DISCUSSION
There is suspicion and some evidence that SARS-COV2 invades ocular
surfaces. Possible mechanisms such as direct conjunctival contact of
infected droplets, hematogenous infection of the lacrimal gland or viral
migration from the upper respiratory system have been described for the
SARS-COV-2 virus to infect the ophthalmic surface (17). The incidence of
conjunctivitis in patients with COVID-19 has been reported as 0.8 and
4.76 percent (18)(19)(20).
In the study conducted by Ping Wu et al., the ocular symptoms of 38
patients who were clinically diagnosed as having COVID-19 and treated as
inpatients were questioned, and RT-PCR was performed by taking
nasopharyngeal and conjunctival samples. Although SARS-CoV-2 was
detected in nasopharyngeal samples in 28 (73.7%) patients, it was shown
in conjunctival samples in only 2 (5.2%) patients. However, in 12 of 38
patients (31.6%), symptoms related to conjunctivitis such as
conjunctival hyperemia, chemosis, and epiphora were observed. Ocular
symptoms were mostly observed in patients with severe pneumonia and the
middle stage of the disease (16).
In an epidemiologic study conducted in China on 534 patients who were
SARS-CoV-2–positive, 25 (4.68%) patients had conjunctival congestion,
and dry eye (112, 20.97%), blurred vision (68, 12.73%), and foreign
body sensation (63, 11.80%) were reported as the most common symptoms
associated with COVID-19 (21). In another epidemiologic study conducted
in a total of 30 hospitals in China, conjunctivitis was found in 9
(0.8%) of 1099 patients who had a positive SARS-CoV-2 test and were
hospitalized (22).
In a study from Wuhan, China, conducted by Deng et al., SARS-CoV-2 was
detected using RT-PCR in nasopharyngeal samples in 90 (76%) of 114
patients followed up in hospital due to COVID-19 pneumonia, and the
virus was not detected in any of the conjunctival samples. In addition,
none of the 114 patients had ocular symptoms such as red eyes or pain
(23). In another study, five patients with COVID-19 presenting only with
symptoms and signs of conjunctivitis were described (24).
In our study, there were 15 (7.44%) patients showing conjunctival
inflammatory response who had foreign body sensation, epiphora, and
conjunctival congestion symptoms, which were not present prior to the
COVID-19 infection. Although more comprehensive studies are needed, our
study seems to be compatible with the existing literature. The rate of
conjunctivitis or conjunctival inflammatory response has been shown in a
wide spectrum in these studies. These spectra were explained by the fact
that no biomicroscopy examination was performed on patients in any
studies in the literature, and even that the data in most studies were
based on patients’ subjective symptoms obtained through teleconferences.
During our study, the fact that the patients were seen by an
ophthalmologist in person and evaluated with a penlight, although a
biomicroscopic examination was not performed, was a positive situation
for the safety of our data.
In a meta-analysis evaluating laboratory findings, 5350 patients from 25
studies were included and high levels of CRP, procalcitonin, D-dimer,
and ferritin were associated with poor outcomes (25). In another study,
it was shown that patients with COVID-19 with ocular symptoms had higher
WNC counts, neutrophil counts, and CRP, LDH, and procalcitonin values
compared with patients without ocular symptoms (16). In another study,
no significant difference was found between patients with and without
SARS-CoV 2 virus isolated from the conjunctiva in terms of laboratory
findings (26). In our study, when the laboratory data of 234 patients
were compared, no significant difference was found between patients with
and without ocular symptoms. Our patients had moderate or severe
symptoms and were hospitalized patients. Patients with very severe
disease in the intensive care unit (ICU) or asymptomatic patients
followed up at home were excluded from the study. As far as we know, no
other comprehensive studies have investigated the relationship between
conjunctivitis and laboratory data in patients with COVID-19.
It was suggested that the ocular surface might be an entry point for
SARS-CoV-2, and ocular involvement was less common thanks to the
antiviral defense system in the conjunctiva and cornea, as well as
lactoferrin and secretory immunoglobulin (Ig)-A (27).
Viruses trigger the immune system, leading to an increase in
immunoglobulin, chemokine and antibody production, and cause tissue
damage, apoptosis, and inflammation (28).
Ocular findings associated with COVID-19 may be due to viral effects or
to dry eye that develops in these patients. There may be several reasons
why dry eye occurs in these patients. The first is the prolongation of
the time of watching screens following restrictions of social activities
in patients. Another reason is that with the use of a mask, the airflow
from the mask to the ocular surface evaporates the tears earlier.
Indeed, there are some viruses associated with dry eye disease (29).
Considering the presence of viruses associated with dry eye disease, it
can be thought that the SARS-CoV-2 virus will affect the conjunctival
goblet cells or the lacrimal gland through blood, disrupting the tear
structure and playing a role in the development of dry eye or
conjunctival inflammatory response.
Our study had some limitations. The sample size was relatively small,
patients with severe clinical findings in the ICU were not included, and
SARS-CoV-2 RT-PCR examinations were not performed on conjunctival
samples.
As a result, there was a significant relationship between COVID-19 and
an acute conjunctival inflammatory response. Blood parameters that
determined progression in patients with COVID-19 were not significant in
terms of ocular findings.
Declarations of interest: none