Study of the Correlation Between Severity of Endophthalmitis and Posterior Vitreous Detachment Using a Rabbit Endophthalmitis Model

Abstract

Purpose We have reported that the absence of posterior vitreous detachment (PVD) is related to the onset and severity of infectious endophthalmitis, based on clinical experience. To demonstrate clinical findings in animal models, we created endophthalmitis models for the presence or absence of PVD and examined differences in severity. Method We estimated a rabbit infectious eye model with and without PVD using Pseudomonas aeruginosa (PVD(+) and PVD(−) groups). After injection of bacteria inoculation for 3, 6, 12, and 24 hours, we evaluated the clinical score of the anterior chamber ( n = 14). Removing the vitreous and retina from the enucleated eyeballs, the number of bacteria was counted using each specimen ( n = 12). In addition, the number of inflammatory cells approximately 3 mm 2 around the optic disc and histopathologic grading of intraocular inflammation was compared from histopathologic images ( n = 7). Electroretinogram (ERG) was performed in experimentally infected rabbit eyes in both groups at three times after injection of the bacterial suspension. Results There was no difference between the two groups in the clinical score of the anterior chamber of each time phase, but the bacterial cultures showed significantly fewer bacteria in the PVD(−) group 24 hours after bacterial inoculation ( P < 0.05). Furthermore, the number of inflammatory cells was significantly less in the PVD group ( P < 0.05). As a result of ERG, the decreases of a- and b-waves in amplitude were significantly greater in the PVD(−) group than in the PVD(+) group. Conclusions The present study confirms using animal models that the absence of PVD contributed to the severity of bacterial endophthalmitis.

In vivo and in vitro efficacy of the ithmid kohl/zinc-oxide nanoparticles, ithmid kohl/Aloe vera, and zinc-oxide nanoparticles/Aloe vera for the treatment of bacterial endophthalmitis

“…To reduce the intraocular pressure to a satisfactory level, an anterior chamber paracentesis was performed using a 27-gauge needle. Subsequently, 100 µl of the K. pneumoniae suspension was injected with a 30-gauge needle 6 mm away from the corneal limbus 14 . After 24 h, the eyes of the rabbits showed signs of endophthalmitis, including hypopyon in the anterior chamber and edema of the conjunctiva 14 .…”

“…Subsequently, 100 µl of the K. pneumoniae suspension was injected with a 30-gauge needle 6 mm away from the corneal limbus 14 . After 24 h, the eyes of the rabbits showed signs of endophthalmitis, including hypopyon in the anterior chamber and edema of the conjunctiva 14 . After 2 days, the inflammatory symptoms intensified, and the eyeballs demonstrated retinal necrosis, indicating the establishment of intraocular infection 14 .…”