Lattice degeneration is a relatively common condition affecting the eye that involves a localized thinning of the retina’s outer edges. This change occurs in the far periphery of the light-sensitive tissue lining the back of the eye, which is responsible for converting light into neural signals. The condition is estimated to affect approximately 6% to 10% of the general population and is often discovered incidentally during a routine eye examination. Although the term “degeneration” sounds concerning, the condition itself rarely causes symptoms in its early stages and is minimally progressive. It is medically significant because it creates a structural weakness that elevates the risk for a serious complication.
Defining Lattice Degeneration
Lattice degeneration is characterized by distinct, oval or linear patches of tissue atrophy in the peripheral retina. These lesions represent areas where the retinal tissue has become significantly thinner, sometimes with associated pigment clumping. The underlying pathology involves a reduction in the retina’s outer layers, coupled with a loss or sclerosis of the associated blood vessels within the area.
The condition earns its name from the appearance of fine, crisscrossing white lines that are sometimes visible within the lesions. These lines are actually the walls of blood vessels that have become sclerosed, or hardened, giving the area a distinctive lattice-like pattern when viewed by a specialist. These thinned areas are located at the anterior-most part of the retina, near the junction with the ciliary body.
The Primary Risk: Retinal Detachment
The main concern associated with lattice degeneration is its potential to lead to a rhegmatogenous retinal detachment. This complication is a result of the abnormal adhesion between the eye’s internal gel, the vitreous, and the weakened retinal tissue. The vitreous gel normally fills the center of the eye and is attached to the retina, but it liquefies and shrinks with age, a process known as posterior vitreous detachment (PVD).
During the PVD process, the shrinking vitreous gel can pull on the retina where it is abnormally adhered, particularly at the margins of the lattice lesions. This traction can mechanically tear the weakened retina, creating a horseshoe-shaped retinal tear. Once a tear or a small atrophic hole forms, liquefied vitreous fluid can pass through the opening and accumulate beneath the retina, lifting it away from the underlying tissue.
Although lattice degeneration is found in up to 30% of eyes that experience a spontaneous retinal detachment, the lifetime risk for any individual with the condition is relatively low, estimated to be less than 1%. The formation of a tear or hole in a lattice lesion is what allows fluid to separate the neurosensory retina from its blood supply, which is the definition of a detachment.
Diagnosis and Patient Monitoring
Lattice degeneration is asymptomatic and typically diagnosed during a comprehensive eye examination using a specialized technique called indirect ophthalmoscopy. The eye doctor will administer dilating drops to widen the pupil, allowing a full view of the peripheral retina where these lesions reside. A procedure called scleral depression may also be used, which gently indents the eye wall to bring the far edges of the retina into view for thorough inspection.
The presence of lattice degeneration is more common in individuals with high myopia, or nearsightedness. Patients diagnosed with this condition must be educated on the subtle but urgent warning signs that indicate a complication has developed. These signs include the sudden onset of new floaters (dark specks or strands that drift across the vision) or the appearance of flashes of light, known as photopsia.
A more advanced sign of retinal detachment is the perception of a shadow or a curtain obscuring part of the peripheral vision, indicating that the retina has physically peeled away from the eye wall. Recognizing these symptoms and seeking immediate care is paramount, as prompt treatment of a retinal tear or early detachment significantly improves the visual outcome.
Treatment Considerations
For the majority of patients with incidentally discovered lattice degeneration, the primary management strategy is careful monitoring rather than immediate intervention. Since the risk of detachment is low, most cases remain stable and do not require treatment. Regular dilated eye examinations are scheduled to monitor the lesions for any changes or new complications.
Prophylactic treatment, such as laser photocoagulation or cryotherapy, is reserved for specific, higher-risk circumstances. Laser photocoagulation involves applying a precise thermal burn around the perimeter of the lesion or tear, creating a strong adhesive scar that acts as a barrier. Cryotherapy uses a freezing probe applied to the outside of the eye to achieve a similar “weld” between the retina and the underlying tissue.
This preventive barrier treatment is typically considered only if the lattice is associated with a retinal tear, or if the patient has a history of retinal detachment in the other eye. The goal of these procedures is to seal the weakened area and prevent liquefied vitreous fluid from passing through, thereby limiting the chance of a vision-threatening detachment.