Among the large family of bacteria, Acinetobacter group has been known as gram-negative, nonfermentative, aerobic coccobacilli which widely exists on skin, mucus membranes and in the urinary tract with relatively low virulence. However, its virulence would aggravate in patients with impaired hosts’ defenses or using broad-spectrum antibiotics in hospital. In contrast to patients who are admitted in the ICU, the rate of community acquired form of Acinetobacter infection is very low (5).
The ocular infections caused by Acinetobacter species are very rare. Patients with exposure of cornea, history of contact lens usage, history of penetrating keratoplasty (PKP), and immunosuppression are vulnerable for Acinetobacter keratitis and ocular infection (2). To best of our knowledge, our study is the first one that reported corneal ulcer by Acinetobacter following not repaired scleral laceration in a patient without mechanical ventilation and any evidences of systemic infection. However, our patient was in a compromised condition and had been admitted in ICU.
There are very few studies reported the ocular involvement provoked by Acinetobacter. It could demonstrates various ocular features. On the other hand, it feasibly could be co infected with fungi and the other bacteria (2, 3, 6, 7). R Roy et al. described the 4 cases of endophthalmitis caused by Acinetobacter baumanni; 3 of endophthalmitis were post cataract surgeries and the last one occurred in a patient with previous corneal repair due to trauma. All these patients underwent intravitreal antibiotic (Ciprofloxacin) and vitreoretinal surgical intervention. Finally, ocular condition of 3 of them deteriorated (one resulted in evisceration, one in phthisic eye and the other one developed retinal detachment, post vitrectomy) and only 1 patients reached to the visual acuity of 20/200 (8). Recently a case of Acinetobacter baumanni endophthalmitis has been reported, which resulted from intravitreal Ranibizumab injection (9).
In 2004, one study showed that one asymptomatic infectious cornea donor could result in post-PKP corneal ulcer in one cornea recipient and post PKP endophthalmitis in the other one (10). Additionally, it indicates the fact that we might be consider this problem in utilizing the corneal graft of patients who were admitted in ICU even without any apparent corneal infiltration.
In consensus with our finding, one study showed that exposure keratitis in patients with systemic diseases and admission in ICU would lead to Acinetobacter corneal ulcer which could be treated by antibiotic and tarsorrhaphy. In contrast to ours, the isolated Acinetobacter from urine that might be a sign of generalized infection with this organism with secondary corneal involvement (2).
Association of Acinetobacter species with soft contact lens–induced infiltration has been proved previously (11, 12). Acinetobacter species were isolated from 16 (13%) of 126 patient corneal infiltration samples. this study demonstrated that patient’s hand microbiota could be recognized as a possible source of Acinetobacter species which be transferred to ocular surface via contact lens (12).
Several studies revealed the trauma induced endophthalmitis with Acinetobacter, due to corneoscleral lacerations (13, 14). Additionally, Crawford et al reported the recurrent endophthalmitis that caused by multiple organisms including Acinetobacter. In this case, the contamination source is presumed to be self-contamination as a result of utilizing non-sterile antibiotic drops (1).
Acinetobacter species has been associated with keratitis and corneal ulcers caused in different settings have been reported (3, 15-17). A report from Korea showed that in contrast to most of bacterial keratitis, corneal ulcers induced by Acinetobacter usually were placed at peripheral site of the cornea (3). However, in our patient, the ulcer located at the lower third of the cornea that may explained by exposure keratitis in this special case.
De Oliveira Ribeiro et al. reported a history of 70-year-old patient who underwent phacoemulsification and intraocular lens (IOL) implantation. On postoperative day (POD) 9, he referred with severe eye pain and redness. B-mode ultrasound scanning showed the vitreous condensation, in favor of endophthalmitis. The posterior vitrectomy and sampling vitreous humor for culture and antibiogram was performed. The antibiogram showed multi drug resistant Acinetobacter baumanni. Hence, due to devastating pain and no response to antibiotic therapy, ocular evisceration was performed for the patient (9).
In conclusion, we should keep in mind to consider Acinetobacter as probable pathogen even in healthy patients but especially in patients stayed at ICU, even while may not show any evidence of Acinetobacter bacteremia simultaneously. It may not response to empiric treatment and progress to a devastating condition. Additionally, hand hygiene among ICU staff would obviate many ocular infections including Acinetobacter keratitis and corneal ulcer.