Exams in use - Créteil Ophtalmo

Salle d'examens d'imagerie en condultation d'ophtalmologie The ophthalmology department of Créteil boasts a complete diagnostic platform encompassing all hi-tech diagnostic devices.

These include fluorescein angiography (FA), indocyanine green angiography (ICGA), optical coherence tomography (OCT), OCT-angiography (OCT-A), ocular ultrasound, the visual field and electrophysiology.

Fluorescein angiography

Fluorescein angiography is the key examination for the diagnosis of retinal diseases and more specifically age-related macular degeneration.

Fluorescein, which is a vital dye, is injected into a vein and emits a specific light when excited by a light of a certain wavelength. Angiography consists of taking photographs of the retina during the passage of fluorescein into the retinal vessels.

Indocyanine green angiography

Aspect en ICG de néovaisseaux occultes. — ICGA appearance of an occult neovascular membrane.

Indocyanine green angiography or ICGA employs another fluorescent dye, the indocyanine green, or the infracyanine.

It is complementary to FA and it makes possible to explore the choroid in better detail, i.e. the vascular tissue located under the retina.

It is used for detecting the so-called occult neovessels in AMD as well as for inflammatory diseases of the retina.

Optical Coherence Tomography

Optical coherence tomography, or OCT is a fast, painless and non-invasive imaging method that does not require the injection of a dye. OCT provides additional information to angiographic images.

OCT allows the fine analysis of the structures of the retina. A light beam generated by a laser source crosses the retina and a device measures the time taken by the light echo to cross the ocular tissues, be reflected and return to the source.

Aspect en OCT : à gauche une rétine normale, à droite lors d'une DMLA exsudative. — OCT appearance: a normal retina (on the left) and exudative AMD (on the right).

OCT-Angiography

Ocular Echography

Mesure de la longueur axiale en mode B guidé par le mode A : coupe de l’œil droit dite "axiale transverse". — Measurement of the axial length in B-SCAN: section of the right eye.

Ocular ultrasound uses ultrasound to explore intraocular structures whenever visualization of the fundus is impossible. For example because of a cataract or a vitreal hemorrhage that prevent accurate observation of the retina. Ultrasound is also used to determine the power of the implant to replace the lens during cataract surgery.
Two modes of ultrasound are used:

A mode (amplitude mode) is the oldest. It consists in interpreting the inflections of a line with respect to a baseline, each structure of the eye results in a peak or a series of peaks corresponding to the echo of this structure.
Mode B (shine mode) is currently the most used. In fact, the echogram is no longer linear but it represents a two-dimensional section of the eyeball, which makes analysis more easy to interpretate.

Visual field

Electroretinography

The electroretinogram or ERG consists in measuring the electrical activity of the retinal cells when they are excited by a light stimulus.

The resulting plot, records the response of cones and rods, which are the photoreceptors of the eye (visual cells). This examination is very useful for the diagnosis of genetic and degenerative diseases of the retina.