Instruments
In Dr. Luigi Fusi’s ophthalmologist’s surgery there are the most modern instruments in the forefront of ophthalmologic diagnosis and therapy. The Soft air puff Tonometer Canon TX-F is useful to measure endocular pressure. The Soft air puff Tonometer combines precision and reliability of the results with a swift execution and, above all, with the absence of a contact with ocular structures, favouring a high degree of sterility in comparison with traditional methods.
The HRT II Tomograph is designed for measurement of the three-dimensional shape of the optic nerve head and of the variations of this shape with the passing of time. Besides, the HRT, through the MEM (Macular Edema Module), supplies a full analysis of the 3D images acquired, calculating the macular edema maps, offering in this way an instrument to evaluate the presence of edema and to make control tests. (read more)1
Role of the Heidelberg Retinal Tomograph (HRT II)
Up to some years ago, the importance to visualize the retinal map containing the information about the morphology of the macular region, of the optical nerve and of the whole retina was almost entirely entrusted to the fluorangiography test and, partially, to perimetry (or campimetry, the visual field test).
The fluorangiography is a photograph obtained thanks to a particular photographic instrument, equipped with a filter able to impress the retinal image, obtained through the introduction of a fluoresceinic liquid injected in a vein of the arm, on a photographic film.
This test is not often well accepted by patients since, in addition to their complete willingness, the dilatation of the pupil is required (so the patients should be accompanied, because they will not be able to drive and to carry out a work for some hours).
Besides, the fluorescein endovenous injection can sometimes cause problems such as sickness, yellow skin, up to an intolerance reaction to contrast medium, resulting sometimes in an anaphylactic shock (luckily very rare). Besides, it is better not to forget that patients must fast before this test, and this can be a problem for patients suffering from accompanying pathologies, such as diabetes, especially in insulin-dependent patients.
The perimetry is an excellent test to evaluate the function of the optic nerve and of the retinal sensitivity from a functional point of view, however it is a psycho-physical test not always easy to do because it requires a high compliance on the patients’ side (not always easily obtainable) and in the first stages evident visual field defects are rarely manifested.
The coming of laser scanning ophthalmoscopy, with the possibility to carry out stereometric investigations of the intraocular structures, made ophthalmoscopy enter a new dimension. Pilot studies to develop a non-invasive laser scanning ophthalmoscope began in 1980 thanks to R. Webb in Boston and J.F. Bille in Heidelberg.
In 1988 the first confocal laser tomograph LTS, that originated the family of the HRT I and II. This instrument measures the three-dimensional shape of the optic nerve head and the variations of this shape with the passing of time. The HRT, through the MEM (Macular Edema Module), supplies a full analysis of the 3D images acquired, calculating the retinic edema maps, offering in this way an instrument to evaluate the presence of edema and to make control tests. Besides, this instrument has been implemented with the Rostock Cornea Module, allowing the analysis and the study of the entire corneal morphology.
The test made with the HRT II does not require a specific preparation of the patient. Generally, a test made with the HRT can be carried out even without pupil dilatation, with the exception of the case in which there is a remarkable reduction of the transparency of the ocular medium (cataract).
The recording of the images has to be made without glasses and in the presence of a good lacrimal film (if eyes are dehydrated and, in particular, for contact lens wearers, it is better to add artificial tears just before the test).
The photographs obtained can be seen on the PC screen in real time and, after some minutes, given to the patient with different representations such as a mere photograph or a detailed analysis of morphometric parameters or a 3D retinal representation.
Besides, the instruments allows to memorize data, to compare and analyze the variations of the edematous macular damage and to support by documentary evidence the evolution of glaucomatous disease as regards the modifications of the papilla (the blind spot) and the thickness of the nerve fibres with the passing of time.
The Stratus OCT is a system to acquire and elaborate bi-dimensional images of a retinal section. The system uses a non-contact procedure and a non-invasive methodology, obtaining images with a resolution of approx. 7/8 micron of a section of the retinal structure. This instrument can supply detailed images of the retinal morphology and can highlight the alterations of the same due to a wide range of pathologies.
Thanks to the laser Lasag Topaz (YAG laser for capsulotomy) it is possible to treat secondary cataract, a condition taking place in a low percentage of cases, some months or years after the operation, in people operated on cataract. It is an outpatient operation (so it is not necessary to stay after the operation), lasting a few minutes, that, with no pain or risk for the patients, eliminates the mist troubling the sight once and for all.
The Confocal Microscope ConfoScan 3 thanks to a highly sensitive optic system, evaluates and displays corneal details never shown before and supplies new information about physiologic and pathologic relations of the corneal layers. Therefore it is fundamental for the diagnosis of a wide range of pathologies.
