Update on ocular complications of systemic cancer chemotherapy

Dihydropyrimidine dehydrogenase 85T>C mutation is associated with ocular toxicity of 5-fluorouracil: a case report

5-Fluorouracil (5-FU), the mainstay of solid tumor chemotherapy over the past 40 years, induces grade III-IV toxicities in up to 15% of patients with polymorphisms in the dihydropyrimidine dehydrogenase (DPYD), thymidylate synthase (TYMS), and methylenetetrahydrofolate reductase (MTHFR) genes. These toxicities include mucositis, neutropenia, nausea, diarrhea, myelosuppression, hand-foot syndrome, and rare ocular adverse effects. Here, we present the case of a female patient with rectal cancer who received 5-FU-based chemotherapy and developed grade III hand-foot syndrome and rare acute ocular adverse effects. Genetic analysis revealed that the patient had an 85T>C mutation in the DPYD gene resulting in a DPYD*9A allele. The clinical and molecular observations indicate that DPYD deficiency may be responsible for the severe ocular adverse effects observed in 5-FU-treated patients. Application of personalized therapy based on molecular testing should help clinicians provide the most effective chemotherapy agents and dose modifications for each patient, although further population-based pharmacogenetic trials for the 5-FU metabolism-related genes are necessary to minimize adverse effects and enhance clinical outcomes.

Posterior segment toxicity after gemcitabine and docetaxel chemotherapy

PURPOSE

To report outer retinal disruption and uveal effusion after gemcitabine and docetaxel combination therapy.

CASE REPORT

A 78-year-old woman presented with blurry vision after two cycles of gemcitabine and docetaxel combination chemotherapy for stage IV sarcoma. At presentation, visual acuity was finger counting and 20/25 in the right and left eyes, respectively. Slit-lamp examination and B-scan ultrasonography revealed severe uveal effusion in the right eye and choroidal folds in the left eye. Spectral domain optical coherence tomography showed disruption of photoreceptor inner segment ellipsoid band in the right eye. The patient was monitored weekly with ophthalmic examination and B-scan ultrasonography, while continuing with gemcitabine monotherapy. At 8 weeks follow-up, uveal effusion improved considerably and visual acuity was 20/40 and 20/20 in the right and left eyes, respectively.

CONCLUSIONS

Uveal effusion and outer retinal disruption were reported after gemcitabine and docetaxel chemotherapy. Early detection and close ophthalmic monitoring may allow concurrent cancer treatment and prevention of possible chemotherapy-induced ocular side effects.

Cystoid macular edema and macular pigmentation associated with nab-Paclitaxel therapy

PURPOSE

To report the first known case of retinal pigment epithelium hyperpigmentation changes and cystoid macular edema in a patient on nab-paclitaxel therapy.

METHODS

Observational case report.

RESULTS

A 72-year-old man on nab-paclitaxel therapy for non-small cell lung carcinoma developed cystoid macular edema with minimal capillary leakage with subsequent retinal pigment epithelium hyperpigmentation after resolution of cystoid macular edema.

CONCLUSION

Nab-paclitaxel therapy may be associated with the development of retinal pigment epithelium hyperpigmentation in the setting of resolved minimal capillary leakage cystoid macular edema.

Ethical analysis as a tool for addressing treatment controversies: radiotherapy timing in children with orbital rhabdomyosarcoma as a case example

PURPOSE

The treatment of orbital rhabdomyosarcoma is a topic of debate between North American and European clinicians, with the utility of radiation therapy as part of initial management in question. Despite differences in philosophy, the dominant North American approach of upfront radiation and the dominant European approach of radiation only in the event of recurrence yield a similar rate of overall survival. We sought to identify the ethical arguments for each approach.

METHODS

Established moral principles and appeals in contemporary medical ethics were utilized to identify the ethical arguments supporting each treatment approach. The potential for technologic advances to alter the analysis was considered.

RESULTS

Emphasizing the principle of beneficence, the North American approach seeks to reduce recurrence rates. In contrast, the European approach seeks to avoid radiation-induced sequelae, emphasizing the principle of nonmaleficence. Both approaches are based on well-established ethical principles, evidence, and clinical experience. Thus, both approaches currently appear to have legitimacy and should be included in the informed consent process. However, if treatment-related toxicity is reduced through improvements in radiation delivery, the North American approach could emerge as ethically superior.

CONCLUSIONS

Ethical analysis can aid in addressing challenges that arise when professional practices and perspectives differ in the management of cancer patients.

Retinal toxicities of cancer therapy drugs: biologics, small molecule inhibitors, and chemotherapies

PURPOSE

To review reported retinal side effects from current cancer therapy drugs.

METHODS

Retinal toxicities from ophthalmologic or oncologic case reports, case series, and clinical trials were identified by a systematic literature search using Lexicomp and PubMed.

RESULTS

Four biologics, 8 small molecule inhibitors, and 17 traditional chemotherapy agents had reported retinal side effects. For biologics, interferon alpha 2b was associated with retinopathy, denileukin diftitiox with pigmentary retinopathy, ipilimumab with a Vogt-Koyanagi-Harada-like syndrome, and trastuzumab with retinal ischemia. For small molecule inhibitors, v-raf murine sarcoma viral oncogene homolog B (BRAF) inhibitors were associated with uveitis, mitogen-activated protein kinase/extracellular signal-regulated kinase inhibitors with pigment epithelium detachments, and tyrosine kinase inhibitors with macular edema. Steroid antagonists were associated with crystalline retinopathy and macular edema. Nitrosoureas, platinum analogs, and cytosine arabinoside were associated with retinal vascular occlusions. Antimicrotubular agents were associated with cystoid macular edema but without fluorescein leakage. Retinoic acid derivatives were associated with impaired night vision, and mitotane was associated with a pigmentary retinopathy and papilledema.

CONCLUSION

Certain agents used in the treatment of systemic cancer are associated with ocular complications. Awareness of these complications will allow early detections and maybe reversal of some of the ocular problems.

Unilateral Optic Disc Papilloedema following Administration of Carboplatin Chemotherapy for Ovarian Carcinoma

A 48-year-old woman with a positive BRCA1 gene mutation was diagnosed with stage 3b high-grade ovarian endometrioid carcinoma. She was treated with adjuvant carboplatin at a dose of 740 mg (AUC 6) in 3-weekly cycles. Five days after her fifth cycle of carboplatin, she awoke with new-onset blurred vision in her left eye. An ophthalmology review showed left-sided disc oedema with normal optic nerve function tests and 6/24 visual acuity. A CT scan of the head and orbits was performed which showed no evidence of metastasis or raised intracranial pressure. An autoimmune screen was performed which did not reveal any explanation for her visual symptoms. Fundus fluorescein angiography showed bilateral intense late disc leakage with no evidence of vasculitis. Her chemotherapy was stopped in view of a radiological and biochemical remission and her visual symptoms were monitored. She was also started on a tapering dose of prednisolone 40 mg daily. Five months after the initial review, she has developed left optic disc atrophy with 6/18 visual acuity, while the right eye remains asymptomatic. The diagnosis was felt to be that of carboplatin-induced unilateral disc oedema, a very rare side effect of this chemotherapy.

Early safety assessment of human oculotoxic drugs using the zebrafish visualmotor response

INTRODUCTION

Many prescribed drugs can adversely affect the eye by causing damage to the function of visual pathways or toxicity to the retina. Zebrafish have the potential to efficiently predict drugs with adverse ocular effects at pre-clinical stages of development. In this study, we explore the potential of using a semi-automated visual behaviour assay to predict drug-induced ocular toxicity in wild-type zebrafish larvae.

METHODS

3 dpf larvae were treated with six known oculotoxic drugs and five control drugs in embryo medium containing 0.1% DMSO. After 48 h, larvae were assessed using the visualmotor response (VMR), an assay which quantifies locomotor responses to light changes; the optokinetic response (OKR), a behavioural assay that quantifies saccadic eye responses to rotating stimuli; and the touch response, a locomotor response to tactile stimuli.

RESULTS

9 of 10 negative control drugs had no effect on zebrafish visual behaviour. 5 of the 6 known oculotoxic drugs (digoxin, gentamicin, ibuprofen, minoxidil and quinine) showed adverse effects on zebrafish visual behaviour assessed by OKR or the more automated VMR. No gross morphological changes were observed in treated larvae. The general locomotor activity of treated larvae, tested using the touch response assay, showed no differences with respect to controls. Overall the VMR assay had a sensitivity of 83%, a specificity of 100% and a positive predictive value of 100%.

DISCUSSION

This study confirms the suitability of the VMR assay as an efficient and predictive pre-clinical approach to evaluate adverse ocular effects of drugs on visual function in vivo.

Neuro-ophthalmological emergencies: which ocular signs or symptoms for which diseases?

There are five possible ocular signs or complaints of a life or sight threatening neuro-ophthalmological condition: diplopia, isolated anisocoria, transient visual loss, severe pain in head or neck (with or without photophobia) and oscillopsia/nystagmus. In this review, the ocular signs and symptoms of neuro-ophthalmological emergencies are described together with their practical work-up and the risks associated with missing the diagnosis. Concerning diplopia, the associated signs pointing to a possible threatening condition are emphasized. Six focus points resuming core messages are displayed throughout this review.

Nasolacrimal duct obstruction after maxillary orthognathic surgery

PURPOSE

To report cases of nasolacrimal duct obstruction (NLDO) after maxillary orthognathic surgery.

MATERIALS AND METHODS

The authors reviewed the clinical manifestations, dacryocystographic images, and orbital computed tomographic scans of 10 patients who were diagnosed with NLDO after undergoing maxillary orthognathic surgery.

RESULTS

Six of the 10 patients (60%) complained of epiphora immediately after the surgery. Bilateral (n = 2, 20%) or unilateral (n = 8, 80%) NLDO occurred in all patients involved in the study. Twelve eyes of 10 patients were examined, and dacryocystography showed that the obstruction was present in the distal ostium in 7 eyes (58.3%), the junction between the sac and duct in 3 eyes (25%), and the common canaliculus in 2 eyes (16.7%). Computed tomographic scans of all subjects showed that mucosal swelling and congestion around the distal NLD opening narrowed the space between the lateral nasal wall and the inferior turbinate of the affected side. Dacryocystorhinostomy was performed in 9 eyes (8 patients), with a success rate of 100%.

CONCLUSIONS

The distal to proximal portion of the NLD can become obstructed after maxillary orthognathic surgery. This obstruction seems to be caused by secondary inflammatory changes associated with an indirect injury of the NLD. Therefore, clinicians should be aware of the possibility of NLDO after orthognathic surgery, which can be treated successfully with dacryocystorhinostomy.

Ocular toxicity from systemically administered xenobiotics

INTRODUCTION

The eye is considered as the most privileged organ because of the blood-ocular barrier that acts as a barrier to systemically administered xenobiotics. However, there has been a significant increase in the number of reports on systemic drug-induced ocular complications. If such complications are left untreated, then it may cause permanent damage to vision. Hence, knowledge of most recent updates on ever-increasing reports of such toxicities has become imperative to develop better therapy while minimizing toxicities.

AREAS COVERED

The article is mainly divided into anterior and posterior segment manifestations caused by systemically administered drugs. The anterior segment is further elaborated on corneal complications where as the posterior segment is focused on optic nerve, retinal and vitreous complications. Furthermore, this article includes recent updates on acute and chronic ocular predicaments, in addition to discussing various associated symptoms caused by drugs.

EXPERT OPINION

Direct correlation of ocular toxicities due to systemic drug therapy is evident from current literature. Therefore, it is necessary to have detailed documentation of these complications to improve understanding and predict toxicities. We made an attempt to ensure that the reader is aware of the characteristic ocular complications, the potential for irreversible drug toxicity and indications for cessation.

Ophthalmology manifestations of pediatric cancer treatment

PURPOSE OF REVIEW

Advances in pediatric oncology care have increased survival rates for children with malignancy. As a result, ophthalmologists are seeing more short-term and long-term complications associated with the treatment of these conditions. Ophthalmologists need to be aware of cancer treatment-related eye disorders.

RECENT FINDINGS

Multiple eye findings are associated with cancer treatment, including chemotherapy, radiation, bone marrow transplantation, and newer modalities such as intra-arterial chemotherapy. Malignancy and treatment cause immunodeficiency that can lead to infectious disease manifestations, including eye involvement. Our understanding of the prevalence of eye involvement in infectious diseases is changing due to newer antimicrobial treatment modalities and earlier screening. Paraneoplastic conditions may manifest with eye findings either before the diagnosis of the primary malignancy or as a late finding. The evolution of IVF has raised concerns of increased cancer risks, including ocular tumors.

SUMMARY

Ophthalmologists who are involved with the care of children undergoing cancer treatment need to be aware of the many eye manifestations that may result.

On-demand controlled release of docetaxel from a battery-less MEMS drug delivery device

We report the development of a magnetically controlled MEMS device capable of on-demand release of defined quantities of an antiproliferative drug, docetaxel (DTX). Controlled release of DTX with a dosage suitable for the treatment of diabetic retinopathy has been achieved for 35 days. The device consists of a drug-loaded microreservoir (Ø6 mm ×∼550 μm), sealed by an elastic magnetic PDMS (polydimethylsiloxane) membrane (Ø6 mm × 40 μm) with a laser-drilled aperture (∼100 × 100 μm(2)). By applying a magnetic field, the magnetic PDMS membrane deforms, causing the discharge of the drug solution from the device. Controlled DTX release at a rate of 171 ± 16.7 ng per actuation interval has been achieved for 35 days using a 255 mT magnetic field. The background leakage of drug solution through the aperture was negligible at 0.053 ± 0.014 ng min(-1). The biological activity of the released drug was investigated using a cytotoxicity assay (cell apoptosis) for two cell lines, HUVEC (human umbilical vein endothelial cells) and PC3 (prostate cancer) cells. Reproducible release rates have been achieved and DTX within the PDMS MEMS reservoir maintains full pharmacological efficacy for more than two months. This device is a proof-of-concept development for targeted delivery of hydrophobic drugs such as DTX and other taxane-based agents that require accurate delivery in nanomolar concentrations.

Abducens ocular neuromyotonia in a patient with nasopharyngeal carcinoma following concurrent chemoradiotherapy

We describe a case of ocular neuromyotonia (ONM) following concurrent chemoradiotherapy for nasopharyngeal carcinoma (NPC). During an episode of neuromyotonia, the patient developed involuntary contraction of the left lateral rectus muscle and globe retraction with down-shoot movement in the left eye. In the quiescent period, ocular motor examination revealed a partial left sixth nerve palsy. While diplopic complaints in patients with NPC raise suspicion of tumor recurrence or radiation-related cranial neuropathy, ONM must also be kept in the differential diagnosis.

Evaluation of multiple neurotoxic outcomes in cancer chemotherapy

Although it is now clear that cognitive dysfunction is a common accompaniment of cancer chemotherapy, its implications await further research and direction. Most of the clinical research relies on standard neuropsychological tests that were developed to diagnose stable traits. Cognitive dysfunction in patients undergoing treatment varies with time, however. Its dimensions will vary during the course of treatment, which generally consists of cycles of drug administration followed by recovery periods. To effectively determine the connection between chemotherapy and cognitive function requires neuropsychological tests based on performance, so that they can be administered repeatedly at specified times during the entire course of treatment and beyond. A number of computerized test batteries, many of which have been developed for environmental neurotoxicology, are now available that fit such criteria. Moreover, cognitive impairment is only one aspect of chemotherapy-induced neurotoxicity. A full appreciation of its scope requires assessment of sensory functions such as vision, audition and somatosensory properties and assessment of motor function. A program of research based on animal models is also essential. Only with animal models is it possible to determine dose-response relationships and to couple behavioral with mechanistic indices such as neuroplasticity. Animal behavior models play a vital role in environmental toxicology because, from them, it is possible to derive some index of exposure that limits adverse effects. However, as in human testing, it is critical to choose situations whose properties remain stable over long periods of time so as to trace the time course of neurotoxicity. Schedule-controlled operant behavior offers the most promising source of animal models.

Corneal perforation with preseptal cellulitis in a patient with acute lymphocytic leukemia

We report a case of corneal perforation with preseptal cellulitis in a patient with acute lymphocytic leukemia (ALL). A 17-yr-old female patient who was undergoing combination chemotherapy for ALL was referred due to upper lid swelling and pain in the right eye for 2 days. Visual acuity in the right eye was 20/20. Initial examination showed no abnormal findings, other than swelling of the right upper eyelid. Computed tomography showed a finding of preseptal cellulitis. Microbiologic study of bloody and purulent discharge revealed Serratia marcescens. Corneal melting and perforation with iris prolapse were detected in the right eye on the 16th day. Emergent tectonic keratoplasty was performed. Seven months after surgery, visual acuity in the right eye was 20/300, and the corneal graft was stable.

Effects on the visual system might contribute to some of the cognitive deficits of cancer chemotherapy-induced 'chemo-fog'

The diminution in certain aspects of cognitive function that is reported to occur in some patients during or after adjuvant cancer chemotherapy is variously known as 'chemo-fog', 'chemo-brain' or other such term. In addition to reported deficits in attention, concentration and other functions, most, if not all, of the studies report deficits involving visual-spatial function or visual memory. Since the visual system is part of the nervous system, it seems reasonable to ask if it is susceptible to some of the deleterious effects produced by adjuvant chemotherapeutic drugs. We propose here the possibility that some portion of the vision-related aspects of the 'chemo-fog' spectrum of cognitive deficits results from a direct action of the adjuvant drugs on the visual system or from drug/drug or site/site interaction between effects on the visual system and other critical brain regions.

Medical issues in cancer survivors--a review

Cancer survivorship is an emerging area of scientific and clinical interest. Several decades ago, most people diagnosed with cancer did not live long beyond their initial diagnosis. Today the number of cancer survivors exceeds ten million, and this group may experience unique healthcare issues related to their cancer treatment. Chemotherapy, surgery, and radiation therapy each have their own late and long-term complications. It is imperative for clinicians who are caring for cancer survivors to be aware of long-term complications of therapy and to treat these appropriately. When cancer therapy has successfully added years of life, it is equally as important that medical care assures the best quality of life during those years.

NANOTECHNOLOGY IN THE TREATMENT AND DETECTION OF INTRAOCULAR CANCERS

Tremendous progress in nanotechnology has lead to the development of nanometer-sized objects as medical implants or devices. Many of these nanodevices have recently been tested in many cancer diagnostic and therapeutic applications, such as leukemia, melanoma, breast tumor, prostate tumor, and brain cancer. Despite the increasing importance of nanotechnology in cancer, the potential of these nanodevices in diagnosing and treating intraocular cancers has not been systematically evaluated. This review summarizes the significant advancements and potential areas for development in the field of nanotechnology-based intraocular drug delivery and imaging.

Chemobrain: a translational challenge for neurotoxicology

Neurotoxicity is a frequent accompaniment of cancer chemotherapy, and held by many oncologists to be the major dose-limiting side effect. It appears in many forms, but attracted attention during the past decade primarily because of complaints by patients of impaired cognitive function they have labeled as "chemobrain". Neuropsychological testing confirmed the validity of these complaints and has generated a substantial literature examining different aspects of cognitive impairment in various clinical populations undergoing a variety of treatments. Cognitive impairment is far from the only manifestation of neurotoxicity induced by chemotherapy, however. It alters sensory function and motor function as well. A critical need for patients is a suite of methods that will enable clinicians to trace the onset and progression of neurotoxicity so as to guide and balance decisions about the course of chemotherapy. This commentary describes some of the potential methods and encourages neurotoxicologists to enlist their unique skills in the service of these needs.

AQ4, an antitumor anthracenedione, inhibits endothelial cell proliferation and vascular endothelial growth factor secretion: implications for the therapy of ocular neovascular disorders

Current clinical options for the treatment of neovascular disorders of the posterior segment of the eye have several drawbacks. Photocoagulation lasers can impair peripheral and night vision. Photodynamic therapies as well as intravitreal macromolecule injections (Macugen and Lucentis) require frequent, invasive administrations. Above all, only modest improvement in vision is achieved with any of the existing treatments. In order to overcome these limitations in the long run, this study investigated the antiangiogenic potential of AQ4, a low molecular weight anthracenedione. The results indicate that AQ4 enters the cell nucleus and inhibits proliferation of choroid-retina endothelial (RF/6A) cells and human retinal pigment epithelial (ARPE-19) cells under hypoxic (1% O(2)) as well as normoxic (21% O(2)) conditions. The IC(50) for these effects ranges from 5.5 to 6.9 muM. AQ4 does not affect the viability of non-dividing RF/6A or ARPE-19 cells up to 0.1 mM. Further, AQ4 (20 muM) reduces vascular endothelial growth factor (VEGF) protein secretion by about 50% in ARPE-19 cells under normoxia as well as hypoxia, possibly by reducing VEGF transcription. AQ4 arrests the growth of endothelial cells in S phase, consistent with interference of AQ4 with DNA replication. These results for the first time suggest that AQ4 can potentially alleviate the neovascularization of choroid/retina by a dual mechanism of inhibiting the proliferation of endothelial cells and by reducing mitogenic VEGF stimulus from retinal pigment epithelial cells.