Fundoscopy Made Easy 3ed

Fundoscopy Made Easy 2010

Fundoscopy Made Easy Apr. 15

Fundoscopy Made Easy

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WONG YEE MING Medical Student, 5th Year, 2010/2011 National University of Malaysia.

© 2010 by medicalpblukm.blogspot.com

1st edition, June 2009 2nd edition, July 2009 3rd edition, April 2010

This is an open project meant to be shared in any form of publication, regardless of being reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise from the author at [email protected]. Credits should be given to medicalpblukm.blogspot.com.

The author welcomes and appreciates feedbacks and reviews of this project in the effort to improve this book in the spirit of information sharing, as well as notifications of usage of this project in any form. Feel free to e‐mail the author at [email protected].


Acknowledgements The 3rd edition of this Fundoscopy Made Easy reflects a continued improvement on the previous editions. The changes that have been made are largely from comments and suggestions by students, as well as review by a senior lecturer and ophthalmologist Dr. Then Kong Yong who have taken time to tell us what they like about the book and how it can be further improved. We understand that this book is far from being perfect, and the flaws are corrected as time goes by, which is why we try to incorporate the comments, suggestions and feedback into this improvised edition.

Specifically, we owe our thanks to the following reviewers: doctors, students and faculty who spent considerable time to provide us with correction, suggestions, improvements and to make this possible. They were gladly the source of inspiration in the continuation of this project to its 3rd edition:

Dr. Then Kong Yong Senior Lecturer Ophtalmology Consulting Specialist (Cornea) University Kebangsaan Malaysia Medical Center Kuala Lumpur, Malaysia

Lee Cun Coon, MS University Kebangsaan Malaysia Medical Center Kuala Lumpur, Malaysia

Jeffrey Lee Soon Yit, MS University Kebangsaan Malaysia Medical Center Kuala Lumpur, Malaysia

Boey Ching Yeen, MS University Kebangsaan Malaysia Medical Center Kuala Lumpur, Malaysia


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Table of Contents Preface ................................................................................. 6

The Tool – Direct Ophthalmoscope ....................................... 7

Note from the Author .......................................................... 9

The Fundus Mapping ........................................................... 10

Fundoscopy Steps ............................................................... 12

1. Optic Disc Abnormalities ................................................. 14

2. Macular abnormalities .................................................... 21

3. Retinal Vessels Abnormalities ........................................ 26

4. Retinal findings .............................................................. 28

Credits: ............................................................................... 36

EXTRAS: Systematic Ophthalmic Examination ................... 37


Preface This open project book is intended for medical students who are newly

exposed to the use of the direct ophthalmoscope. Over the years, basics in fundoscopy has form an essential part of the medical field. However, little has been written specifically to teach the younger generation on how to appreciate through the eyes of the fundoscope. For what the mind does not know, the eyes could not see. And yet, the eyes hold the 8th wonder of the world, being the only place in our bodies where we can look in awe at the living pulses of the blood vessels in our bodies. But first, we as students would need to be exposed and taught of the ways of the fundoscope, and what we can see and expect. We need to be guided in our pursue of perfection, and to tell us that, there is more than meets the eye.

Being one of the many medical students who had struggled from such experience, this book is written with medical students in mind, to help them to master the fundamentals. That is, before they could proceed to appreciate the abnormalities and pathology in the eyes which would never fail to mesmerize those who could see it. We are incredibly grateful to everyone who made this book a reality.

Wong Yee Ming Kuala Lumpur, 2010


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The Tool – Direct Ophthalmoscope


Apertures and Filters There are various apertures and filters in the indirect ophthalmoscope, but beginners may require only a certain few. However, here is a general breakdown of the use of each aperture and filter:

Small Aperture: For easy view of fundus through the undilated pupil. Always start with this while looking at the fundus.

Large Aperture: Standard aperture for dilated pupil and general examination of the eye, particularly the red reflex.

Sm Micro Spot Aperture: Allows easy entry into very small, undilated pupils.

Slit Aperture: Helpful in determining various elevations of lesions, particularly tumors and edematous discs.

Fixation Aperture: The pattern of an open center and thin lines permits easy observation of eccentric fixation without masking the macula.


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Note from the Author Before you conduct a direct fundoscopy, be realistic in your aims and know that practice makes perfect. Nothing beats experience in fundoscopy, even if you are a genius. But of course, do know your fundoscopy steps prior to the examination. You might not want to blind your volunteering patient with your initially wobbly techniques!

Now, I’m sure most of you medical students would have been too enthuasistic on looking at the fundus, having seen many pictures in the books. Do note that fundoscopy pictures in the books are taken with indirect ophthalmoscope which have a wider view. Therefore, tracing is required in direct fundoscopy before you get a full picture of the fundus.

A view of indirect fundoscopy of a normal fundus (on the left) with a highlighted area of focus of direct fundoscopy in the box(on the right).

With this in mind, do not panic if you do not find the optic disc on your first try. All you need is a clear and calm mind, and this book is here to guide you for an enjoyable experience in your use of fundoscopy.


The Fundus Mapping

The major landmarks of the fundus:

1. Optic disc • the point where the optic nerve enters the retina. This is the

blindspot area of your eyes. In the optic disc is a cup which is usually present.

• normal vertical cup disc ratio : 0.1‐0.3 o (pathological changes are suspected if > 0.6)

• the cup is usually at/ near the central of the optic disc, while the crowding of vessels are always on the nasal side of the optic disc.

• this knowledge is useful to identify which side is the eye(left or right).In most pictures from indirect fundoscope, the optic disc is shown on the nasal aspect, making it easier to identify them.


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2. Macula • the pigmented area of the retina which is rich in cone

photoreceptors and is responsible for clear detailed vision.

3. Fovea • a small rodless area of the macula that provides acute

vision. • the foveal light reflex should be seen particularly in a

young healthy adult as a rim of light around the fovea. 4. Vessel branches

• There are 4 main branches of vessels from the optic disc. Each branches off into different directions, mainly superonasally, superotemporally, inferonasally, and inferotemporally.

• In the normal variation, the macula is devoid of retinal vessels, thus it is supplied from the branches of superotemporal and inferotemporal vessels.

• One should remember the embryonic development of retinal vessels which arise from the optic disc, towards the nasal aspect at 8 months of gestation and temporally at 10 months (approximately 1 month neonatally). This is important to understand the concept of retinopathy of prematurity!


Fundoscopy Steps Fundoscopy should be done optimally in a dark or dimmed room. Such preference is essential to keep the pupil as dilated as possible. Alternatively, topical drops can be given to dilate the eyes if there is no contraindications.

1. Fundoscopy should be done on the same side for the patient and you, as the examiner. This being said, the examiner should hold the fundoscope with his right hand, while his right eye should be examining the patient’s right eye. This would avoid both of you rubbing noses! Do remember to rest your other (free) hand on the patient’s forehead, also to prevent you two from knocking heads!

2. Start about an arm’s length away with the illuminated lens disc at +4.00 ‐ +10.00 d (usually green positive) lens using the large aperture. However, this may also depends on whether you are wearing your glasses, so do experiment to get used to it.

3. Illuminate both of the patient’s eyes to enable you to observe the red reflex of the patient and to examine for any media opacities (cataract, corneal scars, large floaters).

4. Select “0” on the illuminated lens disc and start with the small aperture as you approach the patient while fixing the “red reflex” pupil as your target. Remember to ask the patient to look straight at a distance to maintain pupil dilation.

5. Tilting slightly at 15‐25o lateral to the patient, move forward as you direct the light beam into the pupil. The optic disc should be within view as you are about 1‐2 inches from the patient’s eye. remember that the optic disc is slightly towards the nasal aspect of the fundus.

6. Do not panic if you do not see the optic disc initially. Look for a nearby retinal blood vessels. You’ll most likely find the optic disc by tracing at either one “end” or the other of the vessel. This is due to the developmental fact that retinal vessels branch from the optic disc to the peripheral retina.


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7. The optic disc may not be focused as you see it, as hypermetropic patients require more “plus” (green numbers) lenses for clear focus of the fundus while myopia patients require more “minus” (red numbers).

8. Examine the optic disc for (the 4C’s): • color (pink, pale, hyperemia, etc) • contour (margin, shape, elevation, etc) • cup‐disc ratio (compare the vertical diameters) • caliber of vessels (normal AV ratio around 2:3)

‐ the AV ratio mentioned is measured from the width of the vessels before the 3rd bifurcation from the origin on the optic disc..

9. Follow each vessel as far to the periphery as you can and look for any abnormalities such as venous dilatation, AV nipping, etc.

10. To examine the periphery, ask the patient to: • Look up for examination of the superior retina • Look down for inferior retina • Look temporally for temporal retina • Look nasally for nasal retina.

11. Lastly, locate the macula which is approximately 2 disc diameters temporally from the optic disc, between the superotemporal and inferotemporal vessels. Or you can ask the patient to look at the light of the ophthalmoscope, which would put the macula in good view. Look for abnormalities. Red filter facilitates the view of macula.

12. For the examination of the left eye, the same procedure can be repeated, but with left hand and left eye on the left side.


Disc Swelling

i. Disc swelling is a sign, not a diagnosis.

ii. It is essential to test the optic nerve function in all cases of disc swelling.

iii. Tests for optic nerve function includes:

1. Visual acuity

2. Pupil response ‐ direct reflex

‐consensual reflex

‐ relative afferent pupillary defect (RAPD)

3. Visual field

4. Color vision (Red desaturation)

iv. Important causes of optic disc swelling(Disc edema) may include:

• Optic Neuritis

• Papilloedema

• CRVO

• AION

*The term ‘papilloedema’ is usually reserved for bilateral disc swelling (as it is a result of increased intracranial pressure). Thus, check the other eye for optic disc swelling before coming to a conclusion of papilloedema!

*Cases of unilateral papilloedema are very rare.

1. Optic Disc Abnormalities


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v. Papilloedema vs Optic Neuritis

Papilloedema Optic Neuritis Definition Passive swelling of

the optic disc secondary to increased intracranial pressure. Eg. Space Occupying lesion, meningitis, beingn intracranial hypertension (BIH)

Inflammation of the optic nerve. 2 ypes of optic neuritis:

a. Papillitis Optic disc is swollen

b. Retrobulbar neuritis Normal appearance of disc

Unilateral/ Bilateral

Usually Bilateral Usually Unilateral

Pain on eye movement

No Yes (Rectus contraction pulls on optic nerve sheath)

Visual Acuity

Transient obscuration – mostly normal until late stage

Reduced

Pupil reaction

Normal, no RAPD Positive RAPD in unilateral cases

Visual field Enlarged blind spot Central or paracentral scotoma

Color vision Usually normal Red desaturation


Quick Reference: Causes of disc swelling:

Unilateral Bilateral Vascular: eg. AION, CRVO or diabetic papillopathy

Raised intracranial pressure: SOL, hydrocephalus, Benign Intracranial Hypertension (BIH)

Inflammatory: “papillitis”, eg. uveitis, sarcoidosis, viral, SLE

Malignant hypertension

Demyelination: MS‐ may become bilateral

Diabetic papillopathy

Hereditary: Leber’s Hereditary Optic Neuropathy

Infiltrative papilloedema: lymphoma

Infiltrative: tumors such as retinoblastoma, lymphoma

Toxic: ethambutol, chloramphenicol uremia

Infective: Toxoplasmosis, herpes, Lyme’s disease


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Optic Atrophy (Figure 1.1)

Optic atrophy is the final common morphologic endpoint of any disease process that causes a loss of optic nerve fibers at the optic nerve head.

Optic atrophy is actually a misnomer; in the strict histologic definition, atrophy refers to involution of a structure resulting from prolonged disuse.

• Clinical Findings:

a. Poor visual acuity (Severity depending on degree of optic atrophy)

b. Reduced Color Vision

c. Visual field defect (depending on cause)

d. Positive RAPD (unilateral cases)

e. Pale optic disc

Figure 1.1 Optic Atrophy


Common Causes of Optic Atrophy

a. Pressure/ Traction: Glaucoma, Papilloedema b. Hereditary: Autosomal dominant optic atrophy, autosomal

recessive optic atrophy, Leber’s hereditary Optic Atrophy c. Vascular: Central Retinal Artery Occlusion, Antrior ischemic

optic atrophy (acute phase) d. Retinal dystrophy: Cone dystrophy, Retinitis Pigmentosa e. Nuttritional/Toxic: Vitamin B deficiency f. Inflammatory: Sarcoidosis, polyarteritis nodosa g. Demyelination: Multiple Sclerosis h. Compresive: Optic nerve glioma or meningioma


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Glaucomatous optic neuropathy (Figure 1.2)

Findings:

a. Increased Cup/Disc ratio (Normal: 0.1‐0.3) (Abnormal > 0.6)

b. Nasalization/Bayonetting of vessels in the optic disc Bayoneting – double angulation of vessels as it “climbs” from the the cup of the optic disc Nasalization‐displacement of the vessels from center to the nasal aspect of the cup in the optic disc.

c. Lamellar dots (multiple gray dots scattered on cup of optic disc) ‐caused by exposure of lamina cribosa due to loss of neuroretinal tissue (seen in advanced glaucomatous stage)

d. Very deep cup

*not all enlarged cup means glaucoma

Figure 1.2 Glaucoma


Optic Disc Neovascularization (Figure 1.3)

• Disorganized arcades of vessels seen on optic disc • Can be shaped as fronds, with thin and fragile vessels • Neovascularization may involve just the peripheral as well, and

may assume the shape of a “seafan” • Common causes of disc neovascularization:

1. Advanced Diabetic Retinopathy

2. Central Retinal Vein Occlusion

3. Ocular Ischemic Syndrome

Figure 1.3 New vessels formation on optic disc Notice the disorganized tiny vessels on the nasal side of the optic disc, forming a massive

frond‐like stuctures.


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2. Macular abnormalities Macular edema

• Result of increased fluid and protein deposits within the neuroretina in the macula.

• Swelling may distort the central vision, as the macula is near the center of retina.

• May be differentiated into cystoid and non‐cystoid. *It is hard to differentiate between cystoid and non‐cystoid with a direct ophthalmoscope, hence hard exudate seen around the macular region is usually used as an indicator of macular edema.

Figure 2.1 ‐ Left: Hard exudate formation around the macula (Non‐cystoid)

Right: Thickening of fovea associated with microcyst (Cystoid)


• Causes of macular edema may include: i. Retinal vascular disease (Background diabetic

retinopathy, retinal vein occlusion) ii. neovascularization iii. retinitis pigmentosa iv. age‐related macular degenration (ARMD) v. hypertensive choroidopathy, malignant arterial

hypertension vi. iatrogenic (eye surgery, eg: retinal detachment surgery,

retinal cryotherapy)


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Stellate Maculopathy (Figure 2.3)

• Retinal hard exudates forming a macular star • Frequently associated with optic disc swelling • Causes:

o Hypertension – bilateral o Papilloedema – bilateral (may be assymetrical) o Neuroretinitis (usually unilateral) o Capillary angioma, may be on the optic disc or at the

periphery, is associated with macullar star.

Figure 2.2 Macular Star

Diabetic Maculopathy

• Poor near vision, not corrected by Plus lenses • Usually assymetrical • The commonest cause for poor vision in diabetes patients is

macular edema especially in NIDDM.


Cherry Red Spot (Figure 2.4)

• An obvious red round spot of the fovea surrounded by a concentric area of pale retinal background.

• Causes: Central retinal artery occlusion (acute phase), and GM2 gangliosidoses particularly Tay‐Sachs disease.

Figure 2.4: Cherry Red Spot in central retinal artery occlusion(left) and Tay‐Sachs disease(right)

Note the much paler background of the retinal in CRAO

*In CRAO, giant cell arteritis (GCA) should be considered in patients older than 65 years, but do not ignore in younger patients.


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*Central Serous Retinopathy (Of interest) – Figure 2.5

• Localized detachment of sensory retina at the macula secondary to focal RPE defects.

• Self‐limiting, usually affecting young/middle‐aged men with Type A personality.

• Sub‐retinal fluid around macula (elevation as indicated by the “climb” by vessels on macula.

Figure 2.5 Central Serous Retinopathy


3. Retinal Vessels Abnormalities Normal Artery to Venous (A‐V) ratio is 2:3 Reduced in:

• Aging • Hypertension • Old CRAO (due to attenuated arterioles)

Retinal Vasculitis (Figure 3.1)

• Vasculits may affect veins (periphlebitis) or arteries (periarteritis)

• Active vasculitis is characterized by fluffy white haziness (cuffing) of the vessels column.

Figure 3.1 Examples of retinal vasculitis


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Common Causes of Major Changes in Vascular Caliber Arterial attenuation

• Systemic hypertension • Retinal artery occlusion • Diffuse retinal disease

(Retinitis pigmentosa)

Venous dilatation and/or tortuosity

• Retinal vein occlusion • Non‐proliferative diabetic

retinopathy • Hyperviscosity syndrome • Ocular ischemic syndrome • Inherited venous beading

Combined venous and arterial dilatation and tortuosity

• Retinopathy of prematurity • Retinal capillary

hemangioma • Retinal racemose

hemangioma

Figure 3.4 Arterial and venous tortuosity in racemose hemangioma

Figure 3.2 Arterial attenuation in advanced retinitis

pigmentosa

Figure 3.3 Venous beading and dilatation along with new vessels formation on disc (Proliferative Diabetic

Retinopathy)


4. Retinal findings Retinal hemorrhages

i. Superficial Flame shaped hemorrhages (Figure 4.1)

• bleeding near the surface of retina in nerve fiber layer

• follows nerve fiber, giving flame‐shaped appearance • located usually in relation to optic nerve head or

posterior pole, seldom in peripheral retina where nerve fiber layer is thin.

• causes: retinal vein occlusion, diabetic retinopathy, optic nerve disease (acute papilloedema, anterior ischemic optic neuropathy), retinal periphlebitis

Figure 4.1 Flame‐shaped hemorrhage

Notice the unidirectional smudge‐smear like of the hemorrhage, forming the characteristic flame appearance.


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ii. Deep Dot and blot hemorrhages (Figure 4.2)

• bleed from deep retinal capillaries • dot hemorrhages are small round and with uniform density

• blot hemorrhages are larger, with irregular shape and density, forming an irregular patch of bleeding, and darker in color

• dots and blots are mostly found in the peripheral retina where retinal nerve fiber is usually thinner

• causes: retinal vein occlusion, non‐proliferative diabetic retinopathy, ocular ischemic syndrome

Figure 4.2 A clear cut dots and blots hemorrhage appearance


Preretinal Hemorrhage (Figure 4.3) Also known as: Subhyaloid hemorrhage

• Bleeding on the surface of retina, between the retina and hyaloid membrane of vitreous

• Usually solitary and located at the posterior pole • Well defined margin with vessels sometimes seen crossing

BELOW the hemorrhage area. (Not over the hemorrhage) • Initally round but later settle with gravity, giving the “boat‐

like” apperance due to pooling of the blood. • Causes: Proliferative retinopathy, retinal artery

macroaneurysm, wet ARMD, choroidal neovascularization, trauma

Figure 4.3 Preretinal hemorrhage A round preretinal hemorrhage (left) with vessels seen crossing below it. The picture on the

right show a large preretinal hemorrhage which settled into a boat‐like appearance or

pooling of blood.


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Subretinal Hemorrhage (Figure 4.4)

• Bleeding between the photoreceptors and retinal pigment epithelium

• Usually large and bright red with indistinct margin • Vessels are clearly seen ABOVE the hemorrhage (not below the

hemorrhage) • Causes: choroidal neovascularization, retinal tear, Coat’s

disease, sickle cell anemia, blunt trauma

Figure 4.4 Subretinal hemorrhage Note that the vessels are crossing above the hemorrhage area.

Key Points Retinal hemorrhage Superficial: Flame‐shaped

Deep: Dots and blots Preretinal hemorrhage Blood vessels cross BELOW the hemorrhage area Subretinal hemorrhage Blood vessels cross ABOVE the hemorrhage area


Cotton Wool Spots ( Figure 4.5)

• Represents microinfarction of the nerve fiber layer of the retina • Consist of axoplasmic debris • small, white, superficial lesions with indistinct margin, giving it

a fluffy appearance of cotton wool . • Causes: Retinal vein occlusion, non‐proliferative diabetic

retinopathy, vasculitides (SLE, scleroderma), hypertensive retinopathy, AIDS microvasculopathy, microembolic retinal artery occlusion

Figure 4.5 Cotton Wool Spots


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Hard Exudates ( Figure 4.6)

• Leakage of high protein and lipid due to break in blood retinal barrier

• Yellowish glistening intraretinal lesion, usually with a well‐defined margin.

• Commonly seen in any conditions that are associated with chronic vascular leakage , such as::

1. Diabetic retinopathy 2. Hypertensive retinopathy 3. Choroidal neovascularization

Figure 4.6 Hard Exudates Notice the picture on the right where a circinate ring is being formed.

*In fundus with massive hard exudates, check the patient’s lipid profile for hypercholesteremia. It is essential to control the cholesterol level as well!


Drusen (Figure 4.7)

• Drusens are yellowish deposits external to neuroretina and retinal pigment epithelium.

• It may be well‐defined and small (hard) or ill‐defined (soft). • Drusen may be discrete or confluent (coalesce with one

another) and usually are the hallmarks of age‐related change. • Drusens can occur anywhere, in the peripheral retina or macula,

but those occuring at the macula are the ones with clinical significance as they may be related to central visual loss..

• Association: Age‐related macular degeneration (ARMD), autosomal dominant drusens (ADD

Figure 4.7 Drusens on the macular area


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Tigroid retina /fundus (Figure 4.8)

• A normal fundus to which a deeply pigmented choroid gives the appearance of dark polygonal areas between the choroidal vessels, especially in the periphery. Causes: Highly myopic eyes or racial variations.

• Sometimes, it refer to the lacking pigment so that underlying choroid vessels are visible as irregular stripes. Causes: albinism

• The dark stripes at the background resemble the tiger stripes, which therefore give rise to its name: Tigroid fundus

Figure 4.8 Tigroid fundus


With this, the book has come to an end of the basics of fundoscopy. The author did not touch on certain aspects such as fibrosis in retinal detachment but nevertheless important once you have grasp the basics in this book. This book does not intend to replace any textbook in fundoscopy teachings, thus readers are advised to read up more from recommended Ophthalmology textbooks. Last but not least, enjoy your fundoscopy experience!!

Credits: 1. Jack J.Kanski. Clinical Ophthalmology‐ A Systematic Approach.

6th edition 2007. 2. Jack K Kanski, Ken K Nischal. Ophthalmology – Clinical Signs and

Differential Diagnosis. 1999 3. Jane Oliver, Lorraine Cassidy. Opthalmology at a Glance. 2005. 4. E‐Medicine specialties: Ophthalmology,

http://emedicine.medscape.com 5. Digital Reference of Ophthalmology, Edward S. Harkness Eye

Institute. http://dro.hs.columbia.edu/index.htm 6. Prof. Dr Che Muhaya Hj Mohamad. Ophthalmology Checklist for

Undergraduates. Universiti Kebangsaan Malaysia (National University of Malaysia)

7. Dr Zaid Shalchi. Eyes Made Easy.http://eyesmadeeasy.net 8. Dr Faridah Hanom Annuar, our supervisor who had inspired us to

work hard and was always there to guide us in our lessons.


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EXTRAS: Systematic Ophthalmic Examination In a systemic ophthalmic examination, there are 5 essential components to perform, which includes:

1. Visual Acuity 2. External Eye Examination 3. Extraocular Movements 4. Visual Field Test 5. Fundoscopy

Visual Acuity

There are 2 aspects of the visual acuity which should be tested for, namely the distance and the near vision.

Distance vision should be formally done with a Snellen Chart or its equivalent for pediatric cases, at 6 meter. If the acuity is too poor, let the patient try reading at 5 meters instead. For worse cases, check for counting fingers and hand movement.Then, try shining a pentorch from the peripheral retina, to test for light perception. In cataract, light perception is usually preserved.

Near vision can be tested with a Test Chart at 15 inches or 33cm away from the eyes.

*Vision should be checked with and without glasses and pinhole glasses.


External Eye Examination

From general inspection, look for any ptosis, symmetry of the face particularly the eyelids or any obvious changes which have include discoloration of the sclera or a serious red eye. This can be done as soon as your patient steps into the clinic!

1. Lids • The upper lid should cover around 1mm of the upper limbus. • Lower lid should cover just at the lower limbus. • Palpebral aperture should be normal and look at the lashes for

possible malalignment for trichiasis. A normal lash should be pointing anteriorly and laterally.

• Look for the margins for lumps, bumps and any pigmentation.

2. Conjunctiva • The conjunctiva consist of the palpebral, fornix and bulbar

conjunctiva. Inspect each side closely. • Look for any papillae, follicles, dilatation of vasculature

(injection) or subconjunctiva hemorrhage.


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Next would be the Anterior Segment which consist of cornea, anterior chamber, pupil/iris and the lens.

3. Cornea • Looks at the size(normal adult diameter 10‐13mm) and

shape of the cornea which should be round and equal size. • Sharp and pointy cornea is suggestive of keratoconus. • The cornea should be clear and avascular.

(A generalized cloudy cornea is suggestive of corneal edema)

• Look out for any sutures or scar especially at the superior cornea for signs of previous cataract surgery.

4. Anterior chamber • Inspect the content of the anterior chamber, whether if it is

clear, hypopyon or hyphaema. • Shine a torch perpendicular to the limbus from the lateral

aspect and observe the shadow to gauge the depth of anterior chamber. A deep anterior chamber should have no shadow at the medial iris.

5. Pupils/Iris • The pupils should be equal, round and central. • The color of the iris should be same for both eyes, otherwise it

would be heterochromis iridis. • Look out for any previous scars suggestive of peripheral

iridectomy or iridotomy! • Pupillary reflex may be examined, the direct light reflex,

consensual light reflex and relative afferent pupillary defect.


6. Lens • Check for the eye’s red reflex if possible. Shining a torch at the

lens may show a dislocated lens or sometimes an intraocular lens in the anterior chamber.

• Shine a light at the cornea through the pupil. Pseudophakic patients may reveal an obvious double light reflex, a second glistening reflex.

• Also, check for the presence of cataract if the red reflex is absent. The cataract can be anterior subcapsular, posterior subcapsular, nuclear sclerosis or cortical cataract.

Note: There are a total of 4 light reflexes from the eye media when the light is shone thorugh the media (cornea and lens). However, only 1 can be obviously seen as you manouver the light source in a circular motion.

Summary:

External Eye Examination: Lids + conjunctiva + Anterior Segment = Lids + conjunctiva + (Cornea + Anterior Chamber + Pupils/Iris + Lens)

Anterior Segment Examination: Cornea + Anterior Chamber + Pupils/Iris + Lens


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Principles of RAPD (Relative Afferent Pupillary Defect)

RAPD


Extraocular Movement

Extraocular movement is only done in certain patients most of the time. It is not aroutine examination, thus you won’t see such examination done in a patient on diabetic retinopathy follow up.

Indications for such a test include:

• Symptoms of double vision (diplopia) • Strabismus • Patients with also neurological problems • History of trauma to the orbit

There are 2 methods to test for extraocular movement:

i. Bisected H The typical H shape drawn in the air with a target object (pentop or finger). Be sure to not exceed the patient’s range of vision, otherwise you may cause a physiological nystagmus!

Bisected H pathway for extraocular movement


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ii. “Union Jack” This is a test using a pentorch with the light directed at both eyes. With this, the corneal light reflex can be observed while doing the extraocular test, which can rule out pseudosquint if present. This method use a different pathway but applies the same principles as the bisected H.

Pathway for the “Union Jack” extraocular movement test

The actions of the IIIrd, IVth and VIth nerves on the eye movements of the right eye. III= Oculomotor, IV=trochlear, VI= abducent


*Note:

• Test for accomodation as well by bringing the target to around 20 cm from the patient’s eyes and observe the pupil constriction and eye convergence.

• remember to gently pull up the eyelid as the patient looks down to have a clear view of the eyeball positions.

• Observe for the smoothness(smooth pursuit) of the eye movement as it follows the moving target. They can be smooth or jerky.

• Always ask the patient if they see any double vision during the extraocular movement test.

• If there is limitation of the eye movement, you may try occluding the normal eye. That way, you may test if the defect is vergence or version.

• Know the muscles involved in each eyeball movement and the supplying cranial nerves.

The eye muscle movements are:

Abduction‐adduction

Elevation‐depression

Intorsion – extorsion


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Visual Field Test

• This can be done with a confrontation test (1 meter apart and on the same level with the patient) with a white neuropin. Peripheral vision utilizes rods which is predominant in peripheral retina, thus it detects black and white, not color vision.

• Make sure the patient could see in each eye before testing for visual field.

• Remember to bring the neuropin all the way to the center from the peripheral. You might miss a scotoma defect or a central visual defect !

• Blind spot should also be tested with a red neuropin. This is due to the fact that the blind spot is enlarged in disc edema. As the macula is near to the optic disc (blind spot area in your eye), color acuity is the best, thus red pin is used instead of white.

• Move around the blind spot once you found it. Move up or down to check if it is enlarged, and make sure that the reason the patient can’t see the target is not because it is beyond his visual field’s limit!

Fundoscopy

Fundoscopy is the last part of the examination, and it has been described in the early section of the book. Thus, I am sure you would have no difficulty in doing this.

Red pin is also used to test for optic nerve function by checking for red desaturation in all 4 quadrants of the visual field.



47 | P a g e

2010


Documents

Fundoscopy Made Easy 3ed