The Influence of Silicone Oil on Nerve Fiber Layer Thickness After Pars Plana Vitrectomy

The aim of the study is to evaluate the influence of silicone oil on thickness of the retinal nerve fiber layer by using optical coherence tomography (OCT) in patients following pars plana vitrectomy.

The aim of the study is to evaluate the influence of silicone oil on thickness of the retinal nerve fiber layer by using optical coherence tomography (OCT) in patients following pars plana vitrectomy.

The study will include 60 patients with a temporary silicone oil tamponade who will be surgically treated with pars plana vitrectomy for rhegmatogenous retinal detachment and proliferative vitreoretinopathy. All subjects will be subdued to complete ophthalmologic examinations, measurements of the retinal nerve fiber layer thickness by an OCT examination, tests of the visual field with the use of an Octopus computed perimeter (automated static perimetry) and FDT-perimetry - both prior to the surgery, and on control visits for check-up during the postoperative period.

All results provided by postoperative examinations will be compared with one another.

The study is expected to provide data on the effect of the silicone oil on thickness of the retinal nerve fiber layer. It is also planned to show possibilities and advantages of OCT as a method of choice in the follow-up of patients with intraocular silicone oil tamponade.

tertiary care clinic

• Rhegmatogenous Retinal Detachment
• Toxic Effect of Silicone
• Glaucoma Due to Silicon Oil

• Other: Optical coherence tomography

  Optical coherence tomography will be performed in all study patients following pars plans vitrectomy and silicone oil tamponade. A fellow eye of each patient will serve as a control. Each patient enrolled in a study will receive 4 measurements:

  1. On 7th postoperative day
  2. On 30th postoperative day
  3. On 90th postoperative day
  4. On 180th postoperative day
  Other Name: Cirrus HD OCT ( Carl Zeiss Meditec, Dublin, CA )
• Drug: Local medical treatment of raised intraocular pressure

  In patients with raised intraocular pressure following medications will be employed in order to control the intraocular pressure:

  Cosopt (dorzolamide hydrochloride-timolol maleate ophthalmic solution; b.i.d.) Ganfort (Bimatoprost, timolol maleate ophthalmic solution; once daily) Alphagan (Brimonidine ophthalmic solution; b.i.d.) In patients with intraocular pressure less than 27 mmHg Alphagan will be prescribed. In patients with intraocular pressure greater than 27 mmHg either Cosopt, or Ganfort will be prescribed under the discretion of treating physician. If intraocular pressure in patients treated with either Cosopt or Ganfort does not drop under 21 mmHg, Alphagan will be added.

  Other Names:

  • 1. Cosopt

  • 2. Ganfort
  • 
 3. Alphagan

• NO IOP
  Patients without raised IOP
  Intervention: Other: Optical coherence tomography
• RAISED IOP
  Patients with raised IOP
  Interventions:

  • Other: Optical coherence tomography
  • Drug: Local medical treatment of raised intraocular pressure

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Inclusion Criteria:

- patients with rhegmatogenous retinal detachment

Exclusion Criteria:

• preexistent glaucoma
• previous retinal surgery
• placement of scleral buckle during surgery
• patients with more than 1/2 of emulsified silicone oil in anterior chamber postoperatively
• patients who develop silicone oil keratopathy postoperatively
• patients who develop silicone oil cataract which blocks visualization of posterior segment