History
Patients with lattice degeneration are typically asymptomatic, and the lesions are usually an incidental finding of dilated ophthalmologic examination. A presenting complaint of blurriness in the distance may be the result of myopia, a common association with lattice degeneration. The acute onset of floaters, flashes of light, peripheral field loss, or central vision loss may indicate the presence of a retinal tear or detachment, a complication of lattice lesions. [6]
Physical
Clinical features
Lattice degeneration is characterized by oval or linear patches of atrophic retina with a reddish base and is variably located within the equatorial region of the fundus, typically inferotemporal. [2]
Lesions may be isolated or multifocal, variable in dimension, and usually are oriented concentric or slightly oblique to the ora serrata.
Condensed vitreous at the margins of the lattice lesions may appear as vitreous opacities and represent regions of increased vitreoretinal adhesion; overlying vitreal opacities alternatively may be explained by glial proliferation. [7]
Crisscrossing fine white lines that account for the name lattice degeneration are present in roughly only 10% of lesions and most likely represent hyalinized blood vessels; this is shown in the image below.
Example of a lattice lesion containing white crisscrossing wicker lines, which are seen in about 10% of lattice lesions. This lesion is complicated by an extensive retinal tear at the cuff of the lesion.
Various pigmentary disturbances, shown in the image below, occur in more than 80% of lattice lesions. White-yellow occasionally refractile flecks, similar to that seen with degenerative retinoschisis, are an additional common associated feature.
Atrophic retinal holes, shown in the image below, and tractional retinal tears may complicate lattice degeneration and increase the risk of retinal detachment.
Clinical variations
Snail-track degeneration is a morphologic descriptive term for retinal lesions with the same characteristic size, shape, orientation, and location as lattice lesions and is associated with the aforementioned yellowish flecks. Examples of snail-track degeneration are shown in the images below.
A peripheral lattice lesion demonstrating the typical snail-track appearance, with overlying vitreal opacities, which may represent glial proliferations or regions of increased vitreoretinal condensation.
Vitreous base excavations represent lesions of similar shape, size, and orientations as lattice lesions having a uniform reddish base and located within the vitreous base.
Pigmentary degeneration is a term that most likely represents lattice lesions with prominent but variable pigmentary changes, including clumps of pigment sometimes heavily scattered at the base of lattice lesions and demarcation lines circumscribing cuffs of subretinal fluid.
When retinal thinning and pigmentary disturbances are found along retinal vessels, these lattice lesions are referred to as radial perivascular chorioretinal degeneration and are classic findings in Wagner and Stickler disease, a familial vitreoretinal degenerative syndrome. An example of this is shown in the image below.
Radial perivascular chorioretinal degeneration with retinal tear at the margin. These lesions run along vessels and may be found in Wagner's and Stickler's disease.
Clinical examination
Identification of lattice lesions depends largely upon the experience of the examiner and the method of examination used.
In patients with symptomatic lattice degeneration (presence of newly onset flashes or floaters), the retinal periphery must be viewed for 360° of its circumference to identify any retinal breaks, if present. If the general ophthalmologist is unable to do so, referral should be promptly made to a vitreoretinal subspecialist.
The most convenient and frequently used method of examination to detect lattice is with binocular indirect ophthalmoscopy with scleral depression (indentation).
Slit lamp examination with a Goldmann contact lens is used less frequently. This method allows for high magnification of the lattice lesions and the associated vitreoretinal relationships, but evaluation with scleral depression, a critical element of the peripheral examination, becomes technically difficult when using a contact lens.
Clinical course
Lattice lesions are believed to develop early in one's lifetime with minimal progression thereafter. Associated features, such as crisscrossing sclerotic vessels, pigmentation, and atrophic retinal holes, may subsequently develop.
Retinal detachment is a relatively rare complication of lattice degeneration (< 1% of patients with lattice degeneration), but lattice degeneration is associated with as many as 40% of all rhegmatogenous retinal detachments. Lattice degeneration is present in 11% of fellow eyes in patients with rhegmatogenous retinal detachments. [8, 9, 10] Rhegmatogenous retinal detachment is shown in the image below.
A 2015 study reported a higher risk (3.4%) of retinal tears and detachments in myopic eyes (>6 D) over a 10-year period. [11]
An acute rhegmatogenous retinal detachment that may be associated with lattice degeneration. (Lattice lesion not seen in this image.)
Retinal detachments caused by lattice degeneration occur most commonly by a tractional tear at the cuff or posterior margin of the lattice lesion or less commonly by means of an atrophic hole within the zone of lattice.
Tractional tears
Tractional tears located at the margin of lattice account for 55-70% of retinal detachments in lattice degeneration and are the result of a posterior vitreous detachment (PVD).
These patients are typically older than 50 years, and only 40% of such eyes are myopic.
An acute PVD complicated by retinal tear formation usually is signaled by the complaint of new-onset floaters and/or flashing lights (referred to as photopsia)
As in all retinal tears, preretinal or vitreous hemorrhage may be present if the tear extends through peripheral retinal blood vessel.
Patients with these complaints constitute a true ophthalmologic emergency and need urgent ophthalmic examination.
PVD-related lattice detachments typically are superotemporal and not associated with demarcation lines. Surgical repair is anatomically successful in 90% of such cases.
Atrophic holes
Atrophic holes account for 30-45% of retinal detachments associated with lattice degeneration. In another retrospective case-controlled study, 23.6% of patients with retinal detachments had atrophic holes associated with lattice degeneration. [12]
Seventy percent of patients with rhegmatogenous retinal detachment secondary to round atrophic holes in lattice degeneration occur in patients younger than 40 years, and 70% of these detachments occur in myopic eyes. Sixty percent are found in females.
Fellow eye pathology is found in a significant (96%) portion of these patients. Thus, examination of the fellow eye is important in these cases.
The posterior hyaloid gel usually is attached, excluding a PVD-related mechanism. These detachments are typically inferior, occur slowly, and demonstrate demarcation lines on examination resulting from the slow progressive accumulation of subretinal fluid.
A 98-100% success rate exists in repairing such inferior retinal detachments with demarcation lines with an excellent visual prognosis in the absence of macular detachment.
Causes
See Pathophysiology.
Physical Examination
A 360° evaluation of the peripheral retina is conducted using scleral depression or the Goldmann 3-mirror lens.
Complications
Potential complications of lattice degeneration include development of retinal breaks or detachments.
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Example of a lattice lesion containing white crisscrossing wicker lines, which are seen in about 10% of lattice lesions. This lesion is complicated by an extensive retinal tear at the cuff of the lesion.
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Another example of wicker lines seen within a lattice lesion. Prophylactic retinopexy has been performed around this lesion.
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An example of a flap tear at the edge of a lattice lesion and three adjacent holes. This area of lattice degeneration has been barricaded by laser retinopexy.
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A large horseshoe tear at the opposite edge of the lattice lesion pictured above. Laser retinopexy surrounds the tear and lattice lesion.
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A peripheral lattice lesion demonstrating the typical snail-track appearance, with overlying vitreal opacities, which may represent glial proliferations or regions of increased vitreoretinal condensation.
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An example of a heavily pigmented lattice lesion.
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An acute rhegmatogenous retinal detachment that may be associated with lattice degeneration. (Lattice lesion not seen in this image.)
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Another example of a peripheral lattice lesion with a snail-track appearance.
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Lattice lesion containing small atrophic holes.
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Radial perivascular chorioretinal degeneration with retinal tear at the margin. These lesions run along vessels and may be found in Wagner's and Stickler's disease.
