Microbial Keratitis in Thyroid Eye Disease: Clinical Features, Microbiological Profile, and Treatment Outcome

Abstract

Microbial Keratitis occurs in 1.3% cases of Thyroid Eye Disease. It is more common in men, and in active disease. The microbiological spectrum and possible clinical risk factors are presented. Purpose: To report the incidence, clinical features, microbiologic profile, and risk indicators in the development of microbial keratitis in Thyroid Eye Disease (TED). Methods: All patients who were diagnosed to have TED and developed microbial keratitis between the years 2009 to 2017 at the Ophthalmic Plastic Surgery service, LV Prasad Eye Institute were included in this retrospective interventional study. The clinical features, microbiological profile, and treatment outcome of the infection were studied. Possible risk factors leading to the development of microbial keratitis were studied. Results: A total of 1,000 patients of TED were evaluated in the 10-year period. Of the 1,000, 13 patients (14 eyes, 1.4%) were diagnosed with microbial keratitis. The average age at presentation was 44 years (range 1969 years). Of the 13 patients, 10 (77%) were men, 12 (92%) were hyperthyroid, and 12 (92%) were active (average clinical activity score 3) at presentation. Average exophthalmometry value in the involved eye was 24.75mm, and severe eyelid retraction (>2mm scleral show) was noted in 13 of 14 eyes. None of the patients had optic nerve compression. Moderate motility restriction (2 in all gazes) was noted in 6 eyes, and severe motility restriction (4 in all gazes) in 8 eyes. At presentation, 11 (85%) had visual acuity of counting fingers at 1 meter or less, The mean follow up from the time of presentation was 18.3 months (range 566 months). Majority of the eyes (8/14) presented with severe infection (panophthalmitis with microbial keratits = 1, total corneal infiltrate with/without melt = 4, severe thinning/perforation = 4). Microbiological work up of 14 eyes revealed presence of gram-negative bacteria in 5 eyes which included Escherichia coli, Pseudomonas sp., and Acinetobacter sp., and gram-positive bacteria in 4 eyes including Streptococcus pneumoniae, Corynebacterium sp., and Staphylococcus sp. Three eyes revealed a mixed infection of E. coli with Alternaria sp, and E. coli with Corynebacterioum amycolatum while 1 had Corynebacterium pseudodiptheriticum, and S. pneumoniae. Two eyes of the bilateral case showed no growth. Antibiotic susceptibility revealed 6 of the 7 gram-negative isolates were multidrug resistant, whereas the gram-positive isolates were susceptible to most drugs tested. Surgical procedures required were tarsorrhaphy in 7 eyes, tissue adhesive with bandage contact lens in 4, evisceration in 4, levator recession in 2, 3-wall orbital decompression in 2, and penetrating keratoplasty in 1 eye. The visual acuity at presentation was counting fingers or worse in 10/14 eyes. Posttreatment, 10 eyes achieved resolution of infiltrate (with visual improvement in 2), and 4 required evisceration. Conclusions: In the authors large series of TED, microbial keratitis was noted in 1.3% of patients presenting to a tertiary eye center. Majority presented with advanced diseases and ended with a poor outcome. Gram-negative isolates showed multidrug resistance. An association with early phase of active TED (CAS 3 or more), severe eyelid retraction, and moderate-severe motility restriction is suggested.

Comparison of the ocular surface microbiota between thyroid-associated ophthalmopathy patients and healthy subjects

“…The other, cutibacterium acnes , can cause postoperative endophthalmitis ( Fowler et al., 2021 ) and keratitis ( Ovodenko et al., 2009 ), but its detection rate on the ocular surface of TAO patients is significantly higher. In previous studies of TAO-exposed keratitis, successful bacterial culture include Pseudomonas sp., Acinetobacter sp., Corynebacterium sp., Escherichia coli , Streptoccocus pneumoniae , Staphylococcus aureus and Staphylococcus epidermidis , some of which were consistent with the results of sequencing and culture in this study ( Naik et al., 2019 ). This suggests that the presence or increased average relative abundance of these potential pathogens increases the potential risk of ocular surface infection in non-exposed keratitis TAO patients.…”

“…The dominant bacteria, Corynebacterium (average relative abundance, 10.13%) and Staphylococcus (average relative abundance, 6.68%), in all ocular surface samples of TAO, are easier to obtain pure strains under suitable conditions, and the detection rates of Corynebacterium and Staphylococcus were 36.4% and 27.3%, respectively. These two species have also been detected in previous studies on TAO-exposed keratitis, with the detection rates of Corynebacterium and Staphylococcus being 25% and 17.7%, respectively (Naik et al, 2019). However, only Brain-Heart Infusion medium was used in this study, which could not meet the growth conditions of other TAO ocular surface dominant bacteria, such as Cutibacterium, Pseudomonas, and Escherichia-Shigella.…”

“…In this study, the positive rate of sequencing reached 100%, and 756 bacteria were found at the “genus” level, but the positive rate of culture was 67.4%, and 11 bacterial strains were found. Even in previous studies of TAO-exposed keratitis, 14.3% of samples were not successfully cultured ( Naik et al., 2019 ). The findings of the present study suggest that part of the sequencing results was consistent with the culture.…”

“…As can be seen, the pathological mechanism and clinical manifestations of TAO suggest that the disease may alter the ocular surface microbiota of patients. These changes have been confirmed in the study of exposure keratitis in patients with TAO, and various pathogenic bacteria and opportunistic pathogens have been cultured (Naik et al, 2019). However, the changes in ocular surface microbiota of TAO patients without exposed keratitis remain to be further explored.…”

The Nasopharyngeal Carcinoma and Its Effect on the Infectious Eye Disease: A Nationwide Cohort Study

“…Additionally, we only included the infectious keratitis episode that occurred one year after the diagnosis of NPC, thus the time sequence between the NPC and subsequent infectious keratitis had been established. The infectious keratitis occurs more frequently in those with thyroid eye disease and exposure keratopathy according to previous literatures [ 27 , 28 ]. Besides, the patients with dry eye disease are prone to develop corneal disorders, such as the corneal erosion and infectious keratitis [ 29 , 30 ].…”