Degenerative conditions involving the peripheral retina may be termed predisposing or non-predisposing. The predisposition is to retinal breaks and detachment. Lattice degeneration falls into the former category and is therefore an important clinical entity, being an equatorial area of retinal thinning and present in about 40% of patients who have detachment of the retina.
Lattice degeneration is usually bilateral and is not age-related, commencing fairly early in life with a maximum frequency around the second decade. There is no gender predilection, with the condition being more commonly encountered in association with moderate myopia. Some studies have suggested there may be some hereditary transmission. There may be systemic disease associations, with such conditions as Wagner’s disease, and Stickler’s, Marfan’s, Ehlers-Danlos and Turner’s syndromes.
Unless associated with a complicating clinical situation or disease, lattice degeneration of itself is not associated with any visual symptoms.
Lattice degeneration can have a variety of ophthalmoscopic appearances. These zones of retinal thinning typically run parallel to the ora serrata in the equatorial region of the fundus. Alternatively, some can have a paravascular orientation. Several circumferential rows may be present and it is more common superiorly than inferiorly and temporally rather than nasally. Lattice areas may enlarge with time. The criss-cross network of arborising white lines that originally gave rise to the term “lattice” is in fact seen in only a minority of cases. However, pigmentary changes are present in most cases. Snailtrack lesions are probably a variant of lattice degeneration.
Changes in the vitreous are typically encountered, with firm vitreal attachments at the edges of these lesions and areas of liquefied vitreous over the centre of the lesion. Small round atrophic holes are often found in the thin central area. These have been known to lead to retinal detachment and those most at risk are young patients with myopia. Retinal flap tears on the other hand usually occur at the posterior border of the lesion. Marked vitreous traction is present and detachment often occurs.
Lattice degeneration is quite common, being present in about 8-10% of the general population.
Other peripheral degenerative conditions, Pavingstone degeneration; Vitreoretinal tuft; Meridional folds;
Prophylactic treatment may be considered if:
– retinal detachment is or has been present in the other eye;
– cataract surgery is being contemplated;
– the patient has high myopia and extensive lattice;
– there is a strong family history of retinal detachment;
– or an associated systemic disease is present such as Marfan’s syndrome
Patients with asymptomatic atrophic holes and sub-retinal fluid should be treated, and all tears should be treated irrespective of size, symptoms or location in the fundus. Superiorly located tears where sub-retinal fluid is present or there are symptoms of acute posterior vitreous detachment should be treated without delay.
Advice and review
Most cases of lattice degeneration are and remain uncomplicated. Routine review at annual intervals may be indicated. Symptoms of retinal detachment disease may be explained and the need for urgent review advised if the patient experiences such symptoms.
Lattice degeneration with a tear and retinal detachment. Image courtesy of Dr Les Manning
A pigmented area of lattice degeneration in the equatorial superior fundus. The patient was asymptomatic and no retinal breaks or tears were evident.