Intravitreal injection of povidone-iodine for the treatment of vancomycin-resistant Enterococcus faecalis endophthalmitis in rabbit eyes

Clinical characteristics and risk factors for visual prognosis according to the types of infectious endophthalmitis

BACKGROUND

Endophthalmitis is a fatal ophthalmological emergency that needs prompt diagnosis and treatment. This study aimed to evaluate the clinical characteristics and investigate risk factors for the visual prognosis of the different types of endophthalmitis.

METHODS

This retrospective study included 239 eyes diagnosed with endophthalmitis at the Pusan National University Hospital between January 2006 and December 2020. All patients were classified into six groups based on the etiology of endophthalmitis: post-cataract surgery, post-vitrectomy, post-glaucoma surgery, post-intravitreal injection, endogenous, and post-trauma. Demographics and clinical characteristics such as age, sex, laterality, initial symptoms, the interval between the primary causable event and diagnosis of endophthalmitis, initial and final visual acuity, management, and culture results were reviewed and statistically analyzed. Risk factors for poor visual prognosis were also analyzed according to the type of endophthalmitis.

RESULTS

Of the 239 cases of endophthalmitis, the most common cause was post-cataract surgery, that occurs within two weeks post-surgery. Gram-positive Staphylococcus was cultured most frequently. Fusarium was characteristically cultured from delayed post-cataract surgery endophthalmitis (14 days-6 weeks post-surgery). Post-vitrectomy endophthalmitis occurred within 3.3 days post-surgery, but post-glaucoma surgery endophthalmitis developed a long period after surgery, averaging 2,742 days. Post-intravitreal injection endophthalmitis occurred most frequently following bevacizumab injection, and Staphylococcus was most commonly isolated. For endogenous endophthalmitis, the pyogenic liver abscess was the most common underlying disease, and Klebsiella was isolated most frequently. Post-traumatic endophthalmitis mostly occurred in young men. Advanced age and poor initial visual acuity were risk factors for poor visual prognosis (P = 0.041, odds ratio = 1.024 and P < 0.001, odds ratio = 3.904, respectively, using logistic regression analysis).

CONCLUSION

Advanced age and initial visual acuity were risk factors for poor visual prognosis in cases of endophthalmitis caused by various etiologies. Early diagnosis and treatment of endophthalmitis are required, especially in older patients.

Efficacy of intravitreal povidone-iodine administration for the treatment of Candida albicans endophthalmitis in rabbits

This study aimed to investigate the efficacy of intravitreal povidone-iodine (PI) administration for the treatment of Candida albicans endophthalmitis. Forty New Zealand white rabbits were divided into four groups (n = 10 per group). After the induction of endophthalmitis using Candida albicans, groups A, B, and C received single intravitreal injections of 0.035 mg voriconazole, 0.3 mg PI, and their combination, respectively. Rabbits that were administered sham injections were in group D as controls. Fundus photography, vitreous culture, electroretinography (ERG), and histologic examinations of the retina were conducted on day 7. The anterior chamber flare (grade 0 to 4), severity of iritis (grade 0 to 4), and vitreous opacity (grade 0 to 3) were scored. Candida albicans was cultured in the vitreous sample. On day 7, the vitreous opacities were found in all groups. Compared to that in group D, groups A, B, and C showed a lower score for flare (p < 0.001) and iritis (p < 0.001) and less fungal growth in the vitreous culture (n = 2, 1, 1, and 10 in groups A, B, C, and D, respectively; p < 0.001). Furthermore, ERG and histologic findings demonstrated less affected a- and b-waves and damaged retinal tissues in groups A, B, and C. However, these findings were not different among groups A, B, and C. PI significantly improved Candida albicans endophthalmitis, and the effect was comparable that of the voriconazole, although some vitreous opacities remained. No synergistic effect of the combination of PI and voriconazole was observed. Intravitreal PI may be useful to treat Candida albicans endophthalmitis.