Ocular Toxocariasis: Long-Term Follow-Up and Prognosis of Patients following Vitrectomy

The Consistency of Anti-Toxocara IgG Between the Aqueous Humor and Vitreous of Patients With Clinically Suspected Ocular Toxocariasis

PURPOSE

To assess the consistencies of anti-Toxocara IgG (T-IgG) and Goldmann-Witmer coefficient (GWC) between paired aqueous humor (AH) and vitreous samples from patients with clinically suspected ocular toxocariasis (OT).

DESIGN

Inter-test reliability assessment.

METHODS

A total of 47 patients with clinically suspected OT who underwent vitrectomy were included. AH, vitreous, and serum samples from each patient were collected, and levels of specific T-IgG in them were detected. The association and agreement of T-IgG and GWC between AH and vitreous were evaluated. The area under the receiver operating characteristic curve was generated to assess the diagnostic performance of AH.

RESULTS

The T-IgG levels and GWC values in vitreous were higher than those in AH (P = .023 and P = .029, respectively), but similar positivity rates in the T-IgG (P = 1.000) and GWC >3 (P = 1.000) were apparent between vitreous and AH. In addition, there was a positive correlation between the AH and vitreous T-IgG levels (rs = 0.944, P < .001) and the GWC values (rs = 0.455, P = .022). Moreover, the consistencies between AH and vitreous samples in their T-IgG and GWC positivity rates were almost perfect (both, κ = 0.915, 95% CI = 0.799-1.000) in both. The area under the receiver operating characteristic curve reached 0.991, with a 95% confidence interval of 0.971 to 1.000. The best cut-off value for accurate OT diagnosis was found at 1.434, yielding 96% sensitivity and 100% specificity.

CONCLUSIONS

Our findings demonstrate that AH and vitreous samples had significant correlations and perfect agreements for both T-IgG and GWC, suggesting that the AH may serve as a proxy for vitreous to provide a safer, earlier, and more convenient screening of OT.

Ocular Toxocariasis in Adult Caucasian Patients: Clinical Presentations and Treatment Outcomes

PURPOSE

To report the clinical features and treatment outcomes in adult Caucasians with ocular toxocariasis (OT) and investigate their prognosis depending on their serological status.

METHODS

Retrospective observational cohort study (2016-2021) including consecutive adults with uveitis and positive western blot (WB) in the aqueous humor or vitreous. The presence of serum antibodies was not necessary for inclusion, allowing to compare the outcomes depending on the serological status.

RESULTS

Seventeen eyes of 15 patients were included. Mean age at diagnosis was 51.9 years. Vitreous inflammation was the most frequent sign (100%). Vitreoretinal tractions (41.2%) and chorioretinal granulomas (58.8%) were less prevalent. Atypical features were: spontaneous intravitreal hemorrhage (23.5%), exudative retinal detachment (11.8%), isolated macular edema (17.6%), papillitis (29.4%) and vasculitis (47.1%). Twenty percent of patients had a positive serum serology. Baseline clinical features did not differ statistically depending on the serological status; however, the degree of inflammation was numerically higher in patients with negative serology. Overall, macular thickness, anterior and posterior segment inflammation improved significantly after treatment with oral albendazole, systemic ± local corticosteroids. Vitrectomy (47.1%) was performed in case of persistent vitritis (62.5%), retinal detachment (12.5%) and intravitreous hemorrhage (25%).

CONCLUSION

OT has no pathognomonic sign and atypical presentations were not infrequent in this adult Caucasian cohort. Serum antibodies were rarely positive, stressing on the importance of ocular sample analysis, especially in case of atypical features. Serum antibodies may prove useful in forecasting the rapidity of inflammation clearance. Antiparasitic and anti-inflammatory treatment was safe and efficient in most cases.

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.

Management of presumed trematode-induced granulomatous intermediate uveitis

PURPOSE

To describe the surgical management of presumed trematode-induced granulomatous intermediate uveitis (PTIGIU) not responding to medical treatment in controlling the inflammation.

METHODS

A prospective, interventional, single-center study in which patients with a history of fresh canal water contact and PTIGIU were enrolled. All patients underwent lensectomy-pars plana vitrectomy (PPV) and post-operative control of inflammation, functional and anatomical outcomes were assessed.

RESULTS

Fifteen eyes of 12 patients were included in the study with median age of 11.6 ± 4 yrs. Six months following lensectomy-PPV, inflammation was well controlled in all patients. The eyes were divided into two groups: Group A: 10 patients with an attached retina while Group B: 5 patients who were in the cicatricial stage with tractional retinal detachment. All patients in group A had CDVA of 20/40 or better, unlike patients in group B who failed to achieve a CDVA better than 20/70 throughout their follow-up. In group B, final anatomical success was achieved in only 40% with hypotony occurring in 20%.

CONCLUSION

PTIGIU is associated with the presence of ciliary body granuloma which, if left untreated, can lead to drastic outcomes. Early lensectomy-PPV represents a viable management option in cases resistant to medical treatment, with a favorable outcome.

Pars plana vitrectomy in uveitis in the era of microincision vitreous surgery

Pars plana vitrectomy (PPV) in uveitis is indicated for various diagnostic and therapeutic indications. With the advent of microincision vitreous surgery (MIVS), the use of PPV in uveitis has increased with a wider spectrum of indications due to shorter surgical time, less patient discomfort, less conjunctival scarring, and a decreased rate of complications as compared to standard 20G vitrectomy. Because of faster post-operative recovery in terms of visual improvement and reduction of inflammation, and reduced duration of systemic corticosteroids, MIVS has gained popularity in uveitis as an adjunctive therapy to the standard of care medical therapy. The safety and efficacy of MIVS is related to the emerging vitrectomy techniques with better and newer cutters, illuminating probes, and accessory instruments. Because of the instrumentation and fluidics of MIVS, PPV is emerging as a safe and useful alternative for diagnostic challenges in uveitis, aiding in earlier diagnosis and better outcome of inflammatory disease, even in the presence of severe and active inflammation, which was once considered a relative contraindication for performing vitreous surgery. However, for surgical interventions for therapeutic indications and complications of uveitis, it is advisable to achieve an optimum control of inflammation for best results. The increasing reports of the use of MIVS in uveitis have led to its wider acceptance among clinicians practicing uveitis.

Keys to Unlock the Enigma of Ocular Toxocariasis: A Systematic Review and Meta-analysis

Purpose: Ocular toxocariasis (OT) is a zoonotic infection caused by larval stages of Toxocara canis and T. cati. The current review and meta-analysis aimed to evaluate the global prevalence of OT.Methods: Five English (PubMed, Scopus, Science Direct, Web of Science, and Google Scholar) databases were explored and 101 articles met the inclusion criteria.Results: The pooled prevalence (95% confidence interval) of OT was higher in immunological studies (9%. 6-12%) than in studies that applied ophthalmic examination (1%. 1-2%). The lower middle-income level countries had the highest prevalence (6%. 2-12%) as well as the African region (10%. 7-13%). The highest infection rate (4%. 2-7%) was detected in the 1-25 mean age group.Conclusion: Regular anthelminthic treatment of cats and dogs, and removal of animal feces from public places must be considered.