This document provides information on various ophthalmology instruments used for final year medical students, including: - Fluorescein stain strip and Schirmer-1 test for examining the cornea and measuring tear secretion. - Worth's four-dot test and Maddox rod for grading binocular vision and measuring heterophoria. - Instruments like enucleation spoon, evisceration curette, and lacrimal probes for ocular surgeries and procedures. - IOL dialer, iris repositor, and irrigation/aspiration cannula for cataract surgeries. - Forceps, scissors, and speculums for procedures like i

1. Ophthalmology instruments for final
year part 1 students in GSL medical
college
By Somu Venkatesh
Final Year Part 1

3. Fluorescein stain strip
It is used for biomicroscopic examination of antrerior epithelium of cornea
Fluorescein staining of cornea is carried out either using one drop of 2 % freshly
prepared aqueous solution of the dye or a disposable autoclaved filter paper strip
impregnated with the dye .
The are denuded of epithelium due to abarasions or corneal ulcers when stained with
fluorescein appear brilliant green.
When examined using cobalt blue light, the stained area appears opaque green
Other staining methods used for biomicroscopic examination of cornea are
• Bengal rose stain 1%
• Alcian blue dye used in keratoconjunctivitis sicca

5. Schirmer-1 test
• It is one of the tear film test
• It measures total tear secretio0ns
• It is performed with the help of a 5x35 mm
strip of Whatman-41 filter paper which is
folded 5mm from one end and kept in the
lower fornix at the junction of lateral one-third
and medial two-thirds.

6. • The patient is asked to look up and not blink or close
the eyes.
• After 5 minutes wetting of the filter paper strip from
the bent end is measured
• Normal values of Schirmer-1 test are more than 15mm.
• Values of 5-10mm are suggestive of moderate to mild
keratocojunctivitis sicca and less than 5mm of severe
keratoconjunctivitis.
• Others test for tear film test for
1.Tear film break-up
2.Rose Bengal staining

8. Worth’s four-dot test
• It is one test for grading binocular vision
• Normal binocular single vision consists of 3
grades. Sensory anomalies include disturbances
like
1. Binocular vision
2. Eccentric fixation
3. Suppresion
4. Amblyopia
5. Abnormal retinal correspondence
6. Diplopia

9. In W4DT patient wears goggles with red lens in
front of the right(R for R, Red for Right) and
green lens in front of the left eye and views a
box with four lights – one red, two green and
one white

10. Interpretation:
• In normal binocular single vision, the patient sees all
the four lights in the absence of manifest squint
• In abnormal retinal correspondence (ARC) patient sees
4 lights even in the presence of a manifest squint.
• In right suppression the patient sees only 3 green
lights,
• In left suppression the patient sees only 2 red lights,
• In alternating suppression the patient sees only 3 green
lights and 2 red lights, alternately.
• In diplopia the patient sees 5 lights (2 red and 3 green).

11. • Other test are
1. Test for fixation
2. After-image test
3. Sensory function tests with synoptophore
4. Neutral density filter test

13. Maddox rod
• This is used in Maddox rod test
Maddox rod test:
In this patient is asked to fix on a point light in
the center of Maddox tangent scale at a distance
of 6 meters. A Maddox rod (which consists of
many glass rods of red colour set together in a
metallic disc) is placed in front of one eye with
axis of the rod parallel to the axis of deviation

14. The Maddox rod converts the point light image into
a line. Thus, the patient will see a point light with
one eye and a red line with the other. Due to
dissimilar images of the two eyes, fusion is broken
and heterophoria becomes manifest. The number
of Maddox tangent scale where the red line falls will
be the amount of heterophoria in degrees. In the
absence of Maddox tangent scale, the dissociation
between the point light and red line is measured by
the superimposition of the 2 images by means of
prisms placed in front of one eye with apex towards
the phoria

16. Enucleation spoon(optic nerve guide)
• It is a spoon shaped
instrument with a
central cleavage.
Use:
To engage the optic nerve
during enucleation.

18. Evisceration curette
It consists of an oval or
round shallow cup with
blunt margins attached to
a stout handle.
Use:
To curette out the
intraocular contents
during evisceration
operation.

20. Lacrimal probes(Bowman’s)
These are a set of straight
metal wires of varying
thickness(size 0-8) with
blunt rounded ends and
flattened central platform.
Uses:
1. To probe nasolacrimal
duct in congential
blockage.
2. To identify the lacrimal
sac during DCT and DCR
operations.

22. Punctum dilator(Nettleship’s)
It has a cylindrical
corrugated metal handle
with a conical pointed tip.
Uses:
To dilate the punctum and
canaliculus during
syringing, probing,
dacryocystography, DCT
and DCR procedures.

24. Chalazion scoop
• It has a small cup with
sharp margins attached
to a narrow handle.
Uses:
To scoop out contents of
the chalazion during
incision and curettage.

26. IOL dialer or Sinskey hook
It is a fine but stout instrument with a bent tip. The tip
engages the dialing holes of the IOL.
Uses:
1. It is used to dial the PMMA non-foldable IOL for proper
positioning in the capsular bag or ciliary sulcus.
2. It can also be used to manipulate the nucleus in
phacoemulsification surgery.
Nucleus manipulate may be in the form of nucleus rotation
in the capsular bag, cracking of the nucleus and feeding of
the nuclear fragments into the phaco tip.

28. Iris repositor
It consists of a delicate, flat,
malleable, straight or bent
blade with blunt edges and
tip attached to a handle.
Uses:
1. To reposit the iris in the
anterior chamber in any
intraocular surgery.
2. To break synechiae at
the pupillary margin.

30. Two way irrigation and aspiration
cannula
It is available in various
designs, commonly used are
simcoe’s classical or reverse
cannula.
Uses:
1. For irrigation and
aspiration of the lens
matter in extracapsualr
cataract extraction.
2. Aspiration of hyphaema.

32. Wire vectis
It is a wire loop attached
to a metallic handle.
Uses:
It is used to remove
subluxated lens and
anteriorly dislocated lens
in ICCE technique and the
nucleus in ECCE
technique.

34. Chalazion clamp
It consists of 2 limbs like a forceps, which can be clamped
with the help of a screw. The tip of one limb is flattened in
the form of a round disc which is applied on the skin side,
while the tip of the other arm has a small circular ring
applied on the conjunctival side of the chalazion. However,
rarely when the chalazion points towards the skin, the ring
side is applied to the skin.
Uses:
To fix the chalazion and achieve haemostasis during the
incision and curettage operation

36. Iris forceps
These are small and delicate
forceps having fine 1x2 teeth
on the inner side of the limbs.
These are also available in
various shapes and designs.
Uses:
These are used to catch the iris
for the purpose of iridectomy
during operations for cataract,
glaucoma, optical iridectomy
and excision for iris prolapse,
tumours and entangled foreign
bodies.

38. Kelman-McPherson forceps
These are fine forceps
with bent limbs.
Uses:
1. To hold the superior
haptic of IOL during its
placement.
2. To tear off the anterior
capsular flap in ECCE.
3. Can be used for suture
tying.

40. de Wecker’s scissors
They are fine scissors with
small blades directed at
right angles to the arms. The
blades are kept apart,
making V-shape, by spring
action.
Uses:
It is used to perform
iridectomy, iridotomy and to
cut the prolapsed formed
vitreous and pupillary
membrane.

42. Spring action (Barraquer’s type)
needle holder
These are available in various
sizes with straight or curved
tips, in different shapes and
may be with or without locking
system. The jaws of the needle
holder are finely serrated to
hold the fine needles firmly.
Uses:
Spring type needle holder are
used for passing sutures in the
conjunctiva, cornea, sclera and
extraocular muscles.

44. Muscle (strabismus) hook
It is similar to the lens expressor
in but has a blunt guarding knob
at the end to prevent muscle
slippage. The plane of the handle
is the same as that of the
curvature of the hook.
Uses:
1. It is used to engage the
extraocular muscles during
surgery for squint,
enucleation and retinal
detachment.
2. In the absence of lens
expressor, it may be used in
its place.

46. Lens expressor(hook)
It is a flat metal handle with a rounded curve at one end. Tip of
the curve is knobbed. The plane of the handle is at right angle to
the curvature of the hook.
Uses:
1. To apply pressure on the limbs at the 6 O’clock position during
the delivery of lens in intracapsular cataract extraction with
Smith’s (tumbling) and capsule forceps techniques.
2. To express the nucleus in extracapsular cataract extraction.
3. It can also be used as muscle hook if the latter is not available.
4. Also used along with wire vectis to extract out the dislocated
lens.

48. Castroviejo calliper
It is a divider like instrument,
to one arm of which is
attached a graduated scale (in
mm). Its other arm can be
moved by a screw over the
scale.
Uses:
It is used to take
measurements during squint,
ptosis, retinal detachment and
pars plana vitrectomy surgery.
It is also used to measure
corneal diameter and visible
horizontal iris diameter.

50. Universal metallic eye speculum
It is called universal eye
speculum because it can
be used for both eyes i.e.,
right as well as left.
It has 2 limbs and a spring
mechanism with a screw
to adjust the limbs.

52. Desmarre’s retractor
It is a saddle shaped instrument
folded on itself at one end. It is
available in 2 sizes:small(paediatric)
and large (adult).
Uses:
It is used to retract the lids during
examination of the eyeball in cases
of blepharospasm in children, in
cases with marked swelling and
ecchymosis, removal of corneoscleral
sutures, removal of corneal foreign
body and for double eversion of
upper lid to examine the superior
fornix.
Advantages: Allows continuous
adjustment of the lids and width of
the palpebral aperture.

54. Plane mirror retinoscope

55. Spherical
convex lens
Spherical
concave lens
Cylindrical
convex lens
Cylindrical
concave lens