1. Characteristics of Infectious Keratitis Associated with High Intraocular Pressure
Elmira Baghdasaryan1,2, M.D.
Sophie X. Deng1, M.D., Ph.D.
Fei Yu1, Ph.D.
1 Jules Stein Eye Institute, University of California, Los Angeles
2Yerevan State Medical University after M. Heratsi
Authors have no financial interest.

2. Background
Infectious keratitis is an inflammation of the cornea caused by bacteria, fungi, protozoa or viruses.
It is considered an ocular emergency and often associated with pain, photophobia, and redness.
Prevalence of keratitis differs with geographical area, occupation, age, and even different seasons.1,2
In a number of developing countries, microbial keratitis is the second most common cause of preventable blindness after cataracts.3,4
1.Derek Y., Kunimoto S Sh, Prashant Gary, Usha G, et al. Corneal ulceration in the elderly in Hyderabad South India. Br. J ophthalmol 2000;84:54-59.
2. Schaefer Frederic, Olivier Bruttin, Zagrafos, Bacterial keratitis: A prospective cilical and microbiological study. B J Ophthalmology 2001; 85:
3. Upadhyay MP, Karmacharya PC, Koirala S, et al. Epidemiologic characteristics, predisposing factors, and etiologic diagnosis of corneal ulceration in Nepal. Am J Ophthalmol 1991;111(1):92-9.
4. Gonzales CA, Srinivasan M, Whitcher JP, Smolin G. Incidence of corneal ulceration in Madurai district, South India. Ophthalmic Epidemiol 1996;3(3):

3. Purpose
We conducted a retrospective study using a case-control design to describe the risk factors, clinical characteristics, outcomes, and microbiological profiles of acute infectious keratitis associated with high intraocular pressure (IOP).

4. Materials and Methods
A retrospective chart review of 184 cases of culture-proven infectious keratitis was conducted at a single institution from January 2003 to December Fifty-two of these cases, which were associated with high IOP (K-IOP group), were compared to the other 132 cases without IOP elevation (control group).
Elevated IOP was defined as IOP > 21 mm Hg.
Resolution of the ulcer was defined as absence of the epithelial defect.

5. Risk Factors Risk factors that were studied include:
Contact lens wear
Prior ocular trauma
Prior ocular surgery
Diabetes Mellitus (DM)
Neurotrophic keratopathy
Exposure keratopathy
Systemic immunosuppressants
Systemic steroid use
H/o glaucoma
Age, sex, IOP data, rate of performed penetrating keratoplasties (PKP), evisceration, best corrected distance visual acuity (BCDVA), and microbiological profiles were also evaluated.

6. IOP Range for Both Groups
IOP max
(mm Hg)
K – IOP group
(n = 52)
Control group
(n = 132)
Range
22 to 51 mm Hg
10 to 21 mm Hg
Mean ± SD
29.1 ± 6.9 mm Hg
16.3±2.7 mm Hg
Median
27.2 mm Hg
16 mm Hg
a – Fisher exact test

7. Diabetes Mellitus (DM)
Risk Factors
Risk Factors
K-IOP group
(Total = 52)
N (%)
Control group
(Total= 132)
P-value a
Diabetes Mellitus (DM)
15 (29%)
16 (12%)
0.009
H/o glaucoma
18 (14%)
0.02
Prior Ocular Surgery
32 (62%)
43 (33%)
<0.001
Large Ulcer Size (≥4 mm)
34 (65%)
42 (32%)
a – Fisher exact test

8. Neurotrophic Keratopathy
Risk Factors
Risk Factors
K-IOP group
(Total = 52)
N (%)
Control group
(Total= 132)
P-value a
Contact Lens Wear
14 (27%)
62 (47%)
0.013
Neurotrophic Keratopathy
4 (8%)
16 (12%)
0.44
Exposure Keratopathy
9 (17%)
20 (15%)
0.82
Prior Trauma
0.23
Prior Steroid Use
11 (21%)
24 (18%)
0.68
a – Fisher exact test

9. Rate of Surgical Intervention
K-IOP group
Total=52
N (%)
Control Group
Total=132
P-value a
Penetrating keratoplasty
15 (29%)
12 (9 %)
0.002
Evisceration
4 (8 %)
2 (2 %)
0.055
a – Fisher exact test

10. Visual Acuity Percentage of Patients VA at the last follow-up visit b
VA at the initial presentation a
VA at the last follow-up visit b
a – p-value = b- p-value=0.004

11. Results-Summary
IOP elevation, ranging from 22 to 51 mm Hg (mean 29 mm Hg), occurred in 52 of 184 cases (28%) of microbial keratitis. Prior ocular surgery, DM, history of glaucoma, and large ulcer size (>4 mm) were significantly associated with IOP elevation during infection. The other risk factors were not significantly associated with IOP elevation. More patients achieved corrected VA of 20/40 or better at the last follow-up visit in the control group (49 %) than in the K-IOP group (23 %, p= 0.004). Furthermore, significantly more patients required PKP in the K-IOP group than in the control group (p=0.002).

12. Conclusions
Elevated IOP was common, detected in 28% of patients with infectious keratitis.
IOP elevation should be closely monitored during infection and treated.
Patients with elevated IOP had poorer visual acuity and higher rates of penetrating keratoplasty and evisceration. Aggressive treatment should be done to reduce subsequent complications.