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Ophthalmology > RETINA
Lattice Degeneration
Article Last Updated: Feb 27, 2007
AUTHOR AND EDITOR INFORMATION
Section 1 of 10  
Author: David Sarraf, MD, Assistant Clinical Professor of Ophthalmology, Jules Stein Eye Institute, University of California at Los Angeles, Greater Los Angeles Veterans Affairs Healthcare System
David Sarraf is a member of the following medical societies: American Academy of Ophthalmology and Association for Research in Vision and Ophthalmology
Coauthor(s):
Stanley M Saulny, MD, Consulting Staff, Department of Ophthalmology, Ophthalmology Associates of the Valley
Editors: Vytautas A Pakainis, MD, Chief of Ophthalmology, Dorn Veterans Administration Medical Center, Professor of Ophthalmology, Ophthalmology, University of South Carolina School of Medicine; Simon K Law, MD, PharmD, Assistant Professor of Ophthalmology, Jules Stein Eye Institute; Chief of Section of Ophthalmology Surgical Services, Department of Veterans Affairs Healthcare Center, West Los Angeles; Steve Charles, MD, Director of Charles Retina Institute; Clinical Professor, Department of Ophthalmology, University of Tennessee College of Medicine; Lance L Brown, OD, MD, Ophthalmologist, Affiliated With Freeman Hospital and St John's Hospital, Regional Eye Center, Joplin, Missouri; Hampton Roy Sr, MD, Associate Clinical Professor, Department of Ophthalmology, University of Arkansas for Medical Sciences
Author and Editor Disclosure
Synonyms and related keywords:
snail-track degeneration, palisades, etat givre, radial perivascular chorioretinal degeneration, equatorial degeneration, Milky way–like degeneration, vitreous base excavation
Background
Lattice degeneration is a common, atrophic disease of the peripheral retina characterized by oval or linear patches of retinal thinning. The prevalence peaks by the second decade and is believed to be minimally progressive but may be uncommonly complicated by retinal detachment.
Pathophysiology
The pathogenesis of lattice degeneration is not well understood, although several theories have been proposed. Regional developmental absence of the internal limiting membrane versus abnormal vitreoretinal traction dynamics appears to be the most cogent argument proposed.
Frequency
United States
Lattice degeneration affects approximately 10% of the population and is bilateral in 30-50% of patients who are affected. A variable familial risk may be present on the basis of various autosomal dominant pedigrees. An increased prevalence exists in myopic eyes, and its prevalence may be associated with increasing axial length, reaching 15% in the longest eyes.
International
No information is available regarding the international occurrence of lattice degeneration.
Mortality/Morbidity
See discussion of retinal detachment in History and Physical.
Race
No reported racial differences exist in lattice degeneration.
Sex
No reported sex differences exist in lattice degeneration.
Age
See History regarding early onset and progression with age.
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 of 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.
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.
- 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.
- 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.
- Various pigmentary disturbances occur in more than 80% of lattice lesions. White-yellow flecks, similar to that seen with degenerative retinoschisis, are an additional common associated feature.
- Atrophic retinal holes 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.
- 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.
- Clinical examination
- Identification of lattice lesions depends largely upon the experience of the examiner and the method of examination used.
- 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 is associated with as many as 40% of all rhegmatogenous retinal detachments.
- 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 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.
- These patients are predominantly older than 50 years, and only 40% of such eyes are myopic.
- An acute posterior vitreous detachment complicated by retinal tear formation usually is signaled by the complaint of new-onset floaters and/or flashes and the presence of preretinal or vitreous hemorrhage. Patients with these complaints constitute a true ophthalmologic emergency and need urgent ophthalmic examination.
- Tractional lattice-related detachments typically are supertemporal and not associated with demarcation lines. Surgical repair is successful in 90% of such cases.
- Atrophic holes account for 30-45% of retinal detachments in lattice degeneration.
- Seventy percent occur in patients younger than 40 years, and 70% of these detachments occur in myopic eyes.
- The posterior hyaloid gel usually is attached excluding a tractional 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 detachments with an excellent visual prognosis.
Causes
See Pathophysiology.
Retinal Detachment, Exudative
Retinal Detachment, Postoperative
Retinal Detachment, Rhegmatogenous
Other Problems to be Considered
Retinal breaks, holes
Retinal breaks, tears
Lab Studies
- No appropriate lab studies exist for lattice degeneration.
Imaging Studies
- No appropriate imaging studies exist for lattice degeneration.
Procedures
- Examination by direct and indirect ophthalmoscopy
Histologic Findings
Histologic studies of autopsy cases demonstrate that lattice lesions are characterized by 3 invariable features: thinning or atrophy of the inner retinal layers, vitreous liquefaction overlying the area of thinned retina, and vitreous condensation and exaggerated vitreoretinal attachments at the borders of the lesions.
The blood vessels within the lesions are usually patent, but they often show fibrous thickening of their walls, which correlates to the white lattice lines seen clinically. Melanin-laden macrophages may explain the pigmentation seen clinically. Glial proliferations may represent overlying preretinal opacities.
Electron microscopic studies have demonstrated retinal thinning, loss of retinal neurons, internal limiting lamina absence, fibrosis of blood vessels, and accumulation of pigment and/or glial elements.
Medical Care
The presence of uncomplicated lattice does not interfere with visual function and does not constitute a high risk for future development of retinal detachment. Prophylactic treatment is clearly indicated only in the context of specific circumstances.
- Indications for prophylactic treatment
- Lattice degeneration complicated by tractional tears as the result of an acute, symptomatic posterior vitreous detachment represents a high-risk situation for future retinal detachment and is an urgent indication for laser retinopexy. Lattice and atrophic holes complicated by progressively increasing subretinal fluid represents an additional indication for surgical intervention.
- The presence of lattice lesions in fellow eyes of patients who have sustained retinal detachment in the first eye may be treated prophylactically. Exceptions may include eyes with greater than 6 clock hours of lattice lesions and eyes with myopia greater than 6 diopters (D). Strong evidence suggests that subsequent retinal detachments may occur as a result of lesions developing in previously healthy retinas. Moreover, laser scars may increase vitreoretinal adhesion and increase the risk of future retinal tears. Therefore, this indication is controversial. In the absence of the aforementioned features, convincing evidence does not exist to clearly indicate prophylactic laser treatment of lattice lesions.
- Methods of prophylactic treatment
- Laser photocoagulation is the primary method of prophylactic treatment. Recommended laser settings include the following: green, yellow, or red wavelengths via biomicroscope/contact lens or indirect ophthalmoscope delivery systems, duration of 0.1-0.2 seconds, and spot size of 100-200 micrometers. Apply laser in 3 confluent 360° rings around the lesion. Care should be taken to avoid bare retinal pigment epithelium.
- Cryotherapy may be a necessary alternative in cases in which significant hemorrhage prevents laser administration.
- Subclinical retinal detachment (>1 disc diameter of subretinal fluid but <2 disc diameters posterior to the equator) may be treated more effectively with the conservative scleral buckle approach versus a laser barrier.
- Frank rhegmatogenous retinal detachment may be treated with a scleral buckling procedure and/or pars plana vitrectomy and gas administration. All areas of lattice and retinal breaks should be meticulously sought after and barricaded with laser or cryotherapy.
Further Outpatient Care
- Patients with lattice degeneration should be examined on an annual basis.
Complications
- Complications are rare with laser retinal treatment, but retinal detachment may occur.
Prognosis
- The prognosis is favorable.
Patient Education
- Educating patients about the symptoms (eg, new-onset floaters, flashes, visual field defects) of a retinal tear or detachment is critical.
Medical/Legal Pitfalls
- Prophylactic laser retinopexy should be offered to those patients who meet the appropriate treatment criteria. As in any surgical procedure, careful informed consent must be obtained from the patient. While this procedure is fairly common with a good visual prognosis in most patients, it incurs the same risks as most other laser retinal procedures.
- Patients with significant lattice lesions, including those who have had prophylactic treatments, are always at increased risk over the general population for vision loss due to retinal detachment. Therefore, they must have routine follow-up examinations and be informed of the signs and symptoms of retinal and vitreous detachment and the necessity to seek urgent ophthalmic care when needed.
Special Concerns
- This review was partly supported by a Research to Prevent Blindness Grant #OP 31 for David Sarraf, MD.
| Media file 1:
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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| Media file 2:
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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| Media file 3:
An example of a heavily pigmented lattice lesion. |
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| Media file 4:
An acute rhegmatogenous retinal detachment that may be associated with lattice degeneration. (Lattice lesion not seen in this image.) |
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| Media file 5:
Another example of a peripheral lattice lesion with a snail-track appearance. |
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Media type: Photo
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| Media file 6:
Lattice lesion containing small atrophic holes. |
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Media type: Photo
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- Avitabile T, Bonfiglio V, Reibaldi M, et al. Prophylactic treatment of the fellow eye of patients with retinal detachment: a retrospective study. Graefes Arch Clin Exp Ophthalmol. Mar 2004;242(3):191-6. [Medline].
- Byer NE. Long-term natural history of lattice degeneration of the retina. Ophthalmology. Sep 1989;96(9):1396-401; discussion 1401-2. [Medline].
- Byer NE. Lattice degeneration of the retina. Surv Ophthalmol. Jan-Feb 1979;23(4):213-48. [Medline].
- Edwards AO, Robertson JE Jr. Hereditary vitreoretinal degenerations. In: Ryan SJ, ed. Retina. 3rd ed. St Louis, Mo: Mosby;. 2001: 482-98.
- Folk JC, Arrindell EL, Klugman MR. The fellow eye of patients with phakic lattice retinal detachment. Ophthalmology. Jan 1989;96(1):72-9. [Medline].
- Foos RY, Simons KB. Vitreous in lattice degeneration of retina. Ophthalmology. May 1984;91(5):452-7. [Medline].
- Gonzales CR, Gupta A, Schwartz SD, Kreiger AE. The fellow eye of patients with phakic rhegmatogenous retinal detachment from atrophic holes of lattice degeneration without posterior vitreous detachment. Br J Ophthalmol. Nov 2004;88(11):1400-2. [Medline].
- Lewis H. Peripheral retinal degenerations and the risk of retinal detachment. Am J Ophthalmol. Jul 2003;136(1):155-60. [Medline].
- Straatsma BR, Zeegen PD, Foos RY, et al. Lattice degeneration of the retina. XXX Edward Jackson Memorial Lecture. Am J Ophthalmol. May 1974;77(5):619-49. [Medline].
- Wilkinson C. Interventions for asymptomatic retinal breaks and lattice degeneration for preventing retinal detachment. Cochrane Database Syst Rev. 2005;CD003170. [Medline].
- Wilkinson CP. Evidence-based analysis of prophylactic treatment of asymptomatic retinal breaks and lattice degeneration. Ophthalmology. Jan 2000;107(1):12-5; discussion 15-8. [Medline].
Lattice Degeneration excerpt Article Last Updated: Feb 27, 2007
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