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Author: William Trattler, MD, Miami Center for Excellence in Eye Care; Consulting Staff, Department of Ophthalmology, Miami Baptist Hospital

William Trattler is a member of the following medical societies: American Academy of Ophthalmology

Coauthor(s): William Lloyd Clark, MD, Consulting Staff, Palmetto Retina; Natalie Afshari, MD, Assistant Professor, Cornea and Refractive Surgery, Department of Ophthalmology, Duke University Eye Center, Duke University Medical Center

Editors: Fernando H Murillo-Lopez, MD, Senior Surgeon, Unidad Privada de Oftalmologia CEMES; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Christopher J Rapuano, MD, Professor, Department of Ophthalmology, Jefferson Medical College; Co-Chairman of the Cornea Service, Co-Chairman of Refractive Surgery Department, Wills Eye Hospital; 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: lattice dystrophy, corneal dystrophy, stromal dystrophy, stromal dystrophies, corneal erosion, corneal transplant, phototherapeutic keratectomy, PTK

Background

Lattice dystrophy usually is an autosomal dominant condition, and it is the most common of stromal dystrophies. Like granular and Avellino dystrophy, the genetic defect of lattice dystrophy has been mapped to the BIG H3 gene on chromosome 5q. Onset of the corneal changes usually occurs in the first decade of life, although patients may remain asymptomatic for years. Examination of the cornea in the second to third decade of life will reveal branching, refractile lattice lines with intervening haze, which are observed best in retroillumination.

Pathophysiology

The cornea is the clear outer coat of the front of the eye. A dystrophy of the cornea is defined as a bilateral noninflammatory clouding of the cornea. The corneal dystrophies can be placed into 3 categories based on their location within the cornea as follows: (1) the anterior corneal dystrophies affect the corneal epithelium and may involve the Bowman membrane, (2) stromal corneal dystrophies affect the central layer of the cornea (the stroma), and (3) the posterior corneal dystrophies involve the Descemet membrane and the endothelium.

Most corneal dystrophies have an onset prior to age 20 years (exceptions include map-dot-fingerprint dystrophy and Fuchs corneal dystrophy). Most corneal dystrophies are dominantly inherited, exceptions are macular dystrophy, type 3 lattice dystrophy, and the autosomal-recessive form of congenital hereditary endothelial dystrophy.

Frequency

United States

Although lattice dystrophy is the most common of the stromal dystrophies, it is relatively rare.

Mortality/Morbidity

Excessive corneal erosions can lead to decreased visual acuity, which may require a corneal transplant or phototherapeutic keratectomy (PTK).

Sex

No sexual predilection exists.

Age

Onset of the corneal changes usually occurs in the first decade of life, although patients may remain asymptomatic for years. Examination of the cornea in the second to third decade of life reveals branching, refractile lattice lines, which are observed best in retroillumination. Over time, the lattice lines and other opacities coalesce, forming anterior stromal haze that decreases the visual acuity.



History

Patients may have decreased vision, photosensitivity, and/or eye pain (from recurrent corneal erosions). This dystrophy usually is autosomal dominant, so it is likely that one of the parents will have lattice corneal dystrophy as well.

Physical

Lattice corneal dystrophy is characterized by branching, refractile lattice lines, which are observed best in retroillumination. In the most common form, type 1 lattice dystrophy, the refractile lines are more prominent centrally than peripherally. Later in life, stromal haze can develop. Eventually, significant stromal scarring and subepithelial fibrosis may occur.

Causes

The genetic defect of lattice dystrophy has been mapped to the BIG H3 gene of chromosome 5q. Other corneal dystrophies also have genetic defects of the BIG H3 gene, including granular dystrophy, Avellino dystrophy, and Reis-Bückler dystrophy.



Corneal Erosion, Recurrent
Dystrophy, Granular
Dystrophy, Macular


Lab Studies

  • Genetic analysis performed in research labs can reveal the genetic mutation of lattice corneal dystrophy. This is not a routine study at this time.
  • A genetic analysis can determine the specific mutation on the BIG H3 gene of chromosome 5, which can allow for the precise diagnosis of the subtype of lattice dystrophy and can be useful for differentiating lattice dystrophy from Avellino dystrophy, granular dystrophy, and Reis-Bückler dystrophy (all which have mutations of the BIG H3 gene).

Procedures

  • Corneal biopsy (which would never be indicated clinically) would reveal amyloid in the corneal stroma.

Histologic Findings

The deposits are amyloid, which stain orange-red with Congo red. They also stain with periodic-acid Schiff (PAS) and Masson trichrome. Under polarized light, the deposits exhibit birefringence and red-green dichroism.



Medical Care

When recurrent erosions occur with this condition, they are treated similar to any other form of recurrent erosion. Under the care of an ophthalmologist, a bandage contact lens along with antibiotics can be prescribed. Alternatively, patching with an antibiotic ointment can be used. Once the acute episode of recurrent erosion has resolved, preventative treatments may include Muro 128 drops, lubrication drops, and lubricating ointment at bedtime. If recurrent corneal erosions occur despite medical therapy, then excimer laser treatment (PTK) may be considered.

Surgical Care

Excessive corneal erosions or mild visual decreases can be treated with PTK. The excimer laser removes the opacities, smooths the corneal surface, and allows the epithelium to re-adhere more tightly. If the visual acuity drops and the opacities are deep, a lamellar or full-thickness corneal transplant can be performed. Although the success rate for a corneal transplant is very high, lattice deposits can recur.



Medical therapy for recurrent corneal erosions includes hypertonic saline, which is believed to increase adherence of the epithelium to underlying stroma. Lubrication also may help prevent further corneal erosions.

Drug Category: Hypertonic saline

Dehydrates epithelium, allowing epithelium to adhere better to underlying stroma.

Drug NameSodium chloride 5% (Muro 128)
DescriptionFor osmotic pressure control and water distribution. Dehydrates epithelium, allowing epithelium to adhere better to underlying stroma.
Adult DoseSolution: 1-2 gtt into affected eye q3-4h
Pediatric DoseNot established
ContraindicationsDocumented hypersensitivity
InteractionsNone reported
PregnancyA - Safe in pregnancy
PrecautionsCaution in edema and sodium toxicity

Drug Category: Lubricating drops

Can moisten ocular surface, and decrease number of recurrent erosion episodes.

Drug NameArtificial tears (GenTeal, Refresh, Bion tears)
DescriptionCan moisten ocular surface and decrease number of recurrent erosion episodes.
Adult Dose1 gtt to affected eye 4-6 times/d
Pediatric DoseAdminister as in adults
ContraindicationsDocumented hypersensitivity
InteractionsNone reported
PregnancyA - Safe in pregnancy
PrecautionsHyperemia, photophobia, stickiness of eyelashes, and ocular discomfort or irritation may occur



Further Outpatient Care

  • Patients with recurrent erosions should receive regular follow-up care.

Complications

  • Complications of lattice corneal dystrophy include loss of vision and painful recurrent corneal erosions.

Prognosis

  • The prognosis is good, with symptomatic patients being eligible for either laser PTK or corneal transplant.

Patient Education

  • Patients need to understand that this is a genetically inherited condition, which they can pass on to their children.



Medical/Legal Pitfalls

  • Early detection and treatment may decrease the chance of loss of visual acuity.

Special Concerns

  • A variant of lattice dystrophy is called Avellino dystrophy. Its genetic defect also has been mapped to chromosome 5q. In this condition, lattice deposits develop in the cornea years after the typical granular deposits have developed. With age, the deposits enlarge and form a corneal haze. The symptoms are similar to lattice dystrophy, with pain and photophobia due to recurrent corneal erosions.
  • Avellino dystrophy is managed in a similar manner to lattice corneal dystrophy. For excessive recurrent corneal erosions, PTK with the excimer laser can be performed. For patients with vision loss and unsuccessful PTK, a corneal transplant can be performed. The deposits can recur in the donor cornea.
  • Children of patients with lattice corneal dystrophy should be monitored once they reach puberty since this condition has autosomal dominant inheritance.



Media file 1:  Lattice corneal dystrophy. Image courtesy of James J. Reidy, MD, FACS, Associate Professor of Ophthalmology, State University of New York, School of Medicine & Biomedical Sciences, Buffalo, New York.
Click to see larger pictureClick to see detailView Full Size Image
Media type:  Photo

Media file 2:  Slit lamp image of lattice corneal dystrophy. Image courtesy of James J. Reidy, MD, FACS, Associate Professor of Ophthalmology, State University of New York, School of Medicine & Biomedical Sciences, Buffalo, New York.
Click to see larger pictureClick to see detailView Full Size Image
Media type:  Photo



  • Albert D, Jakobiec F. Principles and Practice of Ophthalmology. Vol 1. 1994: 26-49.
  • Das S, Langenbucher A, Seitz B. Excimer laser phototherapeutic keratectomy for granular and lattice corneal dystrophy: a comparative study. J Refract Surg. Nov-Dec 2005;21(6):727-31. [Medline].
  • Das S, Langenbucher A, Seitz B. Delayed healing of corneal epithelium after phototherapeutic keratectomy for lattice dystrophy. Cornea. Apr 2005;24(3):283-7. [Medline].
  • Kawashima M, Yamada M, Funayama T, et al. Six cases of late-onset lattice corneal dystrophy associated with gene mutations induced by the transforming growth factor-beta. Nippon Ganka Gakkai Zasshi. Feb 2005;109(2):93-100. [Medline].
  • Krachmer J. Cornea (3 volume set). Vol 2. 1996.
  • Mashima Y, Yamamoto S, Inoue Y, et al. Association of autosomal dominantly inherited corneal dystrophies with BIGH3 gene mutations in Japan. Am J Ophthalmol. Oct 2000;130(4):516-7. [Medline].
  • Stone EM, Mathers WD, Rosenwasser GO, et al. Three autosomal dominant corneal dystrophies map to chromosome 5q. Nat Genet. 1994;6(1):47-51. [Medline].

Dystrophy, Lattice excerpt

Article Last Updated: Mar 15, 2006