Comparison of the Optos 200Tx non-mydriatic fundus camera and the Topcon TRC-50DX camera for
diabetic retinopathy evaluation

Routine diabetic retinopathy screening is a must for every diabetic patient. To
assess the
entire fundus properly, mydriasis (pupil dilatation) is required. After
pupillary dilatation fundus
photographs are taken or fundoscopy is performed by an ophthalmologist.
Dilatation of the
pupils causes blurred eyesight for at least three to four hours. The eyesight
is impaired to an
extent where we advise patients not to drive home themselves. Most patients
experience this
as an important burden to the diabetes screening.
The conventional funduscamera we use is the Topcon TCR-50DX. One photograph
captures
45 degrees of the fundus. To photograph the most important parts of the fundus,
we need six
photographs. This is done by letting the patient look in different directions
and then taking the
pictures.
A new fundus camera has been developed which abolishes the need for mydriasis.
The
Optos 200Tx funduscamera captures detailed pictures through a narrow pupil. The
second
advantage is the fact that the 200 central degrees of the fundus are
photographed at once.
The comparison between a standard 45 degrees camera and the Optos has been
conducted
on a large scale in the Reykjavik study (1). The point of interest was
assessing the presence
and grading of macular degeneration with both cameras. A 96% agreement between
both
cameras was found.
In this study we will compare the number of micro aneurysms and other small
diabetic
lesions detectable on the photographs. If the smallest lesions are detectable,
the larger
lesions will evidently be seen also. If we find that the quality of the
photographs is equal to
the current camera, we could replace the current camera with the Optos 200Tx
camera. This
would abolish the need for mydriasis in diabetic screening, and the need for
taking six
pictures, saving both time, money and abolishing the burden of mydriasis for
patients. If we
find that the performance of the Optos camera is worse than that of the current
camera, this
might indicate either differences between miosis and mydriasis or between the
Optos and the
current camera. Therefore we also plan to take photographs in mydriasis with
the Optos.

Primary Objective: To compare the quality of fundus photographs taken by (1)
the Optos
camera in miosis and (2) the current camera in mydriasis.

Secondary Objective: To compare the quality of fundus photographs taken by (1)
the Optos
camera in miosis and (2) the Optos camera in mydriasis (taking pictures in
miosis with the
current camera is not feasible).

Cross-sectional observational study in a clinical setting, the outpatient
department of the
department of Ophthalmology, UMCG. We will include patients during 3-4 months.

There are no risks associated with participation.
There are no benifits associated with participation.
The only burden associated with this study is that the patient is having to
spend an additional 5 minutes in our out-patient clinic.