What causes vitreoretinal degeneration and how is it managed?

Causes and Management of Vitreoretinal Degeneration

Vitreoretinal degeneration is primarily caused by abnormal vitreoretinal adhesions, age-related vitreous liquefaction, and genetic factors that lead to structural changes in the vitreous and retina, resulting in various pathological manifestations that can significantly impact vision. 1

Primary Causes of Vitreoretinal Degeneration

Posterior Vitreous Detachment (PVD)

• Occurs as an acute event after substantial age-related liquefaction in the vitreous gel
• Typically affects individuals between ages 45-65, with earlier onset in men
• Occurs earlier in patients with trauma and myopia
• Characterized by separation of posterior vitreous cortex from the internal limiting membrane 1

Abnormal Vitreoretinal Adhesions

• Firm attachments between cortical vitreous and inner retinal surface
• Vitreoretinal traction at sites of significant adhesion is responsible for most retinal breaks
• Traction during PVD may cause retinal breaks at adhesion sites 1

Genetic Factors

• Over 100 genetic loci implicated in retinal degeneration
• Includes both common and rare variants
• Specific genetic conditions:
  • Stickler syndrome (COL2A1 gene mutation) - most common inherited vitreoretinal disorder associated with rhegmatogenous retinal detachment 1
  • Snowflake vitreoretinal degeneration (KCNJ13 gene mutation) - characterized by fibrillar vitreous structure and crystalline retinopathy 2, 3
  • Wagner syndrome - characterized by optically empty vitreous cavity and retinal breaks 4

Other Contributing Factors

• Myopia (especially high myopia)
• Prior eye trauma
• History of ocular surgery (particularly cataract surgery)
• YAG laser capsulotomy
• Intravitreal injections 1

Clinical Manifestations

Structural Changes

• Lattice degeneration: peripheral vitreoretinal lesion with retinal thinning, overlying vitreous liquefaction, and firm vitreoretinal adhesions at margins 1
• Retinal breaks: full-thickness defects in the retina (tears from vitreoretinal traction, holes without traction) 1
• Vitreomacular traction (VMT): partial vitreous separation causing mechanical distortion of the macula 1

Symptomatic Presentations

• Light flashes (photopsias) - most noticeable in the dark
• Floaters (myodesopias) - may be due to blood, vitreous collagen condensations, or epipapillary glial tissue
• Visual field defects (in cases of retinal detachment) 1

Management Approach

Diagnostic Evaluation

1. Comprehensive retinal examination:

   • Examination of vitreous for hemorrhage, detachment, and pigmented cells
   • Careful peripheral fundus examination using scleral depression
   • Indirect ophthalmoscopy with scleral depression (preferred method) 1

2. Advanced imaging:

   • Optical coherence tomography to evaluate and stage PVD
   • B-scan ultrasonography if media opacity precludes adequate examination 1

Risk Stratification

High-risk features requiring closer monitoring:

• Vitreous hemorrhage (direct correlation with likelihood of retinal tear)
• High myopia
• History of retinal detachment in fellow eye (10% increased risk)
• Prior ocular trauma
• Pseudophakia
• Stickler syndrome or other genetic vitreoretinopathies 1

Treatment Options

For Symptomatic PVD

• Close monitoring with follow-up examination within 2-6 weeks if no retinal breaks found initially
• Patient education about warning symptoms requiring immediate evaluation 1

For Retinal Breaks

• Treatment depends on type of break and associated risk factors
• Options include:
  • Laser photocoagulation
  • Cryotherapy
  • Observation for certain low-risk breaks 1

For Rhegmatogenous Retinal Detachment

• Surgical intervention required:
  • Pneumatic retinopexy
  • Scleral buckling
  • Vitrectomy with gas or silicone oil tamponade 1

For Vitreomacular Traction

• Observation for mild cases
• Pharmacologic vitreolysis
• Vitrectomy for persistent or severe cases 1, 5

Special Considerations for Genetic Vitreoretinopathies

• Genetic testing to identify specific mutations
• More aggressive prophylactic treatment of retinal breaks
• Regular monitoring of family members
• Genetic counseling 2, 3

Preventive Measures and Patient Education

• Regular dilated fundus examinations for high-risk individuals
• Immediate evaluation for new onset of flashes or floaters
• Protective eyewear for those at risk of ocular trauma
• Recognition of early symptoms of retinal detachment (curtain-like shadow, sudden increase in floaters) 1

Common Pitfalls to Avoid

1. Failure to perform adequate peripheral retinal examination in symptomatic patients
2. Missing retinal breaks in the presence of vitreous hemorrhage
3. Underestimating the significance of new symptoms in patients with prior PVD
4. Overlooking genetic factors in patients with vitreoretinal degeneration
5. Inadequate follow-up of high-risk patients 1

Remember that between 8% and 22% of patients with acute PVD symptoms have a retinal tear at initial examination, and those with no retinal breaks initially still have a 2-5% chance of developing a break within 6 weeks, highlighting the importance of thorough examination and appropriate follow-up 1.