Key Ocular Signs for Screening:
Examples of signs found in eye images

Contents of This Document

Signs in Conjunctiva Images
Signs in Iris Images Signs in Corneal and Limbus Images Signs in Sclera Images
Signs in Eyelid Images


Signs in Conjunctiva Images
Example Images)


A pinguecula is often referred to as a fatty degeneration of the conjunctival tissue, but it may also reflect deposits of lipids from serous exudate. The fine, nearly transparent collagen fibers of the conjunctiva degenerate and are replaced by thicker, yellowish, more durable fibers and sometimes calcium crystals. This causes the elevated, yellow and sometimes whitish glistening area located near the cornea. There is no effect on vision by a pinguecula, which can appear after only a brief exposure to damaging irritation, such as excessive dryness or sun (ultraviolet radiation). The tissue damage increases with continued exposure. It might take only a day or two to notice a new pinguecula but weeks or months for it to resolve. Removing the source of irritation and providing artificial lubricating drops may shrink and eliminate pingueculae in their early stages; however, long-standing pingueculae do not respond well to treatment and may be permanent. Pinguculae may indicate vitamin A deficiency.

Example of Pinguecula:

© Image from Photo Library of Jon Miles


A pterygium, although produced in a similar way as a pinguecula, often has inflammed blood vessels infusing into it. A pterygium does not emerge from a pinguecula. Unlike a simple pinguecula, a pterygium often is progressive and will involve the cornea if left unchecked. It is triangular in shape, with the base of the triangle located in the conjunctiva and the apex of the triangle encroaching onto the cornea. With corneal involvement, even if arrested surgically, a pterygium can affect vision by warping the surface of the cornea and inducing astigmatism, and/or by actually growing over in front of the pupil and obstructing the entering light. Removing the source of irritation and providing artificial lubricating drops may slow down or halt the growth of pterygia; however, sometimes surgical intervention is necessary to prevent a further decrease in vision.

Example of Pterygium:

© Image from Photo Library of Jon Miles

Bitot Spots

Bitot spots are superficial, irregularly-shaped, foamy gray or white patches that appear on the conjunctiva, the membrane that covers most of the eyeball. Bitot spots are one of the oldest recorded medical conditions. The ancient Egyptians treated this condition with animal liver more than 3500 years ago. Composed of accumulation of keratinized epithelial debris and secretions, Bitot spots develop into a condition called xerophthalmia if not treated. Bitot spots are usually accompanied by night blindness. Eye ulcers develop and the cornea turns to mush (melts) if Bitot spots are not treated. This can result in irreversible blindness. This is an example of an ocular manifestation of a systemic disease.

Bitot spots are most likely due to severe vitamin A deficiency. Bitot spots are also known to occur in people with fat and vitamin malabsorption. Total blindness caused by tissue death due to a severe vitamin A deficiency cannot be treated.

Example of Bitot Spots:


Dry Eye (Xerophthalmia)

Xerophthalmia is extreme dryness and thickening of the conjunctiva, often resulting from a deficiency of vitamin A. Reported incidence of xerophthalmia is rapidly increasing. Xerophthalmia can be associated with systemic diseases such as Sjögren' s syndrome, systemic lupus erythematosus, rheumatoid arthritis, scleroderma, sarcoidosis, amyloidosis, and hypothyroidism; and deficiency of vitamin A. Xerophthalmia results from inadequate function of the lacrimal glands which produce tears. When xerophthalmia is due to vitamin A deficiency, the condition begins with night blindness and conjunctival xerosis (dryness of the eye membranes) and progresses to corneal xerosis (dryness of the cornea), and, in the late stages, to keratomalacia (softening of the cornea). Vitamin A deficiency (with xerophthalmia) is associated with malnutrition and diahrrea and is the major cause of blindness in children.

Example of Xerophthalmia:


Horner-Trantas Dots

Small, white-yellow chalky concretions of the conjunctiva around the limbus. These are associated with vernal conjunctivitis.

Example of Horner-Trantas Dots:


Abnormal Vascular Topography

Studies of the vessel configuration in the bulbar conjunctiva have shown that abnormal vessel topography is an indicator of various cardiovascular diseases.

Example of Vessel Coiling:

© Image from Photo Library of Jon Miles

Arteriolar Narrowing

Arteriolar narrowing in the conjunctiva is an established indicator of hypertension, including subclinical cases (patients that are pre-symptomatic).

Example of Arteriolar Narrowing:

© Image from Photo Library of Jon Miles

Signs in Iris Images

Lisch Nodules

Lisch nodules are melanocytic hamartomas, usually clear yellow to brown, that appear as well defined, dome shaped elevations projecting from the surface of the iris. They may be seen without magnification but a slit lamp examination may be necessary to distinguish them from naevi on the iris which present as flat or minimally elevated, densely pigmented lesions with blurred margins. The nodules are thought not to cause any ophthalmologic complication.

Lisch nodules are the most common clinical finding in adults over 20 years of age with type I neurofibromatosis (NF-1). Unlike cafe au lait spots, multiple nodules are specific for peripheral neurofibromatosis - Von Recklinghausen disease. They may occur in segmental neurofibromatosis which is due to a somatic mutation of the NF-1 gene but are generally absent in central neurofibromatosis. In children, nodules are a more likely finding than neurofibromas. This is an example of an ocular manifestation of a genetic disease. NF-1 has been mapped to a gene defect in chromosome 17.

Example of Lisch Nodules:


Wolfflin Spots

Wolfflin spots are the whitish clumps of connective fibers found in some irides (mostly blue) near the periphery. These are somewhat distinct from Brushfield spots.

Example of Wolfflin Spots:

© Image from Photo Library of M. H. Lopp, OD

Brushfield spots

Brushfield spots are a type of iris feature that is found in 90% of patients having Down syndrome.

Example of Brushfield spots:


Bilateral Heterochromia

If one iris has less color or texture than the other eye, or is relatively greyish, Fuch's Heterochromic Cyclitis may be present.

Example of Bilateral Heterochromia:

© Image from Photo Library of Jon Miles

Gray Iris

A gray iris is often an indication of cyclitis or uveitis.

Example of Gray Iris:

© Image from Photo Library of Jon Miles

Central Heterochromia

Central Heterochromia is where the central (pupillary) zone of the iris is a darker color than the mid-peripheral (ciliary) zone, and may be linked to above average toxic burden in the body.

Example of Central Heterochromia:

© Image from Photo Library of Jon Miles

Sectoral Heterochromia

Sectoral Heterochromia is an inherited trait and may have clinical significance.

Example of Sectoral Heterochromia:

© Image from Photo Library of Jon Miles

Iris Hypoplasia

Iris hypoplasia is a prevalence of fiber separations in the stroma. It is associated with various connective tissue disorders.

Example of Iris Hypoplasia:

© Image from Photo Library of Jon Miles

Signs in Corneal and Limbus Images

Corneal Arcus

Corneal arcus is the appearance of a white deposit in the cornea near the periphery, often greater in the superior sectors. It is indicative of hypercholesterolemia (high levels of serum cholesterol) among those under the age of 60. Above 60 it is relatively common in both hypertensive and normotensive patients; among blacks, it tends to appear 10 years earlier.

Example of Corneal Arcus:

© Image from Photo Library of Jon Miles

Kayser-Fleischer Ring

This is sometimes referred to as a "copper ring" since it appears as a brownish-green copper deposit on the inside surface of the peripheral cornea. It is associated with Wilson disease, a failure to metabolize copper properly. The upper pole is affected more frequently than the lower. Kayser-Fleischer rings are noted in 90% of patients with Wilson disease and occasionally, in patients with prolonged cholestasis or cryptogenic cirrhosis. The ring is noted most easily in patients with blue eyes. In other patients, slit-lamp examination may be required. A corresponding gene defect has been mapped to chromosome 13. This is an example of an ocular manifestation of a genetic disease.

Example of Kayser-Fleischer Ring:


Corneal Neovascularization

Corneal neovascularization is thought to be stimulated by tissue hypoxia, and is detectable in frontal ocular images.

Example of Corneoscleral Neovascularization:

© Image from Photo Library of Jon Miles

Signs in Sclera Images

Conjunctival Vessel Inflammation

Conjunctivitis is readily detected in images.

Example of Conjunctival-scleral Inflammation:

© Image from Photo Library of Jon Miles

Pigmentary Deposits

Brown pigmentary deposits on the sclera near the corneoscleral limbus may indicate a liver disorder.

Example of Conjunctival-scleral Pigment Deposit:

© Image from Photo Library of Jon Miles

Jaundice and Liver Disorders

Jaundice (icterus) is easily detected in the whites of the eye since they tend to turn yellow. Image processing can detect these changes accurately.

Example of Jaundice:


Signs in Eyelid Images


Xanthelasma are tiny (1-2 mm) yellowish plaques that are slightly raised on the skin surface of the upper or lower eyelids. Xanthelasma is caused by tiny deposits of fat in the skin and is often associated with abnormal blood fat levels (hyperlipidemia). Xanthelasma typically appears in or near the eyelids. Under the microscope, Xanthelasma can be seen to be composed of lipid-laden foam cells. These cells, termed histiocytes, contain lipid material in their cytoplasm (the nonnuclear zone of the cell). Xanthelasma may be associated with hypercholesterolemia.

Example of Xanthelasma:



References are on a separate page.