Retinal Detachment

Edited by Assaad Sayah, M.D., Director of EMS, Clinical Instructor, Harvard Medical School, Emergency Department, Brigham and Women's Hospital

Author Email:	Gregory Luke Larkin, MD MS MSPH
Editor's Email:	Assaad Sayah, M.D.

Topic Status		Editing Status
Last Modified	Completed	Format	Medical	Pharmacy	Grammar	CME	Final
11/29/1997 03:53:06	11/29/1997

INTRODUCTION

Background: HISTORY

Retinal detachment was first recognized and described in gross pathologic examination in the early 17001s by de Saint-Yves. Clinical recognition did not occur until 1817 by Beer but the actual diagnostic techniques were not refined until Helmholtz1s invented the ophthalmoscope in 1851. In 1889 Deutschmann treated the first retinal break. It was not until the 19201s that this previously uniform cause of blindness found effective treatment through the dedication and studies of Jules Gonin MD, of Lusanne, Switzerland. Now considered the 3father2 of retinal detachment. Since Gonin surgical repair of RD1s has advanced with the development of scleral buckling, intravitreal gas , laser and cryotherapy techniques and microscopic intraocular approaches so that when diagnosed and treated in an expedient manner visual loss from RD1s can be eliminated or dramatically reduced

Pathophysiology: PATHOPHYSIOLOGY

Retinal detachment is the sole result of subretinal fluid separating the sensory retina from the underlying retinal pigment epithelium (RPE). No one disease process is responsible . It is a result of numerous conditions including congenital malformation, metabolic disorders, traumatic changes (including previous ocular surgery), vascular disease, high myopia or vitreous disease or degeneration.

There are three types of retinal detachment: rhegmatogenous, exudative and tractional. Rhegmatogenous RD is the most common type of retinal detachment, the term is derived from the word rhegma meaning rent or break. Vitreous fluid enters the break and separation the sensory retina from the RPE resulting in detachment. Exudative or serous detachment are a result of a process producing subretinal fluid and detachment without a break in the retina. The etiologic factors are usually tumor growth or inflammation. Tractional retinal detachment occurs as a result of adhesions between the vitreous gel and the retina . Mechanical forces cause the separation of the retina from the RPE without a retinal break. Advanced adhesion may result in the development of a tear or break. The most common causes of tractional RD are proliferative diabetic retinopathy, sickle cell disease, advanced retinopathy of prematurity and penetrating trauma.

Frequency:

• In the U.S.: EPIDEMIOLOGY Although 6% 0f the general population have retinal breaks most of these are benign atrophic holes which without accompanying pathology do not lead to retinal detachment. The incidence of retinal detachment is one in 15,000 people for the general population with a prevalence of 0.3% in the US. Certain groups have higher prevalence. Patients with high myopia (>6 diopters which is more common in males) have 5% risk, individuals who are aphakic (cataract removal without lens implant) have a 2% risk. Cataract extraction complicated by vitreous loss during surgery have an increase detachment rate to 10%. Retinal detachment occurs most common between ages 40 and 70. Males have a 60% rate of detachment . The incidence is unchanged even when corrections for the higher rate of ocular trauma in men is considered.
• Internationally: The most common worldwide etiologic factors associated with RD are myopia, both aphakia (cataract removal without lens implant) and pseudophakia (cataract removal with lens implant) and trauma. Forty to fifty percent of all detachments have myopia (near sighted), 30 to 40% have undergone cataract removal and 10 to 20% have encountered direct ocular trauma. Traumatic detachments are more common in the young and myopic detachment occurs most commonly between the age of 25 to 45 years. Although there are no studies to estimate the incidence of RD related to contact sports there are specific sports which involve have noted increased risk of RD such as boxing and bungee jumping.

History: CLINICAL FACTORS Symptoms 1. Photopsia (the perception of flashing light). 2. Floaters 3. Visual field defect 4. Decreased visual acuity 5. Metamorphopsia (wavy distortion of an image) Photopsia is caused by the pathologic stimulation of the retina and production of phosphenes. Retinal tissue is stimulated by light but also responds to mechanical disturbances. Flashing lights are most commonly caused by separation of the posterior vitreous. As the vitreous gel separates from the retina it stimulates the retinal tissue mechanically resulting in the release of phosphenes and the sensation of light. Posterior vitreous detachment is usually a benign process but 12% of symptomatic detachment will reveal a peripheral tear. The patients location of the light sensation in their visual field has no correlation to the location of a retinal tear within the eye. Floaters are a very common visual symptom in the general population. This is where the patient needs to be specific in their description. The sudden onset of one large floater in the center of the visual axis indicates posterior vitreous detachment (PVD). A circular like floater is observed by the patient when the vitreous detaches from its annular ring surrounding the optic nerve. Numerous curvilinear opacities indicate vitreous degeneration which is considered a normal aspect of a mature eye. Red flags go up when the patient describes hundreds of tiny black specks occurring before their eye. This is pathognomonic for vitreous hemorrhage. The vitreous hemorrhage results from disruption of a retinal vessel due to a retinal tear or mechanical traction of a vitreoretinal adhesion. A few hours after the initial shower of black spots the patient will note ²cobwebs² that result from the blood forming irregular clots. New onset of floaters associated with flashing lights indicates a retinal tear until proven otherwise. Visual field defects are a late symptom of retinal detachment. While symptoms of photopsia and floaters are not helpful in locating the position of the retinal tear or detachment the visual field defect is very specific for locating the detachment. Detachments anterior to the equator of the eye can not be detected with visual field testing. Detachment posterior to the equator can be isolated with visual field testing but the patient usually is unaware of a defect until it involves the posterior pole and macula. A patient will be less aware of a superior field defect (indicating an inferior detachment) than an inferior field defect (indicating a superior retinal detachment). Inferior retinal detachment can be a long standing condition that progresses without symptoms until the detachment reaches the fovea. Bullous (large ballooning) detachments produce dense visual field defects(blackness) and flat detachments produce relative field defects (grayness). When a patient is found to have an extensive detachment it is helpful to inquire as to the initial symptoms of the visual field loss to assist in localization of the tear. The onset of decreased visual acuity dates the duration of fovea involvement of the detachment which correlates with the prognosis for recovery of the central vision. Metamorphopsia is distortion of a visual image commonly described by patients as waviness. It is a result of fluid disrupting the normal position of the retina within the macular area. A history of trauma must be inquired about whether it occur several months prior to symptoms or coincided with the onset of symptoms.. Documentation of head or ocular trauma may be subject to legal investigation. Previous surgery must be noted including cataract extraction, intraocular foreign body removal, and retinal procedures. The patients eye history can be very helpful. Question the patient about previous conditions as uveitis, vitreous hemorrhage, amblyopia, glaucoma and diabetic retinopathy. Systemic diseases associated with retinal detachment include diabetes, tumors (breast cancer and melanoma), angiomatosis of the CNS, sickle cell disease, leukemia, eclampsia, and prematurity. Usually RDıs are sporadic events but certain pedigrees may be prone to detachment so inquire into family history of eye disease.

Physical: Physical Examination 1. Visual acuity, correcting for refractive error 2. External exam for signs of trauma 3. Visual field (usually confrontation field exam is adequate ) 4. Pupil reaction ( a fixed, dilated pupil may indicate previous trauma, a positive Marcus-Gunn pupil will occur with any disturbance of the afferent pupillomotor pathway including RD) 5. Slit lamp Biomicroscopy: The anterior segment is usually normal . The vitreous is examined for signs of pigment or ³tobacco dust² (termed Shaferıs sign) which is pathognomonic for retinal tear in 70% of cases with no pervious eye disease or surgery. 6. Intraocular pressure measurement in both eyes. (Hypotony of at least 4 to 5 mm Hg less than the fellow eye is common). 7. Fundus Examination with Ophthalmoscopy: The pupils must be dilated. Indirect ophthalmoscopy is the definitive means of diagnosing RD with the use of scleral depression. Direct ophthalmoscopy may detect vitreous hemorrhage and large detachment of the posterior pole but are inadequate for complete examination because of the lower magnification and illumination, lack of stereopsis and limited view of the peripheral retina. Three mirror contact lens exam with a slit-lamp may accomplish adequate examination without scleral depression. Obvious detachment is seen as marked elevation of the retina which appears gray with dark blood vessels that may lie in folds. The detached retina may undulate. Shallow detachments are much more difficult to detect. It is helpful to compare the area suspected with an adjacent normal quadrant to detect any change in retinal transparency, stereopsis is necessary. An orange peel appearance of the retinal surface can occur. The limit of a detachment may be demarcated by a pigmented or nonpigmented line. Scleral depression is necessary to identify the location of a retinal tear or hole.

Causes:
Other Problems to be Considered:

DIFFERENTIAL DIAGNOSIS

Rhegmatogenous Retinal Detachment 1. Posterior vitreous detachment 2. Peripheral retinal lesions Enclosed oral bays Meridional folds Cystic retinal tufts Lattice degeneration 3. Myopia 4. Senile retinoschisis 5. Cataract extraction 6. Trauma 7. Intraocular inflammation/infection Acute retinal necrosis syndrome Cytomegalovirus retinitis Ocular toxocariasis Ocular toxoplasmosis Pars planitis 8. Colobomas of the choroid and retina 9. Coloboma of the lens (giant retinal tear) 10. Sticklers syndrome 11. Goldmann-Favre Syndrome 12. Marfanıs Syndrome 13. Homocystinuria 14. Ehlers-Danlos Syndrome

Tractional Retinal Detachment

1. Proliferative diabetic retinopathy 2. Sickle cell disease (Hemoglobin SC and Hemoglobin S-thallassemia) 3. Familial Exudative Vitreoretinopathy 4. Retinopathy of prematurity 5. Penetrating trauma with vitreous bands 6. Cataract surgery with vitreous loss

Exudative Retinal Detachment

1.Primary Tumors Malignant melanoma of the choroid Hemangioma of the choroid Retinoblastoma 2. Metastatic carcinoma to the choroid Breast or lung disease 3.Inflammation Choroiditis (Haradaıs disease) Retinitis (toxoplasmosis, CMV) 4.Vascular Disease Angiomatosis of the retina (von Hippelıs disease) Telangiectasia retina Juvenile Coatıs disease Adult Coatıs disease Ealeıs disease Retinal vein occlusion 5. Optic nerve disease Pit of the optic disc with serous detachment of the macula Nerve head drusen with serosanguinous detachment of adjacent retina Leberıs stellate maculopathy 6. Macular disease Central serous choroidretinopathy Age related macular degeneration Other causes of disceform detachment Presumed ocular histoplamosis Angioid streaks High myopia (>6 diopters) 7. Systemic diseases Toxemia Uremia Lupus erythematosus Leukemia Lesions that may simulate retinal detachment 1. Vitreous Membranes Hemorrhages Inflammation 2. Retinal Primary retinoschisis Juvenile Degenerative Secondary retinoschisis Retinopathy of prematurity Diabetic retinopathy Retinal artery occlusion (mainly branch retinal artery occlusion) 3. Choroidal detachment Serous Hemorrhagic

WORKUP

Lab Studies:

• There are no laboratory test that will diagnosis retinal detachment. Subsequent testing may be necessary to detect underlying causes.

Imaging Studies:

• Imaging techniques such as orbital films, CT or MRI scanning are not necessary or indicated to diagnose retinal detachment but may be necessary to detect intraocular foreign bodies and tumors. If the retina can not be visualized because of corneal changes, cataracts or hemorrhage ultrasonography is necessary. Both A and B scan ultrasound can diagnose RD and differentiate it from posterior vitreous detachment as well as differentiating rhegmatogenous from nonrhegmatogenous detachment. In exudative detachments the presents of underlying subretinal tumors, choroidal hemorrhage or detachment can be detected by ultrasound.

Emergency Department Care: ED treatment of retinal detachment consist solely of evaluating the patient. When diagnosed or highly suspected retinal detachment requires ophthalmologic consultation to confirm the diagnosis and treat the cause. Retinal consultation may even be necessary.

• Repair technique is dependent on the type, location, and size of the detachment. Laser therapy and cryotherapy are ambulatory outpatient procedures. The use of intraocular gas (pneumatic retinopexy) to tamponade the detachment can also be done as an outpatient with close follow up of intraocular pressure. Scleral buckling is possible as an outpatient procedure in which a silicone band indents the eye to approximate the retina and RPE and the tear is closed with supplemental cryotherapy or laser. Intraocular repair with vitrectomy may be necessary in complicated tractional and exudative detachments. This procedure once required hospitalization but is now being done as an outpatient or as a short stay arrangement due to insurance restrictions. Inflammatory retinal detachments are usually treated medically.

Further Inpatient Care:

• Immediate ophthalmologic referral is mandatory.

Transfer:

• In some cases, transfer to a facility with an ophthalmologist or retinal specialist available will be in the patient's best interest after initial ophthalmologic evaluation. These decisions should be made in concert with the patient's wishes and the ophthalmologic consultant.

Complications:

• Blindness is the most obvious complication of a retinal detachment. Loss of vision to hand-motion or light perception is also a frequent complication of RDs that involve the macula (see above).

Prognosis:

• The ultimate outcome depends on the time, the type of RD and whether it involves the macula. The prognosis is inversely related to the degree of macular involvement and the length of time the retina has been off.

CME Question 1: 1. An acute, nonmacular, rhegmatogenous retinal detachment is an ocular emergency requiring repair within what time frame?

A: 0-90 minutes
B: 2-4 hours
C: 6-12 hours
D: within 24 hours
E: within 48 hours

CME Question 2: Which of the following occur most commonly in association with a retinal detachment of a phakic (lens present) eye.

A: a. light flashes
B: b. vitreous hemorrhage
C: c. pigmented granules in the vitreous
D: d. cells in the anterior chamber
E: e. a history of blunt trauma