 | OphthalmologyReferralsat the Downland Veterinary Group |
Martyn C A King, BVMS, BSc, DVOphthal, MRCVS.
Downland Veterinary Group provides a referral service for veterinary surgeons in the south and east of England who have problem eye cases. Animals are also referred that require specialised instrumentation for diagnostic or surgical procedures. Veterinary surgeons throughout Hampshire, West Sussex and Surrey, as well as those from as far afield as Dorset, Wiltshire, Berkshire and East Sussex, regularly refer cases for assessment.
The veterinary ophthalmologist at Downland Veterinary Group is Martyn King.
Martyn first joined the Downland Veterinary Group in 1991. He left the group for two years to complete a residency in ophthalmology at Bristol Univeristy Veterinary School, returning to DVG in 1997 to set up our ophthalmology unit. Martyn gained the Certificate in Ophthalmology in 1996.
Martyn became a Partner in the DVG on the 1st April 2000, and was awarded his Diploma in Veterinary Ophthalmology in May. As well as his routine duties Martyn often lectures to veterinary surgeons at continuing education meetings. He also regularly writes articles for both general and specialised veterinary journals and magazines
Diagnostic equipment.
Ophthalmology is a discipline that requires specialised instrumentation in order to perform a thorough examination of the eye. This equipment is very expensive and is thus not readily available at many practices. Downland Veterinary Group has one of the best equipped ophthalmology units in private practice in our area.
The range of specialised diagnostic equipment includes Slit Lamp Biomicroscopy, Tonopen Applanation Tonometry, Direct and Indirect (monocular and binocular) Ophthalmoscopes, Gonioscopy, Ultrasonography, and Blood Pressure measurement facilities.
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Surgical instrumentation includes a state of the art Zeiss OPM1 operating microscope and phacoemulsification equipment for cataract extraction, and a large range of specialised ophthalmological microsurgery instruments. |  |
Ophthalmologists do it in the dark ;-)
This allows an entire range of ophthalmic procedures to be carried out, including, in addition to the accepted routine surgical procedures.
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Slit lamp biomicroscopy.
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The slit lamp is the most fundamental piece of equipment required for the assessment of eye diseases. The slit lamp provides very high magnification and excellent illumination of ocular structures, allowing the eye to be examined in microscopic detail. The slit lamp also allows the beam of light to be narrowed to a thin slit which can be shone into the eye from an angle to the side of the magnification optics, permitting a three dimensional cross-section of ocular tissue to be examined. The slit lamp is essential in the examination of lid and lashes, the tear film and cornea, the anterior and posterior chambers of the eye, the iris, lens and anterior vitreous. Using additional lenses, the slit lamp can also be used to examine the drainage outflow pathways of the eye (see gonioscopy) and the fundus (the retina and optic nerve head and the back of the eye). |
Tonopen Applanation Tonometry
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Tonometry is the measurement of intraocular pressure. The use of applanation tonometry provides accurate assessment of the intraocular pressure by detecting the pressure required to flatten a known surface area of the cornea. The procedure takes only seconds to perform and causes no discomfort to the patient. A drop of topical anaesthetic is applied to the surface of the eye and the Tonopen is gently tapped against the cornea several times. The intraocular pressure is averaged from several readings and is displayed on a liquid crystal display on the Tonopen. Tonometry is essential in the diagnosis and management of glaucoma (in which the pressure is too high), and uveitis (where the pressure falls below normal). |
Direct and Indirect Ophthalmoscopy
Ophthalmoscopy is used to examine the fundus of the eye (i.e. the retina and optic nerve head). Direct ophthalmoscopy uses a small hand held instrument that allows great magnification of the structures at the back of the eye. By turning a wheel on the direct ophthalmoscope, lenses of different strength can be used to assess elevations or depressions in the fundus, or can be used to examine other structures (such as the vitreous, lens, iris or cornea) in detail. Although great magnification is provided, the area that can be visualised at any one time is small. The advantage of indirect ophthalmoscopy is that much larger areas of the retina can be examined at one time, although the image is less magnified. Monocular indirect ophthalmoscopy is performed with a light source (such as a Finhoff transilluminator or pentorch) and a condensing lens. The light is shone into the eye and the lens is placed just in front of the cornea, allowing a view of the back of the eye. Binocular indirect ophthalmoscopy requires much more specialised equipment in the form of a head set equipped with a light source and optics that allows the image to be split and hence examined by both eyes. This allows stereoptic (three dimensional) examination to be performed which is more sensitive for detecting elevations in the retina (e.g. retinal detachment) or optic nerve head (e.g. papilloedema).
Gonioscopy
Gonioscopy is an essential technique to diagnose the cause of glaucoma. To determine the cause of glaucoma it is essential to examine the drainage outflow pathway to see if there are any abnormalities present. The drainage angle runs around the inside of the eye at the point where the cornea (the clear window) meets the sclera (the white of the eye). Unfortunatly this angle is not able to be directly examined in dogs because the cornea too flat. In order to examine the angle, a small lens (a goniolens) is used which bends the rays of light out of the eye so that the drainage angle can be examined. Topical anaesthesia is applied to the eye and the lens is placed on the cornea. The angle can then be inspected using a slit lamp for magnification. The procedure is painless and is easily accomplished in most conscious animals without sedation. Gonioscopy is also used for other investigations when the peripheral areas of the eye need to be examined, such as in some tumours and inflammations.
Referring Cases to Martyn King
The Veterinary Surgeons who work within the Downland Veterinary Group refer cases to Martyn and ask his opinion on a daily basis. Veterinary Surgeons from other practices can contact the DVG at any time in an emergency. They can also contact the reception at the Emsworth Surgery between 8.30am and 6.30pm weekdays to arrange appointments for their cases to be referred.
Martyn and the Downland Veterinary Group regret that
second opinion cases must be referred by a Veterinary Surgeon
in the normal ethical way, and that we are unable to accept cases other than in this manner
Urgent cases can be seen the same day in most situations, and less urgent cases usually within a day or so. We provide maps and directions by fax or first class post if necessary.
Veterinary Surgeons who wish to refer cases to us are welcome to contact us by telephone in the usual way. For ease of referral we have forms available to ensure that all relevant clinical information is provided, and these are available in advance on request. Case histories are happily accepted by fax, but please contact us initially before transmission in case of fax error.