Evaluation of Multifocal ERG and Visual Field Changes After Vitrectomy and ILM Peeling

Evaluation of Multifocal ERG and Visual Field Changes After Vitrectomy and ILM Peeling

To evulate changes in MfERG, VF and OCT after viterctomy associated with ILM peeling.

Macular epiretinal membrane (ERM) is a disorder of the vitreomacular interface characterized by fibrocellular proliferation on the anterior surface of the internal limiting membrane (ILM) of the macula. Pars plana vitrectomy with ERM removal and inner limiting membrane peeling is the standard surgical treatment for an ERM. ILM peeling is performed to eliminate the scaffold for myofibroblast proliferation and any microscopic ERM in order to prevent ERM recurrence. ILM peeling is indicated for other pathologies other than ERM such as, diabetic macular edema, and macular hole. ILM peeling is a traumatic procedure that may have many effects on the underlying inner retinal layers that may lead to changes in retinal function.

Retinal edema, eccentric scotoma, dissociation of the nerve fiber layer, iatrogenic punctuate chorioretinopathy, and subretinal, retinal, and vitreous hemorrhage are well described secondary to the surgical trauma of peeling in addition to stain toxicity. Investigation of these changes may assist in aiding the development of minimally traumatic techniques for ILM removal .

Evaluation of functional changes may include visual field and Multifocal electroretinography assessment. Visual field defect after vitrectomy a well known post operative complication usually in eyes that underwent fluid air exchange, the cause of visual field defect remain unclear.

Optical Coherence Tomography (OCT), imaging is done to evaluate inner retinal layers after ILM peeling,High myopic eyes might develop more severe, "scattered" inner retinal defects after ILM peeling.

Multifocal electroretinography (mfERG), has been used to assess visual function and the electrophysiologic responses of multiple retinal locations of the macular area

Inclusion Criteria:

1. Idiopathic ERM,
2. Primary full thickness macular hole,
3. Lamellar macular hole, and
4. Vitromacular traction

Exclusion Criteria:

• 1-Patients with a secondary ERM,

  1. diabetic retinopathy,
  2. venous occlusion,
  3. retinal detachment,
  4. uveitis, and
  5. trauma. 2-Other ocular pathologies that could interfere with the functional results
  1. dense cataract ,
  2. glaucoma, and
  3. previous retinal surgery