- Eye Health
|The Centre for Eye Health (CFEH) team has hit the road recently, visiting optometrists to hear first-hand about their experiences with examining for early signs of eye disease.|
Optometrists from suburbs such as Liverpool, Blacktown, Fairfield, Maroubra, Wentworthville and Penrith have talked to us about the issues they face in helping to ensure that patients who are at risk, or show early signs of eye disease are diagnosed as soon as possible.
|For some, the pressure of time is a challenge, and the routine scheduling of shorter consultations can make it difficult to properly assess a patient for risk, and test for early signs of eye disease.|
For others, the costs of acquiring and maintaining the latest imaging instruments is prohibitive, especially when patients are unable to pay extra to cover the investment in such services.
We were told by some optometrists that they are not always confident interpreting a patient’s results, especially when symptoms and clinical findings do not correlate.
CFEH is here to help you manage these issues. We support the optometric profession by improving access to clinical expertise, sophisticated technology and practical continuing professional development (CPD).
We haven’t been able to visit everyone yet, so we encourage you to contact us directly with any suggestions or feedback you may have.
Prof. Michael Kalloniatis
Optic Nerve Head Drusen
|Peter, a 51-year-old male, was referred to CFEH by his optometrist who suspected optic nerve head drusen because of some irregularities at the margin of both optic discs.|
Issues to consider
1. Which tests can provide optometrists with more information about the suspected optic nerve head drusen?
2. Will visual function be affected as a result of the irregularities?
Peter presented at CFEH wearing spectacles for low myopia and astigmatism, with visual acuities of 6/6 in both eyes. He was in good health, although a smoker, and was not using any medications.
The definitive test for ONH drusen is B-scan ultrasonography. However, additional tests are included here to illustrate the presentation of ONH drusen with various imaging modalities.
Stereoscopic assessment of the optic nerve heads (ONHs) indicated that the optic disc margins were raised superiorly and nasally in each eye (Figures 1A and 1B).
Retinal photography, using a blue filter for autofluorescence, revealed drusen in both ONHs at the superior, inferior and nasal locations (Figures 2A and 2B).
Hyper-reflective spots at the head, as shown with B-scan ultrasonography, were consistent with the presence of ONH drusen in each eye (Figures 3A and 3B).
GDx imaging suggested a general thinning of the Retinal Nerve Fibre Layer (RNFL) in both eyes, most particularly in the left eye (Figure 4). Cirrus Optical Coherence Tomography (OCT) results also suggested a thinning of the RNFL in the superior quadrant of the left eye (Figure 5).
Spectralis OCT imaging showed ONH elevation (Figures 6A and 6B) and the Heidelberg HRT3 also confirmed the elevated nature of the ONHs, providing a 3D view of each eye.
In addition to the above anatomical assessments, Peter was also functionally assessed for colour vision, contrast sensitivity and visual fields.
During examination, he failed a monocular colour vision test, with the L’Anthony Desaturated D-15 result showing three crossings in the right eye and two in the left eye (Figures 7A and 7B).
The MARS test revealed normal monocular contrast sensitivity in each eye. Intraocular pressures, measured by the iCare tonometer, were 16mmHg in the right eye and 14mmHg in the left eye.
Visual fields were examined with the Humphrey Visual Field Analyzer Central 30-2 Threshold Test and a ring scotoma was found in the left eye, with an arcuate scotoma in the right eye (see Figures 8A and 8B).
A diagnosis of optic nerve head drusen was made for each eye, with the recommendation that the patient be reviewed annually for progressive field loss which can occur in such cases. It was also pointed out to the referring practitioner that, should the patient develop glaucoma, it may be difficult to detect in view of the ONH and visual field appearance, and the opinion of a glaucoma specialist or neuro-ophthalmologist may be of benefit.
Disclaimer: This newsletter is not intended to provide or substitute advice through the appropriate health service providers. Although every care is taken by CFEH to ensure that this newsletter is free from any error or inaccuracy, CFEH does not make any representation or warranty regarding the currency, accuracy or completeness of this newsletter.
Copyright: © 2011, Centre for Eye Health Limited. All images and content in this letter are the property of Centre for Eye Health Limited and cannot be reproduced without prior written permission of the Director, Centre for Eye Health Limited.