Diagnosing and monitoring glaucoma relies on a combination of clinical examinations and advanced instruments. Each test provides unique information about the condition of the eye, and together they enable the physician to obtain a complete and accurate picture of the disease and to customize treatment on an individual basis.
Intraocular Pressure Measurement (Tonometry)
Intraocular pressure measurement is one of the most fundamental tests in glaucoma evaluation. The gold standard is Goldmann applanation tonometry, performed at the slit lamp after local anesthetic drops. Additional methods include rebound tonometry (iCare), which does not require drops, and non-contact tonometry ('air puff') for initial screening. Intraocular pressure varies throughout the day, so repeated measurements at different times may be necessary.
Corneal Thickness (Pachymetry)
Measuring corneal thickness is important because it affects the accuracy of intraocular pressure measurement. Thick corneas may cause overestimation of pressure, while thin corneas may lead to underestimation — potentially causing delayed diagnosis. Thin corneas are also considered an independent risk factor for glaucoma. The test is performed using an ultrasound or optical device, and is quick and painless.
Visual Field Testing (Perimetry)
Visual field testing measures visual function across different areas of the visual field. It is a critical test that reveals the functional impact of glaucoma — areas where light sensitivity has been impaired. The test is performed using a computerized device (Humphrey) that identifies defects characteristic of glaucoma. Results over time allow monitoring of disease stability or progression.
Gonioscopy
Gonioscopy allows the physician to look directly at the drainage angle of the eye — the structure through which intraocular fluid drains. The examination is performed using a special lens placed on the eye. It is essential for classifying the type of glaucoma (open-angle vs. angle-closure), identifying pathological findings in the angle, and planning treatment. The test is quick and generally does not cause significant discomfort.
Optical Coherence Tomography (OCT)
OCT is an advanced imaging technology that captures layers of the retina and optic nerve at very high resolution. The test measures the thickness of the nerve fiber layer around the optic nerve and the ganglion cell layer — the layers affected first in glaucoma. OCT can detect structural changes even before visual field test changes appear, making it a central tool in early diagnosis and monitoring.
Fundus Photography
Color photography of the fundus objectively documents the appearance of the optic nerve. The photographs allow the physician to compare the nerve's condition over time and identify gradual changes. Important findings include cup-to-disc ratio, presence of small hemorrhages, nerve tissue thinning, and blood vessel patterns. Photography complements the OCT exam and enables direct visual assessment.
Slit Lamp Examination
The slit lamp is a specialized microscope that allows the physician to examine all eye structures under magnification. In the context of glaucoma, the examination enables evaluation of the anterior chamber, chamber depth, iris condition, lens, and angle. Combined with special lenses, the optic nerve and retina can also be examined. This is the foundational examination of every eye visit and provides critical information for diagnosis and follow-up.
Biometry
Biometry is a precise measurement of eye structures, including eye length, anterior chamber depth, and lens thickness. In the context of glaucoma, these measurements are important for identifying short eyes at risk for angle-closure glaucoma. Biometry is also essential for planning cataract surgery in glaucoma patients, where choosing the appropriate lens can affect intraocular pressure.
Genetic Testing
In recent years, significant progress has been made in understanding the genetic factors behind glaucoma. Genetic testing is especially recommended in cases of strong family history, early-onset glaucoma, or unique forms of glaucoma. Identifying specific genetic mutations (such as MYOC, OPTN, and others) can aid in early diagnosis of at-risk family members and sometimes also influence treatment selection. Prof. Leshno incorporates genetic testing as part of a comprehensive evaluation when relevant.