A Scan & IOL Master Biometry
Biometry measurements of the length of the eye are required prior to Cataract surgical procedures in order to calculate the power of the lens to be implanted. At Doncaster Eye Centre we use both the Zeiss IOL Master as well as Immersion A-Scans to perform these calculations.
The IOL Master uses non-contact laser light interference to accurately measure the length of the eye, whereas Immersion A-Scans use Ultrasound waves. The results of these measurements are then applied to multiple mathematical formulae to determine each individual eye’s required lens power.
Visual Field Test
With glaucoma, the peripheral field of vision is usually the first to be affected. Periodic visual fields are performed to detect new field defects, or determine a worsening or deepening of established field loss over time.
Ocular Coherence Tomography (OCT)
The Heidelberg Spectralis OCT provides a three dimensional cross-section contour map of the layers of the back of the eye. High resolution scans help detect subtle changes which are essential for the early diagnosis and treatment of macular and retinal diseases as well as glaucoma.
A Pachymeter is a handheld ultrasound device that utilises echo spike techniques to determine Central Corneal Thickness (CCT). This enables evaluation of the accuracy of intraocular pressure results.
The retinal (fundus) camera is used to take high resolution digital photographs of the back of the eye which can be useful for detecting and monitoring changes caused by diseases such as glaucoma or macular degeneration. These may be taken in colour, black and white, or as part of a fluorescein angiogram. Anterior segment photography may also be taken to detect and monitor changes of the anterior structures such as the cornea, iris or the eyelids.
Fundus Fluorescein Angiography
A fundus Fluorescein angiogram (FFA) is a diagnostic test use to detect abnormalities in the blood vessels and circulation at the back of the eye. Fluorescein dye is injected into the arm and when the dye reaches the blood vessels at the back of the eye a series of photographs are taken at different time intervals. This allows for the detection of any blockage or leakage of dye from the retinal blood vessels.
Selective Laser Trabeculoplasty (SLT)
SLT is a gentle, non-thermal, painless laser procedure which reduces intraocular pressure (IOP) associated with glaucoma. It uses short pulses of low energy light to improve the drainage mechanisms which regulate IOP.
Laser Peripheral Iridotomy
Fluid is constantly being pumped inside the eye and exits the eye at the same rate to maintain a healthy intraocular pressure.
If there is high resistance to the fluid circulation, this results in dangerously high pressure in the eye.
A laser beam (YAG laser) is used to provide an alternate route for fluid inside the eye to access the outflow ports without encountering high resistance.
Diode laser beams are used to treat conditions such as diabetic retinopathy, macular disease and to seal around small retinal tears. The laser beam works by heating the tissues of the eye and sealing leaky blood vessels.
YAG Laser Capsulotomy
Following cataract surgery, some patients may develop a clouding of the lens capsule or bag. This is referred to as posterior capsule opacification. If this affects vision then a YAG laser is used to cut a hole in the center of the clouded back lining of the capsule, allowing light to pass through to the retina, thus restoring optimal vision.
The Pentacam is an illuminated camera system which rotates 360° around the eye to produce a three dimensional map of the thickness and shape of the cornea and allows for the differential diagnosis and monitoring of corneal diseases. It is also used in the pre-operative assessment for refractive laser procedures and cataract surgery.