|Year : 2015 | Volume
| Issue : 2 | Page : 74-77
Endophthalmitis in a tertiary center in Nigeria
Odarosa M Uhumwangho, Efe P Akpata
Department of Ophthalmology, University of Benin Teaching Hospital, Benin City, Nigeria
|Date of Web Publication||14-Jul-2015|
Dr. Odarosa M Uhumwangho
Department of Ophthalmology, University of Benin Teaching Hospital, Benin City, P.M.B. 1111
Background: Endophthalmitis is a sight-threatening condition due to inflammation of intraocular structures usually from infectious organisms. The study aims to identify the pattern of presentation of endophthalmitis in a tertiary center in Nigeria. Materials and Methods: A retrospective observational study of cases with a diagnosis of endophthalmitis. Results: Twenty-six eyes of 26 patients were found comprising, 20 (76.9%) males and 6 (23.1%) females. The mean age of the patients was 32.4 ± 24.5 years (range 2-68 years) of which 11 (42.3%) were ≤ 16 years (P < 0.005). There were 14 (53.8%) right eyes and 12 (46.2%) left eyes involved. The most common etiology was post traumatic infection in 16 (61.5%) cases of which 11 (68.8%) occurred in children ≤ 16 years. Complications of cataract surgery was the only surgically related etiology in 7 (26.9) cases. Endogenous endophthalmitis is a rare occurrence. Conclusion: Supervised play in children, strict adherence to asepsis protocol in surgeries, prompt diagnosis with well-equipped ancillary investigations and appropriate early intervention will help limit the incidence of endophthalmitis and improve outcomes.
Keywords: Endogenous endophthalmitis, microorganisms, postsurgical, post traumatic
|How to cite this article:|
Uhumwangho OM, Akpata EP. Endophthalmitis in a tertiary center in Nigeria. Sahel Med J 2015;18:74-7
| Introduction|| |
Endophthalmitis is a sight-threatening condition characterized by inflammation of the intraocular structures usually from infectious organisms. Clinical features include decreased vision, usually associated with pain, presence of inflammatory cells in the anterior chamber and/or vitreous cavity, hypopyon, vitritis and vitreous exudation. These organisms gain access to the eye via a variety of routes. , It is classified based on the route of entry as either endogenous or exogenous. Endogenous endophthalmitis, also called metastatic endophthalmitis is an intraocular infection which occurs from hematogenous spread of pathogenic microorganisms, usually bacteria and fungi that have crossed the blood ocular barrier from a remote primary source. , It has no age or sex predilection and an immune-compromised state, debilitating diseases, and invasive procedures are high-risk factors. ,, It is less common being responsible for 2-8% of all cases of endophthalmitis. , On the contrary, exogenous endophthalmitis occurs when microorganisms are introduced into the eye via intraocular surgery such as cataract surgery, vitrectomy, intravitreal injections, penetrating keratoplasty and glaucoma filtering surgeries such as trabeculectomy. , The incidence of endophthalmitis and the spectrum of microorganisms following these different procedures varies. Its incidence following cataract surgery ranges from 0.07% to 0.32% , and vitrectomy, from 0.039% to 0.07%. , Other sources of inoculation occur following a breach in the coats of the eye, which occurs in penetrating ocular trauma, intraocular foreign bodies, corneal ulcers, and from the periocular infection. ,, The study was carried out to determine the etiology, profile and outcomes of endophthalmitis at a tertiary hospital in Southern Nigeria.
| Materials and Methods|| |
A retrospective study of consecutive cases of all patients with a diagnosis of endophthalmitis presenting to the University of Benin Teaching Hospital, Benin City, from January 2003 to December 2012 were included in the study. Inclusion criteria were evidence of endophthalmitis defined as the presence of anterior/posterior segment inflammation on ophthalmic examination with or without confirmatory ultrasound findings. Findings on slit lamp examination were presence of lid edema, conjunctival congestion, corneal edema, flare, inflammatory cells and hypopyon in the anterior chamber. Examination of posterior segment revealed vitritis or vitreous exudation. Collected data included patients' demographic characteristics, predisposing risk factors, source of infection, clinical examination, ocular features, investigations performed, microbiological profiles and antibiotic susceptibilities, treatment modalities, and final corrected visual acuity (VA) and anatomic outcome. Vitreous samples were taken and sent for microbiological analysis at the microbiology laboratory of the hospital. The samples were processed on culture media determined by the microbiologist based on likely pathogen. Confirmed microbiological diagnosis was based on microscopy (Gram-staining) and culture positivity. The samples were obtained from vitreal tap through the pars plana at 3 mm, 3.5 mm and 4 mm from the limbus in aphakic, pseudophakic and phakic eyes respectively. A culture was reported as positive following growth of the same organism in >1 media or a confluence of growth on the solid media at the inoculation site. 
Management of all cases consisted of injection of intravitreal broad spectrum antimicrobials after a vitreous aspiration through the pars plana. Intravitreal ceftazidime (2.25 mg/ml) and vancomycin (1.0 mg/ml) were given in suspected cases of bacterial infection. In fungal infection, intravitreal amphotericin B (5 μg/ml) was administered. A repeat injection was performed at 48 h if there was no clinical change, while those with significant improvement were observed. All patients were treated with concomitant systemic therapy (ciprofloxacin or ketoconazole for bacterial and fungal infections respectively). Guttae ciprofloxacin and fluconazole1% were also used in cases with bacterial or fungal etiology respectively. Therapy was modified as appropriate in line with results of microscopy, culture and sensitivity if there was no clinical improvement.
Grading of the VA was done in line with a previous study.  In patients with "beyond Snellen acuities," (count fingers [CF], hand movements [HM], light perception [LP], or no perception of light) pretreatment and posttreatment visual acuities were obtained. This was divided into three groups viz: (1) Improved, (2) unchanged and (3) deteriorated. An improvement was defined as either a gain of ≥ 2 lines of Snellen VA, in patients within Snellen acuity ranges or for those with "beyond Snellen" group, an improvement of one-measured step or more (for example, from HM to CF, or CF to 6/60)  (2) no change, and (3) deterioration defined as either a loss of ≥2 lines of Snellen VA in patients within Snellen acuity ranges, or for those following treatment ending up in the 'beyond Snellen' a loss of one-measured step or more (for example, from CF to HM, or HM to LP). 
Statistical analysis of the mean ages was performed using the GraphPad Instat Software, Inc. version V2.05a software program and comparison regarded as statistically significant for P ≤ 0.05.
| Results|| |
A total of 26 cases were seen during the study period. There were 26 eyes of 26 patients comprising 20 (76.9%) males and 6 (23.1%) females. The mean age of the patients was 32.4 ± 24.5 years (range 2-68 years) of which 11 (42.3%) were ≤ 16 years (P < 0.005). There were 14 (53.8%) right eyes and 12 (46.2%) left eyes involved. The duration of symptoms prior to presentation was 8.5 ± 8.9 days (range 1-30 days). The presenting VA ranged from no light perception (NLP) to 6/12, while the final VA ranged from NLP to 6/6. This is presented in [Table 1]. An improvement in VA was documented in 6 (23.1%) cases, no change in 13 (50.0%) cases, deterioration in 5 (19.2%) cases, and undetermined in 2 (7.7%) cases. The undetermined cases were because the exact VA was not documented thus precluding adequate comparison. Out of the 8 (30.8%) eyes with the final outcome of NLP, 2 (7.7%) cases had evisceration, 1 (3.8%) had enucleation and 2 (7.7%) became phthisical. The etiology of endophthalmitis is presented in [Table 2] showing that the most common cause of endophthalmitis was post traumatic infection in 16 (61.5%) cases of which 11 (68.8%) occurred in children ≤16 years. Complication of diabetes mellitus was a predisposing condition in 2 (7.7%) cases; which included the case with endogenous endophthalmitis. Vitreous samples for microbiological investigation were performed in 7 (26.9%) cases of which 3 (42.9%) cases were culture positive with the following microorganisms: Escherichia More Details coli and Candida sp in 1 (3.8%) case, Alcaligenes sp in 1 (3.8%) and Haemophilus sp and Candida sp in 1 (3.8%) case. Thus, 2 (7.7%) cases had mixed infection. Vitrectomy was not performed in any case.
|Table 1: Initial and final visual acuity in patients with endophthalmitis |
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|Table 2: Etiology, age and sex distribution of patients with endophthalmitis |
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| Discussion|| |
Endophthalmitis showed a higher male preponderance with a male to female ratio of 3.3:1. This may probably be due to the fact that most cases of endophthalmitis occurred following trauma in 61.5% of cases. Males tend to be more involved in trauma prone activities as reflected in previous studies. , The mean duration of symptoms prior to presentation was 8.5 days. Being a sight-threatening condition, early presentation with adequate intervention is paramount to salvage as much vision as possible. Delays in intervention enhance multiplication of microorganisms, increasing microbial load which ultimately, negatively affects prognosis. Factors associated with improved visual outcomes include early presentation for appropriate intervention; better presenting VA and isolation of nonvirulent organisms.  The 2 cases with mixed infection each had a final VA of NLP with phthisis.
There was no case of endophthalmitis from glaucoma filtering surgeries like the trabeculectomy. This is probably due to a decline in the use of surgery as the first-line treatment modality of open-angle glaucoma in the hospital due to the efficacy and increasing availability of drugs. The incidence of endophthalmitis following intravitreal injections is between 0.02% and 0.2%.  Post intravitreal endophthalmitis was not found in this study. This is despite the most frequent use of stock bevacizumab in comparison with ranibizumab primarily due to cost as patients have to pay from their pockets and insurance coverage is low. Appropriate aseptic protocol will produce comparable outcomes in the use of both drugs. The Catt trial has proven comparable outcomes in the use of both bevacizumab and ranibizumab.  Only one case of endogenous endophthalmitis was documented during the study period, which buttresses the fact that it is rare in comparison with exogenous endophthalmitis. Predisposing conditions such as diabetes mellitus was documented in 7.7%, including the case with endogenous endophthalmitis.
The microbiologic yield from laboratory tests of intraocular specimens of aqueous and vitreous is frequently low and dependent on multiple factors. These factors include method of collection of sample such as via a needle biopsy or an automated vitrectomy instrument, type of sample collected as vitreous samples have a higher yield than aqueous samples and the technique for culturing the intraocular specimens of the laboratory. ,, However, there is a need to routinely subject suspected cases of endophthalmitis for confirmatory microbiological investigations as results can determine treatment choices, final outcomes and visual prognosis.
A final VA of ≥ 6/60 was documented in only 3 (11.5%) and improved visual outcomes following treatment in only 6 (23.1%). This may be due to a combination of factors such as delayed presentation, absence of microbiologic investigation in all cases to help tailor treatment regimen instead of routine use of empiric drugs, and the fact that vitrectomy was not performed in any of the cases. Early vitrectomy, an established treatment modality for endophthalmitis increases the probability of attaining useful vision probably due to a reduction in the microbiological load of the organisms during treatment.  However, significant corneal involvement may preclude good visualization for safe vitrectomy. In such cases, intravitreal antimicrobials are still an appropriate treatment modality.
| Conclusion|| |
Endophthalmitis is a serious eye emergency. Visual outcome and prognosis are determined by the interplay of many factors such as delay in presentation, mixed infection and virulence of microorganisms as reflected in this study. It is imperative that the appropriate intervention be instituted as early as possible to limit the visual loss which often occurs.
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[Table 1], [Table 2]