Perifosine-Related Rapidly Progressive Corneal Ring Infiltrate

Corneal ring infiltrate- far more than Acanthamoeba keratitis: review of pathophysiology, morphology, differential diagnosis and management

OBJECTIVE

Ring infiltrates usually accompany numerous infectious and sterile ocular disorders. Nevertheless, systemic conditions, drugs toxicity and contact lens wear may present with corneal ring infiltrate in substantial part. Considering its detrimental effect on vision, detailed knowledge on etiology, pathophysiology, differential diagnosis, and management should be considered essential for every ophthalmologist.

METHODS

The PUBMED database was searched for "corneal ring infiltrate" and "ring infiltrate" phrases, "sterile corneal infiltrate" and "corneal infiltrate". We analyzed articles written in English on risk factors, pathophysiology, clinical manifestation, morphological features, ancillary tests (anterior-segment optical coherence tomography, corneal scraping, in vivo confocal microscopy), differential diagnosis and management of corneal ring infiltrate.

RESULTS

Available literature depicts multifactorial origin of corneal ring infiltrate. Dual immunological pathophysiology, involving both antibodies-dependent and -independent complement activation, is underlined. Furthermore, we found that the worldwide most prevalent among non-infectious and infectious ring infiltrates are ring infiltrates related to contact-lens wear and bacterial keratitis respectively. Despite low incidence of Acanthamoeba keratitis, it manifests with corneal ring infiltrate with the highest proportion of the affected patients (one third). However, similar ring infiltrate might appear as a first sign of general diseases manifestation and require targeted treatment. Every corneal ring infiltrate with compromised epithelium should be scraped and treat as an infectious infiltrate until not proven otherwise. Of note, microbiological ulcer might also lead to immunological ring and therefore require anti-inflammatory treatment.

CONCLUSION

Corneal ring infiltrate might be triggered not only by ocular infectious and non-infectious factors, but also by systemic conditions. Clinical assessment is crucial for empirical diagnosis. Furthermore, treatment is targeted towards the underlying condition but should begin with anti-infectious regimen until not proven otherwise.

Wessely corneal ring phenomenon: An unsolved pathophysiological dilemma

The cornea is a densely innervated, avascular tissue showing exceptional inflammatory and immune responses. The cornea is a site of lymphangiogenic and angiogenic privilege devoid of blood and lymphatic vessels that limits the entry of inflammatory cells from the adjacent and highly immunoreactive conjunctiva. Immunological and anatomical differences between the central and peripheral cornea are also necessary to sustain passive immune privilege. The lower density of antigen-presenting cells in the central cornea and the 5:1 peripheral-to-central corneal ratio of C1 are 2 main features conferring passive immune privilege. C1 activates the complement system by antigen-antibody complexes more effectively in the peripheral cornea and, thus, protects the central corneas' transparency from immune-driven and inflammatory reactions. Wessely rings, also known as corneal immune rings, are non-infectious ring-shaped stromal infiltrates usually formed in the peripheral cornea. They result from a hypersensitivity reaction to foreign antigens, including those of microorganism origin. Thus, they are thought to be composed of inflammatory cells and antigen-antibody complexes. Corneal immune rings have been associated with various infectious and non-infectious causes, including foreign bodies, contact lens wear, refractive procedures, and drugs. We describe the anatomical and immunologic basis underlying Wessely ring formation, its causes, clinical presentation, and management.

Bilateral idiopathic corneal opacity: A report of Ascher ring and a review of the literature

Purpose

To present a case of a rare entity of Ascher ring, a bilateral corneal stromal opacification.

Observation

A 70-year-old male with no ocular history who presented for cataract evaluation was found to have idiopathic bilateral circular stromal corneal rings.

Conclusions

After completion of extensive history, examination, imaging analyses, and laboratory studies for workup of corneal opacities, we arrived at a diagnosis of Ascher corneal ring, an extremely rare entity.

Importance

A rare entity should be considered after excluding other etiologies.

Keratitis occurring in patients treated with miltefosine for post-kala-azar dermal leishmaniasis

AIM

To describe the characteristic clinical features and management of keratitis in the patients receiving miltefosine for post-kala-azar dermal leishmaniasis (PKDL).

METHODS

The medical records of five patients with PKDL who presented with keratitis were reviewed retrospectively from April 2018 to December 2019. The evaluation included a thorough medical history including details on drugs used, particularly miltefosine. The drug causality assessment was also performed. The clinical and microbiological characteristics of keratitis were noted.

RESULTS

The ocular symptoms included pain, redness, watering, photophobia and diminution of vision. Slit-lamp biomicroscopy revealed peripheral, paralimbal, ring-shaped, full-thickness stromal infiltration resulting in ulcerative keratitis in all cases. Two patients had unilateral keratitis, while three had bilateral keratitis. All five patients received miltefosine for an average period of 48 days before the onset of keratitis. The corrected distance visual acuity at presentation ranged from hand movement to 20/125. The causality assessment revealed a 'probable' association between the adverse drug reaction and miltefosine in all patients. Discontinuation of miltefosine and initiation of corticosteroid therapy resulted in resolution of keratitis in all cases. The unilateral keratitis treated with topical corticosteroids had improved outcomes, but poor outcomes were found in the bilateral keratitis.

CONCLUSION

These observations indicate that prolonged use of miltefosine might cause keratitis that resembles infectious keratitis. Early diagnosis with discontinuation of the drug and initiation of corticosteroid therapy are the key to successful management.

Alkylphospholipids are Signal Transduction Modulators with Potential for Anticancer Therapy

BACKGROUND

Alkylphospholipids (APLs) are synthetically derived from cell membrane components, which they target and thus modify cellular signalling and cause diverse effects. This study reviews the mechanism of action of anticancer, antiprotozoal, antibacterial and antiviral activities of ALPs, as well as their clinical use.

METHODS

A literature search was used as the basis of this review.

RESULTS

ALPs target lipid rafts and alter phospholipase D and C signalling cascades, which in turn will modulate the PI3K/Akt/mTOR and RAS/RAF/MEK/ERK pathways. By feedback coupling, the SAPK/JNK signalling chain is also affected. These changes lead to a G2/M phase cell cycle arrest and subsequently induce programmed cell death. The available knowledge on inhibition of AKT phosphorylation, mTOR phosphorylation and Raf down-regulation renders ALPs as attractive candidates for modern medical treatment, which is based on individualized diagnosis and therapy. Corresponding to their unusual profile of activities, their side effects result from cholinomimetic activity mainly and focus on the gastrointestinal tract. These aspects together with their bone marrow sparing features render APCs well suited for modern combination therapy. Although the clinical success has been limited in cancer diseases so far, the use of miltefosine against leishmaniosis is leading the way to better understanding their optimized use.

CONCLUSION

Recent synthetic programs generate congeners with the increased therapeutic ratio, liposomal formulations, as well as diapeutic (or theranostic) derivatives with optimized properties. It is anticipated that these innovative modifications will pave the way for the further successful development of ALPs.

Moraxella atlantae keratitis presenting with an infectious ring ulcer

Purpose

Moraxella atlantae is a rare pathogen. Keratitis from this organism has never been specifically reported or described. In this report we provide the first clinical description and photograph of Moraxella atlantae infectious keratitis.

Observations

A 41 year-old man presented with a three day history of left eye pain. He was found to have a corneal ring ulcer and infiltrate from which Moraxella atlantae was cultured. The patient was successfully treated with intensive topical gatifloxacin (0.5%) and fortified tobramycin (1.5%); oral doxycycline was added to reduce corneal thinning. The patient's infection resolved with a residual scar and final best corrected visual acuity of 20/200 OS.

Conclusions and importance

Moraxella atlantae can present as a ring-shaped infectious corneal infiltrate and ulcer. Ring infiltrates have been observed with other microorganisms, including several other gram negative bacteria and classically, acanthamoeba. Frequently presumed to be purely immunologic, corneal ring infiltrates can have a number of other etiologies, including infectious and toxic. There are different types of immunologic rings as well, making differentiation of corneal rings sometimes difficult for the ophthalmologic generalist and subspecialist alike. In this paper we discuss characteristics of various corneal ring infiltrates, along with their immune pathophysiology. Infectious rings are distinguished from immunologic Wessely rings.

Ophthalmic complications of targeted cancer therapy and recently recognized ophthalmic complications of traditional chemotherapy

As our understanding of cancer pathophysiology has increased, so have the number of targeted therapeutic agents available. By targeting specific molecules involved in tumorigenesis, targeted therapeutic agents offer the potential for significant efficacy against tumor cells while minimizing the adverse effects. We highlight the recently recognized ophthalmic complications of targeted cancer therapy, as well as recently recognized complications of traditional chemotherapeutic agents.

The ophthalmological complications of targeted agents in cancer therapy: what do we need to know as ophthalmologists?

Recently, there has been an increase in the use of targeted therapies for cancer treatments. Nevertheless, the ocular side-effects of the commonly used targeted agents are generally under-reported and not well studied in the literature. We conducted multiple searches in databases, including Medline, EMBASE, Cochrane Library and conference proceedings, using the following strings: 'name of targeted therapeutic agent (both generic and commercial names)' AND 'eye OR ocular OR vision OR ophthalmological'. Various targeted agents have been found to be associated with ocular side-effects due to their specific targeting of activities in the eye. Imatinib commonly causes periorbital oedema, epiphora and occasionally conjunctival haemorrhage. Cetuximab causes corneal lesions, meibomian gland dysfunction, periorbital and lid dermatitis, blepharitis and conjunctivitis. Erlotinib is related to various ocular toxicities, mainly on the ocular surface, and perifosine has been reported to be associated with severe keratitis. Bevacizumab could potentially disrupt intrinsic ocular circulation and lead to the development of thromboembolic events; there are rare reported cases of optic neuritis or optic neuropathy. Other targeted agents, such as trastuzumab, sunitinib and crizotinib, also have specific ocular toxicities. In conclusion, ocular effects of targeted agents are not uncommon in cancer patients receiving targeted therapy. Ophthalmologists should have high indexes of suspicion to diagnose and treat these complications promptly.