Clinical Profile, Treatment, and Visual Outcome of Ocular Toxocara in a Tertiary Eye Care Centre

Intravitreal Dexamethasone Implant (Ozurdex) for Ocular Toxocariasis

This study aimed to evaluate the efficacy and safety of intravitreal dexamethasone implants in the treatment of ocular toxocariasis (OT). A retrospective analysis was performed on 6 cases in which laboratory tests diagnosed OT. All patients were administered with intravitreal dexamethasone implants with or without vitrectomy. The average follow-up time was 19.7 months. All operated eyes achieved anatomic success, and all patients' visual acuity was improved. Five of these six had a visual acuity of 20/100, and three had final acuity of 20/40 or even better. Intravitreal dexamethasone implants can be used to treat different types of OT, which not only effectively control inflammation and improve the patient's vision but also reduce the use of systemic glucocorticoids.

Safety and effectiveness of intravitreal dexamethasone implant in patients with ocular toxocariasis

AIMS

To evaluate the safety and effectiveness of intravitreal dexamethasone (DEX) implant in patients with active uveitis due to ocular toxocariasis (OT).

METHODS

Seventy-eight patients with OT were recruited in this retrospective study, including 51 patients in DEX group treated with intravitreal DEX implant and 27 patients in control group without intervention. The reduction of vitreous haze scores (VHS), the best-corrected visual acuity (BCVA) changes, intraocular pressure (IOP) and cataract progression and formation were recorded at baseline (V0), 1 (V1), 3 (V3) and 6 months (V6) after treatment in DEX group, and V0 and V6 in control group.

RESULTS

There was no change in VHS and BCVA in control group between V0 and V6. Better VHS (p=0.001) and BCVA (p=0.022) was achieved in DEX group; the rate of VHS=0 was 0%, 67.4%, 42.9% and 44.9% at V0, V1, V3 and V6, respectively (p＜0.001), and the mean BCVA was improved from logMAR 1.5±0.9 to 1.2±0.9 at V1, 1.4±1.0 at V3 and 1.4±1.2 at V6. A favourable BCVA at V1 was associated with older age (p=0.038) and uninvolved macula (p=0.000) in DEX group. No significant difference in IOP elevation ≥10 mm Hg, cataract progression and formation between groups. More eyes needed retinal surgery in control group (p<0.001).

CONCLUSIONS

This was the first study to investigate use of intravitreal DEX implant in OT patients, which can efficiently reduce ocular inflammation and improve BCVA in macular uninvolved patients.

Pediatric Posterior Infectious Uveitis

PURPOSE

To describe the most important cause of infectious posterior uveitis in pediatric patients.

METHODS

Review of the literature.

RESULTS

The most important causes of infectious uveitis in pediatric patients are: cat-scratch disease, toxocariasis, tuberculosis, viral diseases and toxoplasmosis. Ocular manifestations include retinitis, neuroretinitis, choroidal granulomas, peripheral granulomas and posterior pole granulomas.

CONCLUSION

Infectious posterior uveitis is a challenging subject and should be considered in the differential diagnosis of any posterior uveitis in children. Infectious uveitis must be excluded before initiating immunosuppressive therapy.

Who Let the Dogs Out? Unmasking the Neglected: A Semi-Systematic Review on the Enduring Impact of Toxocariasis, a Prevalent Zoonotic Infection

Toxocariasis remains an important neglected parasitic infection representing one of the most common zoonotic infections caused by the parasite Toxocara canis or, less frequently, by Toxocara cati. The epidemiology of the disease is complex due to its transmission route by accidental ingestion of embryonated Toxocara eggs or larvae from tissues from domestic or wild paratenic hosts. Even though the World Health Organization and Centers for Disease Control classified toxocariasis amongst the top six parasitic infections of priority to public health, global epidemiological data regarding the relationship between seropositivity and toxocariasis is limited. Although the vast majority of the infected individuals remain asymptomatic or experience a mild disease, the infection is associated with important health and socioeconomic consequences, particularly in underprivileged, tropical, and subtropical areas. Toxocariasis is a disease with multiple clinical presentations, which are classified into five distinct forms: the classical visceral larva migrans, ocular toxocariasis, common toxocariasis, covert toxocariasis, and cerebral toxocariasis or neurotoxocariasis. Anthelmintic agents, for example, albendazole or mebendazole, are the recommended treatment, whereas a combination with topical or systemic corticosteroids for specific forms is suggested. Prevention strategies include educational programs, behavioral and hygienic changes, enhancement of the role of veterinarians, and anthelmintic regimens to control active infections.

The role of helminths in the development of non-communicable diseases

Non-communicable diseases (NCDs) like cardiovascular disease, chronic respiratory diseases, cancers, diabetes, and neuropsychiatric diseases cause significant global morbidity and mortality which disproportionately affect those living in low resource regions including low- and middle-income countries (LMICs). In order to reduce NCD morbidity and mortality in LMIC it is imperative to understand risk factors associated with the development of NCDs. Certain infections are known risk factors for many NCDs. Several parasitic helminth infections, which occur most commonly in LMICs, have been identified as potential drivers of NCDs in parasite-endemic regions. Though understudied, the impact of helminth infections on the development of NCDs is likely related to helminth-specific factors, including species, developmental stage and disease burden. Mechanical and chemical damage induced by the helminth in combination with pathologic host immune responses contribute to the long-term inflammation that increases risk for NCD development. Robust studies from animal models and human clinical trials are needed to understand the immunologic mechanisms of helminth-induced NCDs. Understanding the complex connection between helminths and NCDs will aid in targeted public health programs to reduce helminth-induced NCDs and reduce the high rates of morbidity that affects millions of people living in parasite-endemic, LMICs globally.

Update on the Management of Uveitic Macular Edema

Uveitic macular edema (ME) is a frequent complication in 8.3% of uveitis patients and is a leading cause of serious visual impairment in about 40% of cases. Despite the numerous available drugs for its treatment, at least a third of patients fail to achieve satisfactory improvement in visual acuity. First-line drugs are steroids administered by various routes, but drug intolerance or ineffectiveness occur frequently, requiring the addition of other groups of therapeutic drugs. Immunomodulatory and biological drugs can have positive effects on inflammation and often on the accompanying ME, but most uveitic randomized clinical trials to date have not aimed to reduce ME; hence, there is no clear scientific evidence of their effectiveness in this regard. Before starting therapy to reduce general or local immunity, infectious causes of inflammation should be ruled out. This paper discusses local and systemic drugs, including steroids, biological drugs, immunomodulators, VEGF inhibitors, and anti-infection medication.

As the worm turns: An infant with exotropia

A two-year-old full-term boy with a history of an intermittent exotropia presented to the pediatric ophthalmology clinic for routine follow-up. He was found to have a stable sensorimotor examination however dilated funduscopic examination of the right eye was significant for a dim foveal reflex with a new discrete, white, elevated retinal lesion superotemporal to the fovea with surrounding subretinal exudates. An examination under anesthesia (EUA) was performed two days later that revealed a subretinal posterior pole granuloma with hyperfluorescence and late leakage from the lesion without telangiectatic vessels on fluorescein angiography. A repeat EUA one month later demonstrated an increase in surrounding subretinal and overlying intraretinal fluid. The patient was started on topical 1% prednisolone with a presumed diagnosis of Toxocara granuloma. At EUA, three months later, the subretinal and intraretinal fluid had resolved. The topical steroids were tapered, and the patient continues to be followed closely.

Clinical features of ocular toxocariasis: a comparison between ultra-wide-field and conventional camera imaging

PURPOSE

The purpose of this study is to compare the lesion detection rates of ocular toxocariasis (OT) between ultra-wide-field scanning laser ophthalmoscopy (UWF-SLO) and conventional fundus photography (CFP), and to evaluate the potential diagnostic ability of UWF-SLO in OT.

METHODS

A total of 56 patients with serological/immunological confirmed unilateral OT were enrolled. The presence of OT characteristic features included the posterior granuloma (postG), peripheral granuloma (periG), tractional retinal detachment (TRD), retinal folds (RF), and vitreous strands (VS) and was analyzed in 36 patients with UWF-SLO and 56 patients with CFP. Diagnostic tests were employed using the clinical examination as gold standard.

RESULTS

In total of the 56 OT eyes, granulomas were identified in 91.1% (51/56) of eyes, including postG in 46.4% (26/56) of eyes, periG in 41.1% (23/56) of eyes, and combined granulomas in 3.6% (2/56) of eyes. TRD, RF, and VS were found in 28.6% (16/56), 51.8% (29/56), and 83.9% (47/56) of patients, respectively. Although the specificities of the diagnosis in clinical features were similar by the diagnostic tests, the sensitivities of postG, periG, TRD, RF, and VS using UWF-SLO were 100%, 100%, 66.7%, 95%, and 81.8%, respectively, which were significantly higher those of CFP (72.2%, 31.3%, 11.1%, 55%, and 48.5%). Additionally, the extent of vitreous haze was milder graded by UWF-SLO compared to CFP (p = 0.0099).

CONCLUSIONS

The diagnostic ability of UWF-SLO was superior to CFP using clinical examination as gold standard for the ascertainment of the characteristic manifestations of OT, especially for granulomas and RF.