Aphakia is the absence of the lens of the eye, due to surgical removal, such as in

cataract surgery Cataract surgery, also called lens replacement surgery, is the removal of the natural lens of the eye (also called "crystalline lens") that has developed an opacification, which is referred to as a cataract, and its replacement with an intra ...

, a perforating wound or ulcer, or

congenital A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can ...

anomaly. It causes a loss of accommodation, high degree of farsightedness ( hyperopia), and a deep anterior chamber. Complications include detachment of the

vitreous Vitreous may refer to: Materials * Glass, an amorphous solid material ** Vitreous enamel, a material made by fusing powdered glass to a substrate by firing * Vitreous lustre, a glassy luster or sheen on a mineral surface Biology * Vitreous bod ...

retina The retina (from la, rete "net") is the innermost, light-sensitive layer of tissue of the eye of most vertebrates and some molluscs. The optics of the eye create a focused two-dimensional image of the visual world on the retina, which the ...

, and

glaucoma Glaucoma is a group of eye diseases that result in damage to the optic nerve (or retina) and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for aqueous humor, fluid withi ...

. Babies are rarely born with aphakia. Occurrence most often results from surgery to remove congenital cataract. Congenital cataracts usually develop as a result of infection of the fetus or genetic reasons. It is often difficult to identify the exact cause of these cataracts, especially if only one eye is affected. People with aphakia have relatively small pupils and their pupils dilate to a lesser degree.

Causes

Surgical removal of a lens, mainly in cataract surgery, is the most common cause of aphakia. Spontaneous traumatic absorption or congenital absence of lens matter is rare. Traumatic subluxation or dislocation of a lens may cause it.

Signs and symptoms

* Hypermetropia: Without the focusing power of the lens, the eye becomes very farsighted. * Loss of accommodation: Since the lens and its zonules are responsible for adjusting the focus of vision to different lengths, patients with aphakia will have a total loss of accommodation. * Defective vision: High degree hypermetropia and total loss of accommodation cause defective vision for both distance and near. * Cyanopsia: Absence of lens cause cyanopsia or blue vision. Some individuals have said that they perceive ultraviolet light, invisible to those with a lens, as whitish blue or whitish-violet. * Erythropsia: Sometimes, objects appear reddish. * Deep anterior chamber: Since lens is absent, anterior chamber will be deep. * Iridodonesis: Iridodonesis is the vibration or agitated motion of the iris with eye movement. * Purkinje test shows only two images; the reflection from anterior and posterior corneal surfaces. * Iridectomy mark may be seen in surgical aphakia. *

Astigmatism Astigmatism is a type of refractive error due to rotational asymmetry in the eye's refractive power. This results in distorted or blurred vision at any distance. Other symptoms can include eyestrain, headaches, and trouble driving at n ...

: With-the-rule astigmatism due to corneal wound healing may occur in surgical aphakia, mainly after ICCE or ECCE.

Complications

Main complications of surgical aphakia include: * Spectacle intolerance: Due to image

magnification Magnification is the process of enlarging the apparent size, not physical size, of something. This enlargement is quantified by a calculated number also called "magnification". When this number is less than one, it refers to a reduction in si ...

(up to 30%),

optical aberration In optics, aberration is a property of optical systems, such as lenses, that causes light to be spread out over some region of space rather than focused to a point. Aberrations cause the image formed by a lens to be blurred or distorted, with t ...

, prismatic effect and roving ring scotoma, spectacles are not well tolerated by aphakic patients. Due to high anisometropia, spectacle correction in uniocular aphakia may cause

diplopia Diplopia is the simultaneous perception of two images of a single object that may be displaced horizontally or vertically in relation to each other. Also called double vision, it is a loss of visual focus under regular conditions, and is often v ...

. * Glaucoma: Secondary angle closure glaucoma may occur due to vitreous prolapse. * Retinal detachment * Aphakic bullous keratopathy

Treatment

Aphakia can be corrected by wearing

glasses Glasses, also known as eyeglasses or spectacles, are vision eyewear, with lenses (clear or tinted) mounted in a frame that holds them in front of a person's eyes, typically utilizing a bridge over the nose and hinged arms (known as temples ...

, contact lenses, artificial lens implantation, or refractive corneal surgeries. Eye with artificial lenses are described as " pseudophakic".

Etymology

Gr. ''a-'' alfa priv + ''phakos'', lens, anything shaped like a lensaphakia. (n.d.) Farlex Partner Medical Dictionary. (2012). Retrieved April 13, 2016 from http://medical-dictionary.thefreedictionary.com/aphakia

References

External links

{{Congenital malformations and deformations of eye, ear, face and neck Congenital disorders of eyes Disorders of lens