| TRACTIONAL RETINAL TEARS  SIGNS AND SYMPTOMS
The patient often will report a sudden onset of either a single or multiple floating
spots, along with flashing lights (photopsia). Visual symptoms will be stable within the
patient's visual field. There may be precipitating ocular or head trauma. If there is a
posterior vitreous detachment, there will also be one large floater. If there has been a
vitreous hemorrhage, there will be multiple floaters. There may be a severe loss of vision
if there is a dense vitreous hemorrhage or rhegmatogenous retinal detachment. However, in
a number of cases, the patient is either asymptomatic or experienced symptoms so long ago
that they were forgotten.
PATHOPHYSIOLOGY
Retinal tears result from the vitreous pulling free from the retina during vitreous
detachment. During the course of the PVD, the vitreous may encounter an area where it is
firmly attached to the retina. These include the optic disc, macula, along blood vessels,
vitreous base, at areas of chorioretinal scarring, along the edges of lattice
degeneration, and at vitreoretinal tufts. Traction at any one of these points may result
in the vitreous pulling the retina free from its loose attachment to the retinal pigment
epithelium with a tear developing within the sensory retina. The subsequent break in the
retina can allow liquid vitreous to enter the potential subretinal space, resulting in a
rhegmatogenous retinal detachment. If the vitreous remains attached to the damaged retina,
traction on the edges of the break can serve to further separate the retina from the RPE.
There are three types of tractional retinal tears: the flap tear, the
tear along lattice lesions, and an operculated tear. In the classic flap (or horseshoe)
tear, the retina is pulled incompletely free and forms a triangular appearance. The apex
of the tear is still attached to the mobile vitreous and points towards the posterior
pole. The base of the triangle parallels the vitreous base. The mobile vitreous acts to
further tear the retina and separate it from the RPE. If the tear bridges a blood vessel,
there can be a subsequent vitreous hemorrhage. A similar retinal tear occurs at the
posterior border of lattice lesions due to the same forces, but does not have the
triangular appearance of the flap tear. If an area of retinal tissue is pulled completely
free by the vitreous, it is considered an operculated tear. The retinal tissue, now termed
an operculum, is seen to float in the vitreous above the retinal tear.
In any case of retinal tear, if the vitreous is still attached and
exerting traction on the retina through the break, the mechanical forces on the retina
will be perceived by the patient as flashing lights. This indicates that there are forces
active on the break which may lead to further separation of the retina from the RPE. As
liquid vitreous gains access to the subretinal space, the retina is further separated from
the RPE, and a rhegmatogenous retinal detachment can form.
MANAGEMENT
The standard management of tractional tears has always been prophylactic laser
photocoagulation or cryoretinopexy. This creates an RPE hyperplastic scar around the break
and seals the retina to the RPE, thus preventing the accumulation of subretinal fluid and
subsequent rhegmatogenous retinal detachment. However, not all cases benefit from
prophylactic treatment. If the patient is aphakic or pseudophakic, has a history of
previous retinal detachment in either eye, is about to undergo ocular surgery, or if the
tear is fresh or associated with any hemorrhage, then the patient should receive
prophylactic therapy.
If the patient is symptomatic with photopsia, or if there is more than
one disc diameter of subretinal fluid or elevation extending beyond the edge of the break,
the patient needs treatment, as the risk of detachment is high. Any tractional tears along
the edge of lattice lesions also require treatment. If there are none of the above risk
factors, the patient is asymptomatic and there is no subretinal fluid, monitor the patient
on a six-week, three-month, six-month, 12-month schedule. If you see progression at any
follow up visit, have the patient receive prophylactic treatment.
CLINICAL PEARLS
- The greater the length of time a tractional tear, or any retinal break,
exists in an untreated eye without progressing to retinal detachment, the less likely the
chance that it will progress.
- Most tractional tears without symptoms or risk factors can be safely
monitored without treatment. Often, the RPE will become hyperplastic due to the insult
from the tear and form a chorioretinal scar around the break. If this happens, it becomes
very unlikely that the tear will ever lead to detachment.
- Retinal breaks located superiorly in the retina are no more likely to
progress to retinal detachment than are breaks located inferiorly in the retina. Location
of the break should not be considered when determining risk of detachment.
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