Impact Of Herpes Simplex Virus Endosymbiont And Genotypic Diversity In Visual Outcomes In Patients With Acanthamoeba Keratitis
Published 2023 - 41st Congress of the ESCRS
Reference: FP14.04 | Type: Free paper | DOI: 10.82333/5e9v-ra56
Authors: Juan Carlos Navia* 1 , Paula A. Sepulveda-Beltran 1 , Alfonso Alexander 2 , Jorge Maestre 2 , Heather A. Durkee 3 , Jaime D. Martinez-Martinez 1 , Harry W. Flynn 1 , Eduardo Alfonso 1 , Jean-Marie Parel 3 , Guillermo Amescua 1 , Darlene Miller 2
1Ophthalmology,Bascom Palmer Eye Institute University of Miami,Miami,United States, 2Ocular Microbiology Laboratory,Bascom Palmer Eye Institute University of Miami,Miami,United States, 3Ophthalmic Biophysics Center,Bascom Palmer Eye Institute University of Miami,Miami,United States
Purpose
Acanthamoeba keratitis (AK) is a serious, sight-threatening and challenging infection that is difficult to diagnose. Nearly half of all AK cases are misdiagnosed as herpes simplex keratitis. Some organisms such as viruses, have developed strategies to survive intracellularly, and therefore are defined as endosymbionts. The aforementioned may increase the virulence of Acanthamoeba, leading to worse visual outcomes for patients. This study aimed to characterize the presence of Herpes Simplex Virus (HSV) type 1 and 2 in clinical isolates of patients with microbiological and or/histological confirmed AK at the Bascom Palmer Eye Institute (BPEI), and to assess the relationship between endosymbionts and patient’s visual outcomes.
Setting
The samples and data in this study were collected and processed in the Ocular Microbiology Laboratory of the Bascom Palmer Eye Institute of the University of Miami.
Methods
Ten acanthamoeba isolates were collected from patients with AK and grown on non-nutrient agar. PCR and DNA sequencing were used to identify the Acanthamoeba species, genotype, and screen for the presence of HSV type 1 and 2 as endosymbionts. Retrospective chart review was performed to collect demographic information and best-corrected visual acuities (BCVA) at time of AK diagnosis and last follow up.
Results
A. castellanii was found in (7/10) 70% of the isolates, followed by A. polyphaga in (2/10) 20% and A. triangularis in (1/10) 10%. T4 genotype was found in (10/10) 100% of the samples. HSV was present in (5/10) 50% of the isolates, of which (1/10) 10% was positive for HSV-1, (3/10) 30% for HSV-2, and (1/10) 10% for both. 10 eyes of 10 patients were included, with ages ranging from 19 to 67 years (M=41.8, SD=17.4). 80% being female and 20% male. Patients with HSV as an endosymbiont had an average BCVA of 1.46 and 0.57 LogMAR at diagnosis and final follow-up, respectively. Patients without endosymbionts had BCVA of 2.22 and 0.86 LogMAR at diagnosis and final follow-up.
Conclusions
In this study, we confirmed the presence of HSV endosymbiont in at least half of Acanthamoeba isolates recovered from patients with AK. The presence of the aforementioned was associated with a worse final BCVA compared to those without endosymbionts. Among the identified endosymbionts, HSV-2 was the most prevalent one. A. castellanii was the most frequently found species among the tested samples, and T4 genotype was identified in all samples. The presence of HSV endosymbionts may contribute to the severity of the disease and patients’ visual outcomes.