This document provides an overview of pediatric neuro-ophthalmology and various conditions that can cause visual impairment or loss in children. It discusses cortical visual impairment, congenital optic nerve anomalies, swollen optic discs, brain tumour related visual loss, optic atrophy, pupil abnormalities, and ocular motor nerve palsies. Evaluation and management are outlined for many of the conditions. The seminar aims to review specific topics like optic nerve hypoplasia, morning glory disc anomaly, optic disc coloboma, intracranial hypertension, optic neuritis, and brainstem gliomas among others.

1. PAEDIATRIC
NEUROOPHTHALMOLOGY
DR SAHIL THAKUR: PRESENTER
DR PARUL ICHHPUJANI: CONSULTANT
INCHARGE

2. THE PAEDIATRIC LOW VISION
PATIENT
1 in 1000 children has low vision
75 % learning in early years due to
vision
Vision impairment: Long term
consequences
Vital to diagnose: Scope of Vision
Restoration and Rehabilitation
Centers for Disease Control. NECH P No. 99-0444.
National
Center for Environmental Health, Centers for Disease
Control.

4. 200,000 to 300,000 children with severe visual
impairment.
Only 15,000 in blind school.
Neuro-ophthalmological disease in around 35% of these.
Vision 2020 document, Government of India.

5. SCHEME OF THE SEMINAR
CORTICAL VISUAL IMPAIRMENT
CONGENITAL OPTIC NERVE
ANOMALIES
SWOLLEN OPTIC DISC
BRAIN TUMOUR RELATED
VISUAL LOSS
OPTIC DISC ATROPHY
PUPIL ABNORMALITIES
OCULAR MOTOR NERVE
PALSIES
OCULAR MYASTHENIA GRAVIS
NYSTAGMUS
PHACOMATOSIS
UNEXPLAINED VISUAL LOSS
MANAGEMENT OUTLINE

6. CORTICAL VISUAL
IMPAIRMENT
CVI is defined as
visual impairment
caused by damage
to the central
nervous system.
Most common
cause of bilateral
visual impairment in
the developed world
Associated with:
Prematurity and ROP
Causes:
Hypoxia/Ischemia
Perinatal strokes, defined as occurring between 28
weeks of gestation and 7 days of age, have an
estimated incidence of up to 1 in 4,000 live births.
Most common cause of CVI.
Congenital Brain Malformation
CNS Infection
Ventriculoperitoneal Shunt Block
Head Injury
Child Abuse
Metabolic Irregularity

7. PRESENTAT
ION
Brodsky MC, Fray KJ, Glasier CM. Perinatal cortical and subcortical visual loss: mechanisms of injury
and associated ophthalmologic signs. Ophthalmology. 2002;109:85–94.

8. CVI
DIAGNOSIS/PROGNOSIS/MANAGEM
ENT
Consider the four A’s of visual loss: Acuity,
Assimilation, Attention, and Apraxia.
Poor Visual Function, Lack of Eye Contact
Associated Neurological/Systemic Abnormality
Extensive Role of Neuroimaging (MRI, PET)
Poor Prognosis: depends on initiation of
treatment
Periventricular Leukomalacia (Sub-cortical) is
indicator of damage to optic radiation: Poor
Prognosis, Tonic Down gaze
PERIVENTRICULAR LEUKOMALACIA

9. DELAYED VISUAL
MATURATION
When a child fails to show
the expected visual function
for his age but does so
spontaneously after a period
of time.
These infants often have
straight eyes, no nystagmus,
and brisk pupillary
responses, but seem to
“look straight through” the
examiner.
TYPES:
Type 1: Isolated DVM
Type 2: DVM with associated
systemic disease, mental
retardation, or other
neurodevelopmental disorders
Type 3: DVM with ocular
disease, such as bilateral
cataracts, severe corneal
opacities, colobomas, retinal
dystrophy, optic nerve
hypoplasia, or albinism
Uemura Y, Oguchi Y, Katsumi O. Visual
developmental delay. Ophthalmic Paediatr

10. MANAGEM
ENT
Early diagnosis of CVI is vital
Management is multifocal and requires team
work
Often is patient specific rather than protocol
based
Often the prognosis is poor and visual
outcome is low, 50% will never see, associated
IQ defects, learning disabilityBrodsky MC. Pediatric Neuro-Ophthalmology. Third Edition. Springer. 2016.

11. CONGENITAL OPTIC NERVE
ABNORMALITIES
Optic Nerve Hypoplasia
Excavated Optic Disc
Anomalies
Optic Disc Coloboma
Morning Glory Disc Anomaly
Peripapillary Staphyloma
Optic Pit
Congenital Tilted Disc
Syndrome
Congenital Disc
Pigmentation
Bilateral optic disc anomalies: poor
vision and nystagmus in infancy
Unilateral optic disc anomalies:
preschool presentation with sensory
esotropia
CNS malformations are common in
patients with malformed optic discs,
need imaging
Color Vision Normal
Any unilateral structural abnormality
that reduces visual acuity in infancy
may lead to superimposed amblyopia

12. OPTIC NERVE
HYPOPLASIA
Most common optic
disc anomaly
Clinical Features:
Abnormally small
discs, double ring
sign, vessel
tortuosity
Confirmed on MRI
Systemic
Associations
Amblyopia
ManagementZekki et al, BJO,

13. SYSTEMIC ASSOCIATION:
• 13-34%: pituitary
abnormalities on imaging
like empty sella, ectopic
posterior pituitary,
nonvisualized infundibulum
and posterior pituitary.
• Hypopituitarism occurs in
75% of optic nerve
hypoplasia patients,
although the majority of the
patients have no pituitary
abnormalities on
neuroimaging.
• Additionally growth
hormone deficiency (70%),
hypothyroidism (43%);
DIAGNOSIS:
• Clinical, Imaging
• VER low amplitude, ERG: WNL
PROGNOSIS
• Developmental delay often occurs in
affected children.
• Developmental delay in 32% and
cerebral palsy in 13%
• Patients with bilateral ONH and
abnormal gray or white matter
development had a higher rate of
developmental delay (65%) than
those without abnormalities (35%).
Kaur, Savleen et al. “Optic Nerve Hypoplasia.” Oman
Journal of Ophthalmology 6.2 (2013): 77–82. PMC.
Web. 11 Feb. 2018.

14. MORNING
GLORY OPTIC
DISC
OPTIC DISC
COLOBOMA

15. PHACE
(posterior fossa
malformations,
large facial
hemangiomas,
arterial
anomalies,
cardiac
anomalies and
aortic
coarctation, and
eye anomalies)
syndrome.
Frieden IJ, Reese V, Cohen
D. PHACE syndrome. Arch
Dermatol. 1996;132:307–
11.

16. SWOLLEN OPTIC
DISC
Pseudo Papilledema
Papilledema
IIH
Secondary Intracranial
Hypertension
Disc Edema in
Systemic Disease
Optic Neuritis

17. PSEUDO
PAPILLEDEMA
Optic Disc Drusen
Anterior to the lamina cribrosa,
Lipofuscin
Buried drusen may present as
pseudo disc edema
Visual field defects have been
detected in 71%–87% of eyes with
visible disc drusen and in 21%–39% of
eyes with pseudopapilledema but no
visible drusen
Vascular occlusions have been
reported in patients with disc drusen

18. Other causes of Pseudo
papilledema:
Persistent Fetal
Vasculature
Bermeister’s papilla
Hypermetropic/Nano
ophthalmic eyes
Juxtapapillary Myelination
Hyaloid Traction

19. PAPILLEDEM
A
ICSOL first possibility of
raised ICP
Most common tumors
associated with childhood
papilledema are midbrain and
cerebellar glioma,
medulloblastoma, and
ependymoma.
Clinical Presentation:
Headaches, transient visual

20. IIH/
PSEUDOTUMOU
R CEREBRI
IIH is a condition characterized by
signs and symptoms of increased
intracranial pressure without
evidence of a mass lesion or
hydrocephalus
Dandy Criteria for Primary IIH:
Smith JL. Whence pseudotumor cerebri? J Clin
Neuroophthalmol.1985;5:55–6.
Johnston I, Hawke S, Halmagyi M, Teo C. The pseudotumor syndrome:
disorders of cerebrospinal fl uid circulation causing intracranial
hypertension without ventriculomegaly. Arch Neurol.1991;48:740–7.

21. IIH(PEDIATRICVSADULT)
No gender predisposition
Better response to steroids (80% remission)
Surgery is indicated in progressive visual loss (20%)
Brodsky MC. Pediatric Neuro-Ophthalmology. Third Edition. Springer. 2016.

22. DISC EDEMA IN
SYSTEMIC DISEASE
Malnutrition
Severe Anaemia
Addison's Disease
Organ
Transplantation
Down Syndrome
SLE
Diabetes
Malignant
Hypertension
Sarcoidosis
DIABETIC PAPILLOPATHY SARCOIDOSIS

23. OPTIC
NEURITIS
Paediatric Optic
Neuritis:
Bilateral
Optic Disc Swelling
Often Post Infectious
rather than MS
Pediatric MS accounts
for only 2%–5% of all
MS cases
Neurodiagnostic criteria for pediatric MS
include:
• Two or more non-encephalopathic
clinical CNS events that have presumed
inflammatory cause, separated by more
than 30 days and involving two or more
areas of the CNS.
• One non-encephalopathic episode
typical of MS, associatedwith MR findings
demonstrating dissemination in space
and dissemination in time.
• One prior episode of ADEM followed by
a nonencephalopathic attack, equal or
greater than three months after the initial
symptom onset of ADEM, associated with
new MR lesions and showing
Krupp LB, Tardieu M, Amato MP, et al. International Pediatric Multiple Sclerosis Study Group pediatric
multiple sclerosis and immune-mediated central nervous system demyelinating disorders: revisions to
the 2007 definitions. Mult Scler. 2013;19:1261–7.

24. DIAGNOSTIC
EVALUATION
Battery of
investigations to
rule out other
causes.
Neuroimaging is
essential. (MRI of
head and spine)
Cecocentral
scotomas and largeBrodsky MC. Pediatric Neuro-Ophthalmology. Third Edition. Springer. 2016.

25. TREATME
NT
No clear cut
guidelines
ONTT is used
currently
Steroids are the
mainstay of treatment
after excluding
infectious causes.
Immunomodulators
like azathioprine andBrodsky MC. Pediatric Neuro-Ophthalmology. Third Edition. Springer. 2016.

26. BRAIN TUMOUR RELATED
VISUAL LOSS
Primary brain tumors are the most common solid neoplasms
in children and are second only to leukemia in overall
frequency during childhood.
Pediatric intracranial tumors in general
• Headache (33%)
• Nausea and vomiting (32%)
• Poor coordination or abnormal gait (27%)
• Papilledema (13%)
Pediatric intracranial tumors (age <4 years)
• Macrocephaly (41%)
• Nausea and vomiting (30%)
• Irritability (24%)
• Lethargy (21%)
Wilne S, Collier J, Kennedy C, et al. Presentation of childhood CNS tumors: a systematic review and
meta-analysis. Lancet
Oncol. 2007;8:685–95.

27. VISUAL
PATHWAY
LESIONS
50% intracranial tumours
can present with ocular
findings
Associated Features:
nystagmus, ocular motor
dysfunction, reduced
visual acuity, visual field
deficits,
dyschromatopsia, an
afferent pupillary defect,
anisocoria, optic
atrophy, or papilledema.Wilne S, Collier J, Kennedy C, et al. Presentation of
childhood CNS tumors: a systematic review and
meta-analysis. Lancet
Oncol. 2007;8:685–95.

28. Suprasellar: Suprasellar tumors in
children include optic pathway
gliomas,
craniopharyngiomas,germinomas,
pituitary adenomas.
Supratentorial tumours:
Astrocytomas are the most
common supratentorial tumors in
childhood, constituting
approximately 30% of such
tumors.
Posterior Fossa Tumours:
Medulloblastoma : most common
malignant brain tumor of
childhood.
This embryonal tumors of the posterior
fossa comprises 40% of posterior fossa
tumors.

29. Brain Stem Tumours:
Brainstem gliomas
represent about 15% of
pediatric CNS tumors.
The mean age at diagnosis is
7–9 years, with no gender
predilection.
Most common seen are diffuse
gliomas (58-75%).
Brainstem tumors are
suggested by the triad of long
tract signs, cranial
neuropathies, and ataxia.

30. MANAGEMENT
Unlike adult tumors, extracranial
tumors rarely metastasize to the
intracranial compartment in
children.
However, seeding of certain brain
tumors in children occurs often
along the CSF pathways, causing
invasion of the leptomeninges.
Due to delay in diagnosis, brain
tumors in children may be long
standing, leading to more severe
and less reversible visual loss
Need extensive imaging (MRI,
Angiography, PET, MR
Spectroscopy)
 Long-term survivors of childhood
cancer have a ten times greater
incidence of cerebrovascular disease.
 Treatment is multimodal:
 Chemotherapy
 Surgery
 Radiotherapy,
 Long term follow-up
 Post Radiation:
 SMART: stroke-like migraine
attacks after radiation therapy
 Moyamoya Disease: hazy like a
puff of cigarette smoke drifting
in the air,” is a descriptive name
applied to the angiographic
finding of an abnormal network
of collateral vessels at the base
of the brain in the region of theBrodsky MC. Pediatric Neuro-
Ophthalmology. Third Edition. Springer.

31. Moyamoya Disease

32. OPTIC
ATROPHY
Optic atrophy is a morphologic
sequel to a multitude of anterior
visual pathway insults that
culminate in the loss of retinal
ganglion cell axons.
Leading cause of severe visual
impairment among 2,527 Nordic
children, followed by retinopathy of
prematurity and amblyopia.
Etiology: Tumours
(29%), post
inflammatory
(meningitis, optic
neuritis) (17%),
trauma (11%),
undetermined (11%),
hereditary (9%),
perinatal disease (9%),
hydrocephalus (6%),
neurodegenerative
disease
(5%)
Repka MX, Miller NR. Optic atrophy in children. Am J Ophthalmol.
1988;106:191–3.

33. CAUSESOFOPTIC
ATROPHY

34. PUPILLARY REACTIONS
Extremely Vital
RAPD assessment
Lesion Localisation

35. ANISOCORIA

37. Depending of Localisation:
 Relevant Imaging
 CT, MRI, MRA
 Ipsilateral Horner syndrome
(first order) and
contralateral superior
oblique palsy (fourth nerve
palsy) suggests a lesion of
the trochlear nucleus or its
fascicle in the brainstem
 Ipsilateral Horner syndrome
(third order) and an
abducens paresis (sixth
nerve palsy) suggests a
lesion in the cavernous
sinus
 Acute Painful Horner
Syndrome should be
presumed related to a
dissection of the Ipsilateral
internal carotid artery

38. SYMPATHETIC
PARASYMPATHE
TIC

39. OCULAR MOTOR
NERVE PALSIES
Oculomotor
Nerve
Trochlear Nerve
Abducens Nerve
Multiple Nerves
•Is there history of
trauma?
•Is there diurnal
variation?
•Is there history of
headache?
•Are there neurological
deficits?
•Is there history of
previous episode?
•Is there a head

40. 3RD NERVE
LESIONS
Causes:
Congenital palsy
(43%), trauma (20%),
infection and
inflammation(13%),
tumor (10%),
aneurysm (7%), and
ophthalmoplegic
migraine (7%)
Miller NR. Solitary Oculomotor nerve
palsy in childhood. Am J Ophthalmol.
1977;83:106–11.

41. 3RDNERVELESIONS
LOCALISATION

42. MANAGEMENT OF 3RD
NERVE LESIONS
Treat the underlying cause
Look out for aneurysm of the PCA
Neuroimaging is vital
Goal is: Binocular alignment, Ptosis
correction, Amblyopia management

43. 4TH
NERVE
LESION
S 71.2% have
head tilt
opposite to
side of palsy
 most common
isolated cranial
nerve palsy
and the most
common cause
of acquired
vertical

44. Etiology:
Congenital in
56%,
craniofacial
anomalies12%,
head trauma in
5%, Idiopathic
in
14%.
Tarczy-Hornoch K, Repka
MX. Superior oblique
palsy in pediatric
patients. J AAPOS.
2004;8:133–40.

45. (1) Is there a
right or left
hypertropia in
primary
position?
(2) Does the
deviation
increase in right
gaze or left
gaze?
(3) Does it
increase with
head tilt to the

46. MANAGEMENT OF 4TH
NERVE LESIONS
The trochlear nerves are particularly vulnerable to closed
head trauma when there may be contre coup of the tectum
of the midbrain against the edge of the tentorium.
Management: Surgical
First choice of procedure: ipsilateral inferior oblique muscle
weakening
Second procedure: deviation is greater than 15 prism
diopters is either ipsilateral superior rectus recession, when
the vertical deviation is worse in up gaze, or contralateral
inferior rectus recession, when the deviation is worse in
down gaze.

47. 6TH NERVE
LESIONS
Clinical Features:
 head turn toward the
side of the lesion
 horizontally
incomitant esotropia
that increases in gaze
toward the affected
eye and decreases or
disappears in gaze
away from the

48. Etiology:
neoplasm
(39%), trauma
(20%),
inflammation
(17%), and
idiopathic
conditions
(9%)
Robertson DM, Hines
JD, Rucke CW.
Acquired sixth nerve
paresis in children.
Arch Ophthalmol.
1970;83:574–9.

49. MANAGEMENT OF 6TH
NERVE LESIONS
Newborns: Observation 4 to 10 weeks
Older Infants/ Children: If after period of
fever/immunisation: Observation for 3 months
Extensive imaging, neurological and otolaryngologic
evaluation
The highest rates of spontaneous recovery have
been reported
in idiopathic (67%), infectious (50%), inflammatory
(90%),
and traumatic (33%–50%) cases.
Aroichane M, Repka MX. Outcome of sixth nerve palsy or paresis in young
children. J Pediatr Ophthalmol Strabismus 1995;32(3):152–156.

50. MULTIPLE
CRANIAL
NERVE
PALSIES
 Difficult to manage
 Prognosis depends on
presentation, degree of
nerve involvement and
time of intervention
 Imaging is essential in
every case.

51. SUPRANUCLEAR DISORDERS

52. SACCADE INITIATION
FAILURE OR OCULAR
MOTOR APRAXIA
The term saccade initiation failure or
ocular motor apraxia is used to
specify impaired voluntary saccades
and variable deficit of fast-phase
saccades during vestibular or
optokinetic nystagmus.
Clinical Features: poor head control,
head thrusting fixation using VOR,
hypotonia, motor delay
Evaluation: VEP, Neuroimaging

54. CHILDHOOD DORSAL MIDBRAIN
SYNDROME
Etiology: Pretectal lesions
Clinical Features:The
constellation of deficits are
(1) vertical gaze palsy, (2)
light–near dissociation of
the pupils, (3) eyelid
retraction (Collier’s sign),
(4) disturbance of vergence,
(5) fixation instability, and
(6) skew deviation.
Evaluation: Neuroimaging
Management: Treat the
cause

55. MYASTHENIA
GRAVIS
9.1 per 1 million total population
4.2% were between 0 and 9 years, 9.5% were between
9 and 19 years
Transient Neonatal
Familial Infantile
Congenital Myasthenia Syndromes
Autoimmune Myasthenia
The prognosis for survival, improvement, and
remission in a child with myasthenia gravis is better
than that in an adult.
Brodsky MC. Pediatric Neuro-Ophthalmology. Third Edition. Springer. 2016.

56. Diagnosis:
EMG/NCS
Blood Tests
Genetic Tests
Treatment:
 Breathing Support
 Nutritional Support
 Medications
 Thymectomy
 IVIG
 Plasmapheresis
• 2 years, 57 cases
• AChR antibodies: positive titers were found
in 67%
• Tensilon test: 47% of generalized cases and
in 39% of ocular cases and results were
abnormal in 88% and 100%, respectively.
• Nerve conduction studies: abnormal results
found in 65%
• Pyridostigmine: all demonstrated
improvement.
• 18 patients steroids, improvement 94%.
• 21 patients intravenous immunoglobulin
(IVIG), improvement in 81%.
• Ocular presentations, all were started on
pyridostigmine; improvement occurred in
88% patients.

57. NYSTAGMUS
Record type of movement, frequency, amplitude, direction

58. NYSTAGMUS

59. DETAILED
NYSTAGMUS
WORKUP:
 OCULAR
 NEUROLOGI
CAL
 DEVELOPM
ENTAL
 GENETIC
 BIOCHEMIC
AL
 IMAGING

60. PHACOMATOSIS
Neurofibromatosis
Sturge-Weber syndrome
•seizures/ glaucoma
•cerebral atrophy, calvarial thickening, and cortical calcifications
on CT
Klippel–Trenaunay–Weber syndrome
Von Hippel Lindau
•retinal angiomatosis, central nucleus of the amygdala (CNA)
hemangioblastoma (50%), renal cell carcinoma (22%),
pheochromocytoma (14%)
Tuberous Sclerosis

61. NF1: NEUROFIBROMATOSIS
Clinical Features:
Plexiform
Neurofibroma of the
Lid, Lisch Nodules, Café
au Lait spots, Neural
Hamartomas
Imaging:
MRI: Unidentified Bright
Objects, Optic Nerve Tract
Gliomas, Intracranial

62. Prognosis:
Cognitive disability is another
common problem in children
with NF1
Patients with NF1 have a life
expectancy of about 15 fewer
years less when compared with
the general population, with
malignancies (brain tumors and
malignant peripheral nerve
sheath tumors) and
cerebrovascular disease
contributing disproportionately
to mortality.
Treatment:
Carboplatin and Vincristine
used for glioma reduction.
Poor Prognosis: 32% of
patients showed
improvement, 28% worsen,
40 % no change
Recently Avastin has been
shown to decrease tumor
size.
Radiotherapy not useful,
leads to secondary
malignanciesFisher MJ, Loguidice M, Gutmann DH, et al. Visual outcomes in children with neurofi
bromatosis type 1-associated optic pathway glioma following chemotherapy: a multicenter
retrospective analysis. Neuro Oncol. 2012;14:790–7.

63. NF2:
NEUROFIBROMATO
SIS
Clinical Features: Bilateral
Vestibular Schwannoma,
cutaneous schwannomas, spinal
schwannomas, lack of Lisch
nodules (with rare exceptions),
fewer café au lait spots, and the
presence of juvenile-onset
cataracts, CHRPE, Collision
tumours
Imaging: MRI: Vestibular
Schwannoma, ON sheath

64. TRANSIENT, UNEXPLAINED AND
PSYCHOGENIC VISUAL LOSS
Some children have visual
disturbances that occur in
the absence of, or are out
of proportion to, their
objective ophthalmological
findings.
The most common cause of
episodic visual loss
disturbances in childhood
is migraine.
May occur at some point in
up to 15% of the
population.
Lipton RB, Stewart WF, Diamond S, Diamond ML, Reed M.
Prevalence and burden of migraine in the United States:
data
from the American Migraine Study II. Headache. 2001;41:

65. MIGRAI
NE
Clinical features: Blurred
vision, foggy vision,
flickering lights, colored
lights, zigzag lines, and a
heat-wave sensation.
Descriptions provided by
children tend to be more
picturesque:
“a star breaking into a million
pieces,” “heat waves,” “water
coming down a window,” “lines
coming down from the sky like
Investigation
s:
•MRI
•EEG
•PET
Treatment:
•For abortive phase:
Sumatriptan, Ketorlac,
Prochlorperazine
•For prophylaxis:
Amitriptyline,
Verapamil, Topiramate
•Biofeedback, Relaxation,

66. Vital to differentiate and refer to clinician.
Other diseases like coagulopathy, cardiac disease, infectious
mononucleosis, mental diseases like schizophrenia can also cause
transient visual disturbances.

67. UNEXPLAINEDVISUALLOSS PSYCOGENIC
VISUAL LOSSNon organic loss of vision, diagnosis of
exclusion
Good prognosis with psychiatric help.
Brodsky MC. Pediatric Neuro-Ophthalmology. Third Edition.
Springer. 2016.

68. MEDICAL
MANAGEMENT
• Appropriate refractive correction.
• Surgical intervention whenever required
• Appropriate glare control glasses.
• Prescription and training to use a low vision
device
• Binocular vision therapy.
• Patching therapy in cases of amblyopia
• Appropriate referral for other disability
• Prognosis for improvement should be
explained to the individual.

69. FUNCTIONAL
MANAGEMENT
• Emphasis on size, color, contrast, distance and
illumination of targets
• Choose toys /games keeping in mind the
developmental levels.
• Eye tracking exercise
• Peripheral awareness therapy
• Searching and scanning strategies
• Central or eccentric viewing strategies
• Visual reach activities.
• Office based vision stimulation therapy
• Support from special educators.
• Orientation and mobility instruction

70. EDUCATIONAL
MANAGEMENT
• Levels of lightening and sensitivity to glare
• Positioning of the individual
• Size of material
• Placement of material in optimal visual field
• Appropriate colors
• Brightness
• Need for clutter reduction
• Spacing of visual information
• Orientation and mobility in the environment

71. LOW VISION
AIDS
Principles of magnification at distance point
Magnification is calculated by the formula
M(t)=BVA/TA, BVA =Best Visual Acuity, TA=
Targeted Acuity
Distance vision =6/60 and Goal distance
acuity= 6/15 (as this acuity is required for
reading street signs, bus number and watching
television so 60/15 = 4x
The power ,size and contrast as more is the
power of telescope lesser will be the field of

72. Principles of magnification at near point:
 Relative distance magnification: Moving
the object closer to the eye (shortening the
distance) causing a proportional
enlargement of the retinal image. eg.
Sitting in front of the television, holding a
book close while reading (most children
can easily do this) etc.
 Relative size magnification: Enlarging the
physical size of an object, such as large
print rather than standard print. eg. Large
print books, writing large letters.
 Angular magnification: Using an optical
system such as telescopes, magnifiers.
 Electronic magnification: Enlargement of
Christine Dickinson. Low Vision
Principles and Practices.
Manchester: Butterworth
Heinemann; 2001.
Magnification; pp. 69-118

73. LogMAR visual acuity prior to the introduction of low
vision devices (LVDs) was 0.90 ± 0.05 for distance and
for near it was 0.61 ± 0.05.
After the intervention, the acuities improved significantly
for distance (0.2 ± 0.27; P < 0.0001) and near (0.42 ±
0.17; P = 0.001).
The most common reported difficulties were related to
their academic activities like copying from the blackboard
(80%), reading textbook at arm's length (77.2%), and
writing along a straight line (77.2%).
 Absolute raw score of disability pre-LVD was 15.05
which improved to 7.58 post-LVD. An improvement in
functional vision post visual rehabilitation was especially
found in those activities related to their studying lifestyle

74. SUMMARY

76.  Beyond Retinal
Implants
 Second Sight’s
Orion 1 Cortical
Implant
 Chances of
vision even in
optic nerve,
tract, chiasmal