Epidemiological analysis of cases of uveitis in a tertiary Hospital

Objective: To analyze the distribution of uveitis in patients at Uveitis Sector of Federal Hospital of Servants of Rio de Janeiro State. Methods: Retrospective epidemiological study of 63 appointments performed by ophthalmologist of Uveitis Sector at Federal Hospital of Servants of Rio De Janeiro State, between March and October of 2016. Results: The mean age was 45.54 (±15.8). 50.5% were female. Anterior uveitis corresponded to 63.49%. Only 33.3% of patient had an active inflammation at the moment of medical avaliation. 74.6% of uveitis had non-infeccious causes, and in 12.69% the etiology could not be determined. Ankylosing spondylitis was the most frequent cause, responsible for 28.57% of cases. 55.5% of patients had a bilateral uveitis, and 71.14% non-granulomatous uveitis. Conclusions: Epidemiological studies about uveitis are usually made in terciary hospitals, which do not reflect the epidemiological profile of population in general.


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²) It is estimated to be responsible for 5 to 20% of cases of visual loss in the United States, (³) for 3 to 7% in European countries, and for 3 to 10% in developing countries².The world literature reports great variations in the etiology of uveitis (4) These differences can not be explained only by socioeconomic disparities or access to health services, since factors such as age, gender, race, occupation, life habits and geographic origin can influence them, being this point the importance of epidemiological studies on the etiology of these inflammatory processes.In addition, the comparison between studies performed in different regions of the world and at different times allows us to establish trends and speculate relevant factors to the etiopathogenesis of this disease.
In the absence of a similar study conducted in Rio de Janeiro, and considering that the city is the second largest urban center in Brazil, the present study aims at analyzing the distribution of uveitis in patients treated at the Uveitis Sector of the Ophthalmology Service of Hospital Federal dos Servidores do Estado do Rio de Janeiro.

methods
A retrospective, cross-sectional and descriptive epidemiological study was carried out to analyze the medical records of 63 patients treated at the Uveitis Sector of the Ophthalmology Service of Hospital Federal dos Servidores do Estado do Rio de Janeiro from March to October 2016.
All patients treated in this Sector underwent anamnesis and complete ophthalmologic examination, including assessment of visual acuity, facial ectoscopy, anterior and posterior biomicroscopy, intraocular pressure measurement by aplanation tonometry, and indirect fundoscopy.All patients had fundoscopy assessment performed after adequate pupillary dilation to avoid the spill-over phenomenon, that is, so that the presence of cells in the anterior chamber secondary to retinal inflammation was not erroneously interpreted as anterior uveitis.Further ocular and systemic examinations were performed according to the need, clinical development and diagnostic hypothesis.
Variables like age, gender, etiological and anatomical diagnosis, disease activity, laterality, ocular complications, final visual acuity, and systemic comorbidities of the patient were analyzed.Regardless of the number of visits, each patient was counted only once in the period established by the study in question.
The classification used followed the criteria set out by the International Uveitis Study Group, adapted by SUN (Standardization of Uveitis Nomenclature).It was considered an active disease when there were cells and flare in the anterior chamber, Keratic precipitate (KPs), hypopio, iris nodules, anterior or posterior synechiae, vitreous cells, snowballs, snowbanks, inflammatory lesions in the retina or choroid, vasculitis associated with symptoms such as pain, red eye, photophobia, decreased visual acuity, flying flies, pericytic or limbic hyperemia.
Patients with ocular inflammation in a short postoperative or post-trauma period and with endophthalmitis were excluded from the analysis.
For the calculation of the best corrected visual acuity, the conversion of the Snellen scale to the Log-MAR scale was made.The results collected from the forms were submitted to descriptive statistical treatment by means of percentages, being all data broken down through charts and graphs.

Results
The medical records of all patients treated in the Uveitis sector of Hospital Federal dos Servidores do Estado de Rio de Janeiro (HFSE) from March to October 2016 were evaluated, being 49.2% men and 50.8% women.The age ranged from 3 to 73 years, with an average of 45.54 (± 15.8), with the following distribution: 7% of patients up to 16 years, 28.5% between 17 and 40 years, and 63.5% over 40 years.The visual acuity (VA) varied widely from 20/20 (logMAR 0) to no light perception (NLP).Regarding the origin, 93.6% of patients lived in the city of Rio de Janeiro, 4.8% were from other cities of the state of Rio, and 1.6% were from other states of Brazil.
Using the anatomical diagnosis classification, we found 63.5% of anterior uveitis, 1.6% intermediate, 19.04% posterior, and 15.87% panuveitis.The prevalence of anterior uveitis in all age groups was studied, being 100% in individuals up to 16 years of age, 61.1% from 17 to 40 years, and 60% over 40 years.
As for the activity of the ocular disease during treatment, 33.3% of cases presented active disease, and 66.6% were with no activity.Regarding laterality, 44% had unilateral involvement, with the right eye being affected in 23.8% of cases.Other 56% of patients had binocular involvement.
The etiological diagnosis of the disease was possible in 87.3% of the cases, being it the most frequent etiologies: (Figure 1) Ankylosing Spondylitis with 28.5% of cases, followed by Toxoplasmosis with 9.5%, and Psoriatic Arthritis and Behçet's Disease, both with 7.9% of cases.Other causes were found: Vogt-Koyanagi-Harada disease (VKHD) with 6.3%, Juvenile Idiopathic Arthritis (JIA) and Sarcoidosis with 4.8% each, Crohn's Disease with 3.1%, and Rheumatoid Arthritis, Wegener's Granulomatosis, Takayasu's Arteritis, Reactive Arthritis, Polychondritis, Syphilis, Tuberculosis, and Arteritis of Giant Cells with 1.6% each.Idiopathic or undetermined causes corresponded to 12.7% of cases.
According to the clinical aspect, 10% of cases were classified as granulomatous uveitis, 71% non-granulomatous, and in 19% of cases it was not possible to classify.
Regarding the clinical development of the inflammatory condition, 42.8% were classified as acute, 11.1% as chronic cases, 33.3% as recurrent, and 12.7% could not be determined.Analyzing the associated comorbidities, we obtained 28.57% of cases with a diagnosis of systemic arterial hypertension, 4.76% with Diabetes Mellitus, 3.17% with hypothyroidism, and 3.17% HIV-positive patients.We also found patients with Hepatitis B, Atrial Fibrillation, Systemic Lupus Erythematosus, Rheumatic Fever, Toxoplasmosis, Syphilis, Coronary Artery Disease, Depression, Panic Syndrome, Scleroderma, Crohn's Disease, Rheumatoid Arthritis, and Asthma.
When only cases of anterior uveitis were evaluated, and with 52.5% of cases being males with an average age of 45.15 (± 7.2), only 20% of cases showed active disease in the evaluation.45% of the cases were classified as acute disease, 30% as recurrent, 10% as chronic, and 15% could not be determined.The involvement was bilateral in 55% of cases.Regarding the clinical aspect, 77.5% were non-granulomatous, 5% were granulomatous, and 30% of cases could not be classified.Regarding the etiology, 85% presented non-infectious uveitis, and in 15% of cases it was not possible to determine the specific cause.The main cause alone was undoubtedly Ankylosing Spondylitis, responsible for 40% of cases, followed by undetermined cause with 15%, Psoriatic Arthritis with 12.5%, Behçet's Disease with 10%, Juvenile Idiopathic Arthritis with 7.5%, and Crohn's disease with 5%.It corresponds to 2.5% of each etiologic group in which Rheumatoid Arthritis, Takayasu's Arteritis, Reactive Arthritis, and Polychondritis are included.
When we analyzed patients with posterior uveitis, we noticed that 66.6% of patients were male, with an average age of 45.18 (± 2.49), and 50% of them presented active disease during the ophthalmologic treatment.Infectious causes were the main responsible (50%), and toxoplasmosis was the main one, with 6 patients affected.83.3% of cases were classified in the clinical profile as being non-granulomatous.
Regarding panuveitis, we found an average age of 47.3 years (± 14.86), and 80% of the affected patients were women with active disease in 60% of cases.Regarding the etiology, 80% of cases were identified as non-infectious, and 20% infectious.The main isolated causes were Vogt-Koyanagi-Harada Disease with 40% of cases, and Sarcoidosis with 20%.Syphilis, Tuberculosis, Behçet's Disease, and concomitant VKHD and Ankylosing Spondylitis were responsible for 10% each.
We had only one case of intermediate uveitis of undetermined cause in our study.
Gender was also analyzed.Among the male patients we obtained an average age of 45 years (± 17.6), with 67.74% of cases being of anterior uveitis, followed by 25.8% of posterior, and 6.45% of panuveitis.During the assessment, 67.74% of patients did not present active disease.The involvement was bilateral in 51,6% of patients.Regarding classification, 77.4% of uveitis were non-granulomatous.The main cause of ocular inflammation etiology was Ankylosing Spondylitis with 38.7% of cases, followed by Toxoplasmosis with 12.9%, Wegener's Granulomatosis and JIA with 9.7%, Sarcoidosis, Psoriatic Arthritis and Behçet's Disease with 6.5% each, Reactive Arthritis and Syphilis with 3.23% each, as shown in figure 2.
An etiological analysis by age was also performed, as shown in figures 4, 5 and 6.
Epidemiological analysis of cases of uveitis in a tertiary Hospital Rev Bras Oftalmol.2017; 76 (4): 181-5  Uveitis most commonly affects young adults (5) .Previous studies have shown that 60-80% of patients with uveitis have an average age between 35-45 years of age, (5) which corresponds to the findings in our study, in which we obtained an average age of 45 years.
Regarding gender, previous studies have demonstrated a similar prevalence of uveitis in men and women, or even a slight predominance in women, especially in developed countries.Some studies in underdeveloped countries show a predominance of males, (5,6) mainly in nations with a large rural population in which men are at higher risk developing certain types of uveitis, predominantly the infectious ones, due to etiologies such as Leptospirosis and Onchocerciasis.In addition, some conditions such as HLA-B27-related uveitis are associated with Ankylosing Spondylitis, and are also more frequent in males. (7)In our study, we found a similar overall prevalence of uveitis in both genders.
As for the primary site of infection, most literature reports refer to anterior uveitis as the most frequent one, followed by posterior, diffuse and intermediate.However, said studies are frequently questioned by the possible Routing Bias, that is, as they are usually carried out in tertiary centers such as ours, in which patients followed would have a different etiological profile due to their diverse comorbidities and the reference services available, sometimes they would not reflect the etiological pattern of the general population.A study carried out in the United States in 1996 (³) compared the etiology of uveitis in a tertiary center to that in community clinics, with divergent results.
Our hospital is one of the main Ophthalmology reference centers in Rio de Janeiro, treating patients not only from the capital, but also from the metropolitan region of the State.In addition, the Ophthalmology Sector of our hospital receives direct referral from patients of the Rheumatology Service, which seems to explain our high prevalence of patients with previous uveitis (63.49%), as well as the fact that the main isolated cause of uveitis in the present study being Ankylosing Spondylitis.In addition, some patients with retinal diseases as a consequence of posterior uveitis of etiologies such as Toxoplasmosis or Cytomegalovirus are referred directly to the Retina Sector of our service, which may have contributed to this high rate of anterior chamber disorders.
In our study we found a similar prevalence between bilateral and unilateral involvement, confirming the trend in the literature. (8,9)owever, in some countries such as Japan, in which causes such as Behçet's Disease or VKHD (10,11) have a high incidence, there is a large predominance of bilateral involvement.
Similarly, 71.4% of our patients have no granulomatous uveitis, which also predominates in literature, ranging from 51-89% in previous reports. (5)pidemiological studies dealing with uveitis are mostly carried out in tertiary centers, which could be associated to a referral bias, that is, the presence of rheumatologic services in these hospitals and the ease of direct referral to Ophthalmology could increase the rate of rheumatological etiologies in the sample, thus not reflecting the prevalence found in the general population.In addition, it has been previously demonstrated that in the same place there is a change in the etiological pattern of these ocular inflammations when comparing different observation periods. (8,9)he present retrospective study analyzed the distribution of cases of uveitis in a tertiary service, allowing a high prevalence of anterior uveitis, especially those of rheumatological origin, to be observed, unlike previous reports in the literature in underdeveloped countries, thus resembling more the profile found in developed countries, as shown in table 1.Values expressed in %.

Figure 4 .
Figure 4. Etiology of uveitis in children under 16 years

Figure 5 .Figure 6 .
Figure 5. Etiology of uveitis at the age group from 17 to 40 years