We are able to move in three dimensions, but we feel to be delivered to the fourth dimension of time. No one would prefer a world which is based only on two dimensions. Still, most users of OCT base their diagnosis in the cross sectional images only, called B-Scans and take no care about the third dimension. This space may be very helpful to detect a disease in all its severity. Explore this 3D OCT world with us! Enjoy the images and find more at the member section after login, kind regards Dr. med. Peter Maloca.
Archive for the ‘Eye surgery’ Category
What to do in diabetic retinopathy? by Martin K. Schmid, MD
The strategies change, new knowledge has to be evaluated and proofed. The findings of today may already be obsolete tomorrow. We can only show a snapshot of the current knowledge about diabetes. General recommendations must always be placed in the context of the affected patient. There is no standard diabetes patient, each person is different, everybody needs a customized procedure.
It sounds simple but first of all: the basic frame of all diabetic problems, is the diabetes itself. Diabetic retinopathy represents “only” the complication of the underlying disease, called diabetes. Good interdisciplinary management of the underlying disease means control and treatment of the most important paramaters. Responsible for the treatment and control of the underlying disease are the internist and the patient together.
How should we monitor patients with diabetes?
It is important to know that after 20 years, more than 80 percent of affected patient develop a diabetic retinopathy. There are mainly the situations:
Pregnancy can be a source of danger in diabetes. Pregnancy can lead to a diabetes decompensation. A baseline checkup should already occur if a desire for pregnancy exists. During pregnancy the patient should be checked every three months, even monthly in special cases.
2. Type 1 diabetes:
Currently it is recommended in type 1 diabetes: annual check from the fifth year of manifestation, or from the age of eleven. In the presence of type 1 diabetes without retinopathy annual inspection should be performed. In the presence of type 1 diabetes with retinopathy, the procedure corresponds to the severity.
3. Type 2 diabetes:
In type 2 diabetes, it is different because at diagnosis 36 percent already show a retinopathy. If the retina is healthy in diabetes type 2, nevertheless the retina should be examined annually.
In diabetes with a healthy retina or only a few microaneurysms an annual inspection is recommended.
A moderate diabetic retinopathy means only a few hemorrhages, microaneurysms, beaded veines. In question of an ischemia a fluorescence angiography is worthwhile. An OCT may be helpful in a decrease of visual acuity with looking for a macular edema.
The checks are carried out every 6 to 12 months depending on the situation.
An advanced diabetic retinopathy is characterized by the 4-2-1 – rule
-Presence of more than 20 microaneurysms in the four quadrants
-or venous beading in two quadrants and/or one quadrant with IRMA
View video Strategies in diabetes GETOCT 5:
Download video -> Strategies in Diabetes GETOCT5
Therapeutic strategies in macular edema:
Currently, the treatment of a macular edema is a most discussed topic. A proposal for control and treatment in diabetic macular edema is presented in this video.
A proposal for control and treatment:
In severe diabetic retinopathy a fluorescence angiography (FA) and OCT are performed. These two methods are the basis for the indication of a therapy. The laser is still an important tool, especially for the treatment of ischemia. After treatment, frequent monitoring is necessary.
Consider the morphology and function of the macula:
In a dry macula, good visual acuity and inconspicuous biomicroscopy, checks are carried out every year.
In borderline cases an OCT or fluorescence angiography (FA) should be performed, followed by an appropriate therapy.
In a clinically significant macular edeme, OCT and/or fluorescence angiography (FA) are the basis, followed by Laser and/or anti VEGF therapy. After treatment, a frequent monitoring is necessary in every case.
In cases with a thickened foveola a proposal may be:
If the edema is not located quite centrally, a focal laser may be sufficient. When this laser is not successful, we go back again in the proposed scheme.
If the foveola is thickened centrally, the anti-VEGF therapy is then possible.
If no stabilization occurs, the vision rises an additional laser treatment may be useful.
If therapy stabilized the situation, a break and a close monitoring follows. If everything remains stable, the patient remains in the small control loop.
If the situation worsens, the patient returns to the top level of control.
This is not a fixed regimen, but must be customized and changed over time.
We put together some new trivia questions about diabetes and OCT. For interactive reasons questions are programmed in Flash.
Klick here to play Quiz 2 on diabetes in full size:
OCT from third to the fourth dimension
Thanks OCT, we obtain information to the third dimension. Flurescence angiography allows only limited statements about the spatial extent of processes
The retinal thickness is measured precisely with OCT and an objective quantification is possible. The fourth dimension means a precise control over the course of years at exactly the same place.
The measurements are comparable with each other really well. With OCT is a synchronous mapping and comparison over time is possible and changes are shown. In some OCT devices the scanning area is permanently adjusted, no matter where the patient looks. This is advantageous because the patient can’t fix very well in advanced diseases. From these cross sections thicknesses maps can be produced, even differences over time can be calculated.
Anti-VEGF for diabetic macular edema?
Anti-VEGF for diabetic macular edema has been investigated in many studies.
The combination with ranibizumab turns to an increase in visual acuity. the sole laser therapy worsened the situation at the beginning rather. The number of injections in the combined group with a laser can be reduced.
Immediate or delayed laser?
Another study on laser: what impact does an immediate or delayed laser? If successful, the strategy with immediate laser, a significant gain is produced. When laser was carried out somewhat later, however, a similarly good progress is produced. So it’s not a big difference whether immediate or slightly delayed laser is done.
The results with triamcinolone and laser show in the first 6 months of a profit, then drop due to cataract formation. The number of injections in this study is also at eight to nine injections per year.
Strategies in Diabetes GETOCT 3
An eye surgeon best friend: a reliable microscope
For an eye surgeon are important during an eye operation: a clear and sharp view of the operative field, a maximum resolution, good three-dimensional representation and fatigue-free viewing.
The operation is simplified through a flexible microscope, to use the simple and easy. For the patient’s eye are essentially a low light exposure of the macula and a short operation time.
The Leica makes a good impression by its little spartan, space saving design. The microscope base is compared with its competitors relatively small, yet stable and transportable. The handle is marked red and is a clear invitation to postpone the microscope correctly and to prevent incorrect manipulation.
For small movements the mic is operated intuitively with the very modular pedal:
The foot pedal can be connected by wire, with the pedal of the new generation of wireless communication and has an extremely long-life battery that should last 5-8 years. Fortunately, the pedals are down grade compatible.
An ergonomic work is easy: there are six divers eyepieces (oculars), so that each eye surgeon should find his thing. Above all, there are only a few buttons to be covered with sterile caps, what accelerates the OP preparation. A nice feature is that Leica’s microscope has an option of three different lenses available (175/200/225mm), so the working distance can be adjusted according to the wishes of the surgeons.
An extra performance is the fitting of a “zoom video system”, where the viewing angle can be adjusted at the external video clip between 35-110 mm.
The Leica M844 F40 shows some great advantages. It has a quick setup for a quick and simple page break by the assistant: eyepiece will only swung to the other side and needs no screws, no cumbersome buttons.
Here, time to prepare for surgery can be saved. The disadvantage of this is only that dust particles fogged the lens after some time, but the cleaning is very simple.
The setting of the light source is done via a small standard LCD monitor. Additionally the foot pedal is extremely variable to be programmed before and individual settings are stored.
After the surgery the light intensity and the focus are always different. The engineers have done a good job: If the mik is moved up, an auto reset of all functions is done (reset x-y, zoom-focus, light), without losing valuable time.
For experienced eye surgeons there is the possibility of vitreo-retinal surgery with a biom essay to perform. The biom-optik is easy to control with the same foot pedal, so no need for a additional pedal which blockes the operation theatre.
The core element is the lighting system: it uses a halogen light that comes very close to the natural color perception and gives a pleasant quality of light.
It is a matter of taste whether a halogen, xenon or LED light source should be used. Each system has its advantages and disadvantages.
Light is not light
A otherwise used xenon lamp must be replaced about every two years and costs about 2000 Swiss francs. A halogen bulb as in this Leica mic is considerably cheaper, around 150 Swiss francs but needs to be replaced 1-2 times per year. A LED light source has nearly no time limit and is priced between the other two systems. The light source consists of four optical paths: two beams for the main surgeon (100 percent light) and two beams for the assistant (assistants gets seventy percent and thirty percent is reserved for the tapping of the video signal).
For Leica, the light machine is mounted directly at the microscope and the optical path. A spare bulb is included and can be quickly activated. The lamp is very easily removable. A cost benefit and technical simplification is that no fiber optics is required. This reduces the cost and wear, as well as a fiber optics would have to be changed every two years, which costs up to 3000 Swiss francs.
The light is divided into a central axial light (refelex red) and the ambient light. Only with the Leica, it is possible to enlarge or decrease the diameter of the central light individually.
Naturally, an operation can be recorded with a video module. Therefore the user is guided intuitively on the screen and data storage can be done for example at a USB stick.
What is the disadvantage of the Leica? Unfortunately, few, so the operating properly is fun.
is a corticosteroid which helps to reduce swelling in the macula and inflammation in other parts of the eye, such in cases of macular edema or non-infectious uveitis. It prevents the release of substances in the body that cause inflammation. It is usually given as a short-term treatment and is given as an injection into the eye.
Transient mild effects include slight pain and scratchiness after injection, a small hemorrhage at the site of injection or floaters. Floaters are common and disappear within some weeks. Long-term use of steroids can cause harmful effects on the eyes (glaucoma or cataracts). Intravitreal injection of triamcinolone can cause infection with a small risk.