The
addition of hyperbaric oxygen therapy to standard treatment improved visual
acuity and reduced corneal oedema in patients with keratoendotheliosis.
Clinical Bottom Line:
1.
Hyperbaric oxygen therapy is associated with improved visual acuity and
reduced corneal oedema in patients with keratoendotheliosis.
2.
Hyperbaric oxygen therapy was associated with a lower risk of corneal
neovascularization secondary to keratoendotheliosis.
Appraised
by: Mike Bennett,Dept of Diving and
Hyperbaric Medicine,Prince of Wales Hospital,Sydney; Wednesday, 20 January, 1999
Clinical
Scenario:
A 75 year old patient who developed secondary keratoendotheliosis
following cataract extraction.
Three-part
Question: In patients developing
keratoendotheliosis following cataract surgery, does the administration of
hyperbaric oxygen, in addition to standard care, result in reduction of corneal
oedema or improvement in visual acuity?
Search
Terms: Hyperbaric oxygenation,
Cataract extraction/complications.
The
Study:
Non-blinded randomised
controlled trial with intention-to-treat.
Patients with
keratoendotheliosis secondary to surgical treatment where there was no evidence
of direct endothelial irritation.
Control group (N = 21; 21
analysed): Local corticosteroids, hypertonic saline, antibiotics and
autohaemotherapy. Epithelial stimulators locally if ulcer present. Systemic
diuretics, vitamins, magnesium and potassium salts.
Experimental group (N = 12; 12
analysed): As above plus hyperbaric oxygen at 2ATA for 90 minutes daily for 10
days.
The
Evidence:
|
Outcome |
Time
to Outcome |
Control
rate |
HBO
rate |
Relative
risk reduction |
Absolute
risk reduction |
NNT |
|
visual
acuity not improved |
10
days |
0.76 |
0.17 |
78% |
0.6 |
2 |
|
95%
CI: |
|
|
|
41%
to 100% |
0.31
to 0.87 |
2 to 4 |
|
corneal
width not reduced |
10
days |
0.81 |
0.5 |
38% |
-0.31 |
3 |
|
95%
CI: |
|
|
|
-2%
to 79% |
-0.02
to 0.64 |
NNT=2
to INF NNH=53 to INF |
|
Corneal
oedema not reduced |
10
days |
0.76 |
0.33 |
57% |
0.43 |
3 |
|
95%
CI: |
|
|
|
14%
to 99% |
0.12
to 0.75 |
2
to 10 |
|
Corneal
neovascularization |
10
days |
0.24 |
0 |
100% |
0.24 |
4 |
|
95%
CI: |
|
|
|
|
0.06
to 0.42 |
2
to 18 |
Comments:
1. Poor randomisation with
allocation of those not fit for hyperbaric therapy to the control arm threatens
the validity of this study.
2. No follow-up beyond end of
treatment period.
3. No functional clinical
outcome is given, making the impact of the differences noted difficult to
assess.
Expiry date: October 2003
References:
1. Recupero SM, Cruciani F, Picardo V,
Sposato PA, Tamanti N, Abdolrahimzadeh S. Hyperbaric oxygen therapy in secondary
keratoendotheliosis. Annals of Ophthalmology 1992; 24:448-452.
