Ophthalmic parasitosis: a review article

Outcome of cataract surgery in children with presumed trematode-induced granulomatous anterior uveitis

PURPOSE

To examine the 6-month visual outcomes and complications following cataract surgery in patients with persumed trematode induced granulomatous anterior uveitis.

SETTING

Assiut university hospital, Assiut, Egypt.

DESIGN

This is a retrospective non comparative case series study.

METHODS

Patients presenting with significant cataract secondary to uveitis caused by trematode induced anterior chamber granuloma were included in this study. Cases with active anterior uveitis, within the last 3 months preceding surgery, and those with a history of trauma, were excluded from this study. Data collected included demographic characteristics, history of the condition including when uveitis started, treatment received and history of other health conditions that may be relevant to uveitis.Complete opthalmologic examination including assessment of best corrected visual acuity (BCVA) and OCT macula, if possible, were done. These was repeated 1 week, 1 month, 3 months and 6 months after surgery. Specular microscopy was performed preoperatively and 3 months after surgery. Patients underwent cataract surgery with posterior chamber intra ocular lens and statistical analysis was performed to compare preoperative and postoperative BCVA and corneal endothelial cell counts. Postoperative complications were recorded.

RESULTS

Five eyes of 5 patients were included in the study. All study eyes showed improvement in the post-operative visual acuity. A statistically significant improvement was observed in VA in the sixth postoperative month compared to the baseline measurements (p = 0.004). No statistically significant difference was observed between the preoperative and postoperative endothelial cell counts (p = 0.696). Cystoid macular edema did not occur as a postoperative complication.

CONCLUSION

Visual outcomes of cataract surgery in eyes with persumed trematode induced granulametous anterior uveitis are favorable. No sight threatening complication was observed in our series.

Characteristics of Childhood Presumed Trematode-Induced Granulomatous Anterior Uveitis Using Ultrasound Biomicroscopy

PURPOSE

To investigate the UBM characteristics of presumed trematode-induced granulomatous uveitis.

DESIGN

Prospective case series.

METHODS

Thirty patients who presented with anterior chamber (AC) granuloma were included. UBM Imaging included Cornea, iris, AC angle, posterior chamber, ciliary body, and vitreous base.

RESULTS

Thirty eyes were included with a mean age of 12.4 ± 2.5 years. UBM findings were retrocrneal membrane (33%), sub conjunctival nodule (10%), AC granuloma (100%); peripheral anterior synechia, granuloma-like lesion in posterior chamber; ciliary body edema with localized granuloma at specific site (100%), cataract in 30% either localized or generalized, and dot or thread-like high reflection on vitreous base in (20%).

CONCLUSION

Presumed trematode-induced AC granuloma is common among children living in the rural areas of Egypt. UBM examinations can demonstrate various pathologic changes of anterior segment of the eye and provide objective evidence for the exact origin of those granulomas.

Ocular infestation by a juvenile leech, Myxobdella sinanensis in Japan

Purpose

The case of ocular infestation by a leech is rare. We reported that Myxobdella sinanensis infests conjunctiva.

Observations

A 5-year-old girl presented with blood clots in the inner corner of the left eye, and a history bloody eye discharge and bloody tears for 5 days. She was prescribed 0.5% levofloxacin ophthalmic drops for conjunctival damage. However, her parent watched a worm moving in her conjunctiva while taking a bath. She presented again the same day, and a worm was found in the left eye of the lower conjunctival fornix and was adsorbed to the inner corner. We removed a worm under eye drop anesthesia, the next day the patient had no symptoms. We captured the worm, and it was identified morphologically and genetically as Myxobdella sinanensis. This was the first case reported of Myxobdella sinanensis be infestation in a human.

Conclusions and Importance

The ecological trait of Myxobdella sinanensis still did not remain clear, so this case report was helpful to find out a life cycle of Myxobdella sinanensis. As the outdoor population continues to increase, the cases of human parasites such as leech are expected to increase. When a patient with bloody eye discharge and bloody tears presents, we should carefully examine the conjunctiva and ocular surfaces, and interview recent history of exposure to stream water.

Taenia solium in the Anterior Chamber: Surgical Management of a Rare Case of Live Free-Floating Parasite

Ocular cysticercosis is a preventable cause of blindness. It is a parasitic infestation caused by Cysticercus cellulosae—which is the larval form of Taenia solium. In 1829, Soemmering reported the first case of a live anterior chamber cysticercosis. In the following, we report a rare case of a 13-year-old male who presented with a live adult Taenia solium in the anterior chamber without any systemic features and its successful management.

Case report: an unusual unilateral pterygium - a secondary pterygium caused by parasitosis in the scleral fistula

BACKGROUND

Ocular parasitosis can cause eye damage, which contribute to eye symptoms such as burning, itching and even blindness. It is uncommon to see the parasitosis lying in the sclera layer, neither it causing pterygium. Here, we present an unusual case of a secondary pterygium caused by intrascleral worm.

CASE PRESENTATION

A 52-year-old women complained about discomfort in right eye for 6 years. Slit-lamp examination indicated a thickened triangular layers of conjunctiva extending from the nasal edge to the cornea. The diagnosis was pterygium in the right eye. To our surprise, after scleral of nasal side exposed, we could see a tiny fistula right in the sclera which lied right under the pterygium, with an alive and motile worm inside. An intrascleral fistula was noted. Then the worm was removed by forceps from the fistula, which was creamy white, thread-like and 1 cm long.

DISCUSSION AND CONCLUSIONS

As far as we known, it is the first case of an intrascleral worm hidden beneath the conjunctiva which caused the secondary pterygium. It is hard to know the etiology of the secondary pterygium which caused by parasitosis in the scleral fistula untill excision surgery. It is hard to imagine the worm was living in the sclera of the patient for a long-time.

The first case of periorbital human dirofilariasis in the Czech Republic

Dirofilaria repens and Dirofilaria immitis are the most common filarial species affecting humans in Europe. Dirofilaria repens causes subcutaneous or ocular infection, whereas D. immitis is responsible mainly for the pulmonary form. In this report, we present the first human case of periorbital dirofilariasis in the Czech Republic. A 58-year-old woman suffered from an eyelid oedema, redness and pain in the left eye. After excising the parasite from her eyelid, all clinical symptoms disappeared. Based on the morphology and cytochrome oxidase I sequencing, the parasite was identified as D. repens. Histology revealed that the excised worm was female with absent microfilariae in uteri. With respect to the length of the incubation period and the sequence identity with a known Czech isolate, we concluded that D. repens was most likely of autochthonous origin.

Argon Laser Photocoagulation for Treatment of Presumed Trematode-induced Granulomatous Anterior Uveitis in Children.. [DOI: 10.1101/2020.12.30.20248850]

Background/Aims

To assess the safety and efficacy of argon laser photocoagulation as a new modality for the treatment of presumed trematode-induced granulomatous anterior uveitis (PTGAU) in children.

Methods

Forty-eight eyes of 48 children with PTGAU with pearl-like nodule(s) in the anterior chamber were included in this prospective non- randomised controlled clinical trial. Patients were divided into two groups: group A (23 eyes) was treated with one session of argon laser applied to the anterior chamber nodules, and group B (25 eyes) received medical treatment in the form of topical steroid and cycloplegic eye drops with trans-septal triamcinolone injection.All cases were followed up for 3 monthswith measurement of VA, assessment of anterior chamber reaction, and size of the pearl-like nodules.

Results

In group A, 22 eyes (95.65%) showed regression of the pearl- like nodules with resolution of the anterior chamber reaction (flare and cells) and improvement in visual acuity from 0.52±0.12 to 0.06 ± 0.08logMAR (p value <0.001). Such improvement was maintained within the 3-month follow-up period. In group B, 23 eyes (92%) showed initial regression of the granulomas,whichwas maintained in only 14 eyes (56%),with 9 eyes experiencing recurrence after 3 months of follow-up.

Conclusion

Argon laser photocoagulation is a safe and effective novel treatment for PTGAU with pearl-like nodules in the anterior chamber in children. Larger studies with longer follow-up periods are needed to confirm these results.

PRECIS

Argon laser photocoagulation is a novel non-invasive line of treatment that can be added to the armamentarium for presumed trematode-induced granulomatous anterior uveitis in children.

Initial Evidences of Salt and Pepper Retinal Lesions (SPRL) in Patients with Intestinal Protozoan Infections in Iran

BACKGROUND

It is made clear that salt and pepper retinal lesion (SPRL) has subsequently associated with the infection with Giardia lamblia (G. lamblia). However, little is known regarding the prevalence of SPRL among patients suffered from parasitic infections in the world.

OBJECTIVE

This study aimed to determine the prevalence of SPRL among patients with intestinal protozoan infections, for the first time, in Sari, northern Iran.

METHODS

In this case-control study, a total of 150 subjects participated: 75 were in the patients group diagnosed to have an intestinal parasite and 75 in the control group without any intestinal infection. Fecal samples were obtained from all participants and examined with wet mount and formalin-ether methods. The retina of both groups was examined by an ophthalmologist.

RESULTS

Overall, salt and pepper retinal changes were diagnosed in 12 (16 %) patients with at least one parasitic infection (7 females and 5 males). G. lamblia was diagnosed in 6 subjects (50%), Blastocystis hominis in 5 (41.6%), and Entamoeba coli in 1 (8.3 %). Most of the patients (58.3%) had a mild infection. Bilateral retinal involvement was observed in 75% of the patients. Furthermore, macula involvement was observed in 91.7 % with SPRL.

CONCLUSION

Our findings indicated the relatively high prevalence of SPRL in subjects with giardiasis and blastocystosis. It can be concluded that not only G. lamblia but also B. hominis can cause SPRL in Sari, Iran. Further studies are needed to find other etiologic parasites able to cause retinal damages.

Subconjunctival Dirofilariasis Presenting as Orbital Cellulitis

Human ocular Dirofilariasis is a relatively rare, zoonotic disease, caused by a filarial nematode, Dirofilaria repens. This parasitic infestation usually presents as a subconjunctival nodule with hyperemia. The authors present a case of subconjunctival dirofilariasis in a 91-year-old gentleman, who presented with manifestations of orbital cellulitis. The live worm was surgically removed and identified to be D. repens.

Suprasellar Cysticercosis Cyst with Optic Nerve Compression Masquerading as an Arachnoid Cyst

Cysticercosis is a parasitic infection caused by the larvae of the cestode Taenia solium. Ocular parasitosis in humans is well recognized; however, cysticercosis of the optic nerve is rare. Here, we report a case of an adult male who presented with right-sided headache and a gradual loss of vision in the right eye. Optical coherence tomography indicated severe loss of ganglion cells in the right eye. Magnetic resonance imaging showed a predominantly suprasellar cystic lesion thought to represent an arachnoid cyst. We performed a craniotomy to excise the cyst. Histopathological examination of the excised cyst revealed internal living larvae of T. soilum. After co-administration of praziquantel and albendazole, vision was restored, and the headaches ceased. Vision has since been restored in both eyes. A higher degree of neurocysticercosis suspicion should be maintained for patients living in endemic areas who present with ophthalmic symptoms where the brain scans show cystic lesions.

Irreversible Ocular Lesions in a Dog With Angiostrongylus Vasorum Infection

This report describes a 10-month-old dog with a sudden loss of vision and severe dyspnoea. The ocular examination revealed bilateral panuveitis, lens subluxation, secondary glaucoma, and retinal detachment. In addition, the ocular ultrasound showed in the vitreous body of the right eye, a small doubled-lined foreign body compatible with an intraocular parasite. Radiographs of the thorax revealed an increased opacity with mixed lung pattern (alveolar and bronchial) and thoracic ultrasonography showed several subpleural nodules. The presence of Angiostrongylus vasorum first stage larvae was confirmed with 324 larvae per gram of feces and an antigen test for the parasite (AngioDetect, IDEXX) also yielded a positive result. The severe and irreversible ocular lesions described in this case enhanced the complexity of the clinical picture of canine angiostrongylosis. Infection with the parasite should be included in the list of differential diagnoses for ocular uveitis to avoid potentially serious complications related to a missed or delayed diagnosis.

Treatment of presumed trematode-induced granulomatous anterior uveitis among children in rural areas of Egypt

PURPOSE

The purpose of this study is to evaluate the efficacy of systemic antiparasitic medications alone or in combination with surgical aspiration in management of presumed trematode-induced anterior uveitis in children.

PATIENTS AND METHODS

Prospective case series. Children who presented with anterior chamber (AC) granuloma were included in the study. All patients received antiparasitic treatment and after 2 weeks; patients were divided based on their clinical improvement in terms of the baseline granuloma area into two groups: group A (<2.5 mm²) who continued on antiparasitic medications only (n = 15) and group B (≥2.5 mm²) who underwent surgical aspiration (n = 15). Basic demographics data, visual acuity (VA), corneal thickness, granuloma area and AC activity (cells and flare) were recorded and analysed. Systemic work-up including stool and urine analysis, full blood count, chest X-ray and schistosomiasis titre were performed.

RESULTS

Thirty eyes of 30 patients were included in the study with a mean age of 13.4 ± 2.42 years. All patients were male. Patients were examined and followed at Mansoura Ophthalmic Center, Mansoura University. Both groups showed statistically significant improvement in VA, AC activity, corneal thickness and granuloma area (p-value < 0.001), which was achieved with medical treatment only in group A. However, in group B granuloma required aspiration and did not recur after that.

CONCLUSION

Presumed trematode-induced AC granuloma is common among children living in the rural areas of Egypt. Antiparasitic medication alone was found to be effective for small-sized granulomas. Surgical aspiration is an effective adjuvant procedure to treat large-sized ones.

Ocular Parasitosis Caused by Protozoan Infection during Travel: Focus on Prevention and Treatment

International travel is rising quickly worldwide. Many people travel to tropical and subtropical areas, where there has been increasing exposure of travelers to infectious pathogens. Ocular parasitic infections are more prevalent in these geographical areas and they can lead to morbidity and mortality, often due to late or misdiagnosis due to the unfamiliarity of health staff with these diseases. This is an up-to-date comprehensive review article that familiarizes physicians with ocular signs and symptoms, treatment, prevention, and geographic distribution of some parasites associated with travel.

Water related ocular diseases

A number of ocular diseases can be attributed to contaminated water and we have coined a term "Water-related ocular diseases (WRODs)" to denote this wide-spectrum of conditions. WRODs are directly related to human contact with water and can occur through toxic, allergic, inflammatory or infective mechanisms. The non-infective causes can include chemicals used to clean swimming pools, oil spills and water-sport related injuries. Similarly, a number of infective organisms causing ocular diseases are transmitted through water. Since, these conditions can occasionally prove devastating, a review was done with the following aims: (i) To study the epidemiology of WRODs (ii) To assess the clinical presentation and current management of WRODs (iii) To highlight the future challenges and possible solutions to these problems. The online search was conducted utilizing search engines such as PubMed, Google Scholar, ClinicalKey and the Virtual Library of the Ministry of Health, Malaysia for relevant terms such as water-borne, swimming pool and eye infections.

A new worm infiltrating the human cornea: A report of three cases

Purpose

To characterize a new species of parasitic nematode that triggers uveitis.

Observations

Three previously healthy, relatively young people each contracted a corneal stromal nematode that, upon surgical removal and examination, did not match any known nematodes. Clinical ocular findings included corneal opacification, visible corneal worms, conjunctival injection, and uveitis.

Conclusions and Importance

The three cases presented here represent a previously undescribed parasitic infection of the cornea by an unidentified nematode. These findings may represent a previously unrecognized zoonotic infection from wildlife sources and potentially a newly documented nematode requiring description. Future clinical findings regarding this newly described nematode are needed to further develop our understanding of the disease.

Α molecular epidemiological analysis of adenoviruses from excess conjunctivitis cases

BACKGROUND

Τo perform a molecular epidemiological analysis of viral conjunctivitis among excess conjunctivitis cases recorded at the University Hospital of Patras, Greece, for the period March to June 2012.

METHODS

A structured questionnaire containing demographic and clinical data was developed in order to collect retrospective data on the cases. Eye swab specimens were collected and molecular detection of adenoviruses was performed by nested PCR. Positive results were confirmed by sequencing. To determine the relatedness between the isolated sequences, a phylogenetic analysis was conducted.

RESULTS

The epidemiological analysis (including retrospective data) included 231 conjunctivitis cases (47.1% male, and 52.8% female). Based on clinical features 205 of the cases were diagnosed of viral origin (46.3% male and 53.7% female), 4 of bacterial origin (50% male and 50% female) while 22 were undefined conjunctivitis. The outbreak excess cases (included 156 cases) affected all age groups regardless gender predilection. For the positive samples indicated that 29 samples (72.5%) were AdV17, and 5 (12.5%) as AdV54.

CONCLUSIONS

Molecular analysis could define the cause of viral conjunctivitis, while epidemiological data contributed to the assessment of the risk factors and underlined possible preventive measures. This study is one of the very few on viral conjunctivitis in Greece. This outbreak underscores the need for a national surveillance system for acute infectious conjunctivitis outbreaks. The epidemiological as well as molecular investigation on HAdV ocular infections is rather absent in Greece, which has no surveillance system for viral conjunctivitis.

Characterization of the parasite-induced lesions in the posterior segment of the eye

Ocular lesions are frequently associated with different parasitic infections. The classes of infection include protozoa, nematodes, cestodes, and ectoparasites. Ocular parasitic infections can manifest in any part of the eye; the disease manifestations are frequently characterized as either posterior or anterior eye disease. Parasite-induced lesions may be due to damage directly caused by the parasite, indirect pathology caused by toxic products or the immune response initiated by infectious parasitism. This review characterized the parasite-induced lesions in the posterior segment of the eye. Prompt diagnosis and early treatment of these lesions can reduce ocular morbidity. The method of the literature search was conducted on PubMed, Elsevier Scopus database, and Google Scholar with no limitation on the year of publication databases. It was limited to English articles published for ocular lesions in clinical studies and was focused on parasitic infections of the eye.

Update on pathology of ocular parasitic disease

Parasites are a group of eukaryotic organisms that may be free-living or form a symbiotic or parasitic relationship with the hosts. Consisting of over 800,000 recognized species, parasites may be unicellular (Protozoa) or multicellular (helminths and arthropods). The association of parasites with human population started long before the emergence of civilization. Parasitic zoonotic diseases are prevalent worldwide including India. Appropriate epidemiological data are lacking on existing zoonotic parasitic diseases, and newer diseases are emerging in our scenario. Systemic diseases such as cysticercosis, paragonimiasis, hydatidosis, and toxoplasmosis are fairly common. Acquired Toxoplasma infections are rising in immune-deficient individuals. Amongst the ocular parasitic diseases, various protozoas such as Cystoidea, trematodes, tissue flagellates, sporozoas etc. affect humans in general and eyes in particular, in different parts of the world. These zoonoses seem to be a real health related problem globally. Recent intensification of research throughout the world has led to specialization in biological fields, creating a conducive situation for researchers interested in this subject. The basics of parasitology lie in morphology, pathology, and with recent updates in molecular parasitology, the scope has extended further. The current review is to address the recent update in ophthalmic parasites with special reference to pathology and give a glimpse of further research in this field.

Trematode Fluke Procerovum varium as Cause of Ocular Inflammation in Children, South India

Larvae of this fluke are novel causes of granulomatous eye disease in children.

Trematodes are recognized as a group of emerging parasites in tropical countries. We identified a trematode as a cause of ocular granulomas that developed in children who bathed in ponds or rivers in South India. DNA was isolated from patients’ surgically excised granulomas and from the trematode cercariae (larvae) released by the snail Melanoidestuberculata in water in which the children bathed. Real-time and conventional PCRs were performed that targeted ribosomal DNA regions spanning the internal transcribed spacer 2 and 28S sequences of this trematode. The PCR-amplified products were subjected to bidirectional sequencing. Analysis of sequences for the granuloma samples and the trematode cercariae showed maximum sequence similarity with Procerovumvarium (family Heterophyidae). Our results confirmed the etiology of the ocular infection, implicating snail vectors as environmental risk factors for ocular parasitosis.

Intraocular Nematode Affixed to Posterior Lens Capsule

The clinical presentation of an intraocular nematode unusually affixed to the posterior lens capsule is described. A 64-year-old female patient presented with a 7-year history of gradually declining vision and enlarging central scotoma, but no inflammation. On follow-up 2 years later, vision had further declined and a non-motile, 8-mm nematode was seen affixed to the posterior lens capsule that remained unchanged through final follow-up. The patient disclosed having resided in Africa as a child. Systemic review revealed no evidence of extraocular involvement. Nematode carcasses may remain preserved in the human eye for extended periods without ongoing inflammation.

Sitting at the window to the world--ocular parasites

Parasitic infections cause significant ophthalmic disease, both in developing countries and in the Western world. The parasitic infections Acanthamoeba keratitis, ocular toxoplasmosis, and ocular toxocariasis are responsible for a significant proportion of ocular pathology. Especially in light of the recent increase of immunocompromised (i.e. using immunosuppressants or HIV) and aged populations, parasitic infections of the eye are rising in number. This reviews aims to describe the pathogenesis, symptoms, diagnosis and management of infection, as well as preventative measures for these three parasitic ocular diseases.