Vision and Eye Disease, Part 3

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Vision and Eye Disease, Part 3

Department of Blind and Vision ImpairedCreated by Carmen Valdes & Lisa Shearman

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Review of Observations

Learning Objectives for Part 3:1. Definition of normal vision in infants and toddlers.

2. Physical observations of problematic vision.

3. Types of eye diseases

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What is Normal Vision in Infants?Normal Vision • Infants are born with an underdeveloped visual system. Throughout the

first year of life, the child's vision will grow and develop with him or her. • Babies usually see movement before anything else, as their vision is still

evolving. • Full-term babies should be able to see their mother's facial expression

within a week of birth. • Color vision is not yet fully developed at this time. • Depth perception will also mature during the first year of life, as long as

both of the child's eyes are working as a team. • Eye muscle coordination in a newborn, as well as a small child, is also

very immature.

http://www.allaboutvision.com/parents/infants.htm

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Infant Vision Over 6 Months Newborn 4 weeks 8 weeks 3 months 6 months

Using technology developed at Stanford University, see how a child would view a picture at five different ages. The new born does see light variation and movement. At 4 weeks the vision of the infant can detect some definition of elements but is predominantly a blur. When the infant reaches 8 weeks their vision can define some shapes and details, but everything is still not clear. By 3 months the infant can recognize detailed shapes, forms, depth and definition of color. At 6 months the infants full vision defines small details and coloring.http://www.tinyeyes.com/tinyeyes/tryit2.php

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Physical Observations

Reasons to see an ophthalmologist:

• Visible features of the eye such as changes in the lid (hanging lids),

• Opaqueness in the cornea, • Pupil irregularities (grayish white coloring), • Twitching eyes, • Shyness to light or • Abnormally large eyes

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Examples of Physical Observations

Drooping eyelid which obscures the pupil.

Obvious abnormalities in the shape or structure of the eyes.

Absence of a clear, black pupil, i.e. cataracts.

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Tilts or turns head in certain positions when looking at an object (i.e. nystagmus, myopia, hemianopsia).

Unusual Gaze or Head Positions

Holds objects close to eyes (i.e. myopia, Stargardt's, albinism).

Averts gaze or seems to be looking beside, under or above the object of focus (i.e. retinitis pigmentosa, hemianopsia, Stargardt's).

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Types of Eye Diseases

• Myopia• Cataracts• Glaucoma• Macular Degeneration / Stargardt’s• Albinism• Retinopathy of Prematurity• Cortical Visual Impairment• Nystagmus• Other Eye Diseases

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Myopia

Nearsightedness or myopia, occurs when light entering the eye focuses in front of the retina instead of directly on it. This is caused by a cornea that is steeper, or an eye that is longer, than a normal eye. Nearsighted people typically see well up close, but have difficulty seeing far away. Many children with myopia fall into the progressive myopia camp. This means that their myopia, or nearsightedness, will only get worse over time. Understandably, many parents would like to slow the progression of their child's myopia, especially if they are highly myopic themselves.

MyopiaNormal Vision

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Cataract

A clouding of the normally clear lens of the eye. It's like trying to see through a frosty or fogged-up window. Cataracts commonly affect distance vision and cause problems with glare.

Normal Eye

Cataract Eye Normal Vision Cataract Vision

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Glaucoma

A condition of increased fluid pressure inside the eye. The increased pressure causes compression of the retina and the optic nerve which can eventually lead to nerve damage. Glaucoma can cause partial vision loss, with blindness as a possible eventual outcome. Congenital glaucoma requires immediate treatment. Symptoms associated with Glaucoma in infants and children are redness and watering, enlargement of the eyes, corneal clouding and photophobia (aversion to light).

GlaucomaNormal Vision

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Macular Degeneration / Stargardt’s

Macular Degeneration - a disease that breaks down the macula, the light-sensitive part of the retina responsible for the sharp, direct vision needed to read or drive. Juvenile macular degeneration (JMD) is a broad term used to describe several eye disorders that primarily affect infants. An inherited disorder, caused by mutated genes.

Stargardt's disease is the most common type of JMD. Symptoms usually develop between the ages of 7 and 12, although some people do not experience visual impairment until their 30s or 40s. Manifestation of Stargardt’s includes yellow spots composed of the pigment lipofuscein, scarring of the macula, and central vision loss.

Normal Vision Macular Degeneration

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Vision problems in albinism result from a lack of pigment in the eyes (retina), hair and skin. This is usually associated with decreased visual acuity, nystagmus and light sensitivity. Visual acuities may highly vary.

Albinism

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Retinopathy of Prematurity

Retinopathy of Prematurity (ROP) causes a disease of the retina. It affects prematurely born babies. It consists of abnormal retinal vessels that grow mostly in an area where normal vessels have not yet grown in the retina (Fig. 20). ROP is divided into stages 1 to 5.

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Cortical Visual Impairment (CVI)

Cortical Visual Impairment (CVI) is a temporary or permanent visual impairment caused by the disturbance of the posterior visual pathways and/or the occipital lobes of the brain. The degree of vision impairment can range from severe visual impairment to total blindness. The degree of neurological damage and visual impairment depends upon the time of onset, as well as the location and intensity of the insult. It is a condition that indicates that the visual systems of the brain do not consistently understand or interpret what the eyes see. The presence of CVI is not an indicator of the child's cognitive ability.

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Involuntary rhythmic or jerky eye movements: “Pendular nystagmus is thought to be a result of a delay in messages to the brainstem {Glaser, 1990}. It can be congenital or acquired and is characterized by eye movements that are equally paced in each direction.”

Involuntary rhythmic or jerky eye movements.

Jerk Nystagmus: “Jerk nystagmus is characterized by an obvious FEM (fast eye movement) in one direction and a slower movement in the opposite direction.”

Nystagmus

http://www.youtube.com/watch?feature=endscreen&v=yAe6r_-5Pfw&NR=1

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Amblyopia: Also known as lazy eye loss of visual acuity in one eye caused by lack of use of that eye in early childhood.

Strabismus: Also known as "cross eyes." One or both eyes turn in, out, up or down, independent of the other eye. (NERF) - The condition in which binocular fixation is not present under normal seeing conditions, i.e. the line of sight of one eye does or does not intersect the other at the object of fixation. Also commonly referred to as "crossed eyes."

Amblyopia / Strabismus