance when to remove them before topography or tomography. Timing depends on lens type and the diagnostic protocol.
Limitations and safety
Cross-linking is not prescribed automatically on the basis of a diagnosis alone.
Book a consultation
Stages
Stage 1
Consultation and progression assessment.
The clinician reviews symptoms, prior prescriptions, and serial imaging to determine whether progression is present.
Stage 2
Corneal diagnostics.
Corneal biomechanics, shape and thickness are assessed, including topography or tomography and pachymetry as indicated.
Stage 3
Topical anesthesia.
KazRIED’s service page describes anesthetic eye drops.
Stage 4
Corneal preparation.
In the current KazRIED isotonic CXL description, the epithelium is removed to improve riboflavin penetration.
Stage 5
Riboflavin loading.
KazRIED describes 15–30 minutes of riboflavin instillation until adequate tissue saturation is achieved.
Stage 6
UV-A exposure.
The doctor individually selects UV-A mode, power and exposure duration.
Stage 7
Postoperative review
The surface is checked during healing, and later serial corneal measurements are compared to determine whether ectasia has stabilized.
Service benefits
Limiting progression
In progressive ectasia, cross-linking aims to strengthen the cornea and slow further changes.
Strengthening the patient's own cornea
Cross-linking treats corneal tissue without replacing it with a donor graft.
A basis for further correction
Stabilising the condition helps plan optical correction; improved visual acuity is not a guaranteed result of the procedure.
Monitoring shape and thickness
Repeat investigations allow corneal stability and the need to adjust treatment to be assessed.
Methods comparison · 1
Criterion
Standard epi-off
Transepithelial epi-on
Local / individualised
Epithelial removal
Yes, central zone
Epithelium is not removed
Depends on protocol and zone
Riboflavin penetration
More predictable
Limited by the epithelial barrier
Planned according to the selected technique
Evidence in progressive ectasia
The most studied standard
Less consistent results
Depends on technology and patient selection
Early discomfort
Usually higher
Usually lower
Depends on the extent of epithelial treatment
Standard epi-off
Epithelial removal
Riboflavin penetration
Evidence in progressive ectasia
Early discomfort
Yes, central zone
More predictable
The most studied standard
Usually higher
Epithelium is not removed
Limited by the epithelial barrier
Less consistent results
Usually lower
Depends on protocol and zone
Planned according to the selected technique
Depends on technology and patient selection
Depends on the extent of epithelial treatment
Methods comparison · 2
Method
Cross-linking
Glasses / contact / scleral lenses
Intrastromal segments
Current availability at KazRIED requires separate confirmation.
Primary goal
Stabilise progressive ectasia
Improve image quality
Modify corneal shape and optical parameters in selected patients
Replace diseased tissue in severe structural pathology
What it does not do
Does not guarantee elimination of irregular astigmatism
Do not strengthen the cornea or stop progression
Not a direct equivalent of cross-linking
Not the first step in early progressive keratoconus
Role and availability
Main service
Additional optical rehabilitation
KazRIED publicly states that corneal transplantation at its base is temporarily suspended
Cross-linking
Primary goal
What it does not do
Role and availability
Stabilise progressive ectasia
Does not guarantee elimination of irregular astigmatism
Main service
Improve image quality
Do not strengthen the cornea or stop progression
Additional optical rehabilitation
Modify corneal shape and optical parameters in selected patients
Not a direct equivalent of cross-linking
Replace diseased tissue in severe structural pathology
Not the first step in early progressive keratoconus
KazRIED publicly states that corneal transplantation at its base is temporarily suspended
Book an appointment
Book a KazRIED consultation to assess keratoconus progression, corneal shape and thickness, and whether cross-linking is indicated. The treating physician selects the protocol after examination.
Procedure prices
Service name
Price
Isotonic corneal cross-linking (per eye)
from 197 000 ₸
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
Experience: 12 years
Ophthalmologist
Tadzhimetov Murat Mikhaylovich
Highest-category ophthalmologist
Corneal cross-linking: goals, methods, and follow-up
Corneal cross-linking changes the cornea’s biomechanical properties to improve its stability. It is not intended to reshape the cornea by ablation or eliminate refractive error.
Riboflavin acts as a photosensitizer, while controlled UV-A exposure triggers photochemical reactions that increase cross-links within the corneal collagen structure.
When is cross-linking considered?
In progressive keratoconus and other ectatic conditions, the main goal is to stop or slow documented progression, improve corneal biomechanical stability, and reduce the risk of further deformation and thinning.
Before treatment, it is important to confirm the diagnosis and assess changes in corneal shape and thickness over time.
If keratoconus is newly diagnosed but the measurements remain stable, the clinician may recommend monitoring rather than immediate intervention.
How do the protocols differ?
The standard epi-off approach involves temporary removal of the central epithelium to improve riboflavin penetration. Professional sources regard it as the most extensively studied and predictable approach for progressive ectasia.
Transepithelial and individualized protocols also exist, but their effectiveness and indications depend on the specific technology.
For a very thin cornea or significant scarring, the standard isotonic protocol may be unsuitable. Further management is determined by a specialist surgeon.
Why might glasses or contact lenses still be needed?
Cross-linking and vision correction serve different purposes. Strengthening the cornea may stabilize the disease, but it does not automatically create an optically regular surface or guarantee improved visual acuity.
Blurred vision after treatment does not, by itself, mean that stabilization has failed. Glasses, rigid contact lenses, or scleral lenses may be needed to improve image quality.
Cross-linking should not automatically be considered preparation for conventional laser vision correction.
How is the outcome monitored?
After the early recovery period, the clinician assesses visual acuity and the stability of corneal topography or tomography findings.
If corneal measurements continue to change, the clinician reassesses progression, adherence to recommendations, ocular surface condition, and the need for an alternative or repeat procedure.
The decision for the other eye is made separately, based on its own measurements and changes over time.
Once stability has been assessed, further visual rehabilitation is discussed: glasses, contact or scleral lenses, and, in selected clinical situations, other surgical methods.
Availability of additional methods at KazRIED
The availability of intrastromal corneal ring segment implantation at KazRIED requires separate confirmation. It should not be presented as a currently confirmed service without clarification.
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 corneal cross-linking?
Corneal cross-linking is a procedure that uses riboflavin and controlled UVA light to increase corneal biomechanical stability. In keratoconus and other ectatic disorders, its main goal is to reduce the risk of further progression.
Does cross-linking completely cure keratoconus?
Cross-linking does not restore a completely normal corneal shape or automatically eliminate existing irregular astigmatism. Its main goal is to stabilize progressive ectasia. Spectacles or contact lenses may still be required for visual correction.
Will my vision improve after cross-linking?
Some patients may experience favorable changes in corneal shape, refraction or visual acuity after stabilization. However, visual improvement is not guaranteed and is not the primary goal of treatment.
Does every patient with keratoconus need cross-linking?
No. The decision depends mainly on evidence or risk of progression as well as age, corneal thickness and clarity, shape, epithelial and ocular-surface status and other clinical factors. Stable keratoconus does not always require immediate CXL.
How is keratoconus progression determined?
The doctor compares serial corneal topography or tomography, keratometry, pachymetry, refraction and visual function. Reproducible change across several parameters is important because a single scan or measurement may not establish progression.
How much does corneal cross-linking cost?
Cost depends on the treatment protocol, required diagnostic assessment and other components of care. Current pricing is available in the price list of KazRI of eye diseases.
Is diagnostic testing included in the cross-linking price?
Package contents may vary. The current price list should be checked to confirm whether consultation, corneal tomography or topography, other tests, consumables and postoperative visits are included.
What anaesthesia is used for cross-linking?
Most standard procedures are performed with topical local anaesthesia. The exact approach depends on the technique, age, ability to tolerate the procedure and other medical factors.
How long does corneal cross-linking take?
There is no single duration. Conventional and accelerated protocols differ in epithelial preparation, riboflavin loading, UVA intensity and irradiation time.
Is the corneal epithelium removed during cross-linking?
It depends on the protocol. In epi-off CXL, the central epithelium is temporarily removed to facilitate stromal riboflavin penetration. Transepithelial approaches are also available in which the epithelium is not fully removed.