Retinal ischemia with neovascularization in cisplatin related retinal toxicity

Ocular side effects of oncological therapies: Review

With the advance of cancer therapy in recent years, the knowledge of the mechanisms involved in this disease has increased, which has meant an increase in the quality of life and survival of patients with tumor pathologies previously considered incurable or refractory to treatment. The number of drugs used has increased exponentially in number, and although the implicit toxicity is lower than that of conventional antineoplastic therapy, they lead to the appearance of new associated adverse effects that the ophthalmologist must recognize and manage.

Ocular complications of antineoplastic therapies

Ocular complications of antineoplastic agents can have a profound effect on the quality of life of cancer patients. New oncologic treatments like monoclonal antibodies, immunotherapies, antibody-drug conjugates, checkpoint inhibitors and growth factor receptors have resulted in increased ocular complications. These ocular complications differs in respect to distinct mechanisms of actions and lead to significant challenges in the management of cancer patients. In this review, we reviewed literature, clinical studies and cases detailing ocular complications due to administration of antineoplastic agents and emphasized the need for communication between oncologists and ophthalmologists toward early detection and management of ocular complications.

Chemotherapy-Induced Retinopathy in a Diabetic and Hypertensive Patient With Stage 4 Metastatic Pancreatic Adenocarcinoma

Purpose: To describe a case of presumed Purtscher-like retinopathy in association with 2 chemotherapies. Methods: A retrospective chart review was performed. Results: A 40-year-old Black woman was diagnosed with pancreatic adenocarcinoma with metastasis to the liver. Cotton-wool spots and microaneurysms (dot/blot hemorrhages) were found on a routine examination 1 month after the patient started gemcitabine/paclitaxel. An increase in cotton-wool spots was noticed after she stopped gemcitabine/cisplatin therapy and started 5-fluorouracil/irinotecan/leucovorin therapy. These retinal changes were observed until the time of death. Conclusions: We believe that the Purtscher-like retinopathy began with gemcitabine toxicity but that the irreversible damage was the result of cisplatin chemotherapy. The patient's uncontrolled hypertension and type II diabetes likely put her at greater risk for developing this retinopathy.

The Impact of Systemic Medications on Retinal Function

This study will provide a thorough review of systemic (and select intravitreal) medications, along with illicit drugs that are capable of causing various patterns of retinal toxicity. The diagnosis is established by taking a thorough medication and drug history, and then by pattern recognition of the clinical retinal changes and multimodal imaging features. Examples of all of these types of toxicity will be thoroughly reviewed, including agents that cause retinal pigment epithelial disruption (hydroxychloroquine, thioridazine, pentosan polysulfate sodium, dideoxyinosine), retinal vascular occlusion (quinine, oral contraceptives), cystoid macular edema/retinal edema (nicotinic acid, sulfa-containing medications, taxels, glitazones), crystalline deposition (tamoxifen, canthaxanthin, methoxyflurane), uveitis, miscellaneous, and subjective visual symptoms (digoxin, sildenafil). The impact of newer chemotherapeutics and immunotherapeutics (tyrosine kinase inhibitor, mitogen-activated protein kinase kinase, checkpoint, anaplastic lymphoma kinase, extracellular signal-regulated kinase inhibitors, and others), will also be thoroughly reviewed. The mechanism of action will be explored in detail when known. When applicable, preventive measures will be discussed, and treatment will be reviewed. Illicit drugs (cannabinoids, cocaine, heroin, methamphetamine, alkyl nitrite), will also be reviewed in terms of the potential impact on retinal function.

Azilsartan suppresses the antiapoptotic biomarker and pro-inflammatory cytokines in rat model of cisplatin-induced retinal and optic nerve toxicity

BACKGROUND

The local renin-angiotensin system has been discovered in the eyes; thus, this study evaluates the Azilsartan effect in the retina and optic nerve toxicity induced by Cisplatin in vivo.

METHODOLOGY

Forty-eight male rats were randomly assigned into six groups of 8 animals. Group 1 was healthy control that received 0.5 mL/day of 0.5% carboxymethyl cellulose (CMC) orally (PO). Group 2 received a single dose of the 7.0 mg/kg CIS intraperitoneally with 0.5 mL/day of 0.5% CMC-PO. Groups 3 and 4 received 3.5 and 7.0 mg/kg/day of AZIL-PO, respectively. Groups 5 and 6 received 3.5 and 7.0 mg/kg/day of AZIL-PO, respectively together with a single dose of 7.0 mg/kg of CIS-IP. The ocular tissue and serum estimated the TNF-α, NF-kβ, and Casp-3. A complete blood count was also measured, and the eye was sent for histological examination.

RESULTS

The administration of the 3.5 mg/kg AZIL significantly (p < 0.05) reduced the ocular tissue and serum TNF-α, NF-kB, and Casp-3 levels, when given to CIS treated group, while the 7.0 mg/kg AZIL does not. Additionally, azilsartan shows no negative impact on the CBC in rats. Finally, the eye histological examination showed a significant (p < 0.05) drop in the signs of inflammation and cellular degeneration, particularly after administration of the 3.5 mg/kg AZIL to the CIS-treated group.

CONCLUSION

A low dose of AZIL exerts an anti-inflammation and an anti-apoptotic effect through significant suppression of the pro-inflammatory mediators and an apoptotic biomarker by blocking the local angiotensin II type.

Use of Visual Electrophysiology to Monitor Retinal and Optic Nerve Toxicity of Medications

It is important for clinicians to consider exposure to toxic substances and nutritional deficiencies when diagnosing and managing cases of vision loss. In these cases, physiologic damage can alter the function of key components of the visual pathway before morphologic changes can be detected by traditional imaging methods. Electrophysiologic tests can aid in the early detection of such functional changes to visual pathway components, including the retina or optic nerve. This review provides an overview of various electrophysiologic techniques, including multifocal electroretinogram (mfERG), full-field ERG (ffERG), electrooculogram (EOG), pattern electroretinogram (PERG), and visual evoked potential (VEP) in monitoring the retinal and optic nerve toxicities of alcohol, amiodarone, cefuroxime, cisplatin, deferoxamine, digoxin, ethambutol, hydroxychloroquine, isotretinoin, ocular siderosis, pentosane, PDE5 inhibitors, phenothiazines (chlorpromazine and thioridazine), quinine, tamoxifen, topiramate, vigabatrin, and vitamin A deficiency.

Potential Ophthalmological Side Effects Induced by Anti-Neoplastic Regimens for the Treatment of Genitourinary Cancers: A Review

The outcomes of patients with genitourinary (GU) cancers have been steadily improving in recent years. Novel therapies have entered our armamentarium, while several other regimens are currently being studied in clinical trials. This recent explosion of new agents has improved patient survival and the quality of life for patients, but has also significantly increased the frequency of several side effects. The current review will focus on the potential ocular adverse reactions of GU neoplastic treatments. The broad spectrum of manifestations of ocular toxicity underscores the uniqueness and complexity of the anatomic, physiologic, and metabolic features of the human eye. Most side effects are mild in severity and transient, but some can be severe, disabling, and irreversible. Clinicians should be aware of complications that might be vision threatening and impact the patient's quality of life. In this review, we focused on the ocular toxicity of the antineoplastic regimens that are currently used for the treatment of GU, including prostate cancer, bladder cancer, renal cell carcinoma, testicular cancer, pheochromocytoma, adrenocortical carcinoma, and penile cancer.

Increased interdigitation zone visibility on optical coherence tomography following systemic fibroblast growth factor receptor 1-3 tyrosine kinase inhibitor anticancer therapy

BACKGROUND

To describe ocular adverse events and retinal changes during fibroblast growth factor receptor (FGFR) inhibitor (AZD4547) anticancer therapy.

METHODS

This is a sub-study examining ocular adverse effects from AZD4547 therapy (single-centre, open-label, single arm phase II clinical trial). Comprehensive ocular examinations were performed 3 weekly in 24 patients. Macular optical coherence tomography (OCT) scan (30⁰  × 25⁰ ) was obtained at each visit and OCT parameters [central 1 mm retinal thickness (CRT) and total macular volume in central 6 mm] extracted. OCT scans were subdivided into outer (ELM to RPE) and inner (ELM to ILM) layers to compare outer and inner retinal changes.

RESULTS

In 24 patients, AZD4547 was associated with eyelash elongation (n = 5, 21%) and punctate corneal erosion (n = 2, 8%). One patient developed clinically significant posterior capsular opacification during the study. OCT data were available in 23 patients, retinal changes ranged from an asymptomatic increased visibility of the interdigitation zone (IDZ) (n = 10, 43%) to multilobular subretinal fluid pockets (n = 5, 22%), which was associated with mild visual acuity loss. In a subset of patients (n = 9) with pre-AZD4547 dosing OCT baseline, CRT increased by mean (SD) of 9 (4) μm in those with IDZ change only compared with 64 (38) μm in those with other retinal changes. Retinal changes tended to be bilateral, self-limiting and improved over time without medical intervention.

CONCLUSIONS

The ocular signs and symptoms did not result in dose cessation. Posteriorly, FGFR inhibition leads to outer retinal changes ranging from increased visibility of IDZ to distinct, multiple fluid pockets.

Retinal toxicities of systemic anticancer drugs

Newer anticancer drugs have revolutionized cancer treatment in the last decade, but conventional chemotherapy still occupies a central position in many cancers, with combination therapy and newer methods of delivery increasing their efficacy while minimizing toxicities. We discuss the retinal toxicities of anticancer drugs with an emphasis on the mechanism of toxicity. Uveitis is seen with the use of v-raf murine sarcoma viral oncogene homolog B editing anticancer inhibitors as well as immunotherapy. Most of the cases are mild with only anterior uveitis, but severe cases of posterior uveitis, panuveitis, and Vogt-Koyanagi-Harada-like disease may also occur. In the retina, a transient neurosensory detachment is observed in almost all patients on mitogen-activated protein kinase kinase (MEK) inhibitors. Microvasculopathy is often seen with interferon α, but vascular occlusion is a more serious toxicity caused by interferon α and MEK inhibitors. Crystalline retinopathy with or without macular edema may occur with tamoxifen; however, even asymptomatic patients may develop cavitatory spaces seen on optical coherence tomography. A unique macular edema with angiographic silence is characteristic of taxanes. Delayed dark adaptation has been observed with fenretinide. Interestingly, this drug is finding potential application in Stargardt disease and age-related macular degeneration.

Central Serous Chorioretinopathy in a Case of Regressed Familial Retinoblastoma

Purpose

To present a case of central serous chorioretinopathy (CSC) in association with regressed familial retinoblastoma.

Case Report

A 23-year-old man with regressed unilateral familial retinoblastoma in his left eye presented with decreased vision of the left eye since two months ago. The patient had undergone chemotherapy and cryotherapy for the treatment of retinoblastoma 20 years ago. In the left eye, funduscopy disclosed regressed mass of retinoblastoma, inferonasal to the optic disc, and focal subfoveal neurosensory detachment. Optical coherence tomography (OCT) and fluorescein angiography revealed CSC. As there was no sign of recurrence of retinoblastoma and retinal findings did not show late-onset chemotherapy-related retinopathy, the patient was diagnosed with CSC and followed up. After two months, visual acuity of the left eye improved, and repeated macular OCT revealed absorption of the subretinal fluid.

Conclusion

Subretinal fluid accumulation in a patient with regressed retinoblastoma is not always a sign of tumor recurrence or a treatment-related retinopathy.

Chemotherapy-Induced Central Retinal Artery Occlusion in Gestational Trophoblastic Neoplasia: Case Report

The use of anticancer chemotherapy (ACC) has resulted in longer patient survival but has also increased drug-related adverse effects. A 22-year-old female receiving cisplatin-based intravenous chemotherapy for high risk variant of gestational trophoblastic neoplasia (GTN) presented with complaints of sudden painless loss of vision in her right eye for a duration of 4 hours. Ocular findings were suggestive of central retinal artery occlusion (CRAO). After exclusion of other potential aetiological risk factors, the patient was diagnosed with CRAO associated with cisplatin. Cancer patients are prone to thromboembolic events (TEE) not only due to primary disease but also due to underlying comorbidities and treatment modalities. The high incidence of TEE in patients under cisplatin therapy mandates a high degree of suspicion among the treating physicians. This rare possibility of irreversible visual toxicity should also be considered among the patients under cisplatin chemotherapy.

Bilateral subfoveal serous detachment following Cisplatin chemotherapy

A 74-year-old gentleman with a background of metastatic pancreatic neuroendocrine tumour on combination chemotherapy of Cisplatin and Etoposide presented with a 3-week history of bilateral visual loss. Snellen visual acuity was right 6/9 and left 6/60. Fundus examination revealed clear media with isolated macular oedema in both eyes. Optical coherence tomography of the maculae showed localised bilateral subfoveal serous detachments. Cisplatin was thought to be the causative agent and was withheld following discussion with the treating Oncology team. Eight weeks after withholding Cisplatin, his vision improved with complete resolution of the subretinal fluid. To the authors' knowledge, this is the first report to have illustrated bilateral subfoveal serous detachment caused by Cisplatin which resolved completely with cessation of offending drug.

Advances in Toxicological Research of the Anticancer Drug Cisplatin

Cisplatin is one of the most widely used chemotherapeutic agents for various solid tumors in the clinic due to its high efficacy and broad spectrum. The antineoplastic activity of cisplatin is mainly due to its ability to cross-link with DNA, thus blocking transcription and replication. Unfortunately, the clinical use of cisplatin is limited by its severe, dose-dependent toxic side effects. There are approximately 40 specific toxicities of cisplatin, among which nephrotoxicity is the most common one. Other common side effects include ototoxicity, neurotoxicity, gastrointestinal toxicity, hematological toxicity, cardiotoxicity, and hepatotoxicity. These side effects together reduce the life quality of patients and require lowering the dosage of the drug, even stopping administration, thus weakening the treatment effect. Few effective measures exist clinically against these side effects because the exact mechanisms of various side effects from cisplatin remain still unclear. Therefore, substantial effort has been made to explore the complicated biochemical processes involved in the toxicology of cisplatin, aiming to identify effective ways to reduce or eradicate its toxicity. This review summarizes and reviews the updated advances in the toxicological research of cisplatin. We anticipate to provide insights into the understanding of the mechanisms underlying the side effects of cisplatin and designing comprehensive therapeutic strategies involving cisplatin.

SEROUS RETINOPATHY ASSOCIATED WITH CISPLATIN TREATMENT

BACKGROUND/PURPOSE

To describe a case of serous retinopathy and associated photoreceptor atrophy after intravenous cisplatin therapy.

METHODS

Evaluation was performed using electroretinogram, optical coherence tomography, fundus autofluorescence, and funduscopic examinations to assess the extent of retinal disease, toxicity, and eventual atrophy.

RESULTS

A 56 year-old man with metastatic small cell carcinoma with vision changes after initiation of cisplatin therapy. The patient developed loss of vision to 20/400. A serous retinopathy was found on spectral domain optical coherence tomography with associated outer retinal atrophy and subretinal fibrosis. He developed outer ellipsoid layer atrophy after discontinuation of cisplatin therapy. He had patchy hypoautofluorescent areas in his macula on fundus autofluorescence and decreased cone response and slowed b-wave on electroretinogram. The serous retinopathy resolved with discontinuation of cisplatin and the malignancy was further managed with etoposide without recurrence of subretinal serous fluid or further vision loss.

CONCLUSION

Commonly used to treat various solid tumors, cisplatin is not without significant neurologic, ocular, and retinal toxicities. Multimodal imaging may further the authors' understanding of toxicity and this case highlights the benefits of optical coherence tomography, especially with color vision deviation or visual acuity change.

Retinal crystalline deposits in a patient who received chemotherapy and radiotherapy for nasopharyngeal carcinoma and subsequent anti-VEGF treatment for the bilateral radiation maculopathy

We report the occurrence of intraretinal crystalline deposits in a patient who received several anti-VEGF injections and one session of focal laser treatment for the treatment of radiation retinopathy during the treatment process. She had received three cycles of epirubicin and cisplatin together with radiation therapy seven years prior to detection of the maculopathy. The multimodal imaging features and the possible cause of the retinal crystalline deposits are discussed.

Cilioretinal artery occlusion associated with cisplatin

Introduction

Cancer is an important risk factor for venous and arterial thromboembolic events. Treatment with chemotherapy was associated with a 6.5-fold increase in the risk of thromboembolic events. Here, we present a patient with cilioretinal artery emboli during cisplatin-based therapy.

Case report

A 54-year-old male patient with a diagnosis of metastatic small cell carcinoma was under cisplatin-based regimen. He presented with visual disturbance. Retinal fluorescein angiography showed multiple plaques located in cilioretinal artery and cilioretinal artery occlusion. After excluding other potential etiological factors, patient was diagnosed with cilioretinal artery occlusion associated with cisplatin.

Discussion

In oncology practice, patients are prone to thromboembolic events due to primary disease, underlying comorbidities and treatment modalities. In addition to numerous toxicities, cisplatin is an important risk factor for thromboembolic events. Clinicians caring patients with a diagnosis of cancer should be aware of this rare complication of cisplatin-based therapies.

Uveoretinal Adverse Effects Presented during Systemic Anticancer Chemotherapy: a 10-Year Single Center Experience

BACKGROUND

The present study describes our 10-year experience with uveoretinal adverse events that manifest because of chemotherapy.

METHODS

A retrospective chart review was performed for all patients who presented to the ophthalmologic department while undergoing systemic chemotherapy between July 2005 and June 2015.

RESULTS

A total of 55 patients (mean age, 51.2 years, 38 women [69.1%]) suspected of having uveoretinal disease owing to the use of chemotherapeutic agents alone were enrolled. Breast cancer was the predominant disease (36.4%); noninfectious anterior uveitis (21.8%) was the most common condition. Bilateral involvement was observed in 16 patients (29.1%). Although cisplatin (21.8%) was the most commonly used drug, daunorubicin, cytarabine, tamoxifen, toremifene, and imatinib were also frequently used. The median duration until ophthalmologic diagnosis was 208.5 days (range, 19-5,945 days). The proportion of patients with final visual acuity (VA) < 20/40 Snellen VA (0.5 decimal VA) was 32.7%. However, no relationship was observed between final VA < 20/40 and age, sex, therapeutic agents, and metastasis.

CONCLUSION

Uveoretinal complications were mostly mild to moderate and exhibited a favorable response to conservative therapy. A considerable number of patients exhibited significant irreversible loss of vision after cessation of the causative chemotherapeutic agent. Ophthalmological monitoring is required during chemotherapy.

Bilateral blindness with secondary retinitis pigmentosa following postoperative docetaxel and platinum combination chemotherapy in primary small-cell carcinoma of the endometrium: An unusual case report and review of the literature

Ocular toxicity is an uncommon complication of cytotoxic chemotherapy. Bilateral blindness with secondary retinitis pigmentosa (RP) following docetaxel and platinum combination chemotherapy at the recommended dose is extremely rare. The present study reports a case of advanced small-cell carcinoma (SCC) of the endometrium in a patient with diabetes mellitus type 2. The patient suffered from RP with a sharp decline in vision after the fourth course of postoperative docetaxel and platinum combination chemotherapy. Unfortunately, the patient developed bilateral blindness after another course of chemotherapy at a reduced dose. No tumor recurrence was observed during the 33 months of follow-up. A total of 35 cases of docetaxel- and/or platinum-induced retinal toxicity were found in the English literature and reviewed. The ischemic and electrophysiological hypotheses may have been implicated in the pathogenesis of ocular toxicity in the present case, particularly with the history of diabetes. Understanding the ocular side effects of this combination chemotherapy may assist gynecological oncologists and ophthalmologists with early recognition and timely intervention before blindness is established.

Toxic effects of systemic cisplatin on rat eyes and the protective effect of hesperidin against this toxicity

CONTEXT

In the present study, cisplatin (CP) induced eye toxicity and the beneficial effect of hesperidin (HP) was investigated.

METHODS

Twenty-eight rats were equally divided into four groups; the first group was kept as control. In the second and third group, CP and HP were given at the doses of 7 mg/kg and 50 mg/kg/d, respectively. In the fourth group, CP and HP were given together at the same doses. Tissue samples were collected on day 14 of CP treatment.

RESULTS

The results demonstrated that CP caused a significant increase in thiobarbituric acid reactive substances (TBARS) levels and decrease of glutathione levels and antioxidant enzyme activity (catalase, superoxide dismutase and glutathione peroxidase) in eye tissues compared to other groups, HP prevented these effects of CP. Besides, CP led to histopathological damage in the retina and cornea. On the other hand, HP treatment prevented histopathological effects of CP.

CONCLUSION

CP had severe dose-limiting toxic effects and HP treatment can be beneficial against the toxic ocular effects of CP. Thus, it appears that co-administration of HP with CP may be a useful approach to attenuate the negative effects of CP on the eye.

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.

Paclitaxel- and/or cisplatin-induced ocular neurotoxicity: a case report and literature review

Paclitaxel (PTX) and/or cisplatin (CDDP), as important cytotoxic anti-cancer agents, are widely used to treat various solid tumors. Both may cause moderate or severe neurotoxicity, but ocular neurotoxicity is also occasionally reported. A patient diagnosed with nasopharyngeal cancer suffering acute ocular neurotoxicity 10 days after paclitaxel and CDDP administration at the recommended dose is described in the present case report, and PTX- and/or CDDP-induced ocular neurotoxicity are summarized according to previous reports. Possible mechanisms and the potential diagnostic, therapeutic and predictive strategies of PTX- and/or CDDP-induced ocular neurotoxicity are reviewed, to help the oncologist to take the infrequent toxicity of cytotoxic drugs into account and improve patient safety during anti-cancer therapy.

Usefulness of optical coherence tomography to detect central serous chorioretinopathy in monkeys

Many systemic drugs can induce ocular toxicity and several ocular side-effects have been identified in clinical studies. However, it is difficult to detect ocular toxicity in preclinical studies because of the lack of appropriate evaluation methods. Optical coherence tomography (OCT) is useful because it can provide real-time images throughout a study period, whereas histopathology only provides images of sacrificed animals. Using OCT alongside histopathology, attempts were made to find effective approaches for screening of drug-induced ocular toxicity in monkeys. Such approaches could be used in preclinical studies prior to human trials. Six male cynomolgus monkeys (Macaca fascicularis Raffles) were orally administered one of six candidate MAPK/ERK kinase (MEK) inhibitors. Central serous chorioretinopathy, a known side-effect of such inhibitors, was identified in four monkeys by OCT. Artifacts generated during tissue processing meant that histopathology could not detect edematous changes. Thus, OCT is a useful tool to detect ocular toxicity which cannot be detected by histopathology in preclinical studies.

Nanocarriers for delivery of platinum anticancer drugs

Platinum based anticancer drugs have revolutionized cancer chemotherapy, and continue to be in widespread clinical use especially for management of tumors of the ovary, testes, and the head and neck. However, several dose limiting toxicities associated with platinum drug use, partial anti-tumor response in most patients, development of drug resistance, tumor relapse, and many other challenges have severely limited the patient quality of life. These limitations have motivated an extensive research effort towards development of new strategies for improving platinum therapy. Nanocarrier-based delivery of platinum compounds is one such area of intense research effort beginning to provide encouraging preclinical and clinical results and may allow the development of the next generation of platinum chemotherapy. This review highlights current understanding on the pharmacology and limitations of platinum compounds in clinical use, and provides a comprehensive analysis of various platinum-polymer complexes, micelles, dendrimers, liposomes and other nanoparticles currently under investigation for delivery of platinum drugs.

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.