Influence of Cataract on Straylight and Optical Coherence Tomography

Optical Coherence Tomography (OCT) is a relatively new imaging technique,
similar to ultrasonography, which uses near-infrared light waves, instead of
ultrasound, to obtain a reflectivity profile of the retina. OCT is widely used
for imaging the vitreoretinal interface, for monitoring macular edema and
retinal thickness, retinal nerve fiber layer (RNFL) thickness and optic nerve
head parameters in a wide variety of patients. The OCT technique currently
available in clinical practice is also referred to as time-domain OCT (TDOCT),
because the depth information of the retina is acquired as a sequence of
samples, over time. Several efforts have been made to improve TD-OCT imaging
quality. Only recently, major advances in imaging speed, sensitivity and image
resolution have been achieved with the introduction of spectral-domain OCT
(SDOCT). In the elderly population, cataract is a common cause of media opacity
that can affect diagnostic imaging quality.
Cataract is likely to cause light scattering and is one of the commenest cause
of loss of useful vision. The presents of cataract alone does not determine the
indication of a cataractextraction. The ophthalmologist rests his therapy
choice on the patients complaints, physical and additional examination. Despite
these examinations it can be difficult to predict the outcome and value of a
cataractextraction because of the interference of other unknown factors. The
effect of straylight caused by a cataractious lens is one of the possible
factors. Patients complaints may, among other things, include problems of
difficulty with against-the ligt face recognition and halos around bright
lights. Functionloss is now qualified by visus alone, but this has little
importance. In june 2005 a device that assesses retinal straylight came on the
market, the socalled C-quant.

Primary
1. Influence of cataract on the image quality of the new generation OCT
device, the SD-OCT, and to evaluate the difference with TD-OCT.
2. Interrelationship of straylightvalues and the affect of cataract on OCT
image quality:
a. To evaluate the correlation between straylightvalues and the affect of
cataract on OCT image quality.
b. To evaluate if the OCT image quality is a prognostic factor for the amount
of straylight?

Secondary
- Wich gain in straylightvalue is achieved by performing a cataractextraction?
- Corelates the alteration in straylightvalue with de alteration of complains?
- Corelates the alteration in straylightvalue with the alteration in
visus-related quality of life, irrespective of alteration in visus.
- What is the relationship of the type of cataract with the image quality of
the OCT and straylightvalues?

a Study design

prospective obeservational cohort study

b summary (outlined in appendix B)

* standard ophthalmologic examination
* classification: LOCSIII score9
* straylight measurement
* OCT measurements
* VFQ-25 guestionnaire

c. sample size: 60.
d. duration: 12 months
e. participating departments:

Ophthalmology AMC; dr. F.D. Verbraak
mw. drs. I. van der Meulen
mw. drs. P.H.B. Kok
mw. drs. L.A. Engelbrecht
N.I.N.; dr. T.J.T.P van den Berg

Straylight measurement:
CE quality mark, non-ivasive, non-contact, no risks

OCT measurements:
CE quality mark, non-invasive, non-contact, no risks

The opthalmic examination is standard procedure.

The patients needs to fill in the questionnaire twice.