Liver abscess is the most common risk factor for endogenous endophthalmitis in East Asian countries including China. A retrospective analysis of 19 related cases was conducted, of which 14 cases (14/19,73.7%)had febrile symptoms before onset, it is suggested that there is septicemia and the bacteria have spread into the blood.
Therefore, fever is a dangerous signal that a liver abscess may harm the eyes, and endophthalmitis may also occur in some patients without fever. It shows that bacteria can infect eye tissue through bacteremia without fever. Of the 19 patients in our study, 13 (68.4%) had diabetes, which was roughly consistent with previous studies. The incidence of endophthalmitis caused by a liver abscess in patients with diabetes is 3.6–11.0 times higher than that in normal people [5]. Because diabetes can cause microcirculation disturbance, reduce vascular stability, increase vascular permeability, destroy the blood-retinal barrier, and create conditions for pathogenic bacteria to invade the eye [6].
We compared the visual outcome of endophthalmitis caused by liver abscess and exogenous endophthalmitis in our hospital. It is suggested that the prognosis of endophthalmitis caused by liver abscess is worse than that of exogenous endophthalmitis. We think there are three reasons for this phenomenon.
First, the time interval between the infection of the eye and going to the ophthalmology for treatment for the first time is different. Most of the patients with exogenous endophthalmitis are primary lesions on the eyes, and the patients are easy to detect in the early stage because the attention of the patients is focused on the eyes and the compliance of the patients is good. Patients with endophthalmitis caused by liver abscess are accompanied by systemic diseases, and some patients have general discomfort during the onset of the disease, which diverts the patient's attention, and the focus of the patient's attention may be on the systemic condition while ignoring the eye symptoms.
Five of our patients did not first go to the ophthalmology department for treatment. The average duration of ophthalmic symptoms of patients who go to non-ophthalmology for diagnosis and treatment for the first time was 12.2 ± 3.58 days, which was significantly longer than that of 5.71 ± 1.25 days go to ophthalmology for the first time. The duration of ophthalmic symptoms before ophthalmology treatment is significantly related to the first diagnosis department. The patients go to non-ophthalmology for diagnosis and treatment for the first time will delay the patient's condition and delay the early diagnosis of endophthalmitis. Therefore, departments related to systemic diseases that may cause endogenous endophthalmitis should strengthen doctors' understanding of endophthalmitis, pay attention to patients' eye symptoms, and inquire about eye performance as a routine consultation of the disease.
Second, the difference in virulence of pathogenic bacteria leads to a great difference in prognosis. Most of the bacteria causing exogenous endophthalmitis are less virulent bacteria such as staphylococcus epidermidis, β-streptococcus, and staphylococcus aureus. While the main pathogen of endogenous endophthalmitis caused by liver abscess is KP. In our study, 7 eyes out of 21 eyes showed positive results of vitreous fluid bacterial culture, all of which were Klebsiella pneumonia, with a positive rate of 33.3%. Drug sensitivity tests showed that KP was sensitive to antibiotics except for ampicillin, which was consistent with the results of pathogens and drug resistance reported in previous experiments.
The high virulence of KP is mainly due to the irreversible damage of retinal photoreceptor cells within 48 hours after infecting the intraocular environment, so it is the golden rescue time for endophthalmitis caused by liver abscess within 48 hours after the onset of ocular symptoms. The final visual acuity of 7 eyes with positive results of microbial culture was improved by-0.0003 ± 0.0005, and the average visual acuity of 14 eyes with negative results was improved by 0.098 ± 0.134. It can be seen that the toxicity of KP will have a serious impact on visual function, if the bacteria and their toxins can not be cleaned up in the early stage, it will have a devastating effect on visual function. Therefore, the early detection and early treatment of the disease is particularly important, especially within 48 hours after the occurrence of eye discomfort. However, bacteria invade the eye at an early stage, the patient may not have any eye symptoms, and when the patient has eye symptoms, it indicates that the infection has developed to a serious extent, so the time left for ophthalmologists to save visual function will be more urgent.
Third, the accumulation sites of pathogenic bacteria and pus are different, and the pathogenic bacteria of exogenous endophthalmitis are mostly located in the anterior chamber and vitreous cavity. The pathogenic bacteria of endophthalmitis caused by liver abscess spread into the eye through the blood. In addition to the anterior chamber and vitreous cavity, a large number of bacteria accumulate under the retina, and it is more difficult to deal with subretinal bacteria and pus. The blood-eye barrier and the physical barrier of the retina limit the effect of systemic or vitreous injection on the subretinal lesions, and the failure to completely remove the subretinal lesions will lead to repeated attacks of the disease, so patients treated with IVI may need multiple injections, and the prognosis is poor. Of the 11 eyes who underwent vitrectomy, subretinal empyema was found in 6 eyes. Thorough removal of subretinal pus during the operation is a key factor affecting the prognosis of the affected eyes. For patients with endophthalmitis caused by a liver abscess, vitrectomy is of great significance to improve the prognosis, and to avoid the pain caused by repeated vitreous injection after the operation. The advantage of vitrectomy over simple vitreous injection is that it can quickly clean up the pathogenic bacteria in the vitreous cavity, clean up the subretinal pus and pathogenic bacteria that are difficult to be improved by conventional drug treatment, and improve the intraocular environment in time, create conditions for the recovery of retinal function.
Among the patients we treated, 3 eyes of 9 eyes treated with simple vitreous injection were treated with evisceration because the inflammation could not be controlled, so the inflammation control rate of IVI combined with systemic antibiotics was low for some pathogenic bacteria hidden in the subretinal lesions, and it was more likely that the subretinal lesions could not be cleared and the inflammation would eventually develop to panophthalmitis. In 12 eyes treated by vitrectomy, the evisceration of ocular contents was performed in 1 eye with panophthalmitis caused by recurrent inflammation. The patient with recurrent endophthalmitis after vitrectomy is transferred to hepatobiliary surgery after eye condition stable to continue treatment of liver abscess, the patient with unstable liver abscess and discharged from hospital, and systemic antibiotics are not regularly used outside the hospital, resulting in recurrent infection caused by a liver abscess. Therefore, different from the treatment of exogenous endophthalmitis only focusing on the eye condition, endophthalmitis caused by liver abscess must be actively treated based on the treatment of eye diseases. The unliquefied liver abscess is given sufficient antibiotics, and the liquefied liver abscess should be given corresponding surgical treatment actively, which is of great significance to prevent the recurrence of endophthalmitis caused by a liver abscess.
To sum up, we should strengthen education for patients with liver abscess and diabetes, pay attention to the symptoms of eye discomfort, especially teach patients to alternately cover the eye and monocular vision every day when they have symptoms of fever, to detect the loss of monocular vision which is not easy to detect in the early stage. Also, the publicity and education to other fraternal departments are of great significance. While treating systemic diseases, we should pay attention to the main complaints of patients' eye discomfort, and shorten the interval for patients to receive treatment in ophthalmology, to achieve the purpose of early detection and early treatment. The pathogenic characteristics of Klebsiella pneumonia indicate that the early detection and early intervention of endophthalmitis caused by liver abscess are of great significance to improve the prognosis. Most of the endophthalmitis caused by liver abscess have subretinal abscess lesions, and the treatment of subretinal lesions is the key to successful treatment, so vitrectomy has a better prognosis than vitreous injection alone.