Ribbon-like dystrophy type 2 is a hereditary disease characterized by progressive damage to the corneal stroma with the formation of specific protein deposits. The pathology belongs to the group of primary corneal dystrophies and manifests itself in the form of linear or ribbon-like optically dense formations located mainly in the anterior layers of the stroma. The clinical picture includes a gradual decrease in visual acuity, photophobia and discomfort when wearing contact lenses. A feature of this type of dystrophy is a more severe course compared to type 1, which is due to the earlier onset and rapid progression of the pathological process.
History of the disease and interesting historical facts
The first descriptions of lattice corneal dystrophy appeared in the mid-20th century, when ophthalmologists began to systematize various forms of hereditary corneal dystrophies. In 1967, Bjornstad and Tonnesen described the clinical picture of the disease in detail, noting the characteristic ribbon-like shape of the deposits. Interestingly, it was during the study of this pathology that modern methods of genetic diagnostics in ophthalmology were first used. “This disease became the starting point for understanding the molecular mechanisms of the development of hereditary corneal dystrophies,” notes a study in the Journal of Medical Genetics, 1995.
Epidemiology (statistics of disease occurrence)
Lattice corneal dystrophy type 2 occurs with a frequency of approximately 1 case per 500,000 population. The disease has a universal distribution, but some studies indicate a higher frequency of detection in Scandinavian populations. According to statistics:
- The average age of manifestation is 20-30 years.
- Men and women are affected with equal frequency
- In approximately 85% cases, the disease manifests itself before age 40
- The penetrance of the mutation reaches 95%
Genetic predisposition to the disease (involved genes and mutations)
The disease is inherited in an autosomal dominant manner and is associated with mutations in the TGFBI (transforming growth factor beta-induced) gene, located on chromosome 5q31. The most common mutation is R124H, which results in the replacement of arginine with histidine at position 124. The mechanism of pathogenesis is associated with the accumulation of mutated keratoepithelin protein in the corneal stroma. Studies show that "the mutated protein forms aggregates that disrupt the normal structure of collagen fibrils," as stated in the American Journal of Ophthalmology, 2001.
Risk factors for the development of this disease
Although the main factor in development is genetic predisposition, there are additional factors that contribute to the acceleration of the disease progression:
- Long-term exposure to ultraviolet radiation
- Corneal injuries of various etiologies
- Chronic inflammatory processes of the ocular surface
- Disorders of amino acid metabolism
- Effects of toxic substances on the ocular surface
The combined effects of several factors simultaneously are especially dangerous.
Diagnosis of this disease
The main symptoms include gradual loss of vision, photophobia and blurred vision. The diagnostic algorithm includes the following methods:
- Slit lamp biomicroscopy reveals characteristic band-like deposits
- Confocal microscopy - assessment of lesion depth
- Keratotopography - determination of the degree of corneal irregularity
- Genetic testing - confirmation of R124H mutation
Differential diagnosis is carried out with other forms of hereditary corneal dystrophies, as well as with secondary corneal opacities.
Treatment
General therapy is aimed at slowing the progression of the disease and correcting refractive disorders. Pharmacological treatment includes the use of drugs that stabilize corneal metabolism. In case of significant vision loss, surgical treatment is indicated:
- Photorefractive keratectomy (PRK) - in early stages
- Corneal transplant (keratoplasty) - for severe changes
- Laser therapy - to remove superficial deposits
Alternative treatments include collagen crosslinking.
List of drugs used to treat this disease
- Corticosteroid drops (Dexamethasone 0.1%) - to control inflammation
- Artificial tears (Hypromellose 0.3%) - for moisturizing
- Antioxidants of local action (Taurine 4%) - to protect the epithelium
- Anti-inflammatory drugs (Diclofenac 0.1%) - during exacerbation
- Antimetabolites (Mitomycin-C) - during PRK
Disease monitoring (control stages, prognosis, complications)
Regular monitoring includes annual examinations with biomicroscopy and keratotopography. The prognosis with timely treatment is relatively favorable, but complications are possible:
- Development of postoperative astigmatism
- Graft rejection in keratoplasty
- Recurrence of deposits in donor cornea
- The occurrence of secondary glaucoma
Age-related features of the disease (how it progresses in different age groups)
At a young age, the disease is more aggressive, with rapid progression of changes. In older patients, the pathological process develops more slowly, which may be associated with a general slowdown in metabolic processes. However, elderly patients have a higher risk of complications after surgical treatment.
Questions and Answers
- How often should you undergo examination for this disease? An annual examination is recommended, and if progression occurs, every 6 months.
- Is it possible to prevent the development of the disease? It is impossible to prevent it completely, but its progression can be slowed down.
- How does pregnancy affect the course of the disease? May temporarily worsen the condition due to hormonal changes.
- Is the disease transmitted to offspring? Yes, the risk of transmission is 50%.
- Does nutrition affect the course of the disease? An antioxidant diet may slow progression.
Advice from Dr. Oleg Korzhikov
Patients often ask: "Can I use contact lenses with this disease?" Answer: in the early stages, it is possible to wear special rigid gas-permeable lenses, but under strict supervision of a doctor. "How can I protect my eyes from deterioration?" many people ask. I recommend using high-quality sunglasses with a UV filter of categories 3-4. An important question: "When should I plan an operation?" A decision must be made when visual acuity decreases below 0.5 or severe discomfort appears.
