Clement Clarke Perkins Mk2 User manual

Perkins Mk2
Hand-Held
Applanation Tonometer
Instruction Manual
Manuel d’instructions
Bedienungsanleitung
Manuale di istruzioni
Manual de instrucciones
Please read these instructions
before using the equipment
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Page
English . . . . . . . . . . . . . . . . . . . . 1
French . . . . . . . . . . . . . . . . . . . . 34
German . . . . . . . . . . . . . . . . . . . . 67
Italian . . . . . . . . . . . . . . . . . . . . 101
Spanish. . . . . . . . . . . . . . . . . . . . 134

Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1 Technical Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2 Purpose of Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Brief Description of the Appliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. General Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4/5
3. Safety and Regulatory Information . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1 Safety Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2 Measuring Prism Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.3 Transportation and Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
3.4 Notes on Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.5 Statutory Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.6 Caution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.7 Regulatory Information: CE Mark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
3.8 Environmental Conditions of Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
3.9 EMC (Electromagnetic Compatibility) Declaration . . . . . . . . . . . . . . . . . . 11
3.10 Product Labelling and Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . .12
3.11 Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4. Taking a Pressure Measurement . . . . . . . . . . . . . . . . . . . . . . . . . .13/14
5. To Prepare the Prism for Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.1 Remove Perkins Mk2 Tonometer From Case . . . . . . . . . . . . . . . . . . . . . . 15
5.2 Doubling Prism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.3 To Insert Prism into Prism Holder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.4 Tonosafe Disposable Prism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
5.5 Batteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15/16
6. Operating the Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.1 Preparing the Patient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
6.2 Instruction to the Patient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7. Cleaning the Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
8. General Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
8.1 Astigmatism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20/21
8.2 To Use the Instrument on Animals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
8.3 Special Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9. Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22/23
9.1 Sources of Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
9.2 Inaccurate Horizontal Centering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
9.3 Inaccurate Vertical Centering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
9.4 Inaccurate Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
10. Case Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
11. Calibration Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
12. Storage of Prism and Tonometer . . . . . . . . . . . . . . . . . . . . . . . . . 30
13. Technical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
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Whilst the information is provided in good faith and is based on the latest information available at the time of
issue, this booklet gives only a general indication of product capacity, performance and suitability. Such
information must not be taken as establishing any contractual or other commitment on the part of the
manufacturer and in no way should be construed as a warranty or representation concerning the product.

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1. Introduction
We would like to thank you for your decision to purchase this CLEMENT CLARKE product.
If the instructions in this manual are carefully followed, we are confident that this product will
give you reliable and trouble-free usage.
We will be forced to disclaim any warranty and liability if the instrument is altered in any way
or if routine maintenance is neglected or not carried out according to factory specifications.
Only original CLEMENT CLARKE accessories are to be used to ensure continued reliability of
the instrument.
Because the Perkins tonometer is capable of being used in all positions, the mass of the
Goldmann doubling prism must be controlled accurately. Only HAAG-STREIT prisms
should be used or the disposable Tonosafe prism can be used to prevent cross-infection.
Any other prisms may give a false reading if used in the Perkins tonometer.
1. 1 Technical Description
A pair of spiral wound flat springs connected in series are progressively tensioned by rotation
of the operator’s calibrated thumb-wheel. The resulting force stored in the spring is
transmitted through a balanced arm to the applanation doubling prism or the Tonosafe prism
mounted at its end.
The battery charger conforms to Class II insulation and has also been tested to EN60601.
This equipment is designed and manufactured to be as safe as is reasonably practicable
when installed and used correctly by persons qualified to do so in accordance with the
manufacturer’s instructions. Any misuse, incorrect assembly or installation could result in
the equipment becoming unsafe. It must not be repaired except by competent
persons under the manufacturer’s instructions.
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1.Introduction - continued
1. 2 Purpose of Use
Applanation Tonometers are used at room temperature in the examination,
diagnosis and documentation of the human eye.
Applanation tonometry may only be performed by healthcare professionals who are
qualified by their respective authorities to do so.
1. 3 Brief Description of the Appliance
The Applanation Tonometer functions according to the “Goldmann” method:The
measuring of the pressure required to maintain a uniform applanation of the surface
of the cornea.
Advantages
•High accuracy of the measurement - the average deviation in any one
single examination does not exceed ± 0.5 mm Hg.
•The intraocular pressure in mm Hg is found by multiplying the drum reading
by ten.
•Scleral-rigidity is not to be taken into account as the small volumetric
displacement of 0.56 mm3increases the intraocular tension by about
2.5% only.
•Massage effect DOES occur if repeated measurement occurs.
•There are no standardization and calibration difficulties.
Hospital and Optician use only
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2. General Layout
Fig 1
1Forehead rest
2Forehead rest locking screw
3Forehead rest stem
4Prism holder
5Filter Holder Assemblies
6Illumination bulbs
3
2
4
1
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2. General Layout - continued
Fig 2
7Viewing lens
8Milled thumb-wheel
9Scale
10 Battery handle securing buttons
11 Battery handle
9
8
10
7
11
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3. Safety and Regulatory Information
3. 1 Safety Notices
No user serviceable parts inside.
Do not open the Tonometer case moulding under any circumstances.
Caution: In the event of any malfunction, contact your local distributor or
visit our website to contact us directly.
This product is intended for indoor use only.
This product is not suitable for operation in the presence of a flammable
anaesthetic mixture with air or with oxygen or with nitrous oxide.
Not protected against the ingress of water or other fluids.
The following instructions should be observed to ensure
the safety of patients:
Avoid examinations in cases of eye infections or injured corneas
• There is no known contraindication for performing tonometry. Medical assessment
is necessary and due care is to be exercised in cases of eye infections and injuries
to the cornea.
Only clean and disinfected measuring prisms should be used
• Examinations should be conducted with cleaned and disinfected measuring
prisms.
• Tonometer prisms are not dispatched in a disinfected state and should always be
disinfected before use.
• The disinfecting of contact glasses e.g. with cotton wool or a damp cloth without
putting them into disinfecting fluid is insufficient and should not be allowed.
• Incorrect medical disinfecting can cause patients to be infected and can also
cause damage to the eyes.
• Residue from the disinfecting may cause a caustic reaction to the patient’s eye,
therefore rinse thoroughly.
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3. Safety and Regulatory Information - continued
3. 1 Safety Notices - continued
No damaged prisms should be used
Before each use the contact surface of all prisms should be checked for
contamination or damage (such as scratching, rips or sharp edges).
A slit lamp microscope or Loupe is best used for this purpose, at a magnification
of 10x to 16x.
• If cracks form, the disinfectant may get into the hollow interior and can enter the
patient’s eye while tonometry is taking place, leading to irritation of the cornea.
Defective measuring prisms should not be used, to avoid any damage to the
patient’s cornea.
3. 2Measuring Prism Replacement
• Due to the number of variables involved - type and concentration of disinfecting
material used, number of patients, handling etc. - it is almost impossible to put a
figure on the number of times and/or period of time that a measuring prism can
safely be used for.
• Our experience, and that of our users, indicates that under ‘normal’ usage (i.e. as
per the instructions contained within this instruction manual) a maximum of two
years provides an adequate safety factor.
• HAAG-STREIT therefore recommend strongly that no measuring prism is used
beyond two years from it’s date of first usage (a measuring prism may be retained
as a spare indefinitely - deterioration does not start until it is first used).
• The recommended time is overruled if the prism is in any way damaged within
this time period - damaged prisms should be immediately discarded.

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3. Safety and Regulatory Information - continued
3. 3Transportation and Storage
• The Applanation Tonometer conforms to ISO 15004-1:2006 for Storage and
Transport Conditions and should always be stored in its carry case when not
in use.
Transport Conditions
Temperature: -40˚C to +70˚C
Relative Humidity: 10% to 95%
Atmospheric Pressure: 500hPa to 1060hPa
Vibration, Sinusoidal: 10Hz to 500Hz: 0.5g
Shock: 30g, duration 6 ms
Bump: 10g, duration 6 ms
Storage Conditions
Temperature: -10˚C to +55˚C
Relative Humidity: 10% t0 95%
Atmospheric Pressure: 700Pha to 1060hPa
• The Applanation Tonometer should be checked for damage after unpacking.
• Defective equipment should always be returned in appropriate packaging.
• The equipment may only be operated with the listed accessories (see page 33)
according to the corresponding operating instructions.
3. 4Notes on Usage
• Only qualified and trained personnel may operate the equipment.
• The training of the operating personnel is the responsibility of the equipment user.
• This type of sensitive measuring equipment should be checked after exposure
to external force (e.g. unintentional shocks or being allowed to fall) and if
necessary, should be returned to the manufacturer for repair.
• The manufacturers of the equipment will not be liable for any loss or damage
resulting from unauthorized intervention.
In particular, it is forbidden to loosen any screws; this may reduce the accuracy
of the measurement. All ensuing warranty claims will be deemed null and void as
a result of unauthorized intervention.
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3. Safety and Regulatory Information - continued
3. 5Statutory Requirements
• The Applanation Tonometer is designed as a Class IIa device under the Medical
Device Directive 93/42/EEC.
• The Applanation Tonometer complies with the Tonometer regulation
ISO 8612:2009 & ISO 15004-1: 2006.
3. 6Caution
• The safety regulations displayed in the operating instructions are to be
observed with special care.
Caution
Strictly observe all warning notices!
3. 7Regulatory Information: CE-Mark
The products fulfil the requirements according to the following
standards:
Safety: EN60601-1 Part 1: General Requirements for Safety,
Medical Electrical Equipment
Electrical: EN60601-1-2 Part 2: Collateral Standard: Electromagnetic
Compatibility
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3. Safety and Regulatory Information - continued
3. 8Environmental Conditions of Use
Temperature: +10˚C to +35˚C.
Relative Humidity: 30% to 90%
Atmospheric Pressure: 800hPa to 1060hPa
Shock (without packing): 10g, duration 6 ms
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3. Safety and Regulatory Information - continued
3. 9 EMC (Electro Magnetic Compatibility) Declaration
With the increased number of electronic devices such as PC’s and mobiles, medical
devices in use may be susceptible to electromagnetic interference from these
devices. Which may result in incorrect operation of the medical device and create a
potentially unsafe situation. Medical devices should also not interfere with other
devices.
In order to regulate the requirements for EMC with the aim to prevent unsafe product
situations, the EN60601-1-2 standard has been implemented. This standard defines
the levels of immunity to electromagnetic interferences as well as maximum levels of
electromagnetic emissions for medical devices.
Medical devices manufactured by Haag-Streit-UK Ltd conform to this EN60601-1-2
standard for both immunity and emissions.
Nevertheless, special precautions need to be observed:
The use of accessories and cables other than those specified by Haag-Streit-UK Ltd,
with the exception of cables sold by Haag-Streit-UK Ltd as replacement parts for
internal components, may result in increased emission or decreased immunity
of the device.
The medical devices should not be used adjacent to or stacked with other
equipment.
If adjacent or stacked use is unavoidable, the medical device should be seen to
operate normally as it should in this situation.
Further guidance regarding the EMC environment (in accordance with
EN60601-1-2) in which the device should be used is available at:
http://www.haagstreituk.com/medicalquality

3. Safety and Regulatory Information - continued
3.10 Product Labelling and Safety Symbols
The labels affixed to the equipment are there to remind you of safety precautions.
Do not remove these labels.
3.11 Safety Symbols
The Perkins Mk2 Tonometer and its labels include the following markings:
Caution (Consult ‘Instructions for Use’)
This product complies with the essential requirements of the
medical devices directive (93/42/EEC).
Compliance has been verified by UK notified body per
0120 (SGS United Kingdom Ltd).
Do not dispose of with household refuse.
Please contact your local authority for your nearest
recycling centre.
Manufacturer
Medical Electrical Equipment Type B
Year of Manufacture
e.g. SN0001 T3 Serial number Perkins Mk2 Tonometer (Example)
!
0120
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2010
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Caution of Hot surfaces - Do not touch

4. aking a Pressure Measurement
The cornea is applanated with a measuring prism of organic glass that is fitted in a
ring shaped holder at the end of the feeler arm. The contact surface of the
measuring prism has a diameter of 7.0mm. It is planar with rounded edges to
obviate any damage to the cornea.
The measuring prism is brought into contact with the eye. The measuring drum is
turned to increase pressure on the eye until a continuously regular surface of
3.06 mm ø = 7.354 mm2 has been applanated.
Position of the Force Pressure
measuring drum
1.33 kPa
1 9.81 mN =10mm Hg
The relationship between the measuring drum position, force and
pressure on the applanation surface
The intraocular pressure in mm Hg is found by multiplying the drum reading by ten.
SI-Units according to standard ISO 1000
According to ISO 1000 the derived unit of force is the
N (Newton) and its decimal sub-multiple the mN (milli Newton).
The conversion of mm Hg into the SI pressure unit kPa (Kilo
Pascal) can be made on the comparison scale in Fig 3.
The measurement of the flattened surface is made directly on
the cornea. The built-in duplication system in the measuring
prism divides the image and displaces the two semi circular
halves from each other by 3.06 mm.
Before measuring, it will be necessary to anaesthetise the
cornea locally, to place a strip of fluorescein paper in the
conjunctival sac and switch on the blue filter of the tonometer.
The inner border of the ring represents the line of demarcation
between the cornea flattened by applanation and the cornea
not flattened.
Fig 3
Comparative scale
13
mmHg k a
0
1
2
3
4
5
6
7
8
9
10
0
10
20
30
40
50
60
70
80
HAAG-STREIT BERN
1 Interval=1.471 mN
1 Interval=1.471 mN
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4. aking a Pressure Measurement - continued
The major advantage of applanation tonometry is the small bulbous deformation
that amounts to only 0.56 mm3. The values found by this method of tonometry are
only slightly influenced by scleral rigidity and radius of corneal curvature.
The principle of applanation tonometry is simple. The careful construction of the
apparatus is a guarantee of its continued correct performance.
Nevertheless, in order to obtain exact results, the method of use indicated must be
strictly followed.
The readings obtained are based on the assumption that a cornea with a ‘normal’
thickness is being measured - alteration of the corneal thickness leads to changes
in the measured IOP.
A ‘normal’ corneal thickness is considered to be within the area of 530-560
microns. There is no universally agreed formula for the adjustment of the measured
tonometry reading against altered corneal thickness.
The users should bear these two facts in mind and keep themselves informed,
through the current literature, with regard to the various formulae for adjusting
measured tonometry readings in the event of thinned, or thickened, corneas
being measured.
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5. o Prepare the Prism for Use
5. 1Remove Perkins Mk2 Tonometer from case
Remove the Perkins tonometer from the carrying case by holding the main body. Under no
circumstances should it be lifted by the prism holder (4 Fig 1).
5. 2Doubling Prism
The doubling prism should be prepared for use by cleaning following the cleaning instructions
supplied with the prisms.
5. 3To Insert Prism into Prism Holder
Fig 4
To insert the prism into the prism holder (4Fig 1) gently press prism cone downward into the
prism holder (AFig 4) and push into position along horizontal axis (BFig 4).
N.B. Failure to follow these instructions could result in severe damage being
caused to the instrument.
5. 4Tonosafe Disposable Prism
Alternatively, Tonosafe disposable prisms may be used. These are supplied as sterile single
use items to help eliminate the risk of cross infection.
Tonosafe and the prism holder have the same mass as the original doubling prism, so no
conversion of results is required. The disposable prism can be inserted in the same manner
as above.
5. 5Batteries
The battery handle will accept four standard size AA batteries. To fit them in the instrument
proceed as follows:-
Press the two battery handle securing buttons (10 Fig 2) simultaneously and withdraw the
battery case (11 Fig 2), which forms the handle portion of the tonometer. Place the batteries
into the battery handle (11 Fig 2) ensuring they are positioned as indicated by the symbols on
the base (Fig 5a, p16).

5. o Prepare the Prism for Use - continued
5. 5Batteries - continued
Replace the handle and advance the thumb-wheel to check that both bulbs are switched on.
Fig 5a Fig 5b
Note:
Ensure batteries are inserted into handle with the correct polarity, as marked on the base and
in accordance with the Instruction Manual (Page 16, Batteries). Failure to do this will cause
short circuiting of batteries and dangerous overheating will occur.
Disposal of used batteries
Discharged non-rechargeable batteries should not be incinerated, but should be disposed of
in accordance with local environmental legislation.
Note: All batteries are subject to slow deterioration. Under no circumstances should batteries
be left indefinitely in the instrument as this could result in the instrument becoming
damaged. They should be removed after use and stored in the carrying case.
Bulbs
The bulbs, two in number, are “lens” lamps (6Fig 1). They are clear and require the blue
filter sleeves to be fitted over them (5Fig 1). The bulbs are fixed in position to create
maximum fluorescent effect during measurement. Bulbs must be screwed fully and firmly
in and periodically inspected for discolouration.
Forehead Rest
This is the concave disc (1Fig 1) which snaps on to the rounded end of the forehead rest
stem (3Fig 1). To adjust the stem, loosen the locking screw (2Fig 1), slide the stem to
the required position as described in Method of Use and tighten the locking screw. The
adjustment allows for considerable variation in the size and shape of a subject’s physical
features. The disc of the forehead rest should be cleaned regularly.
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6. Operating the Equipment
Caution
It is imperative to read chapter 3. Safety and Regulatory Information, and to observe
its precautions before operating the equipment.
Perfect functioning can only be guaranteed with the use of an original HAAG-
STREIT prism or Tonosafe.
Sterilized fluorescein paper strips should always be used, as pathogenic exciters
thrive well in fluorescein solutions.
Regular calibration of the Tonometer is advised.
Do not use without prism fitted.
6. 1Preparing the Patient
1. Both eyes must always be anaesthetized (e.g. 2-3 drops each of an anaesthetic within
half a minute) to reduce movements of the lids during examination.
2. Place a fluorescein paper strip near the external canthus in the lower conjunctival sac.
After a few seconds the lacrimal fluid is sufficiently coloured and the paper can be
removed.
Alternatively combined anaesthetic fluorescein eye drops can be used.
When using drops, a solution of sodium fluorescein 0.25% to 0.5% is advisable.
Caution: If the prism touches the cornea without any force applied, the pressure arm
can vibrate and may disturb the patient. For this reason, the scale is set to
read 1 before applying the prism face to the cornea.
The Perkins tonometer should be held so that the thumb rests on the milled wheel
( Fig 2, 8) controlling the spring.
If the forehead rest (Fig 1, 1) is to be used, the stem (Fig 1, 3), should be extended after
loosening the locking screw (Fig 1, 2). When the forehead rest is correctly positioned, tighten
the locking screw and the instrument can then be brought towards the patient so that the
face of the prism cone comes into contact with the cornea.
It is usually easier to hold the tonometer obliquely with the handle slanted away from the nose
(Fig 6). Care should be taken to prevent the prism touching the eyelid margin.