Manual of Ophthalmic Diagnosis E Ahmed
Chapter Notes

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Differential Diagnosis of Ocular Symptoms and Signs1

Acute Red Eye
  1. Bilateral, painless with good visual acuity
    1. Bacterial conjunctivitis
    2. Viral conjunctivitis
    3. Allergic conjunctivitis.
  2. Bilateral, painful with or without impaired vision
    1. Viral keratoconjunctivitis
    2. Chlamydial keratoconjunctivitis.
  3. Unilateral, painless with normal visual acuity
    1. Conjunctivitis—sometimes unilateral
    2. Inflamed pinguecula
    3. Progressive pterygium.
    4. Episcleritis—often irritation rather than pain is present
  4. Unilateral, painful with normal visual acuity
    1. Marginal corneal ulcer
    2. Scleritis
    3. Early stage of anterior uveitis.
  5. Unilateral, painful with decreased visual acuity
    1. Herpetic keratitis
    2. Severe uveitis
    3. Acute closed-angle glaucoma
    4. Secondary glaucoma2
    5. Corneal ulcer
    6. Zoster keratitis.
See under Diseases of the Conjunctiva, P 76
Gradual Visual Loss in Senile Age-group
  1. Is the affection uniocular or binocular?
  2. What is the duration?
  3. Is the visual defect central or global?
  4. Is there any family history of glaucoma?
  5. Is the patient suffering from diabetes, hypertension or other systemic disease?
  6. What is the nature of treatment done so far?
  1. Distant and near vision (Figs 1.1 and 1.2)
  2. Vision with pin-hole (Fig. 1.3)—when defective vision improves with pin-hole it indicates that the vision will improve with lenses
  3. Rough assessment of visual field by confrontation test
  4. Examination of the cornea, anterior chamber and pupil
  5. Measurement of intraocular pressure (IOP)
    zoom view
    Fig. 1.1: Snellen distant test types
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    Fig. 1.2: Near vision test type
  6. Ophthalmoscopy after pupil dilatation
  7. Occasionally testing of colour vision.
  1. Major
    1. Cataract
    2. Primary open-angle glaucoma
    3. Macular degeneration
    4. Diabetic maculopathy
  2. Rare
    1. Optic atrophy
    2. Vitreous opacity.4
    zoom view
    Fig. 1.3: Pin-hole
Acute Painless Visual Loss
Visual loss lasts longer than 24 hours.
  1. Unilateral
    1. Central retinal artery occlusion
    2. Central retinal vein thrombosis
    3. Central serous retinopathy
    4. Retinal detachment
    5. Vitreous haemorrhage
    6. Ischaemic optic neuropathy
    7. Choroiditis.
  2. Bilateral
    1. Malignant hypertension causing macular oedema
    2. Long-standing papilloedema
    3. Chiasmal and retrochiasmal lesions.5
Investigations for Acute Painless Visual Loss
  1. Is it in one eye?
  2. Are both eyes affected?
  3. Are the symptoms constant or intermittent?
  4. Is the condition static, improving or worsening?
  5. Is the visual loss mild or severe?
  6. Is the patient hypertensive or diabetic?
  1. Checkup of visual acuity
  2. If feasible, check up visual field
  3. Pupil reactions before dilatation of the pupils
  4. Direct or indirect ophthalmoscopy
  5. Colour fundus photography
  6. Fundus fluorescein angiography
  7. Ultrasonography.
Acute Painful Visual Loss
  1. Acute closed-angle glaucoma
  2. Optic neuritis
  3. Uveitis
  4. Acute keratoconus-corneal hydrops.
Transient Visual Loss (Amaurosis Fugax)
Vision returns to normal usually within one hour.
  1. Transient ischaemic attack
  2. Papilloedema
  3. Migraine
  4. Ischaemic optic neuropathy
  5. Impending central retinal vein thrombosis
  6. Postural hypotension
  7. Severe anaemia.6
Ocular Pain
  1. Conjunctivitis
  2. Episcleritis
  3. Scleritis
  4. Keratitis
  5. Acute glaucoma.
Orbital Pain
  1. Orbital pseudotumour
  2. Retrobulbar neuritis
  3. Diabetic cranial nerve palsy
  4. Sinusitis
  5. Uncorrected refractive error.
Investigations for Headaches
  1. Enquire about location, intensity, frequency and possible precipitating factors
  2. Age of onset
  3. Family history.
Complete Ocular Examination
  1. Pupillary reactions
  2. Ocular motility
  3. Measurement of IOP
  4. Evaluation of visual field
  5. Cycloplegic refraction
  6. Ophthalmoscopy after pupil dilatation.
  1. Blood pressure
  2. Ear, nose and throat7
  3. Nervous system
  4. Superficial temporal artery—palpation to find toruosity, thickening, tenderness and absence of palpation
  5. Only in selected cases, CT and MRI may be advised.
Watering may occur in children or in adults, the latter being painless or painful.
  1. In children
    1. Obstruction of the nasolacrimal duct
    2. Congenital glaucoma
    3. Conjunctival or corneal foreign body
    4. Any irritative affection.
  2. In adults
    1. Minimum or no pain is present in conjunctivitis, blepharitis, dry eye, ectropion and abnormality of the lacrimal passages.
    2. Watering with pain is present in
      • Foreign body in the conjunctiva and cornea
      • Trichiasis
      • Corneal erosions
      • Anterior uveitis.
Burning Sensation of Eyes
  1. Blepharitis
  2. Dry eye
  3. Conjunctivitis
  4. Inflamed pinguecula
  5. Pterygium.
Conjunctival Discharge
  1. Infective conjunctivitis8
  2. Allergic conjunctivitis
  3. Canaliculitis
  4. Dacryocystitis.
Metamorphopsia (Distorsion of vision), Micropsia (Objects Appearing Smaller) and Macropsia (Objects Appearing Larger)
  1. Astigmatism
  2. Corneal irregularity
  3. Retinal detachment
  4. Macular disease
  5. Migraine.
Double Vision (Diplopia)
  1. Uniocular—diplopia remains on covering the unaffected eye
    1. Incipient cataract
    2. Dislocated lens or lens implant
    3. Irregular astigmatism or improper correction of high astigmatism
    4. Multiple sclerosis.
  2. Binocular—diplopia disappears when either eye is occluded
    1. Isolated 3rd, 4th or 6th cranial nerve palsy
    2. Internuclear ophthalmoplegia
    3. Abnormal retinal correspondence.
Diplopia may be Horizontal, Vertical or Torsional
In horizontal diplopia, the false image may be on the same side of the deviating eye (homonymous diplopia) or on the opposite side of the deviating eye (heteronymous or crossed diplopia).
Itching of Eyes
  1. Allergic conjunctivitis9
  2. Viral conjunctivitis
  3. Blepharitis
  4. Dry eye
  5. Topical drug allergy
  6. Following contact lens-wear.
Foreign Body Sensation
  1. Blepharitis
  2. Dry eye
  3. Trichiasis
  4. Corneal abrasion
  5. Corneal foreign body
  6. Superficial punctate keratitis.
  1. Corneal abrasion
  2. Corneal oedema
  3. Anterior uveitis
  4. Albinism
  5. Aniridia.
Night Blindness
  1. Uncorrected myopia
  2. Vitamin A deficiency
  3. Pigmentary retinal dystrophy
  4. Choroideraemia
  5. Gyrate atrophy
  6. Advanced glaucoma.
Spots in Front of the Eye(s)
  1. Posterior vitreous detachment10
  2. Posterior uveitis
  3. Vitreous haemorrhage
  4. Retinal detachment
  5. Corneal opacity
  6. Migraine—transient phenomenon.
Haloes Round Lights
  1. Corneal scar
  2. Corneal oedema
  3. Closed-angle glaucoma
  4. Cataract.
Flashes of Light (Photopsia)
  1. Retinal break
  2. Retinal detachment
  3. Posterior vitreous detachment
  4. Retinitis
  5. Migraine.
Chromatopsia (Coloured Vision)
This may be red (erythropsia), blue (cyanopsia), yellow (xanthopsia) and green(chloropsia).
  1. Erythropsia—as in vitreous or retinal haemorrhage, aphakia and post-iridectomy
  2. Cyanopsia—as after digitalis or atebrine therapy
  3. Xanthopsia—as after IV fluorescein, jaundice, chlorothiazide and sulphonamide therapy
  4. Chloropsia—as after griseofulvin therapy.
Whorl-like Opacity in the Corneal Epithelium.11
  1. Fabry's disease
  2. Prolonged use of chloroquine, indomethacin and phenothiazine.
Prominent Corneal Nerves
  1. Leprosy
  2. Neurofibromatosis
  3. Primary amyloidosis
  4. Keratoconus.
Heterochromic Irides
Heterochromia iridis is an ocular sign in which the two irides have different colours (Figs 1.4A and B).
  1. Iris hyperchromia
    1. Naevus of ota (Oculodermal melanocytosis)
    2. Siderosis bulbi
    3. Pigmented iris tumours like naevus and melanoma
    4. Sturge-Weber syndrome
    5. Following use of latanoprost.
  2. Hypochromia of iris
    1. Congenital as in Waardenburg's syndrome
    2. Horner's syndrome
    3. Fuchs' heterochromic cyclitis.
Iridescent Lens Particles
  1. Myotonic dystrophy
  2. Hypocalcaemia
  3. Familial
  4. Drugs.12
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Fig. 1.4A: Heterochromic irides in a child(photo by RN Sen, ECRC, Kolkata)
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Fig. 1.4B: The colour of the right iris is blue except in one sector in the same patient(photo by RN Sen, ECRC, Kolkata)
Acute Rise of Intraocular Pressure
  1. Acute congestive glaucoma
  2. Inflammatory open-angle glaucoma
  3. Posner-Schlossman syndrome
  4. Malignant glaucoma13
  5. Post-operative glaucoma
  6. Retrobulbar haemorrhage.
Bone Corpuscle Pigment in the Fundus
  1. Pigmentary dystrophy of the retina and associated syndromes
  2. Disseminated chorioretinitis of syphilitic origin
  3. Ageing retina
  4. Old vascular occlusion.
Decreased Vision but Normal Fundus
  1. Retrobulbar neuritis
  2. Early retinal dystrophies-like Stargadt's syndrome and cone dystrophy
  3. Amblyopia
  4. Leber's congenital amaurosis
  5. Achromatopsia
  6. Congenital stationary night blindness
  7. Cortical visual impairment.
Differential Diagnosis
  1. Retrobulbar neuritis
    • Usually unilateral
    • Orbital pain with ocular movement
    • Relative afferent papillary defect
    • Decreased colour vision
    • Visual field defects—central or centrocaecal, arcuate or altitudinal.
  2. Stargadt's syndrome (Fundus Flavimaculatus)
    • Bilateral affection in child or young adult
    • Relatively normal-looking fundus
    • Atrophic macular degeneration.14
  3. Amblyopia
    • Usually asymptomatic
    • Poor visual acuity not improved with any glass
    • Presence of crowding phenomenon (individual letters are better seen than the whole line).
  4. Leber's congenital amaurosis
    • Nystagmus—upbeat, i.e.vertical nystagmus with fast phase upward or roving
    • Abnormal or flat electroretinogram.
  5. Achromatopsia (Rod Monochromatism)
    • Total colour blindness
    • Nystagmus
    • Photophobia.
  6. Congenital stationary night blindness
    • Night blindness
    • Myopia
    • Nystagmus.
  7. Cortical blindness (Anton's syndrome)
    • Bilateral severe visual loss
    • Normal pupillary responses
    • Checkup by neurologist
    • MRI of the brain.
Sheathing of the Retinal Veins (Periphlebitis)
  1. Pars planitis
  2. Eales' disease
  3. Sarcoidosis
  4. Multiple sclerosis
  5. Tuberculosis
  6. Behcet's syndrome
  7. Sickle cell disease.
Embolus in the Ocular Fundus
The embolus may be:
  1. Platelet-fibrin (dull grey and elongated)—in carotid disease15
  2. Cholesterol (yellow, at bifurcation of the arteries)—in carotid disease
  3. Calcium (dull white, on or around the disc)—in cardiac disease
  4. Lipid or air—as in Purtscher retinopathy
  5. Others like tumour cells and parasites.
Macular Exudates
  1. Diabetic retinopathy
  2. Malignant hypertension
  3. Choroidal neovascular membrane
  4. Central retinal vein thrombosis
  5. Papilloedema
  6. Coats' disease.
Chorioretinal Fold
  1. Hypotony
  2. Optic disc oedema
  3. Choroidal tumours
  4. Following scleral buckling
  5. Dysthyroid ophthalmopathy
  6. Orbital pseudotumour.
Blind Spot Enlargement
  1. Papilloedema
  2. Glaucoma
  3. Opaque nerve fibres
  4. Optic nerve drusen
  5. Optic nerve coloboma
  6. Myopic disc with crescent.16
The different types are:
  1. Positive discovered by the patient;
  2. Negative detected by the observer;
  3. Central;
  4. Arcuate (Bjerrum);
  5. Paracentral (adjacent to the fixation point);
  6. Pericentral (around the fixation point);
  7. Pericaecal (round the blind spot);
  8. Paracaecal (near the blind spot);
  9. Centrocaecal (between fixation point and blind spot) and
  10. Scintillating.
Central and Centrocaecal Scotomas (Figs 1.5 and 1.6)
  1. Macular lesions
  2. Papillitis
    zoom view
    Fig. 1.5: Central scotoma
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    Fig. 1.6: Centrocaecal scotoma
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    Fig. 1.7: Arcuate scrotoma
  3. Retrobulbar neuritis
  4. Toxic agents
  5. Occipital lesion—rare.
Arcuate (Bjerrum) Scotoma (Fig. 1.7)
This is narrower on the temporal side and wider on the nasal side of the field and is due to nerve fibre bundle defect.
  1. Glaucoma
  2. Anterior ischaemic optic neuropathy
  3. High myopia
  4. Optic disc drusen.
Altitudinal Hemianopia
Defect is detected in the upper or lower half of the visual field.
  1. Anterior ischaemic optic neuropathy
  2. Hemi-branch retinal artery or vein occlusion
  3. Glaucoma
  4. Optic nerve lesion
  5. Chiasmal lesion.
Binasal Hemianopia
Defects are present in the nasal half of visual field.18
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Fig. 1.8: Bitemporal hemianopia in lesion of optic chiasma
  1. Glaucoma
  2. Aneurysm of the internal carotid artery
  3. Pituitary tumour with third ventricle dilatation extending laterally
  4. Bilateral occipital lesion.
Bitemporal Hemianopia (Fig. 1.8)
Defects are found in each temporal half of the visual field.
  1. Pituitary adenoma
  2. Craniopharyngioma
  3. Meningioma of the
    • Olfactory groove
    • Sphenoid ridge
    • Suprasellar region
  4. Optic nerve glioma
  5. Aneurysm of the internal carotid artery
  6. Basal meningitis.
Homonymous Hemianopia (Fig.1.9)
This is hemianopia affecting the right or left halves of the visual field.19
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Fig. 1.9: Left homonymous hemianopia in lesion of right optic tract, optic radiation or visual cortex
  1. Lesions of the optic tract—due to craniopharyngioma, pituitary tumour, aneurysm of the internal carotid artery, multiple sclerosis, etc
  2. Temporo-parietal lesions—like vascular lesions (sudden onset) and tumours
  3. Occipital lesions—include vascular lesions, tumours and demyelinating disease.
Constriction of the Peripheral Fields
  1. Glaucoma
  2. Pigmentary dystrophy of retina
  3. Chronic papilloedema.
Quadrantanopia (Figs 1.10 to 1.12)
Sector-shaped defect bounded by vertical and horizontal radii. This may be unilateral or bilateral-homonymous or crossed.
  • In homonymous:loss of one quadrant in the upper or lower and right or left visual fields in temporal, parietal or occipital lobe lesions lobe lesions
  • In crossed:upper quadrant of one visual field and lower quadrant of the opposite field lost as in glaucoma and chiasmal compression.20
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Fig. 1.10: Left upper quadrantanopia due to lesion of anterior loop of right optic radiation
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Fig. 1.11: Left lower quadrantanopia due to involvement of upper part of right optic radiation
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Fig. 1.12: Left upper quadrantanopia due to involvement of anterior loop of optic radiation
Dilated Episcleral Vessels
  1. Underlying uveal melanoma
  2. Carotido-cavernous fistula
  3. Cavernous sinus thrombosis
  4. Ophthalmic vein thrombosis
  5. Untreated glaucoma.
Decreased Scleral Rigidity
  1. High myopia
  2. Thyrotropic exophthalmos
  3. Drinking of water
  4. Use of strong miotic.
Extrinsic Muscle Thickening
  1. Dysthyroid ophthalmopathy (Fig. 1.13)
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    Fig. 1.13: Extrinsic muscle thickening in dysthyroid ophthalmopathy seen by A and B scan ultrasonography
  2. Orbital pseudotumour
  3. Extension of lacrimal gland tumour to a muscle.
Ocular Hypotony
  1. Choroidal or ciliary body detachment
  2. Serous detachment of retina
  3. Intraocular operation or trauma
  4. Phthisis bulbi
  5. Diabetic coma
  6. Hyperosmotic agents miotics or acetazolamide.
Progressive Hypermetropia
  1. Presbyopia
  2. Central serous detachment
  3. Hypoglycaemia
  4. Orbital tumour pressing on the back surface of the eye.
Progressive Myopia
  1. High myopia
  2. Staphyloma
  3. Diabetes mellitus.
Colour Blindness (Figs 1.14A and B)
  1. Trichromat—red, green and blue anomalies
  2. Dichromat—red, green and blue deficiencies
  3. Monchromat—cone or rod deficient
  4. Turner's syndrome
  1. Retrobulbar neuritis23
    zoom view
    Fig. 1.14A: Ishihara colour vision plate—the patient with both normal colour vision and defective colour vision can equally recognize 12
    zoom view
    Fig. 1.14B: Ishihara colour vision plate—the paptient with normal colour vision sees it as 74, but patient with defective color vision sees it as 21
  2. Age-related macular degeneration
  3. Glaucoma
  1. Papillitis.24
Causes include post-traumatic or post-operative, herpes simplex or zoster iritis, intraocular tumour and blood dyscrasia.
Causes include corneal ulcer, acute uveitis, endophthalmitis and retinoblastoma (pseudohypopyon).
Restricted Ocular Motility
  1. With proptosis and resistant to retropulsion
    1. Orbital mass
    2. Restrictive myopathy—as in dysthyroid ophthalmopathy
    3. Ocular motor nerve palsy
    4. Orbital fracture with entrapment of muscle.
  2. With resistance to retropulsion
    1. Ocular motor nerve palsy—isolated 4th, 6th or multiple
    2. Myasthenia gravis
    3. Superior orbital fissure syndrome
    4. Cavernous sinus thrombosis
    5. Chronic progressive external ophthalmoplegia
    6. Blow-out fracture of the orbit
    7. Duane's retraction syndrome.