|Year : 2017 | Volume
| Issue : 2 | Page : 77-80
Ocular manifestations in mosquito-borne viral fevers
Suma Unnikrishnan1, Kuzhupally Vallon Raju2
1 Department of Ophthalmology, Government Medical College, Kozhikode, Kerala, India
2 Department of Internal Medicine, Government Medical College, Kozhikode, Kerala, India
|Date of Submission||26-Aug-2015|
|Date of Acceptance||18-Jul-2016|
|Date of Web Publication||25-Apr-2017|
Department of Ophthalmology, Government Medical College, Kozhikode - 673 008, Kerala
Source of Support: None, Conflict of Interest: None
Background: The ocular manifestations of dengue and chikungunya have been reported in different parts of the world, but they differ in different areas and epidemics. As these major mosquito-borne viral febrile illnesses are considered to be an important public health concern, ocular manifestations if any, may give a clue to the disease severity, significant cases can be referred early to the tertiary center. Aim: To study the pattern of ocular manifestations in mosquito-borne viral fever cases admitted in a tertiary care hospital. Study Design: Descriptive observational case series study. Materials and Methods: Forty-two patients admitted in the medical wards having clinical features of chikungunya and dengue with serological confirmation during the epidemic between April and October 2010 were included in this study. They were subjected to ophthalmological evaluation with necessary investigations. Statistical analysis was done by software SPSS-16. Results: The ocular manifestations associated with the epidemic of mosquito-borne viral fever were periorbital ecchymosis, conjunctivitis, subconjunctival hemorrhage, episcleritis, scleritis, nongranulomatous anterior uveitis, trabeculitis, posterior uveitis, retinal vasculitis, and macular edema. These patients were having significant thrombocytopenia and leukopenia. The visual prognosis was generally good with treatment. Conclusion: Considerable number of patients had various ocular manifestations in patients with dengue and chikungunya.
Keywords: Chikungunya, dengue, thrombocytopenia
|How to cite this article:|
Unnikrishnan S, Raju KV. Ocular manifestations in mosquito-borne viral fevers. J Clin Ophthalmol Res 2017;5:77-80
The two major mosquito-borne viral fevers detected in South India are dengue and chikungunya and are transmitted through the bite of infected female Aedes aegypti or Aedes albopictus mosquito, which are domestic day biting ones with preference to human blood.
Dengue is caused by one of the genus Flavivirus of the family Flaviviridae. The disease spectrum ranges from mild influenza-like illness to life-threatening hemorrhagic fever/shock syndrome with epistaxis, bleeding gums, and bleeding tendencies anywhere in the body. Chikungunya is caused by Alphavirus of the family Togaviridae.
Symptoms are fever of abrupt onset, headache, myalgia, arthralgia, nausea, vomiting, and maculopapular rashes. The various ocular manifestations have been reported from different countries which may vary with each outbreak. The aim of the study was to find out the pattern of ocular manifestations in mosquito-borne viral fever cases reported in a tertiary care hospital in South India.
| Materials and Methods|| |
This was a descriptive observational case series study. Patients admitted to the medical wards of a tertiary care center with a clinical diagnosis of chikungunya fever, dengue fever, and dengue hemorrhagic fever during the epidemic between April and October 2010 were included in this study. Patients with a serological diagnosis of chikungunya and dengue fever were studied. Patients were analyzed for the demographic features, ocular and systemic symptoms, ocular signs, and laboratory investigations. Laboratory investigations included complete hemogram and Elisa tests for immunoglobulin M (IgM) dengue and chikungunya. Patients with other infectious fevers including leptospirosis, tuberculosis, human immunodeficiency virus, and patients with preexisting ocular diseases both congenital and acquired were excluded from this study. Symptomatic patients were followed up in the ophthalmology outpatient department. All other patients were asked to attend Ophthalmology Department if they develop ocular symptoms over a period of 1 month. All these patients were subjected to complete ophthalmological evaluation including slit-lamp examination, tonometry, and dilated fundus examination with indirect ophthalmoscope and 90 diopter (D) lens. Functional examinations such as best-corrected visual acuity with Snellen's chart, color vision testing, and visual fields charting were done. Those patients with vision-threatening complications such as optic neuritis, retinal vasculitis, and maculopathy were treated with systemic prednisolone 1 mg/kg bodyweight in tapering doses. Conditions such as anterior uveitis, episcleritis, scleritis, and conjunctivitis were treated as per guidelines given in the literature. This study was conducted after getting written informed consent from the patients. There were no drugs trial or other modalities of treatment imposed upon the patient other than described in the literature. This study was approved by the Institutional Research Committee and Ethics Committee in accordance with the Indian Council of Medical Research.
| Results|| |
Forty-two patients admitted in the medical wards having clinical features of chikungunya or dengue were analyzed for the presence of ocular manifestations. Patients with positive IgM chikungunya/dengue were studied. Statistical analysis was done with the software SPSS-16 version (SPSS Inc, Chicago, USA). The age of the patients ranged from 9 to 69 years, mean age being 36 with a standard deviation of 16. Males were affected more than females (52%, n = 22). Both eyes were affected in twelve patients. IgM dengue and IgM chikungunya were found to be positive in 28 and 8 patients, respectively. Six patients were positive for both dengue and chikungunya indicating mixed infection. Out of the 42 confirmed patients evaluated, 24 (57%) had associated ocular signs.
Time of onset of ocular symptoms varied from 1 day to 1 week in majority of the cases, 16 out of 24. Ocular symptoms started along with fever in six patients. In four patients with isolated chikungunya positivity, ocular symptoms started 4 weeks after the onset of fever. The predominant systemic symptoms were myalgia, rashes, joint pain, and headache [Figure 1]. Predominant ocular symptoms are documented in [Figure 2]. The ocular signs varied from lid involvement to anterior and posterior segment involvement [Table 1]. Periorbital ecchymosis was found in one patient. Anterior and posterior segment signs were present in 21 and 3 patients, respectively.
|Figure 1: Nodular scleritis in a patient with both dengue and chikungunya|
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|Figure 2: (a and b) Fundus photo showing macular edema with vasculitis and foveolitis|
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Thrombocytopenia was noticed in 76% (n = 32). Leukopenia was detected in 10 patients out of 42. Other investigation results are illustrated in [Table 2], Charts 1 and 2.
| Discussion|| |
The onset of ocular problems coincides with the resolution of fever and appearance of thrombocytopenia, usually ranges from 1 to 2 weeks. Late onset was seen in four patients with isolated chikungunya positivity.
In this study, myalgia (86%, n = 36) was the predominant general symptom followed by joint pain (76%, n = 32) and headache (74%, n = 31).
Significant ocular symptoms were redness in 16 followed by retro-orbital pain in 12, blurred vision in nine, photophobia in eight, and discharge in one patient. Characteristic retro-orbital pain associated with dengue and chikungunya has been reported previously in various studies. Both eyes were affected in 12 patients. When these patients were evaluated, 24 had associated ocular symptoms/signs. The rest 18 were asymptomatic, which is very well matching with previous studies. Twenty-eight patients had isolated IgM dengue and eight had IgM chikungunya positivity. Six were positive for both dengue and chikungunya. In isolated dengue patients, 12 out of 28 developed ocular problems within a week in the form of periorbital ecchymosis, acute conjunctivitis, subconjunctival hemorrhage, scleritis, keratitis, and acute iridocyclitis [Table 3].
Probable pathogenic factors responsible for this could be viremia and thrombocytopenia. In some epidemics, bleeding complications are more common. In our study, acute conjunctivitis was the most common presentation in dengue patients when compared to the previous study where subconjunctival petechial hemorrhage, secondary to marked thrombocytopenia, was the most common ocular involvement.
In contrary to the previous study, here all patients had dengue fever without any hemorrhagic complications so that there were no cases of retinal or macular hemorrhage even though statistically significant thrombocytopenia was present in these patients. In this study, patients with isolated chikungunya infection presented with ocular features as shown in [Table 4].
Anterior uveitis needs special mention here. There was marked pigment release in the anterior chamber with pigmented keratic precipitates while posterior synechiae were insignificant. This was similar to previous reports of chikungunya iridocyclitis as mentioned in the article by Khairallah et al. Late onset of ocular symptoms in chikungunya, postulates an immune-mediated mechanism rather than acute viremia. Compared to the previous study, we did not have any patient with retinitis in pure chikungunya infection. In their study out of the nine patients with chikungunya, one had nodular episcleritis, five presented with acute iridocyclitis, and three had retinitis. Furthermore, in their study, the ocular problems started 4 weeks after the onset of fever. Although there were no specific changes of iridocyclitis that were diagnostic of the fever, the retinal changes were consistent with viral retinitis. All patients recovered from the infection with relatively good vision. Out of the six patients with mixed infection, four showed ocular problems. One patient each had acute conjunctivitis, episcleritis, scleritis, and retinal vasculitis with foveolitis causing macular edema. Moreover, all of them developed ocular features within the 1st week. Two of them had bilateral involvement. One patient with nodular scleritis needed immunosuppressive therapy and reference to palliative medicine department for symptomatic relief. Majority of the patients had normal visual acuity (83%) and those presented with blurring of vision due to various posterior segment pathologies improved after the course of the disease with treatment. The causes for defective vision were iridocyclitis in six patients. Posterior uveitis and retinal vasculitis were responsible for the same in one patient each. One patient had defective vision due to macular edema. The postulated theory behind these inflammatory responses is that vasoactive and inflammatory mediators cause capillary leakage and produce macular edema and breakdown of the blood-aqueous barrier, resulting in anterior uveitis and periphlebitis.
Blurring of vision typically coincides with the incidence of thrombocytopenia and occurs within a week after onset of fever.
The intraocular pressure was unaffected in all these 42 patients except one who was serologically positive for chikungunya. She had trabeculitis with a moderate rise in intraocular pressure. Her symptoms started 2 days after the onset of fever. Posterior segment involvement in the form of posterior uveitis, retinal vasculitis, and macular edema was seen in one patient each. They responded well to systemic steroids.
Previous studies have reported a sudden loss of vision with central scotoma during the recovery phase of dengue, i.e., 1 week after the onset of fever due to dengue maculopathy.
Chikungunya virus infection has recently been reported to cause different ocular manifestations such as nongranulomatous anterior uveitis, episcleritis, panuveitis, granulomatous anterior uveitis, optic neuritis, sixth nerve palsy, retrobulbar neuritis, retinitis with vitritis, neuroretinitis, keratitis, central retinal artery occlusion, multifocal choroiditis, exudative retinal detachment, and secondary glaucoma.
The ocular manifestations in chikungunya fever in this series could be an immune-mediated process rather than a direct viral infection. Further studies are required to understand the pathogenesis of this disease.
Regarding hematological evaluation, thrombocytopenia was noticed in 76% (n = 32). Leukopenia was detected in ten patients. Presence of thrombocytopenia was statistically significant with P = 0.001. All the six patients with mixed infection had thrombocytopenia. In spite of that hemorrhagic complications were less in our study when compared to another study  where most common ophthalmic signs were macular edema in 76.9% and macular hemorrhage in 69.2%.
Since our study was hospital based, it may not represent the general population. The sample size is small, and the number of subgroups is not comparable. In addition, polymerase chain reaction studies were not done as it was not affordable to our study population. These factors can be considered as limitations.
| Conclusion|| |
The main ocular manifestations associated with epidemic of mosquito-borne viral fever in North Kerala, India, included periorbital ecchymosis, conjunctivitis, subconjunctival hemorrhage, episcleritis, scleritis, nongranulomatous anterior uveitis, trabeculitis, and retinal vasculitis with macular edema. The visual prognosis was good after treatment with systemic steroids in indicated cases. Statistically significant thrombocytopenia was present in patients having ocular manifestations. Hence, the presence of thrombocytopenia will give a clue to the general practitioners in the periphery to refer such patients to the ophthalmologists at the earliest.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4]