Optic atrophy following prophylactic chemotherapy and cranial radiation for acute lymphocytic leukemia

Ocular adverse effects of anti-cancer chemotherapy

Cancer ranks as the second leading cause of mortality in Europe, following cardiovascular diseases. Every year, 2.6 million people are diagnosed with this disease, and 1.2 million die. It has an impact not only on individual health but also on society and the economy. The survival rate has improved with the introduction of new diagnostic methods and anti-cancer chemotherapy. While more aggressive chemotherapeutic regimens and combination therapies have demonstrated efficacy against cancer cells, they also have detrimental effects on normal cells, leading to systemic and ocular adverse reactions associated with cytotoxicity, inflammation, and neurotoxicity. Consequently, we have an increased survival rate, but the appearance of these ocular adverse effects decreases the quality of life. Ocular toxicity induced by chemotherapeutic agents is often underestimated. While prevention may not be possible, proper management by an ophthalmologist, an integral part of the oncology patient's medical team, is crucial. The ophthalmologist should assess the patient before initiating chemotherapeutic treatment and continue monitoring throughout to identify any adverse ocular reactions resulting from the systemic chemotherapy. This article aimed to briefly highlight the adverse reactions occurring at the ocular surface in patients undergoing chemotherapeutic treatment. Fortunately, these ocular side effects are limited only to the period in which the chemotherapeutic treatment is done, with most of them disappearing a few weeks after stopping the treatment.

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.

Optic neuropathy in the context of leukemia or lymphoma: diagnostic approach to a neuro-oncologic emergency

Background

Optic neuropathy in the context of leukemia or lymphoma has a broad differential diagnosis, including infiltration, infection, inflammation, compression, and medication effects. Confirming the underlying etiology in a timely manner is crucial as, while infiltration carries a poor prognosis, treatment modalities can have serious consequences themselves.

Methods

A review of the literature was conducted for cases of isolated optic neuropathy in the context of leukemia or lymphoma, in which the underlying etiology remained unclear following initial clinical examination and neuroimaging. Clinical, radiological, and pathological characteristics of the cases are summarized.

Results

Ninety-two cases meeting inclusion criteria were identified. Leukemic or lymphomatous infiltration was the presumed diagnosis in 72% of the reports, indicating this is the most likely etiology in such cases. The remaining reports were attributed to inflammation, infection, or drug toxicity. For illustrative purposes, the previously unpublished case of an 11-year-old girl with remitted T lymphoblastic lymphoma is presented. She suffered recurrence in the form of isolated left optic nerve infiltration that required transconjunctival biopsy to confirm diagnosis.

Conclusions

Optic nerve infiltration by leukemia or lymphoma requires both diagnostic certainty and urgent management. Recommendations are made for a step-wise, yet rapid investigative approach that may ultimately require biopsy of the optic nerve.

Etiology and clinical profile of childhood optic nerve atrophy at a tertiary eye care center in South India

Background:

Optic nerve atrophy is an important ophthalmological sign that may be associated with serious systemic conditions having a significant bearing on the overall morbidity of the child. Studies specific to etiology of childhood optic atrophy are scarce, this being the first such study from India to the best of our knowledge.

Aim:

The aim was to analyze the clinical features and etiology of diagnosed cases of optic nerve atrophy in children <16 years of age.

Materials and Methods:

Retrospective review of records of children diagnosed with optic nerve atrophy between the ages of 0 and 16 years from 2006 to 2011.

Results:

A total of 324 children (583 eyes) were identified. Among these 160 (49%) presented with defective vision, 71 (22%) with strabismus, 18 (6%) with only nystagmus. Rest had a combination of two or three of the above symptoms. Sixty-five patients (20%) had a unilateral affection. Hypoxic ischemic encephalopathy seen in 133 patients (41%) was the most frequent cause of childhood optic atrophy, followed by idiopathic in 98 (30%), hydrocephalus in 24 (7%), compressive etiology in 18 (5%), infective in 19 (6%), congenital in 6 (2%), inflammatory in 5 (2%) patients, respectively.

Conclusion:

Hypoxic ischemic encephalopathy appears to be the most common cause of optic atrophy in children in this series. The most common presenting complaint was defective vision.

Late radiation injury to peripheral nerves

Although the peripheral nerve has often been considered as radioresistant, clinical practice demonstrates the occurrence of radiation-induced peripheral neuropathies. Because these complications appear late, usually several years after the course of radiotherapy, their occurrence is explained by improvement in the prognosis of several cancers. Their physiopathology is not fully understood. Compression by radio-induced fibrosis probably plays a central role but direct injury to nerves and blood vessels is probably also involved. The most frequent and best known form of postradiation neuropathy is brachial plexopathy, which may follow irradiation for breast cancer. Recent reports demonstrate that postradiation neuropathies show a great heterogeneity, particularly in the anatomical sites, but also in the clinical, electrophysiological, and neuroimaging features. The link with radiotherapy may be difficult for the clinician to establish. Patients with radiation-induced lumbosacral radiculoplexopathy may be misdiagnosed with amyotrophic lateral sclerosis as they often present with pure lower motor neuron syndrome, or with leptomeningeal metastases since nodular MRI enhancement of the nerve roots of the cauda equina and increased CSF protein content can be observed. From a pathophysiological perspective, radiation-induced neuropathy offers an interesting model for deciphering the mechanisms of peripheral neuropathies due to environmental factors. Recent developments show promising strategies for the prevention and treatment of these complications, which have a considerable impact on a patient's quality of life.

[Radiation-induced neuropathies: collateral damage of improved cancer prognosis]

INTRODUCTION

Because of the improvement of cancer prognosis, long-term damages of treatments become a medical and public health problem. Among the iatrogenic complications, neurological impairment is crucial to consider since motor disability and pain have a considerable impact on quality of life of long cancer survivors. However, radiation-induced neuropathies have not been the focus of great attention. The objective of this paper is to provide an updated review about the radiation-induced lesions of the peripheral nerve system.

STATE OF THE ART

Radiation-induced neuropathies are characterized by their heterogeneity in both symptoms and disease course. Signs and symptoms depend on the affected structures of the peripheral nerve system (nerve roots, nerve plexus or nerve trunks). Early-onset complications are often transient and late complications are usually progressive and associated with a poor prognosis. The most frequent and well known is delayed radiation-induced brachial plexopathy, which may follow breast cancer irradiation. Radiation-induced lumbosacral radiculoplexopathy is characterized by pure or predominant lower motor neuron signs. They can be misdiagnosed, confused with amyotrophic lateral sclerosis (ALS) or with leptomeningeal metastases since nodular MRI enhancement of the nerve roots of the cauda equina and increased cerebrospinal fluid protein content can be observed. In the absence of specific markers of the link with radiotherapy, the diagnosis of post-radiation neuropathy may be difficult. Recently, a posteriori conformal radiotherapy with 3D dosimetric reconstitution has been developed to link a precise anatomical site to unexpected excess irradiation.

PERSPECTIVES AND CONCLUSION

The importance of early diagnosis of radiation-induced neuropathies is underscored by the emergence of new disease-modifying treatments. Although the pathophysiology is not fully understood, it is already possible to target radiation-induced fibrosis but also associated factors such as ischemia, oxidative stress and inflammation. A phase III trial evaluating the association of pentoxifylline, tocopherol and clodronate (PENTOCLO, NCT01291433) in radiation-induced neuropathies is now recruiting.

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.

Ophthalmic Regional Block

Key words: Optic chiasm, Optic nerve, Radionecrosis, Radiotherapy, Vision loss

Hyperbaric Oxygen Therapy for Radiation-induced Optic Neuropathy

Introduction: Radiation-induced optic neuropathy (RON) is an infrequent but devastating consequence of radiation exposure to the visual pathways, usually following months to years after the treatment of paranasal or intracranial tumours. Hyperbaric oxygen (HBO) therapy is one of several therapies that have been tried for this condition. The purpose of this review is to describe the clinical characteristics of RON, the rationale for the use of HBO in this condition, and the available clinical data on its safety and efficacy. Methods: MEDLINE searches were performed on radiation optic neuropathy, hyperbaric oxygen therapy, and similar terms, and selected references were reviewed. The results were combined with the experience at our own institution. Results: RON typically follows a fulminant course with characteristic symptoms, examination findings, and imaging. The threshold for prior radiation exposure depends upon the delivery system used and patient characteristics. Therapy with anticoagulants or steroids has been unsuccessful. While there are case reports in the literature of successful treatment with HBO, therapy with HBO has to be initiated soon after the onset of vision loss, and even then yields variable results at best. Conclusions: There is still no consistently successful treatment for RON. HBO may be attempted in selected cases, but the prognosis for preservation of vision remains grim. Key words: Optic chiasm, Optic nerve, Radionecrosis, Radiotherapy, Vision loss

Update on ocular complications of systemic cancer chemotherapy

The constantly growing list of cytotoxic chemotherapeutics requires a new survey of ophthalmic complications, which are often underestimated. Based on the review by Imperia et al (1989), an update on ophthalmic complications of currently used cytotoxic chemotherapeutics in oncology was written. Vision is a quality of life issue, which must be nurtured, especially if loss of vision can be prevented. The broad spectrum of ophthalmic complications induced by cytotoxic chemotherapy includes reversible and irreversible acute and chronic disorders. Mild to moderate ophthalmic complications are very common and reversible after cessation of anti-cancer therapy. Some major ocular toxicities may require a dose reduction or the discontinuation of cytotoxic chemotherapy in order to prevent visual loss. Ocular toxicities can be treated or even prevented, if detected early enough. That is why an ophthalmic baseline examination for patients receiving cytosine arabinoside, 5-fluorourocil, methotrexate, or docetaxel should be taken into consideration, and a consultation with an ophthalmologist has to be done as soon as symptoms are recognized. Oncologists and ophthalmologists must be aware of potential ophthalmic complications during cytotoxic chemotherapy, and should work together.

Does altered fractionation influence the risk of radiation-induced optic neuropathy?

PURPOSE

To analyze the parameters that influence the risk of radiation-induced optic neuropathy (RION) after radiotherapy for head-and-neck tumors.

METHODS AND MATERIALS

Between 1964 and 2000, 273 patients with tumors of the nasopharynx, paranasal sinuses, nasal cavity, and hard palate adenoid cystic carcinomas were treated with curative intent and had radiation fields that included the optic nerves and/or chiasm. Patients were followed for at least 1 year after radiotherapy.

RESULTS

Radiation-induced optic neuropathy developed in 32 eyes of 24 patients (9%). The 5-year rates of freedom from RION according to the total dose and once- vs. twice-daily fractionation were as follows: < or =63 Gy once daily, 95%; < or =63 Gy twice daily, 98%; >63 Gy once daily, 78%; and >63 Gy twice daily, 91%. Multivariate analysis revealed that the total dose affected the risk of RION (p = 0.0047), with patient age (p = 0.0909), once-daily vs. twice-daily fractionation (p = 0.0684), and overall treatment time (p = 0.0972) were marginally significant. The use of adjuvant chemotherapy did not significantly influence the likelihood of developing RION.

CONCLUSION

The likelihood of developing RION is primarily influenced by the total dose. Hyperfractionation may reduce the risk of experiencing this complication.

Friendly fire: neurogenic visual loss from radiation therapy

The author's experience and review of the medical literature suggest that radiation-induced neurogenic visual loss presents on average 18 months after treatment and usually after cumulative doses of radiation that exceed 50 Gy or single doses to the visual apparatus of greater than 10 Gy. Visual loss may result from lesions of the disc, retrobulbar segment of the optic nerve, optic chiasm, or retrogeniculate pathways. Magnetic resonance imaging, the best means of demonstrating radiation injury to the visual pathway, may show abnormalities before the loss of vision. The second eye may show clinical manifestations of optic neuropathy many months after the diagnosis in the first involved eye. Spontaneous improvement in visual function may rarely occur. Treatment has been disappointing, but if visual dysfunction is detected early, hyperbaric oxygen might be beneficial. The risk of neurogenic visual loss must be factored into the decision to irradiate the brain.

Optic neuropathy secondary to radiotherapy for nasal melanoma

Optic neuropathy is a rare but important complication of radiotherapy used in the treatment of cancers of the head and neck, usually resulting in rapidly progressive blindness in one or both eyes. The case is presented of a 77-year-old woman with bilateral optic neuropathy resulting in blindness, secondary to radiotherapy for a melanoma of the nasal cavity. The onset of optic neuropathy occurred 9 months post-radiotherapy, at a cumulative dose of 6000 rad. The left eye was first involved, with the right eye becoming involved within 2 weeks. Despite treatment with oral anticoagulation and high dose intravenous methylprednisolone, there was progressive deterioration resulting in bilateral optic atrophy, with final visual acuities of perception of light in the right eye and no perception of light in the left eye. This case demonstrates that oral anticoagulation was ineffective in the treatment of progressive radiation-induced optic neuropathy.

Acute neurologic complications in children with systemic cancer

Neurologic complications are common in children with cancer, but the literature dealing with this subject is sparse. Using a symptoms and signs approach, the most common causes for requesting a neurologic evaluation for this population are reviewed. The spectrum of neurologic symptoms in children with cancer differs from adults and requires the consulting neurologist to have a thorough knowledge of childhood cancer and its effects on the nervous system.

Optic nerve sheath fenestration for a reversible optic neuropathy in radiation oncology

To the authors' knowledge, there is a paucity of published accounts of management of radiation-induced optic neuropathy (RION) by optic nerve sheath fenestration (ONSF) in the conventional medical literature. With higher doses of radiation being given by using conformal techniques, more radiation-induced optic neuritis and neuropathy will be identified. We report here the successful use of ONSF to restore vision to three consecutive patients with pending anterior RION, and the importance of early identification and intervention in these potentially reversible cases.

Ocular toxicity and cancer chemotherapy. A review

BACKGROUND

Systemic anticancer therapies can produce acute and chronic organ damage, but the eye is usually considered a protected site. Nonetheless, the oculo-visual system has a potentially high degree of sensitivity to toxic substances. Ocular toxicity induced by cancer chemotherapy includes a broad spectrum of disorders, reflecting the unique anatomic, physiologic, and biochemical features of this essential organ.

METHODS

A review of the literature regarding the ocular toxicity of chemotherapeutic agents, hormonal agents, biologic agents, and high dose chemotherapy with allogeneic and autologous bone marrow transplantation was conducted.

RESULTS

Ocular toxicity induced by anticancer chemotherapy is not uncommon. The development of more aggressive regimens as well as new agents and combination chemotherapies have resulted in a significant increase of reported cases of chemotherapy-induced ocular side effects. In most instances, the mechanisms of ocular toxicity continue to be poorly understood.

CONCLUSIONS

Ocular toxicities induced by chemotherapeutic agents are generally not preventable; therefore, clinicians must be aware of potential vision-threatening complications. Prompt consultation with an ophthalmologist can lead to early detection, proper diagnosis, and appropriate therapeutic measures. Dose reduction or discontinuation of incriminated drugs may help in reducing the severity and the duration of side effects.

Optic nerve head infiltration in acute leukemia in children: an indication for emergency optic nerve radiation therapy

Two pediatric patients with acute leukemia who developed optic nerve head leukemic infiltration are presented. In one patient both eyes were involved at diagnosis as well as her central nervous system. Despite systemic and intrathecal chemotherapy she lost her vision within a few weeks. Cranial irradiation at that point could not reverse this outcome. In the second patient optic nerve head infiltration was found a few months after diagnosis, treated promptly with cranial irradiation and her vision was saved. Her central nervous system (CNS) was not involved at any time. It is stressed that ocular complaints including eye pain or blurred vision in the pediatric patient with leukemia should be investigated without delay by an ophthalmologist. In the young child these complaints may be absent and change in the visual behavior should then alert the pediatric oncologist for possible ocular problems. If optic nerve head leukemic infiltration is diagnosed and promptly treated with emergency radiation, vision can be salvaged.

Visual loss following treatment of sphenoid sinus carcinoma

A 71-year-old woman developed complete third nerve palsy and total blindness of the right eye one month after completing a course of radiotherapy for sphenoid sinus carcinoma over a 13-month period. Differential diagnosis included recurrence of the tumor, radiation-induced second neoplasm, empty sella with chiasmal prolapse and secondary chiasmal arachnoid adhesions, and radionecrosis. Magnetic resonance imaging demonstrated gadolinium contrast enhancement of the right intracranial optic nerve and chiasm, suggesting a radionecrosis process.

Radiation optic neuropathy after megavoltage external-beam irradiation: analysis of time-dose factors

PURPOSE

To investigate the risk of radiation-induced optic neuropathy according to total radiotherapy dose and fraction size, based on both retrospective and prospectively collected data.

METHODS AND MATERIALS

Between October 1964 and May 1989, 215 optic nerves in 131 patients received fractionated external-beam irradiation during the treatment of primary extracranial head and neck tumors. All patients had a minimum of 3 years of ophthalmologic follow-up (range, 3 to 21 years). The clinical end point was visual acuity of 20/100 or worse as a result of optic nerve injury.

RESULTS

Anterior ischemic optic neuropathy developed in five nerves (at mean and median times of 32 and 30 months, respectively, and a range of 2-4 years). Retrobulbar optic neuropathy developed in 12 nerves (at mean and median times of 47 and 28 months, respectively, and a range of 1-14 years). No injuries were observed in 106 optic nerves that received a total dose of < 59 Gy. Among nerves that received doses of > or = 60 Gy, the dose per fraction was more important than the total dose in producing optic neuropathy. The 15-year actuarial risk of optic neuropathy after doses of > or = 60 Gy was 11% when treatment was administered in fraction sizes of < 1.9 Gy, compared with 47% when given in fraction sizes of > or = 1.9 Gy. The data also suggest an increased risk of optic nerve injury with increasing age.

CONCLUSION

As there is no effective treatment of radiation-induced optic neuropathy, efforts should be directed at its prevention by minimizing the total dose, paying attention to the dose per fraction to the nerve, and using reduced-field techniques where appropriate to limit the volume of tissues that receive high-dose irradiation.

Radiation and chemotherapy injury: pathophysiology, diagnosis, and treatment

The text in general is not meant to represent the participants' entire presentations. The lecture presenters in general are not responsible for the summaries, and cannot necessarily be assumed to agree with all that is stated, but they deserve credit for providing the lecture and handout material on which the summaries are based, and in most cases have contributed far more to the summaries than I have.

Eye sequelae following external irradiation

The early reactions of the eye to radiation are conjunctivitis and, with higher doses, corneal damage. The inflammatory reactions are transient and remit within a few weeks after the end of radiotherapy. Doses above 60 Gy can produce corneal ulcerations with the risk of perforation and loss of the eye. The most frequent late reaction of the eye is cataract of the lens. The tolerance dose (about 5 Gy) is extremely low and the latent period varies from 6 months to 3 years. The lens in children has a much lower tolerance. The increasing potential for optical support and ophthalmic surgery over recent decades has reduced the fear of this complication. The most severe late complications are retinopathy (RR) and neuropathy of the optic nerve (RON), both of which are caused by radiation-induced microangiopathy. Visual loss is very frequent and complete blindness is seen with high doses in the range of 50-60 Gy. The latent period of these injuries varies widely from 1 month to 15 years, but they usually occur within 3 years of treatment. Conflicting frequencies are reported in the literature. Beyond 30 Gy, usually no RR is seen. However, the lowest recorded dose producing RR is 11 Gy. In the high dose range of 60-70 Gy RR and RON are found in 10%-100% of patients. There is a great need for prospective trials to estimate the true risk to patients with nasopharyngeal, maxillo-ethmoidal, and orbital tumors, pituitary adenomas, and tumors of the salivary glands. To minimize complications of radiotherapy to the eyes daily fractions should be reduced to 1.7-1.8Gy.(ABSTRACT TRUNCATED AT 250 WORDS)

Do visual evoked potentials detect neural damage in children treated for cancer?

Abnormal visual evoked potentials (VEPs) have been reported in children treated for acute lymphoblastic leukaemia (ALL), which suggests that VEPs may be useful in screening for toxicity. The authors investigated this by recording flash and pattern VEPs in a control group of 34 siblings of patients, a group of six children studied longitudinally during the early stages of treatment for ALL, and three other follow-up groups. In only three follow-up patients were VEP results outside the normal range and the six ALL patients did not develop new abnormalities during early treatment. Although differences were detected between the groups, there was no evidence of VEPs being a useful means of monitoring the treatment of individual patients.

Early blindness and coma during intrathecal chemotherapy for meningeal carcinomatosis

A 35-year-old woman was treated with intraventricular methotrexate (MTX) with a total dose of 70 mg followed by cytosine arabinoside (Ara-C) with a total dose of 80 mg for meningeal metastasis of breast carcinoma. Radiation therapy was not given. Despite a response of the meningeal tumor the patient developed in the third week of MTX treatment a progressive visual loss and loss of consciousness which worsened during subsequent Ara-C treatment and led to death within 3 weeks. Postmortem examination revealed only minimal neoplastic infiltration of the meninges. Multiple foci of axonal degeneration and demyelination were found in the optic nerves and chiasm, the superficial layers of the brainstem, and spinal cord and to some extent in other cranial nerves and spinal nerve roots. The possible causes of this previously unreported early complication are discussed.

Visual involvement in primary non-Hodgkin's lymphomas

This paper reviews the modalities of involvement of the visual function in patients with primary non-Hodgkin's lymphomas. They include the lymphomatous uveitis, the invasion of the orbital cavities and cavernous sinuses, and the involvement of the optic nerves, chiasm and optic tracts by lymphomatous lesions. Two cases of primary non-Hodgkin's lymphomas with visual disturbances are reported and the different mechanisms of visual pathway damage and clinical troubles are discussed from a large review of the pertinent literature.

Ocular complications of systemic cancer chemotherapy

Cancer chemotherapy has changed rapidly in recent years. New agents are constantly being developed. Established agents are being used with increased frequency, in new combinations, at higher dosages, and via new routes of administration. Enhanced survival, as well as increased drug toxicity, has resulted. Ocular toxicity is not uncommon and can greatly impact on quality of life. Practitioners in all fields are increasingly caring for patients who are receiving cancer chemotherapy. The recognition of eye disease resulting from chemotherapy is essential to appropriate patient management. We provide a review of the rapidly growing body of literature on the ocular toxicity of systemic cancer chemotherapy with particular attention to context, clinical course, mechanism, prevention and treatment.

Progressive loss of vision in patients with high-grade non-Hodgkin's lymphoma

Three cases of double-sided neuritis of the optic nerve in patients with lymphomas are described. Two patients with lymphoblastic lymphoma had no other signs of central nervous system (CNS) relapse. All three cases responded to high doses of corticosteroids and/or radiotherapy, suggesting a lymphomatous cause of the papillitis. Optic nerve involvement is reported to be rare in lymphomas, but may become more prominent with aggressive systemic therapy controlling manifestations outside the CNS. Possible causes of optic neuritis in patients with lymphoma are discussed and therapeutic measures are suggested.

Posterior ischemic optic neuropathy during general surgery

We examined two patients who awoke with profound bilateral visual loss after operations under general anesthesia. Their fundi, initially normal, later showed bilateral optic atrophy. Neither patient showed other neurologic deficits, although one demonstrated radiologic evidence of a small cerebral infarction in the deep white matter. These patients probably suffered intraoperative infarction of the retrobulbar segments of both optic nerves, producing posterior ischemic optic neuropathy. Profound systemic hypotension may have been a contributing factor in one patient, the use of the pump-oxygenator in the other, and anemia in both.

Sudden onset of blindness in patients treated with oral CCNU and low-dose cranial irradiation

Three patients developed the sudden onset of total blindness several months after treatment with oral CCNU and low-dose whole-brain radiation. The anterior visual system was included in the radiation field in all patients. Radiotherapy was given for a frontal-lobe glioblastoma multiforme, for central nervous system prophylaxis in a patient with oat cell carcinoma of the lung, and for a parietal-lobe glioblastoma multiforme. None of the neoplasms involved the anterior visual system. The radiation dose ranged from 3000 to 4650 rad and the oral CCNU dosage from 300 mg to 1050 mg. Patients 1 and 2 also received other chemotherapeutic agents. Patient 3 who was treated only with oral CCNU and cranial irradiation died. At autopsy the brain showed a widely infiltrating residual high-grade glioma as well as patchy coagulative necrosis with swollen axons and dystrophic calcifications. The optic chiasm showed severe demyelination, axonal loss, and hyalinized vessels. Synergism between oral CCNU and radiation may account for the blindness produced.

Hyperbaric oxygen in the treatment of radiation-induced optic neuropathy

Four patients with radiation-induced optic neuropathies were treated with hyperbaric oxygen. They had received radiation therapy for treatment of pituitary tumors, reticulum cell sarcoma, and meningioma. Two presented with amaurosis fugax before the onset of unilateral visual loss and began hyperbaria within 72 hours after development of unilateral optic neuropathy. Both had return of visual function to baseline levels. The others initiated treatment two to six weeks after visual loss occurred in the second eye and had no significant improvement of vision. Treatment consisted of daily administration of 100% oxygen under 2.8 atmospheres of pressure for 14-28 days. There were no medical complications of hyperbaria. While hyperbaric oxygen is effective in the treatment of radiation-induced optic neuropathy, it must be instituted within several days of deterioration in vision for restoration of baseline function.

Neuro-ocular damage in pediatric oncology patients: predictor of long-term visual disability or tool for limiting toxicity?

We present a group of eight pediatric cancer patients with a spectrum of visual afferent pathway abnormalities. Changes include decreased visual acuity, visual field alterations, abnormal visual evoked potentials, changes in the optic disc and nerve fiber layer of the retina, radiation retinopathy, and CNS injury. These changes occur in long term survivors of pediatric malignancy (especially those with prolonged, multimodal, and multicourse therapy), but they may be minimally symptomatic. The changes appear to be analogous to the CNS changes (leukoencephalopathy) described in patients with leukemia and attributed to multimodal therapy. By taking advantage of opportunities to detect adverse effects earlier in the treatment course, the present excellent cure rate may be improved by refinements in therapy that also improve the quality of survival.

Radiation retinopathy following treatment of posterior nasal space carcinoma

Posterior nasal space carcinoma has a high mortality and most patients are treated with radiotherapy. Radiation retinopathy was encountered in 7 out of 10 survivors included in this study. Five of the affected patients lost vision as a result of the retinopathy. One patient required laser photocoagulation and responded well to this treatment. There was a variation in the severity of the retinopathy among the patients studied despite the fact that all patients received a similar dose of radiotherapy. We suspect that previously unrecognised factors in the planning of radiotherapy fields may explain this difference.

Radiation therapy for Graves' disease

We used radiation therapy (a total of 2,000 rads) to treat 14 patients (three men and 11 women, ranging in age from 27 to 72 years) with Graves' disease. Three of these patients had refused to take corticosteroids and the other 11 had failed to respond to them, had experienced side effects, or had other contraindications to their use. After follow-up periods ranging from six months to three years, soft-tissue inflammation was reduced in 13 of the 14 patients. All but two patients showed a decrease in proptosis of 1 to 3 mm. Myopathy showed the least improvement. Although we noted transient eyelid erythema, there were no permanent sequelae and none of the patients has had a recurrence of the inflammation.

Ocular toxicity of antineoplastic agents

The increased use of chemotherapeutic agents has resulted in longer patient survival; consequently, the ophthalmologist is seeing more patients with adverse ocular side effects secondary to these antineoplastic agents. Many of these drugs cause aggravating ocular irritation (fluorouracil, methotrexate), canalicular fibrosis with epiphora (fluorouracil), retinopathy (mitotane, tamoxifen), corneal opacities (tamoxifen), cataracts (busulfan, methotrexate), and optic or ocular motor abnormalities (carmustine, vinblastine, vincristine). Based on the data in the National Registry of Drug-Induced Ocular Side Effects and the literature, adverse ocular reactions of the more commonly used chemotherapeutic agents are reviewed.

Ocular side effects of cancer chemotherapy

The ocular side effects of cancer chemotherapeutic drugs are relatively uncommon. Patients with cancer may develop ocular problems due to metastases to the eye or central nervous system, side effects and radiotherapy or chemotherapy, or totally independent eye disorders. We present a review of the reported ocular toxicities of chemotherapeutic agents to assist the oncologist caring for such patients.

The treatment of primary childhood acute lymphocytic leukemia with intermediate dose methotrexate

Fifty-four consecutive children with acute lymphocytic leukemia (ALL) were treated from August 1974 until December of 1976 at Rosewell Park Memorial Institute (RPMI) according to a protocol which substituted cranial irradiation with systemic intermediate dose methotrexate (IDM) 500 mg/m2 each 3 weeks for a total of 3 courses immediately following induction. Of 54 patients, 52 went into remission (96%). There were 35 standard risk and 17 increased risk patients according to age and presenting white blood count (WBC). As of September 1979 9 of the 35 standard risk patients had relapsed: (five central nervous system (CNS), three systemic, and one testicular. The overall disease control is comparable to other published methods of therapy involving cranial irradiation but has the added advantage of not exposing these children to the long range side effects currently being observed in children who had previously been treated with prophylactic cranial irradiation.

Posterior ocular abnormalities after irradiation for retinoblastoma: a histopathological study

Radiation-induced ocular lesions in the posterior eye and orbit were investigated in 33 surgical specimens of patients with retinoblastoma. The eyes were obtained from children 7 months to 6 years of age. Seventeen eyes were irradiated; 16 eyes had not received irradiation and served as controls. The majority of the irradiated eyes were treated with 6000 rads of external beam radiation. They were removed at a mean of 23 months after radiotherapy. All specimens were examined simultaneously by 2 observers without knowledge of treatment and analysed for the presence or absence of 15 lesions. The most consistent lesions in the irradiated eyes were abnormalities of the retinal vessels (11 of 17 eyes) and striking changes in the ciliary arteries (13 of 17 eyes). The retinal vessels showed thickening of the wall, often caused by deposition of fibrillary material, sometimes with fibrin deposits. The most consistent lesion was myointimal proliferation with narrowing of the ciliary arteries. Lesions of the central retinal artery were less common but occurred only in irradiated patients.

Optic neuritis and systemic lymphoma

A 26-year-old man with stage IV poorly differentiated lymphocytic lymphoma complained of visual loss of two weeks' duration. Examination revealed visual acuity of light perception in the right eye secondary to optic neuritis and other tests revealed the presence of lymphomatous leptomeningeal infiltration. Combined treatment with intrathecal methotrexate, prednisone, and whole brain radiation resulted in rapid long-lasting recovery of visual function of the right eye. The cerebrospinal fluid contained a large amount of thymus-derived lymphocytes and the subsequent clinical course observed with characteristic of T-cell or malignant lymphoblastic lymphoma.

Leukemic iris infiltration

A 7-year-old boy with acute lymphocytic leukemia developed iris infiltration, blood-streaked hypopyon, and high intraocular pressure. A diagnostic anterior chamber paracentesis was performed, which provided a cytologic diagnosis. The aspirate was studied by both the millipore filter technique with Papanicolaou stain and a dried smear using the Wright's stain. Wright's stain provided more distinct cellular details. Irradiation of the anterior segment resulted in clearing of leukemic iris infiltration, hypopyon, and glaucoma.

Unilateral optic neuropathy following vincristine chemotherapy

Two subjects with acute lymphatic leukemia have been observed to have unilateral optic neuropathy five to seven days following administration of Vincristine (2.0 mg/sq m) during maintenance chemotherapy. Both subjects were in mission at the time their ocular problems developed. After discontinuance of Vincristine therapy, marked vision improvement in the affected eye occurred over the ensuing months. It is presumed that Vincristine therapy was the cause of toxic optic neuropathy in these patients.

Intermediate dose methotrexate (IDM) in childhood acute lymphocytic leukemia (ALL)

We employed three courses of intermediate dose Methotrexate (IDM) added onto a standard induction and maintenance program with the concept of both central nervous system (CNS) prophylaxis and simultaneous systemic intensification. Cranial radiation (RT) was not employed as CNS prophylaxis. Fifty of 52 patients (to age 18) achieved complete remission. Time on study now ranges from 22-68 months with a median time of 33 months. We separated the children into standard risk and increased risk. We defined increased risk as a WBC over 30 000/mm3 at presentation and an age of less than two years or greater than 10 years at presentation. There have been 15 relapses on these 50 patients; 11 occurred in increased risk patients (of 22 increased risk patients) and four occurred in standard risk patients (of 28 standard risk patients). There were seven CNS relapses, six systemic relapses, one simultaneous systemic and CNS relapse and one testicular relapse. Toxicity to the IDM was small with the worst problem being mucositis. No leukoencephalopathy occurred. The control of hematological relapse is excellent and the avoidance of potential long-term complications notes is even of greater importance.