The impact of anticancer drugs on the ocular surface

Ophthalmic rehabilitation in oncology care

Ophthalmic rehabilitation refers to the multidisciplinary approach to restoring, maximizing, and preserving the visual function and quality of life for patients affected by ocular manifestations of cancer or its treatments. Besides its approach to low vision, ophthalmic rehabilitation also encompasses a series of reconstructive interventions to mitigate anatomic deficits that may interplay with visual impairment. A gamut of oncologic conditions may result in ocular disabilities, including primary intraocular tumours, secondary metastases, or adverse effects of systemic therapies such as chemotherapy, radiation, and surgery. Methods of ophthalmic rehabilitation are evolving constantly and involve the prescription of optical aids and adaptive technologies to enhance remaining vision, as well as supportive training and counselling to address psychosocial effects. Although studies in low vision have mostly covered aspects of rehabilitation in inherited and degenerative eye conditions, ophthalmic rehabilitation within the context of cancer carries specificities that have been poorly explored in the literature on ophthalmology and oncology. This review aims to build on the trends of low vision management, ocular oncology treatments, orbital reconstructive surgery, and visual therapy to revise the published rationale behind evaluating and managing patients facing debilitating ocular sequelae as the result of cancer.

Longitudinal Changes of Ocular Surface Microbiome in Patients Undergoing Hemopoietic Stem Cell Transplant (HSCT)

PURPOSE

To evaluate changes in the ocular surface microbiome (OSM) between pre- and post-haemopoietic stem cell transplant (HSCT) in the same patient, and to assess the potential impact of these changes in ocular graft-versus-host disease (o)GVHD development.

METHODS

Lower fornix conjunctival swabs of 24 patients were obtained before and after HSCT and subjected to DNA extraction for amplification and sequencing of the V3-V4 regions of the bacterial 16S rRNA gene. The obtained reads were reconstructed, filtered, and clustered into zero-radius operational taxonomic units (zOTUs) at 97% identity level before taxonomic assignment, and biodiversity indexes were calculated. Transplant characteristics were recorded, and dry eye was diagnosed and staged 1-4 according to the Dry Eye WorkShop (DEWS) score.

RESULTS

No significant difference in OSM alpha diversity between pre- and post-transplant was found. A significant difference in beta diversity was observed between patients with a DEWS score of 1 versus 3 (p = 0.035). Increased corneal damage between pre- and post-HSCT was significantly associated with a decrease in alpha diversity. The changes in OSM were not associated with oGVHD, nor with any transplant parameter.

CONCLUSIONS

This preliminary study is the first study to analyse changes in the OSM before and after HSCT longitudinally. No trend in OSM biodiversity, microbial profile, or overall composition changes before and after HSCT was significant or associated with oGVHD onset. The great variability in the observed OSM profiles seems to suggest the absence of a patient-specific OSM "signature".

Antibody-Drug Conjugates and Ocular Toxicity

Antibody-drug conjugates (ADCs) are a growing class of chemotherapeutic agents for the purpose of treating cancers that often have relapsed or failed first- and second-line treatments. ADCs are composed of extremely potent cytotoxins with a variety of side effects, one of the most significant being ocular toxicity. The available literature describes these toxicities as varying in severity and in incidence, although with disparate methods of evaluation and management. Some of the most common toxicities include microcyst-like epithelial keratopathy and dry eye. We discuss proposed mechanisms of ocular toxicity and describe the reports that mention these toxicities. We focus on ADCs with the most published literature and the most significant effects on ocular tissue. We propose areas for further investigation and possible ideas of future management. We provide a comprehensive look at the reports of ADCs in current literature to better inform clinicians on an expanding drug class.

Corneal Findings Associated to Belantamab-Mafodotin (Belamaf) Use in a Series of Patients Examined Longitudinally by Means of Advanced Corneal Imaging

Belantamab mafodotin (belamaf) is a novel antibody–drug conjugate developed for the treatment of patients with relapsed or refractory multiple myeloma (RRMM). Although the drug has demonstrated a good efficacy, corneal adverse events have been reported. In this prospective study, consecutive patients with RRMM who received belamaf infusions were included. The standard ophthalmological visit was implemented with anterior segment (AS)-optical coherence tomography (OCT) and in vivo confocal microscopy (IVCM). Five patients (three males, two females; mean age 66 ± 6.0 years) with MMRR and unremarkable ocular findings at baseline who received belamaf infusion were included. After a median time of 28 days from the first infusion, four of them developed corneal alterations with transient vision reduction to a variable extent. In particular, corneal deposits of microcyst-like epithelial changes (MECs) were detected centrally in one patient and peripherally in three patients. AS-OCT scans showed a bilateral heterogeneous increase in signal intensity, together with hyper-reflective lesions confined within the epithelium in all cases, except for one case in which they also involved the stroma. Corneal maps showed a transient increase in epithelial thickness in the first phase that was followed by a diffuse decrease in the subsequent phase. IVCM scans showed MECs as hyper-reflective opacities located at the level of corneal epithelium, largely intracellular. Multimodal corneal imaging may implement the current clinical scale, helping us to detect corneal abnormalities in patients under belamaf therapy. This workup provides useful data for monitoring over time corneal findings and for optimizing systemic therapy.

Incidence, Risk Factors and Complications of Ocular Graft-Versus-Host Disease Following Hematopoietic Stem Cell Transplantation

PURPOSE

The purpose of this research was to evaluate the incidence, risk factors, and complications of ocular graft-versus-host disease (GVHD) in a large single-center study.

DESIGN

Retrospective observational case series.

METHODS

This study included 283 patients who underwent hematopoietic stem cell transplantation (HSCT) between 2005 and 2020. Ocular GVHD was diagnosed according to International Chronic Ocular GVHD Consensus Group criteria. Potential risk factors for ocular GVHD were evaluated using the Cox proportional hazards model.

RESULTS

The cumulative incidence of ocular GVHD was 19.7% at 1 year, 29.3% at 2 years, 40.7% at 3 years, 47.2% at 4 years, and 49.7% at 5 years. Ocular GVHD was significantly associated with recipient age (hazard ratio [HR]: 1.228; 95% confidence interval [CI]: 1.033-1.459; P = .020); female sex (HR: 1.797; 95% CI: 1.195-2.703; P = .005); peripheral blood stem cell use (PBSC) (HR: 2.079; 95% CI: 1.268-3.411; P = .004); and previous acute GVHD (HR: 1.276; 95% CI: 1.073-1.518; P = .006). Ocular complications after HSCT included cataract, corneal ulcer, corneal perforation, lacrimal obstruction, herpetic keratitis, and cytomegalovirus retinitis.

CONCLUSIONS

Half of patients developed ocular GVHD in the 5 years following HSCT. Older age, female sex, use of PBSC, and acute GVHD disease were significant predictors of ocular GVHD. Hematologists and ophthalmologists should be aware of its vision threating complications.

Corneal nerve changes following treatment with neurotoxic anticancer drugs

Survival rates of cancer has improved with the development of anticancer drugs including systemic chemotherapeutic agents. However, long-lasting side effects could impact treated patients. Neurotoxic anticancer drugs are specific agents which cause chemotherapy-induced peripheral neuropathy (CIPN), a debilitating condition that severely deteriorates quality of life of cancer patients and survivors. The ocular surface is also prone to neurotoxicity but investigation into the effects of neurotoxic chemotherapy on the ocular surface has been more limited compared to other systemic etiologies such as diabetes. There is also no standardized protocol for CIPN diagnosis with an absence of a reliable, objective method of observing nerve damage structurally. As the cornea is the most densely innervated region of the body, researchers have started to focus on corneal neuropathic changes that are associated with neurotoxic chemotherapy treatment. In-vivo corneal confocal microscopy enables rapid and objective structural imaging of ocular surface microscopic structures such as corneal nerves, while esthesiometers provide means of functional assessment by examining corneal sensitivity. The current article explores the current guidelines and gaps in our knowledge of CIPN diagnosis and the potential role of in-vivo corneal confocal microscopy as a diagnostic or prognostic tool. Corneal neuropathic changes with neurotoxic anticancer drugs from animal research progressing through to human clinical studies are also discussed, with a focus on how these data inform our understanding of CIPN.

Ocular surface disease associated with immune checkpoint inhibitor therapy

Immune-related adverse events (irAEs) is a term used to describe the various toxicities associated with immune checkpoint inhibitor (ICI) use. As this class of cancer immunotherapy grows, the diversity of documented irAEs also continues to expand. Ocular toxicities secondary to ICI use are relatively rare, with dry eye and uveitis as the most frequently reported ocular side effects. This article specifically investigates the relationship between ocular surface disease and ICI therapy through a review of the existing literature. Dry eye disease (DED), conjunctivitis, and keratitis were the most commonly reported irAEs affecting the ocular surface across the 29 studies reviewed. Keratoplasty graft rejection was also described in two case reports. Our review of eight clinical trials found the incidence of DED, the most common ocular surface irAE, to range from 1 to 4%. Nearly all cases of ocular surface irAEs were graded as mild or moderate in severity and were often self-limited or controlled with conservative treatment. Duration of checkpoint inhibitor use prior to onset of ocular surface side effects varied widely, ranging from days to months. Ocular surface toxicities associated with checkpoint immunotherapy appear to be under-reported and under-investigated. Further work remains to be done to investigate the full breadth of ocular surface pathologies and the molecular mechanisms by which these toxicities occur.

A cross-sectional study of ocular surface discomfort and corneal nerve dysfunction after paclitaxel treatment for cancer

Ocular surface dysfunction is common in patients receiving anti-cancer drug treatment. The effects of paclitaxel, a neurotoxic chemotherapeutic drug, on ocular surface discomfort associated with dry eye disease was investigated. Patients with cancer who had completed paclitaxel treatment between 3 and 24 months prior to assessment (n = 29) and age- and sex-matched healthy control subjects (n = 29) were recruited and assessed with the Ocular Surface Disease Index (OSDI) to measure ocular surface discomfort. In-vivo corneal confocal microscopy was used to evaluate corneal nerve parameters in the right eye. Peripheral neurotoxicity was assessed using patient-reported outcomes and clinical grading scales. The paclitaxel group had significantly worse OSDI total scores compared with controls (Median, Md = 19.3 and Md = 0, p = 0.007, respectively). Corneal nerve fiber and inferior whorl lengths were reduced in the paclitaxel group compared with controls (14.2 ± 4.0 and 14.4 ± 4.0 mm/mm² vs. 16.4 ± 4.0 and 16.9 ± 4.9 mm/mm², respectively, p = 0.04). When analyzed by presence of peripheral neuropathy, paclitaxel-treated patients with neuropathy showed worse OSDI total scores compared to those without peripheral neuropathy post-treatment (p = 0.001) and healthy controls (p < 0.001). More severe ocular discomfort and worse visual function was associated with greater peripheral neurotoxicity symptoms (r = 0.60, p = 0.001) and neuropathy severity (r = 0.49, p = 0.008), respectively. Patients who have been treated with paclitaxel have a higher risk of ocular surface discomfort associated with dry eye disease, particularly those with peripheral neuropathy. Future longitudinal studies should investigate the clinical impact of corneal nerve reduction in dry eye disease.

Subepithelial Corneal Deposits Associated with Exemestane

This is a case report of corneal deposits noted in a 69-year-old female patient taking the aromatase inhibitor, exemestane, after undergoing a mastectomy and chemotherapy for breast cancer. The patient presented to our eye clinic for a new-onset floater in one eye, and bilateral subepithelial opacities were found incidentally on exam. The patient completed a 5-year course of the medication shortly after her initial visit with us and was noted to have a slight improvement in the density of the opacities on a follow-up visit 3 months later. We believe these corneal changes were most likely secondary to exemestane. The effect of aromatase inhibitors on the eye deserves further exploration as an increasing number of patients are prescribed these medications.