Retinoschisis
Encyclopedia
Retinoschisis is an eye
disease characterized by the abnormal splitting of the retina
's neurosensory layers, usually in the outer plexiform layer
, resulting in a loss of vision in the corresponding visual field in some rarer forms. More common forms are usually asymptomatic.
word meaning splitting, describing the splitting of the retinal layers from each other. However, schisis is a word fragment, and the term retinoschisis should be used, as should the term iridoschisis when describing splitting of the iris. If the retinoschisis involves the macula
, then the high-resolution central area of vision used to view detail is lost, and this one form of macular disease. Although it might be described by some as a "degeneration", the term macular degeneration should be reserved for the specific disease "age-related macular degeneration".
Retinoschisis can be caused by an X-linked genetic defect, affecting the vision of men who inherit the disease from their unaffected carrier mothers. The genetic form of this disease usually starts during childhood and is called X-linked Juvenile Retinoschisis (XLRS) or Congenital Retinoschisis. Affected males are usually identified in grade school, but occasionally are identified as young infants.
Very few affected individuals go completely blind
from retinoschisis, but some sufferers have very limited reading vision and are "legally blind". Visual acuity can be reduced to less than 20/200 in both eyes. Individuals affected by XLRS are at an increased risk for retinal detachment and eye hemorrhage, among other potential complications.
Retinoschisis causes acuity loss in the center of the visual field through the formation of tiny cyst
s in the retina, often forming a "spoke-wheel" pattern that can be very subtle. The cysts are usually only detectable by a trained clinician. In some cases vision cannot be improved by glasses
, as the nerve tissue itself is damaged by these cysts.
The National Eye Institute (NEI) of the National Institutes of Health (NIH) is currently conducting clinical and genetic studies of X-Linked Juvenile Retinoschisis. This study is currently recruiting patients. A better understanding of why and how XLRS develops might lead to improved treatments. Males diagnosed with X-linked juvenile retinoschisis and females who are suspected carriers may be eligible to participate. In addition to giving a medical history and submitting medical records, participants submit a blood sample and the NEI will perform a genetic analysis. There is no cost to participate in this study.
a) The vitreomacular traction syndrome; b) Proliferative diabetic retinopathy with vitreoretinal traction; c) Atypical cases of impending macular hole.
followed by vitrectomy and gas injection followed by face-down positioning is very effective in treating this condition.
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
disease characterized by the abnormal splitting of the retina
Retina
The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...
's neurosensory layers, usually in the outer plexiform layer
Outer plexiform layer
The outer plexiform layer is a layer of neuronal synapses in the retina of the eye. It consists of a dense network of synapses between dendrites of horizontal cells from the inner nuclear layer, and photoreceptor cell inner segments from the outer nuclear layer...
, resulting in a loss of vision in the corresponding visual field in some rarer forms. More common forms are usually asymptomatic.
Classification
- Degenerative
- Typical
- Reticular
- Hereditary
- X linked juvenile retinoschisis
- Familial foveal retinoschisis
- Tractional
- Exudative
- Secondary to Optic disc pit
Degenerative Retinoschisis
This type of retinoschisis is very common with a prevalence of up to 7 percent in normal persons. Its etiology is unknown. It can easily be confused with retinal detachment by the non-expert observer and in difficult cases even the expert may have difficulty differentiating the two. Such differentiation is important since retinal detachment almost always requires treatment while retinoschisis never itself requires treatment and leads to retinal detachment (and hence to visual loss) only occasionally. Unfortunately one still sees cases of uncomplicated retinoschisis treated by laser retinopexy or cryopexy in an attempt to stop its progression towards the macula,. Such treatments are not only ineffective but unnecessarily risk complications. There is no documented case in the literature of degenerative retinoschisis itself (as opposed to the occasional situation of retinal detachment complicating retinoschisis) in which the splitting of the retina has progressed through the fovea. There is no clinical utility in differentiating between typical and reticular retinoschisis. Degenerative retinoschisis is not known to be a genetically inherited condition.Hereditary Retinoschisis
It is estimated that this much less common form of retinoschisis affects one in 5,000 to 25,000 individuals, primarily young males. Schisis is derived from the GreekGreek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
word meaning splitting, describing the splitting of the retinal layers from each other. However, schisis is a word fragment, and the term retinoschisis should be used, as should the term iridoschisis when describing splitting of the iris. If the retinoschisis involves the macula
Macula
The macula or macula lutea is an oval-shaped highly pigmented yellow spot near the center of the retina of the human eye. It has a diameter of around 5 mm and is often histologically defined as having two or more layers of ganglion cells...
, then the high-resolution central area of vision used to view detail is lost, and this one form of macular disease. Although it might be described by some as a "degeneration", the term macular degeneration should be reserved for the specific disease "age-related macular degeneration".
Retinoschisis can be caused by an X-linked genetic defect, affecting the vision of men who inherit the disease from their unaffected carrier mothers. The genetic form of this disease usually starts during childhood and is called X-linked Juvenile Retinoschisis (XLRS) or Congenital Retinoschisis. Affected males are usually identified in grade school, but occasionally are identified as young infants.
Very few affected individuals go completely blind
Blindness
Blindness is the condition of lacking visual perception due to physiological or neurological factors.Various scales have been developed to describe the extent of vision loss and define blindness...
from retinoschisis, but some sufferers have very limited reading vision and are "legally blind". Visual acuity can be reduced to less than 20/200 in both eyes. Individuals affected by XLRS are at an increased risk for retinal detachment and eye hemorrhage, among other potential complications.
Retinoschisis causes acuity loss in the center of the visual field through the formation of tiny cyst
Cyst
A cyst is a closed sac, having a distinct membrane and division on the nearby tissue. It may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst could go away on its own or may have to be removed through surgery.- Locations :* Acne...
s in the retina, often forming a "spoke-wheel" pattern that can be very subtle. The cysts are usually only detectable by a trained clinician. In some cases vision cannot be improved by glasses
Glasses
Glasses, also known as eyeglasses , spectacles or simply specs , are frames bearing lenses worn in front of the eyes. They are normally used for vision correction or eye protection. Safety glasses are a kind of eye protection against flying debris or against visible and near visible light or...
, as the nerve tissue itself is damaged by these cysts.
The National Eye Institute (NEI) of the National Institutes of Health (NIH) is currently conducting clinical and genetic studies of X-Linked Juvenile Retinoschisis. This study is currently recruiting patients. A better understanding of why and how XLRS develops might lead to improved treatments. Males diagnosed with X-linked juvenile retinoschisis and females who are suspected carriers may be eligible to participate. In addition to giving a medical history and submitting medical records, participants submit a blood sample and the NEI will perform a genetic analysis. There is no cost to participate in this study.
Tractional Retinoschisis
This may be present in conditions causing traction on the retina especially at the macula. This may occur in:a) The vitreomacular traction syndrome; b) Proliferative diabetic retinopathy with vitreoretinal traction; c) Atypical cases of impending macular hole.
Exudative Retinoschisis
Retinoschisis involving the central part of the retina secondary to an optic disc pit was erroneously considered to be a serous retinal detachment until correctly described by Lincoff as retinoschisis. Significant visual loss may occur and following a period of observation for spontaneous resolution, treatment with temporal peripapillary laser photocoagulationLaser photocoagulation
Laser coagulation or laser photocoagulation surgery is used to treat a number of eye diseases and has become widely used in recent decades...
followed by vitrectomy and gas injection followed by face-down positioning is very effective in treating this condition.