This document discusses various causes of elevated intraocular pressure (IOP) after pars plana vitrectomy (PPV) surgery and treatment strategies. Some causes include using an incorrect gas mixture which leads to a higher gas concentration, overfilling the vitreous cavity with gas or silicone oil, and injecting too much silicone oil without checking the IOP. Treatment approaches depend on the specific cause but may include medical management, silicone oil removal, filtering surgeries, or drainage implants. Understanding the mechanisms that cause elevated IOP guides selecting the best treatment.

1. Mohamed ELShafie
Lecturer of ophthalmology
Kafr ELShiekh university

2. Expansile gas
Silicon oil
Steroid
Particulate
viscosity

3. (almost always iatrogenic)
 Incorrect gas mixture:
Smaller syringe than usual
same volume but greater concentration
 High gas concentration in sever PDR
 Partial fill of vitreous cavity with gas > 25%
SF6
 Total fluid air exchange followed by 100 %
gas injection

4.  IOP maximum 4 – 8 hs postoperative, patient
not seen…. CRAO or optic nerve ischemia
 prescribing pain medications, patient calls at
night reporting pain
pain is secondary to high IOP, not to surgery.

5. Injecting too much oil, not check IOP
thinking that volume will decrease
with time.
incorrect air silicone exchange causing
over pressurization.

6.  Never leave capsule for sulcus implantation:
- Capsular fibrosis close inferior iridectomy needed
to enable silicon oil to enter AC
- concave iris adhere to capsule (iridocapsular
adhesions), makes sulcus implantation of an IOL
rarely possible.

7. (A) Intial medical treatment is effective in most
cases.
(B) Surgical
1. silicone oil removal alone ?!
2. Conventional filtering surgeries ?!
3. drainage implant
- Inferior quadrant: prevent silicone oil blocking the
tube, BUT interfere with supine ocular massage
- Viscoelastic in AC to keep silicon back

8.  Silicon oil emulsification:
- inflammation decrease
- bleeding surface
- viscoelastic …(viscodissiction) tension
- incomplete fill

9.  perfluorocarbon droplet:
- used for 2 w. in inferior RD or Gaint tear
PFO or emulsified silicon oil: never absorb
- two needle technique for AC
- PPV revision for vitreous cavity
- tube shunt inferiorly in oil filled eye with viscot filling AC

10.  Retained lens particles:
Phacolytic or phacoanaphylactic glaucoma
Lens particles:
- small : absorb
- large : need to remove
- frosted appearance on surface caused by
macrophages: indicator for removal.

11.  High protein content in AC:
- inflammation:
o Iritis
o trabeculitis
o uveitis
- Iris, TM neovessels
 Retained viscoelastic in AC:
- used to keep silicon or gas back especially
viscot in combined phacoviterctomy

12.  subconjunctival:
- triamcinolone long acting than dexamethazone
 Topical:
- Difluprednate more potent than prednisolone
 Intravitreal:
- Triamcinolone, Dexamethasone or Fluocinolone
• delayed onset: days to weeks

13. • all patients are steroid responders if high dose
prednisolone
Difluprednate
Dexamethasone
Triamcinolone
Fluocinolone

14.  Pars plana tap:
- 30 G needle for gas
- 23 – 25 G needle for silicon oil
 AC paracentesis :
- oil or gas migrate anteriorly in AC
 Inferior laser iridectomy:
- if not performed or closed

15. - A variety of mechanisms can cause elevated IOP
after PPV.
- Understanding them drives selection of optimal
treatment strategies.

16. Thank You
Mohamed ELShafie