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Effects of megavolt therapy of cancer on the eye
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CURRENTOPHTHALMOLOGY
Effects of Megavolt Therapy of Cancer on the Eye, by E. Nordman, L.E.O. Nordman and A. Voutilainen. Strahientherapie 152:254-259, 1976 Twenty-two patients treated by megavoltage therapy between 1968 and 1972 for malignant tumours adjacent to the eye are presented. Among these patients, there were nine epidermal carcinomas, five lymphomas, one basal cell, one adenoid cystic, three other carcinomas and one metastasis. There was one tibrosarcoma and one hemangiopericytoma. Eight of the tumors were situated in the maxilla, five in the nasal cavity, four in orbit, three in ethmoidal sinuses, and two in the buccal region. The total dosage varied from 1400 to 6300 rad to the globe in three to eight weeks. The followup time was 12 to 60 months. In five cases the patient died or the eye was enucleated in connection with extirpation of the tumor within seven months. Four of the patients had no complications caused by radiotherapy, their doses having ranged from 1400 to 5 100 rad. Cataract was verified in seven cases after doses of 3400 to 6000 rad. Radiation keratitis was documented in fifteen cases after a dose of 3000 to 6300 rad. In three cases a cornea1 ulcer developed with doses of 4900 to 6ooO rad. Glaucoma developed in three cases after doses of 3600 to 6000 rad; two of these patients had an accompanying iritis. These complications seemed to have correlation to the total dose. Radiation retinopathy developed in two cases after doses of 4000 and 5700 rad. The latency time for cataract, glaucoma and radiation retinopathy was 3 to 60 months. Keratitis appeared usually during the last part of radiation treatment. This complication had no correlation to the total dose administered. The visual acuity was established in fifteen eyes during radiotherapy and during the followup time; in spite of quite high dose therapy to the eye, the visual acuity was preserved in ten eyes as 0.5 or better. Only in one case did the eye have to be enucleated because of irradiation sequelae (glaucoma, iritis, cornea1 ulcer), following a dose of 6000 rad. In the other cases the distressing symptoms were relieved with appropriate therapy. It would seem that enucleation of the irradiated eye is rarely indicated as long the dose delivered to the globe remains below 6000 rad. As the prognosis for malignant tumors in this area usually is not favorable, radiation sequelae to the eye on the affected side is to be accepted as a calculated risk to achieve a more effective cancer control. A cataract can be operated and a painful globe with glaucoma can be enucleated later on, if necessary. Even if the irradiated eye is blind, the patient prefers his own eye to an artificial one. (abstract by E. Nordman)
Comment This article helps fill a gap in the literature. Only on rare occasions do we read of a study with a 12-60 month followup period after cobalt-60-unit or linear acceleration megavoltage radiation therapy to the globe. In only 2 of the 22 cases could the eye be shielded. The results are in general gratifying. Only one eye had to be enucleated due to the sequelae of irradiation. This is in contrast to the results following radiation therapy to an unshielded globe during the era prior to split dose megavoltage therapy. In such instances, perforation of the globe and enucleation were not uncommon. The authors state that they undertook “appropriate” therapy for each complication of irradiation in several instances; details of this therapy were not discussed. I have found that the application of a soft lens reduces the severity of keratitis following irradiation. In many instances, the keratitis is exacerbated by the sandpaper effect of the keratinized palpebral conjunctiva which occurs following radiation. After some months, the keratinization resolves. I believe that soft lens therapy had decreased our incidence of perforation. Following the above report, it seems likely the mode of radiation itself has improved the prognosis, It is difficult to calculate the median followup period as the symbol that denotes “greater than” was used to denote the observation period in 13 of the 22 cases. Median observation time was approximately 26 months when “greater than” was discounted. JULES L. BAUM
Optical Performance of the Penguin Eye in Air and Water, by J.G. Sivak and M. Millodot. J. Comp. Physiol. 129:241-247, 1977 On land, the penguin reminds us of a laughable little man in a tuxedo, waddling amongst its neighbors as if slightly tipsy at a formal bail. Yet in the water, it becomes a sleek mariner, efficiently overtaking its prey, or eluding its enemies. The authors of this paper became curious about the eyes of this fascinating
CURRENTOPHTHALMOLOGY
Effects of Megavolt Therapy of Cancer on the Eye, by E. Nordman, L.E.O. Nordman and A. Voutilainen. Strahientherapie 152:254-259, 1976 Twenty-two patients treated by megavoltage therapy between 1968 and 1972 for malignant tumours adjacent to the eye are presented. Among these patients, there were nine epidermal carcinomas, five lymphomas, one basal cell, one adenoid cystic, three other carcinomas and one metastasis. There was one tibrosarcoma and one hemangiopericytoma. Eight of the tumors were situated in the maxilla, five in the nasal cavity, four in orbit, three in ethmoidal sinuses, and two in the buccal region. The total dosage varied from 1400 to 6300 rad to the globe in three to eight weeks. The followup time was 12 to 60 months. In five cases the patient died or the eye was enucleated in connection with extirpation of the tumor within seven months. Four of the patients had no complications caused by radiotherapy, their doses having ranged from 1400 to 5 100 rad. Cataract was verified in seven cases after doses of 3400 to 6000 rad. Radiation keratitis was documented in fifteen cases after a dose of 3000 to 6300 rad. In three cases a cornea1 ulcer developed with doses of 4900 to 6ooO rad. Glaucoma developed in three cases after doses of 3600 to 6000 rad; two of these patients had an accompanying iritis. These complications seemed to have correlation to the total dose. Radiation retinopathy developed in two cases after doses of 4000 and 5700 rad. The latency time for cataract, glaucoma and radiation retinopathy was 3 to 60 months. Keratitis appeared usually during the last part of radiation treatment. This complication had no correlation to the total dose administered. The visual acuity was established in fifteen eyes during radiotherapy and during the followup time; in spite of quite high dose therapy to the eye, the visual acuity was preserved in ten eyes as 0.5 or better. Only in one case did the eye have to be enucleated because of irradiation sequelae (glaucoma, iritis, cornea1 ulcer), following a dose of 6000 rad. In the other cases the distressing symptoms were relieved with appropriate therapy. It would seem that enucleation of the irradiated eye is rarely indicated as long the dose delivered to the globe remains below 6000 rad. As the prognosis for malignant tumors in this area usually is not favorable, radiation sequelae to the eye on the affected side is to be accepted as a calculated risk to achieve a more effective cancer control. A cataract can be operated and a painful globe with glaucoma can be enucleated later on, if necessary. Even if the irradiated eye is blind, the patient prefers his own eye to an artificial one. (abstract by E. Nordman)
Comment This article helps fill a gap in the literature. Only on rare occasions do we read of a study with a 12-60 month followup period after cobalt-60-unit or linear acceleration megavoltage radiation therapy to the globe. In only 2 of the 22 cases could the eye be shielded. The results are in general gratifying. Only one eye had to be enucleated due to the sequelae of irradiation. This is in contrast to the results following radiation therapy to an unshielded globe during the era prior to split dose megavoltage therapy. In such instances, perforation of the globe and enucleation were not uncommon. The authors state that they undertook “appropriate” therapy for each complication of irradiation in several instances; details of this therapy were not discussed. I have found that the application of a soft lens reduces the severity of keratitis following irradiation. In many instances, the keratitis is exacerbated by the sandpaper effect of the keratinized palpebral conjunctiva which occurs following radiation. After some months, the keratinization resolves. I believe that soft lens therapy had decreased our incidence of perforation. Following the above report, it seems likely the mode of radiation itself has improved the prognosis, It is difficult to calculate the median followup period as the symbol that denotes “greater than” was used to denote the observation period in 13 of the 22 cases. Median observation time was approximately 26 months when “greater than” was discounted. JULES L. BAUM
Optical Performance of the Penguin Eye in Air and Water, by J.G. Sivak and M. Millodot. J. Comp. Physiol. 129:241-247, 1977 On land, the penguin reminds us of a laughable little man in a tuxedo, waddling amongst its neighbors as if slightly tipsy at a formal bail. Yet in the water, it becomes a sleek mariner, efficiently overtaking its prey, or eluding its enemies. The authors of this paper became curious about the eyes of this fascinating