Limits...
The fundus slit lamp.

Gellrich MM - Springerplus (2015)

Bottom Line: The three lenses +90/+60/+40D are a good choice for imaging the whole spectrum of retinal diseases.A reconstruction of larger fundus areas is feasible for imaging in vitreoretinal surgery or occlusive vessel disease.Even a basic fundus controlled perimetry is possible.

View Article: PubMed Central - PubMed

Affiliation: Ophthalmological practice, Ziegeleiweg 10, 25548 Kellinghusen, Germany.

ABSTRACT
Fundus biomicroscopy with the slit lamp as it is practiced widely nowadays was not established until the 1980-es with the introduction of the Volk lenses +90 and +60D. Thereafter little progress has been made in retinal imaging with the slit lamp. It is the aim of this paper to fully exploit the potential of a video slit lamp for fundus documentation by using easily accessible additions. Suitable still images are easily retrieved from videorecordings of slit lamp examinations. The effects of changements in the slit lamp itself (slit beam and apertures) and its examination equipment (converging lenses from +40 to +90D) on quality and spectrum of fundus images are demonstrated. Imaging software is applied for reconstruction of larger fundus areas in a mosaic pattern (Hugin®) and to perform the flicker test in order to visualize changes in the same fundus area at different points of time (Power Point®). The three lenses +90/+60/+40D are a good choice for imaging the whole spectrum of retinal diseases. Displacement of the oblique slit light can be used to assess changes in the surface profile of the inner retina which occurs e.g. in macular holes or pigment epithelial detachment. The mosaic function in its easiest form (one strip macula adapted to one strip with the optic disc) provides an overview of the posterior pole comparable to a fundus camera's image. A reconstruction of larger fundus areas is feasible for imaging in vitreoretinal surgery or occlusive vessel disease. The flicker test is a fine tool for monitoring progressive glaucoma by changes in the optic disc, and it is also a valuable diagnostic tool in macular disease. Nearly all retinal diseases can be imaged with the slit lamp - irrespective whether they affect the posterior pole, mainly the optic nerve or the macula, the whole retina or only its periphery. Even a basic fundus controlled perimetry is possible. Therefore fundus videography with the slit lamp is a worthwhile approach especially for the many ophthalmologists without access to the most recent diagnostic equipment or a professional photographer at hand.

No MeSH data available.


Related in: MedlinePlus

(same eye as in Figure2and3). Surface analysis of the retina with the slit lamp: Projection of narrow slit beam through a fundoscopic lens (+40D/20x) at a 5° angle temporal to the direction of observation. In the area of the macular hole, the slit light is displaced away from the incident ray (white arrows), indicating a fundus depression. In the end a slit lamp’s “en face” view contains information about the surface contour of the retina by applying the well-known technique of the optic section. On the right the same area is analyzed by a typical vertical OCT section.
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Fig6: (same eye as in Figure2and3). Surface analysis of the retina with the slit lamp: Projection of narrow slit beam through a fundoscopic lens (+40D/20x) at a 5° angle temporal to the direction of observation. In the area of the macular hole, the slit light is displaced away from the incident ray (white arrows), indicating a fundus depression. In the end a slit lamp’s “en face” view contains information about the surface contour of the retina by applying the well-known technique of the optic section. On the right the same area is analyzed by a typical vertical OCT section.

Mentions: The surface structure of the fundus can be evaluated further by a slightly oblique slit beam (e.g. 5° between illumination and observation - see Figure 6). Running over a fundus depression like a macular hole the narrowed slit beam will be deflected away from the side of the slit beam’s arm (this is as seen through the oculars and as shown in this article, but not on the real upright fundus, of course). On the contrary, a fundus elevation (like a tumour, pigment epithelial detachment or large drusen) will deflect the slit beam towards the side of the slit beam’s arm. In both cases the deflection increases with the angle between observation and illumination and with the niveau difference at the fundus. To make this principle as effective as the optic section in anterior segment biomicroscopy a “surround illumination” for easier orientation on the fundus would be an asset.Figure 6


The fundus slit lamp.

Gellrich MM - Springerplus (2015)

(same eye as in Figure2and3). Surface analysis of the retina with the slit lamp: Projection of narrow slit beam through a fundoscopic lens (+40D/20x) at a 5° angle temporal to the direction of observation. In the area of the macular hole, the slit light is displaced away from the incident ray (white arrows), indicating a fundus depression. In the end a slit lamp’s “en face” view contains information about the surface contour of the retina by applying the well-known technique of the optic section. On the right the same area is analyzed by a typical vertical OCT section.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4401483&req=5

Fig6: (same eye as in Figure2and3). Surface analysis of the retina with the slit lamp: Projection of narrow slit beam through a fundoscopic lens (+40D/20x) at a 5° angle temporal to the direction of observation. In the area of the macular hole, the slit light is displaced away from the incident ray (white arrows), indicating a fundus depression. In the end a slit lamp’s “en face” view contains information about the surface contour of the retina by applying the well-known technique of the optic section. On the right the same area is analyzed by a typical vertical OCT section.
Mentions: The surface structure of the fundus can be evaluated further by a slightly oblique slit beam (e.g. 5° between illumination and observation - see Figure 6). Running over a fundus depression like a macular hole the narrowed slit beam will be deflected away from the side of the slit beam’s arm (this is as seen through the oculars and as shown in this article, but not on the real upright fundus, of course). On the contrary, a fundus elevation (like a tumour, pigment epithelial detachment or large drusen) will deflect the slit beam towards the side of the slit beam’s arm. In both cases the deflection increases with the angle between observation and illumination and with the niveau difference at the fundus. To make this principle as effective as the optic section in anterior segment biomicroscopy a “surround illumination” for easier orientation on the fundus would be an asset.Figure 6

Bottom Line: The three lenses +90/+60/+40D are a good choice for imaging the whole spectrum of retinal diseases.A reconstruction of larger fundus areas is feasible for imaging in vitreoretinal surgery or occlusive vessel disease.Even a basic fundus controlled perimetry is possible.

View Article: PubMed Central - PubMed

Affiliation: Ophthalmological practice, Ziegeleiweg 10, 25548 Kellinghusen, Germany.

ABSTRACT
Fundus biomicroscopy with the slit lamp as it is practiced widely nowadays was not established until the 1980-es with the introduction of the Volk lenses +90 and +60D. Thereafter little progress has been made in retinal imaging with the slit lamp. It is the aim of this paper to fully exploit the potential of a video slit lamp for fundus documentation by using easily accessible additions. Suitable still images are easily retrieved from videorecordings of slit lamp examinations. The effects of changements in the slit lamp itself (slit beam and apertures) and its examination equipment (converging lenses from +40 to +90D) on quality and spectrum of fundus images are demonstrated. Imaging software is applied for reconstruction of larger fundus areas in a mosaic pattern (Hugin®) and to perform the flicker test in order to visualize changes in the same fundus area at different points of time (Power Point®). The three lenses +90/+60/+40D are a good choice for imaging the whole spectrum of retinal diseases. Displacement of the oblique slit light can be used to assess changes in the surface profile of the inner retina which occurs e.g. in macular holes or pigment epithelial detachment. The mosaic function in its easiest form (one strip macula adapted to one strip with the optic disc) provides an overview of the posterior pole comparable to a fundus camera's image. A reconstruction of larger fundus areas is feasible for imaging in vitreoretinal surgery or occlusive vessel disease. The flicker test is a fine tool for monitoring progressive glaucoma by changes in the optic disc, and it is also a valuable diagnostic tool in macular disease. Nearly all retinal diseases can be imaged with the slit lamp - irrespective whether they affect the posterior pole, mainly the optic nerve or the macula, the whole retina or only its periphery. Even a basic fundus controlled perimetry is possible. Therefore fundus videography with the slit lamp is a worthwhile approach especially for the many ophthalmologists without access to the most recent diagnostic equipment or a professional photographer at hand.

No MeSH data available.


Related in: MedlinePlus