Ultrasound biomicroscopic diagnosis of an occult intrascleral foreign body: an unusual case of ocular siderosis

Siderotic glaucoma without detectable intraocular foreign body in a pseudophakic eye: a case report

Background

Ocular siderosis is induced by a retained intraocular foreign body (IOFB) containing iron and can present as siderotic glaucoma. We report a rare case of histopathologically proven siderotic glaucoma in a middle-aged blacksmith with a preceding history of ocular trauma but no radiologically detectable IOFB.

Case presentation

A 42-year-old blacksmith presented with an elevation of intraocular pressure (IOP) in left eye showing iris heterochromia and brownish deposits throughout the trabecular meshwork (TM). Preoperative ophthalmic examination did not reveal any retained IOFBs. Electroretinography showed the classic changes of retinal degeneration in ocular siderosis. Histopathologic staining of the TM verified the presence of iron deposits.

Conclusion

This case underlines the importance of the close monitoring of patients with a history of ocular trauma and highlights the necessity of electroretinography, histopathologic study, and detailed ophthalmic examination in the diagnosis of siderotic glaucoma, even if there is no definite radiologically detectable IOFB.

Ocular siderosis: a misdiagnosed cause of visual loss due to ferrous intraocular foreign bodies-epidemiology, pathogenesis, clinical signs, imaging and available treatment options

Purpose

The purpose of this paper is to provide a meaningful literature review about the epidemiology, pathogenesis, clinical signs, imaging and treatment of ocular siderosis (OS).

Methods

A computerized search from inception up to March 2020 of the online electronic database PubMed was performed using the following search strings: “ocular siderosis” and “siderosis bulbi”. The reference list in each article was analysed for additional relevant publications.

Results

OS is an uncommon cause of visual loss due to a retained ferrous intraocular foreign body (IOFB). It may develop from 18 days to years after a penetrating trauma that usually occurs during hammering. On average, patients are 22–25 years old, and the vast majority are male. The most common cause of OS development is delayed presentation by the patient or missed diagnosis of IOFB after trauma. The pathophysiology is not fully understood; nevertheless, iron deposition causes hydroxyl radical formation, which damages photoreceptors and retinal pigment epithelium. Moreover, iron damages retinal vessels with consequent inner retinal layers degeneration. The most frequent signs are iris heterochromia, pupillary mydriasis, cataract development and retinal arteriolar narrowing with pigmentary retinal degeneration. Electroretinogram signs, in particular, b-wave amplitude reduction, arise earlier than clinical signs. Orbital CT scans and ultrasonography play an essential role in detecting IOFBs. Treatment depends on the IOFB location and OS development. However, it is crucial to remove the IOFB after OS development because visual acuity and clinical signs may improve. Anterior segment IOFBs can be dislodged using an intraocular magnet (IOM) or forceps through limbal paracentesis. In contrast, posterior segment IOFBs require a pars plana vitrectomy and IOM or forceps to be removed through an enlarged sclerotomy or the limbus.

Conclusion

Recommending the usage of protective glasses and spreading knowledge about OS may further benefit patient care.

Missed Diagnosis of an Intraorbital Foreign Body of Homemade Fireworks Origin: A Case Report

Purpose

We report a rare case of traumatic injury to the eye caused by homemade fireworks in a Chinese juvenile patient with a metal ring left in the orbit after having been sutured at the Emergency Department.

Methods

An 11-year-old boy presented with a traumatic injury to the right eye from homemade fireworks. Following initial assessment involving maxillofacial computed tomography (CT) and suturing at the Emergency Department, he was transferred to our department for further evaluation because of his poor sight 1 day later. On examination, a skin laceration beneath the right eyebrow was noted, but the superior orbit was not fully visible on the maxillofacial CT performed 1 day previously. Therefore, an orbital CT scan was carried out on the second day, which showed a hyperdense ring embedded in the superior border of the orbital wall; the ring was surgically removed. On postoperative day 7, a fundus examination revealed resolving vitreous hemorrhage, blunt traumatic retinal detachment, and a large retinal tear superior to the macula. The patient refused to take surgery for retinal detachment into consideration. Therefore, we opted for oral steroids and careful observation.

Results

After 2 months’ observation, the large retinal tear had healed and white fibrous scar tissue had developed, and the retinal detachment superior to the macula had reattached itself spontaneously. The patient's vision had further improved to 20/200. During 1 year of follow-up, he remained clinically stable.

Conclusion

To avoid missing the diagnosis, a complete history of the mechanism of injury and accurate imaging still prove most useful. Complete removal of the foreign body by the emergency physician is necessary because of the ocular toxicity of an iron-containing foreign body. As evidenced by the current case, oral steroids and observation for a period of several months is a management of choice for traumatic retinal detachment and retinal tear superior to the macula associated with homemade fireworks in children.

Iron Foreign Body in the Optic Nerve without Ocular Siderosis

BACKGROUND AND PURPOSE

An intraocular iron foreign body may cause many ocular complications, sometimes even blindness. Therefore, if possible, it should be removed to avoid ocular siderosis. We report a case in which a foreign body was trapped in the optic nerve and could not be removed. After a 2-year follow-up, no ocular siderosis or progressive deterioration in vision was found. This is the first case report of a foreign body in the optic nerve behind the eyeball in the PubMed literature.

METHODS

The authors describe the case of a 33-year-old man with an ocular trauma history at work. A metal iron foreign body was trapped in the optic nerve behind the eyeball, which was demonstrated by computed tomography.

RESULTS

There was no significant vision change and ocular siderosis by electroretinogram after 2 years of follow-up.

CONCLUSIONS

Intra-optic-nerve foreign body may have a better ocular prognosis. Siderosis may not be seen in patients with optic nerve iron foreign body. Intraocular foreign body should be accurately studied before surgical procedures.

Excimer laser phototherapeutic keratectomy in eyes with anterior corneal dystrophies: short-term clinical outcomes with and without an antihyperopia treatment and poor effectiveness of ultrasound biomicroscopic evaluation

PURPOSE

To evaluate the use of high-frequency ultrasound biomicroscopy (UBM) in determining the depth of corneal pathology in eyes undergoing excimer laser phototherapeutic keratectomy (PTK) for primary or recurrent anterior stromal corneal dystrophies. Corneal clarity, visual acuity, and refractive changes in eyes with and without an antihyperopia treatment were also analyzed.

METHODS

Twenty eyes of 14 patients with anterior stromal corneal dystrophies were treated with PTK. Eyes were evaluated pre- and 6-8 weeks postoperatively with slit-lamp biomicroscopy, manifest refraction, keratometry, computerized corneal topography, ultrasound pachymetry, and UBM.

RESULTS

Nineteen of 20 corneas (95%) had greatly improved corneal clarity after PTK. Mean uncorrected Snellen vision improved from 20/102 to 20/69, and best corrected vision improved from 20/62 to 20/38. Nine eyes (45%) improved two or more lines of uncorrected vision, and 13 eyes (65%) improved two or more lines of best corrected vision. Mean change in spherical equivalent was just -0.92 diopters (SD 4.3 diopters); however, the range was large (-13 to +3.88 diopters). UBM measurement of central corneal pathology did not correlate significantly with the actual PTK ablation depth (P = 0.07). The amount of antihyperopia treatment did not correlate with changes in manifest refraction spherical equivalent, keratometry, or computerized corneal topography readings but did correlate with length of time until corneal reepithelialization after PTK (P = 0.003).

CONCLUSIONS

PTK resulted in improvements in corneal clarity and visual acuity in most patients with superficial corneal stromal dystrophies. UBM was not an effective tool to accurately measure the depth of corneal pathology preoperatively. The combined approach of minimizing ablation depth and selective use of an antihyperopia treatment resulted in minimal mean change in spherical equivalent; however, the range was large. PTK is a very good minimally invasive technique to improve vision in eyes with anterior stromal corneal dystrophies.