Corneal pachymetry
Pachymetry measures corneal thickness.
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Almaty, Astana, Shymkent
Pre-Laser Vision Correction Diagnostic Assessment
from 28.000 ₸
What is important to know before booking an appointment
Soft contact lenses can temporarily alter the shape of the cornea and distort measurement results. Therefore, they should be removed 2-3 days prior to the examination.
If pharmacological pupil dilation is planned, you may experience light sensitivity and blurred near vision for 3 to 4 hours afterward.
Service options
Tonometry
Tonometry measures intraocular pressure using a contact or non-contact method.
Learn moreOCT
OCT produces cross-sectional images of eye structures without surgery.
Learn moreVisual field testing
Perimetry tests the visual field and helps identify areas of reduced sensitivity.
Learn more
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About the service
A preoperative examination assesses the safety of laser vision correction and helps select a suitable method. It evaluates refraction, corneal shape and thickness, the ocular surface and other eye structures.
Who the service is for
Planning laser vision correction
Who is this assessment for? For patients with myopia, hyperopia or astigmatism who want to understand whether laser vision correction can safely be considered and which approach should be discussed with a refractive surgeon.
What to discuss at assessment
What symptoms or goals commonly lead to assessment? blurred distance vision; blurred near vision; myopia; hyperopia; astigmatism; dependence on glasses; dependence on contact lenses; poor contact-lens tolerance; glare or halos in dim light; a desire to reduce dependence on optical correction.
Age-related visual changes
Age and presbyopia After about age 40, near vision and the possible future need for reading correction should be discussed separately. Laser correction of refractive error does not stop the natural age-related changes in the eye's ability to focus at near. A good distance-vision result therefore does not mean that the patient will never need reading glasses.
Refractive stability
The doctor may defer a final decision for unstable refraction, active inflammation, marked dry eye, an unstable ocular surface, suspected keratoconus or ectasia, an uncertain corneal map, retinal changes or another eye condition requiring treatment or further diagnostics.
Assessment before choosing treatment
Treatment, observation or repeat measurements come first.
Realistic expectations
Diagnostics do not guarantee a specific postoperative acuity.
Dryness and the ocular surface
An unstable ocular surface can reduce corneal measurement reliability.
Keratoconus and ectasia
Suspected keratoconus or ectasia needs separate assessment.
Corneal thickness
A thin cornea does not automatically exclude correction, but requires comprehensive assessment; nor does it automatically establish suitability for Femto LASIK, PRK or another method.
Retinal condition
Peripheral retinal changes do not automatically require prophylactic laser. A specialist decides on specific indications.
Pupil dilation and eye drops
After drug-induced pupil dilation, light sensitivity and blurred near vision may last 3–4 hours.
Corneal shape
An inadequate lens break may distort topography or tomography. Soft contact lenses may temporarily alter corneal shape and distort measurements. They should therefore be removed 2–3 days before diagnostics.
Travel after the appointment
After dilation, do not drive until vision and light sensitivity return to a comfortable level.
What to tell the doctor
What is particularly important to tell the doctor? How your glasses or contact lens prescription has changed in recent years; which contact lenses you use; whether you have worn orthokeratology lenses; any dryness, burning or gritty sensation; previous eye injuries or operations; corneal disease; retinal disease; glaucoma; chronic and systemic conditions; and all regularly used medicines.
When is urgent eye care more appropriate?
Urgent ophthalmic assessment is more appropriate than routine refractive-surgery screening if there is: sudden significant vision loss; severe eye pain; marked redness; a curtain-like shadow; a sudden increase in floaters; new flashes of light; eye trauma.
Limitations and safety
Diagnostics do not guarantee surgical eligibility.
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Stages
Stage 1
Medical history and visual goals
The doctor clarifies symptoms, the history of refractive changes, contact lens type and wearing schedule, previous diseases and operations, medications, occupation, sports and expectations of laser vision correction.
Takes: 15 min
Stage 2
Visual acuity and refraction
Vision without and with optimal correction, and objective and subjective refraction, are assessed.
Takes: 10 min
Stage 3
Corneal mapping
Maps of the anterior and posterior corneal surfaces and thickness distribution are obtained.
Takes: 5 min
Stage 4
Corneal thickness
Pachymetry and additional measurements assess corneal thickness and anterior-segment anatomy in relation to the proposed correction method.
Takes: 5 min
Stage 5
Ocular surface assessment
Biomicroscopy and tear-film assessment help detect dryness, inflammation, eyelid and corneal disease and other conditions affecting measurement accuracy and postoperative comfort.
Takes: 5 min
Stage 6
Intraocular pressure
Tonometry assesses intraocular pressure.
Takes: 5 min
Stage 7
Fundus examination
The pupil may be dilated to assess the retina, macula and optic disc according to protocol and indications.
Takes: 30 - 40 min
Stage 8
Surgeon’s assessment
The doctor integrates all results, discusses candidacy, limitations and alternatives, explains realistic expectations and provides a next-step plan.
Takes: 20 min
Service benefits
Identifying limitations before surgery
Diagnostics help detect ectasia signs and other findings that may influence the choice of procedure.
Data for choosing correction
Corneal and refractive measurements help the surgeon assess suitability and plan the selected laser technique.
More reliable measurements
Ocular surface assessment helps identify dryness and address it before final calculations when needed.
Understanding the expected result
Before intervention, the doctor discusses visual goals, limitations and possible need for glasses afterwards.
Table 1. Core tests
Criterion
Visual acuity + refraction
Topography / tomography
Pachymetry
Biomicroscopy + ocular surface
Tonometry
What it assesses
Visual acuity and refraction
Anterior and posterior surface shape and corneal map
Corneal thickness
Anterior segment, tear film, eyelids and cornea
Intraocular pressure
Why needed before correction
Establishes the optical goal and best-corrected vision
Screening for keratoconus, ectasia, irregular astigmatism and lens-related changes
Assesses tissue reserve and feasibility of the selected treatment
Detects surface problems affecting measurements and recovery
Detects pressure abnormalities needing further assessment
Eye contact
No / depends on the method
Usually no
Depends on technology
Examination without surgery; some tests may contact the surface
Non-contact or contact
Is pupil dilation needed
Usually not; cycloplegia when indicated
No
No
No
No
Effect of contact lenses
May affect refraction
Very important: lenses can temporarily alter corneal maps
May affect interpretation
May affect the ocular surface
Usually limited
Influence on method selection
High
Critical
Critical
High
Moderate / depends on findings
If the result is uncertain
Repeat after refractive stabilisation
Repeat after an adequate lens break and surface stabilisation
Compare with tomography and planned treatment
Treat dryness or inflammation first, then repeat measurements
Further glaucoma assessment when indicated
Visual acuity + refraction
What it assesses
Why needed before correction
Eye contact
Is pupil dilation needed
Effect of contact lenses
Influence on method selection
If the result is uncertain
Visual acuity and refraction
Establishes the optical goal and best-corrected vision
No / depends on the method
Usually not; cycloplegia when indicated
May affect refraction
High
Repeat after refractive stabilisation
Anterior and posterior surface shape and corneal map
Screening for keratoconus, ectasia, irregular astigmatism and lens-related changes
Usually no
No
Very important: lenses can temporarily alter corneal maps
Critical
Repeat after an adequate lens break and surface stabilisation
Corneal thickness
Assesses tissue reserve and feasibility of the selected treatment
Depends on technology
No
May affect interpretation
Critical
Compare with tomography and planned treatment
Anterior segment, tear film, eyelids and cornea
Detects surface problems affecting measurements and recovery
Examination without surgery; some tests may contact the surface
No
May affect the ocular surface
High
Treat dryness or inflammation first, then repeat measurements
Intraocular pressure
Detects pressure abnormalities needing further assessment
Non-contact or contact
No
Usually limited
Moderate / depends on findings
Further glaucoma assessment when indicated
Table 2. Additional tests
Criterion
Cycloplegic refraction
Fundus examination
Retinal / optic disc OCT
Aberrometry / pupillometry
Additional biometry / perimetry
Main purpose
Clarify refraction without accommodation
Assess retina, macula, periphery and optic disc
Layer-by-layer retinal and optic nerve assessment when indicated
Assess optical aberrations and pupil size, including dim light
Clarify anatomy or visual field for a specific clinical question
Is it needed for everyone
Per protocol and indication
Often part of preoperative assessment, particularly in myopia
No, when indicated
Depends on technology and protocol
No, when indicated
Can it change the decision
Yes, if refraction differs substantially
Yes, if retinal disease is found
Yes, if significant disease is found
May influence personalisation and visual-quality discussion
May influence planning if an associated disorder is found
Pupil dilation needed
Cycloplegic drops are used
Often yes
Sometimes
No
Usually no
After testing
Temporary near-focusing difficulty
Possible light sensitivity and blurred near vision
Usually no restrictions
Usually no restrictions
Usually no restrictions
Role across Femto LASIK / SMILE / CLEAR / PRK
Refines refractive target
Assesses coexisting risk rather than selecting a technique itself
Adds information in selected cases
May support customized treatment and night-vision counselling
Complements the core protocol
Cycloplegic refraction
Main purpose
Is it needed for everyone
Can it change the decision
Pupil dilation needed
After testing
Role across Femto LASIK / SMILE / CLEAR / PRK
Clarify refraction without accommodation
Per protocol and indication
Yes, if refraction differs substantially
Cycloplegic drops are used
Temporary near-focusing difficulty
Refines refractive target
Assess retina, macula, periphery and optic disc
Often part of preoperative assessment, particularly in myopia
Yes, if retinal disease is found
Often yes
Possible light sensitivity and blurred near vision
Assesses coexisting risk rather than selecting a technique itself
Layer-by-layer retinal and optic nerve assessment when indicated
No, when indicated
Yes, if significant disease is found
Sometimes
Usually no restrictions
Adds information in selected cases
Assess optical aberrations and pupil size, including dim light
Depends on technology and protocol
May influence personalisation and visual-quality discussion
No
Usually no restrictions
May support customized treatment and night-vision counselling
Clarify anatomy or visual field for a specific clinical question
No, when indicated
May influence planning if an associated disorder is found
Usually no
Usually no restrictions
Complements the core protocol
Find out whether laser correction suits you after comprehensive diagnostics
Book an examination so the doctor can assess vision and corneal measurements, exclude significant limitations and explain correction methods or alternatives. Book an assessment
Procedure prices
Service name
Price
Preoperative assessment for laser vision correction
from 28 000 ₸
Our doctors
A team of experienced doctors across specialties.
Experience: 26 years
Head
Zhakybekov Ruslan Adilovich
Candidate of Medical Sciences; Highest-category ophthalmologist
Experience: 13 years
Ophthalmologist
Kalshabekov Alibi Sembaevich
Highest-category ophthalmologist
Experience: 8 years
Ophthalmologist
Ondosinov Eldos Nurbekuly
Second-category ophthalmologist
Experience: 9 years
Ophthalmologist
Otegenova Gulsanim Meyrambekqyzy
Second-category ophthalmologist
Experience: 7 years
Ophthalmologist
Zhunusov Omirkhan Maratuly
Experience: 14 years
Ophthalmic Diagnostics Physician
Nurzhanova Dinara Nurbolatovna
Experience: 3 years
Ophthalmologist
Seyt Aydar Abilkhanuly
Why pre-laser diagnostics differ from a routine vision test
A routine test may establish how well a person sees and which optical correction is needed.
Preoperative refractive assessment asks more complex questions: is refraction stable, is the cornea suitable for the procedure, are there signs of ectasia or ocular-surface disease, what is best-corrected acuity, and are there associated findings that alter treatment?
The assessment should explain not only eligibility but why, which methods can be discussed, which restrictions remain and whether ocular-surface, retinal or other disease needs treatment first.
Diagnostic equipment supplies measurements but does not automatically select surgery. The decision follows comparison of all findings, the capabilities of the particular technology and the patient's visual needs.
The ophthalmologist correlates refraction and visual acuity with corneal topography or tomography and thickness, ocular surface status, intraocular pressure and retinal findings.
The outcome is not a promise of surgery, but a medical conclusion: whether laser vision correction can be considered, which methods should be discussed, which limitations must be taken into account, and whether additional steps are needed before treatment.
Further procedure details
Visual acuity and refraction
Vision without and with optimal correction, and objective and subjective refraction, are assessed.
The doctor assesses refraction after cycloplegia when needed to reduce the effect of accommodation.
Corneal mapping
Maps of the anterior and posterior corneal surfaces and thickness distribution are obtained.
This is a key screening stage for keratoconus, other ectasias, irregular astigmatism and lens-related corneal shape changes.
Intraocular pressure
Tonometry assesses intraocular pressure.
Abnormal findings may require further diagnostics to exclude or assess glaucoma.
Fundus examination
The pupil may be dilated to assess the retina, macula and optic disc according to protocol and indications.
A specialist determines further management if suspicious changes are found.
Additional advice and situations
Before the visit
Discontinue contact lenses for the interval set by KazRIED.
Bring:
- Current glasses;
- Current prescription;
- Previous medical summaries;
- Examination results;
- Information on previous operations.
If the ocular surface is unstable
Dryness, blepharitis or inflammation is treated first.
Key corneal measurements may be repeated after surface stabilisation.
If the corneal map is uncertain
The doctor may recommend:
- A longer contact-lens break;
- Repeat tomography;
- Further ectasia assessment;
- Follow-up over time
If retinal changes are found
The patient may be referred to a retinal specialist or laser surgeon.
Additional treatment is given only for medical indications.
If corneal laser correction is unsuitable
The doctor explains why and, when indicated, may discuss:
- Glasses;
- Contact lenses;
- Phakic IOLs;
- Other correction methods.
Before surgery
After clearance, the patient receives separate KazRIED instructions covering:
- Preparation
- Required tests;
- Medicines;
- Restrictions;
- Surgery date;
- Instructions for the day before treatment.
The diagnostic package includes Pentacam, Corvis ST, Schwind Sirius, cycloscopy and a doctor's consultation. Additional tests indicated clinically are charged separately.
Further information
The value lies in the doctor's interpretation of all findings, not the number of devices or measurements.
A good report answers specific questions:
- Is vision stable;
- Is the cornea healthy;
- Is its shape suitable for refractive surgery;
- Is it thick enough;
- Are there ocular-surface problems;
- Are there retinal changes;
- Which correction methods can be discussed;
- What can realistically be expected after surgery.
Related information: Contact Lenses for Children.
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
Why do I need a separate assessment if I already have a glasses prescription?
A glasses prescription describes refraction but does not assess corneal shape and thickness, ocular surface, retina and other factors needed for refractive-surgery planning.
Can candidacy be decided from my prescription alone?
No. Refractive error matters, but stability, corneal findings, ocular-surface health, coexisting disease and the planned technology are also important.
Do I need to stop wearing contact lenses?
Yes. Contact lenses can temporarily change corneal shape.
Will my pupils be dilated?
It depends on protocol and clinical findings. Dilation may be used for retinal examination and/or to clarify refraction.
Can I drive after the assessment?
If dilating or cycloplegic drops are used, avoid driving until vision and light sensitivity have returned to a comfortable level.
Is the assessment painful?
Most tests are non-invasive and well tolerated. Brief discomfort can occur with an air-puff test, eye drops or certain contact tests.
How long does it take?
It depends on the number of tests, pupil dilation and whether measurements must be repeated.
What are corneal topography and tomography?
They map corneal shape. Tomography can also evaluate the posterior cornea and pachymetric distribution, which is particularly important in ectasia screening.
Why is corneal thickness measured?
Corneal laser procedures reshape the cornea. Pachymetry helps determine whether there is adequate tissue reserve for the procedure being considered.
Does a thin cornea automatically rule out laser correction?
Not always. The decision uses tomography, refractive error, planned tissue effect and other parameters. Another procedure or non-laser option may sometimes be more appropriate.