Corneal thickness
Patients before laser correction, with suspected keratoconus or other corneal disease, with glaucoma or ocular hypertension requiring central-thickness assessment, after corneal surgery, and when monitoring over time is needed.
About the service
Pachymetry measures corneal thickness. The measurements inform corneal assessment, interpretation of eye pressure and planning of selected procedures.
Who the service is for
Inflammation and infection
If there is acute pain, trauma, marked inflammation or an epithelial defect, clinical examination should precede any contact test.
Corneal thickness
Pachymetry may be ordered for reduced vision, image distortion, photophobia, recurrent oedema or other symptoms when the doctor suspects corneal disease. Symptoms alone are not an indication specifically for pachymetry.
Keratoconus and ectasia
Keratoconus and other ectasias, corneal dystrophy or oedema, post-cross-linking/keratoplasty states, refractive-surgery screening, glaucoma and ocular hypertension.
Dryness and the ocular surface
Different technologies are not identical. Opacity, marked irregularity, poor fixation, tear-film issues, contact lenses and postoperative changes can affect quality.
Corneal thickness
Fresh corneal trauma, severe pain, sudden vision loss, chemical injury, purulent discharge or marked redness require urgent clinical assessment rather than a stand-alone scheduled pachymetry test. CCT does not diagnose glaucoma and does not replace tonometry, OCT, visual fields or gonioscopy. Do not mechanically correct IOP using an arbitrary CCT formula.
Assessment before choosing treatment
A universal “normal” thickness must not be used without considering the device, measurement area and clinical context.
Interpreting results
Measurements from different devices may have systematic differences and may not be interchangeable.
Corneal thickness
Before laser correction, thickness alone is insufficient: corneal shape and other parameters must also be assessed.
Corneal thickness
Fasting and pupil dilation are usually unnecessary for pachymetry itself. If pachymetry is performed before laser correction or to assess keratoconus, the doctor must confirm the exact lens-free interval.
Contact lenses
Usually minimal. Remove contact lenses; refractive-surgery protocols may require a longer lens-free period. Remove contact lenses before the test.
Results and documents
Bring previous pachymetry maps, topography or tomography and tonometry results: comparable tests are important for monitoring.
Eye injury
Report previous LASIK, PRK, SMILE, cross-linking, keratoplasty, injuries and corneal disease.
Limitations and safety
Pachymetry does not diagnose keratoconus by itself.
Book a consultation
Stages
Stage 1
Define the clinical question
The specialist clarifies the goal: corneal assessment, glaucoma, surgery preparation or monitoring.
Takes: 1 min
Stage 2
Preparation for measurement
Contact lenses are removed.
Takes: 1 min
Stage 3
Thickness measurement
The patient fixates while the device scans or the specialist takes a point measurement.
Takes: 1 min
Stage 4
Quality control
The specialist checks centration and scan or measurement quality and repeats if needed.
Takes: 1 min
Stage 5
Interpretation
The ophthalmologist compares thickness with topography or tomography, pressure, corneal health and other findings to determine management.
Takes: 5 min
Service benefits
Measuring corneal thickness
Pachymetry measures corneal thickness for use in diagnosis and treatment planning.
Better context for pressure readings
Corneal thickness informs the interpretation of tonometry and overall glaucoma risk assessment.
Data for choosing correction
Corneal and refractive measurements help the surgeon assess suitability and plan the selected laser technique.
Monitoring change
Comparable repeat measurements help the doctor detect deterioration or stability.
Method comparison, part 1
Criterion
Ultrasound pachymetry
Spectralis AS-OCT
Cirrus-HD AS-OCT
DRI OCT Triton
Orbscan / slit-scanning
Principle
Ultrasound time-of-flight through cornea
Anterior-segment optical coherence tomography
Spectral-domain anterior-segment OCT
3D / swept-source OCT pachymetry mode
Optical slit-scanning topography/pachymetry
Corneal contact
Yes
No
No
No
No
Topical anaesthesia
Usually required
Not required
Not required
Not required
Not required
Output
Point measurement, dependent on probe placement
Optical central/regional thickness depending on protocol
Anterior-segment pachymetric data
Pachymetric data/map depending on protocol
Corneal thickness map across the surface
Refractive-surgery assessment
Useful for thickness but does not replace tomography
Useful in a full work-up
Useful in a full work-up
Useful in a full work-up
Useful for combined thickness/shape assessment; current availability to confirm
Glaucoma / CCT
Suitable for central thickness
Suitable
Suitable
Suitable
Can provide CCT; serial follow-up should use comparable methods
Patient sensation
Brief contact after anaesthesia
Minimal
Minimal
Minimal
Minimal
Ultrasound pachymetry
Principle
Corneal contact
Topical anaesthesia
Output
Refractive-surgery assessment
Glaucoma / CCT
Patient sensation
Ultrasound time-of-flight through cornea
Yes
Usually required
Point measurement, dependent on probe placement
Useful for thickness but does not replace tomography
Suitable for central thickness
Brief contact after anaesthesia
Anterior-segment optical coherence tomography
No
Not required
Optical central/regional thickness depending on protocol
Useful in a full work-up
Suitable
Minimal
Spectral-domain anterior-segment OCT
No
Not required
Anterior-segment pachymetric data
Useful in a full work-up
Suitable
Minimal
3D / swept-source OCT pachymetry mode
No
Not required
Pachymetric data/map depending on protocol
Useful in a full work-up
Suitable
Minimal
Optical slit-scanning topography/pachymetry
No
Not required
Corneal thickness map across the surface
Useful for combined thickness/shape assessment; current availability to confirm
Can provide CCT; serial follow-up should use comparable methods
Minimal
Method comparison, part 2
Criterion
Ultrasound pachymetry
Spectralis AS-OCT
Cirrus-HD AS-OCT
DRI OCT Triton
Orbscan / slit-scanning
Main limitation
Contact and the need for precise perpendicular probe positioning; probe pressure may affect the result.
Depends on optical signal and segmentation quality
Depends on scan quality and device algorithm
Depends on scan/fixation and algorithms
Depends on optical clarity and reconstruction algorithms
Serial comparison
Prefer same device/technique
Prefer same device/protocol
Prefer same device/protocol
Prefer same device/protocol
Prefer same device/protocol
Interchangeability
Values from different technologies must not be treated as fully interchangeable.
Same
Same
Same
Same
Clinical output
Thickness at measurement point
Optical CCT/anterior-segment thickness data
Thickness/anterior-segment data
Pachymetric data in DRI OCT mode
Thickness distribution map and corneal geometry within the system
Ultrasound pachymetry
Main limitation
Serial comparison
Interchangeability
Clinical output
Contact and the need for precise perpendicular probe positioning; probe pressure may affect the result.
Prefer same device/technique
Values from different technologies must not be treated as fully interchangeable.
Thickness at measurement point
Depends on optical signal and segmentation quality
Prefer same device/protocol
Same
Optical CCT/anterior-segment thickness data
Depends on scan quality and device algorithm
Prefer same device/protocol
Same
Thickness/anterior-segment data
Depends on scan/fixation and algorithms
Prefer same device/protocol
Same
Pachymetric data in DRI OCT mode
Depends on optical clarity and reconstruction algorithms
Prefer same device/protocol
Same
Thickness distribution map and corneal geometry within the system
Book corneal pachymetry
Book an examination if your clinician recommends corneal thickness measurement, you are being assessed for laser vision correction, or pachymetry is needed in glaucoma or corneal disease evaluation. KazRIED will select the appropriate technique and interpret the result within the full eye examination.
Procedure prices
Service name
Price
Spectralis anterior-segment pachymetry
Cost determined after consultation
Cirrus-HD anterior segment, pachymetry, cornea and anterior chamber angle
from 2 900 ₸
3D OCT pachymetry
Cost determined after consultation
The quoted Cirrus-HD price is per eye.
Our doctors
A team of experienced doctors across specialties.
Experience: 13 years
Ophthalmologist
Kalshabekov Alibi Sembaevich
Highest-category ophthalmologist
Experience: 12 years
Ophthalmologist
Tadzhimetov Murat Mikhaylovich
Highest-category ophthalmologist
Experience: 8 years
Ophthalmologist
Ondosinov Eldos Nurbekuly
Second-category ophthalmologist
Experience: 8 years
Ophthalmologist, Ultrasound and OCT Diagnostics
Amanzhanova Aziza Asqarqyzy
Experience: 14 years
Ophthalmologist
Botabekov Rustem Makhamadalievich
Experience: 7 years
Ophthalmologist
Zhunusov Omirkhan Maratuly
Experience: 3 years
Ophthalmologist
Seyt Aydar Abilkhanuly
Experience: 18 years
Consultant Physician
Tasboltaev Beknur Rakhimberdievich
Experience: 11 years
Consultant Physician
Ualieva Perizat Serikkazyevna
Pachymetry — Measuring Corneal Thickness
Pachymetry measures corneal thickness in the central area or across the entire cornea, depending on the technology used. The examination serves a range of clinical purposes.
When is pachymetry used?
- During a glaucoma assessment, central corneal thickness helps clinicians interpret intraocular pressure (IOP) measurements correctly.
- Before refractive surgery, corneal thickness is one of the parameters used to assess the safety of the procedure.
- In corneal diseases, the clinician evaluates not only the numerical measurement but also the thickness profile, corneal shape, the thinnest point, and changes over time.
What should be considered?
Pachymetry does not replace corneal topography or tomography. Pachymetry alone cannot establish a diagnosis of keratoconus.
Preparation for measurement
Contact lenses are removed. Non-contact OCT usually needs no anaesthetic; contact ultrasound requires local anaesthesia.
Additional advice and situations
If the value is within the expected range
The result is still interpreted with other tests; a typical thickness does not exclude corneal disease or glaucoma.
If the cornea is thin
Detailed corneal tomography/topography and assessment of other factors may be needed. The thickness value alone does not mean keratoconus.
If the cornea is thick
The doctor assesses possible oedema, endothelial status and other causes using slit-lamp examination and additional tests.
If performed before refractive surgery
The value is incorporated into surgical planning together with refraction corneal shape and other parameters.
If monitoring over time
Use the same or comparable device where possible and document device-related differences.
When preparing for laser vision correction, combined assessment of corneal thickness and shape is particularly useful; availability of the specific method must be confirmed.
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 pachymetry?
Pachymetry measures corneal thickness. Depending on the device, the result may be a central value, point measurements or a corneal thickness map.
What exactly is measured?
The test measures the distance between the anterior and posterior corneal surfaces at one or multiple locations, usually reported in micrometres.
Why is corneal thickness important?
Corneal thickness is important in corneal assessment, refractive surgery planning, monitoring keratoconus and corneal oedema, and interpreting intraocular pressure.
Does pachymetry diagnose keratoconus?
No. Corneal thinning may be one finding, but keratoconus is assessed using corneal topography or tomography, corneal shape and the clinical examination.
Does pachymetry diagnose glaucoma?
No. Central corneal thickness helps interpret tonometry and overall risk, but glaucoma is diagnosed using multiple clinical findings.
What is a normal corneal thickness?
There is no single cut-off that applies to every patient and every device. Corneal thickness varies with individual anatomy, measurement location and technology.
Why is one number not enough?
A central value does not describe the entire corneal thickness profile. The thinnest point, thickness distribution and tomography findings may also be important.
How does optical pachymetry differ from ultrasound pachymetry?
Optical pachymetry is non-contact and may generate a corneal thickness map. Ultrasound pachymetry uses a probe that touches the anaesthetised cornea and usually provides point measurements.
Is anaesthesia needed?
Anaesthesia is usually not required for non-contact optical pachymetry. Topical anaesthetic drops are used for contact ultrasound pachymetry.
Is pachymetry painful?
Non-contact pachymetry is generally painless. Ultrasound pachymetry is performed after topical anaesthesia, so significant pain is not expected.