Radiation optic neuropathy and retinopathy with low dose (20 Gy) radiation treatment

Does occupational radiation exposure affect retinal nerve fiber thickness?

PURPOSE

To evaluate the thickness of peripapillary nerve fibers in radiation-exposed healthcare workers.

METHODS

The study included 60 radiation-exposed healthcare workers and 60 healthy control groups. SD-OCT was used to measure mean peripapillary RNFL thickness along with peripapillary RNFL thickness in the upper, lower, nasal, and temporal quadrants.

RESULTS

The mean age of the subjects participating in the study was 37 ± 6.3 (range 25-50) in the radiation-exposed group and 38 ± 4.9 (range 26-48) in the control group. The mean duration of exposure to radiation in healthcare workers was 11 ± 5 years (range 5-27). While the mean total rim thickness was 94.25 ± 8.2 in the radiation-exposed group, it was 102.8 ± 7.4 in the control group (p < 0.001). The mean superior rim thickness was 123.93 ± 15.13 in the radiation-exposed group, while it was measured as 129.75 ± 14.64 in the control group (p = 0.34). While the mean inferior rim thickness was 110.88 ± 13.43 in the group exposed to radiation, it was 130.08 ± 13.44 in the control group (p < 0.001). The mean nasal rim thickness was 70.25 ± 9.50 in the group exposed to radiation, while it was 75.38 ± 13.77 in the control group (p = 0.46). While the mean temporal rim thickness was 71.77 ± 8.73 in the group exposed to radiation, it was measured as 75.78 ± 13.15 in the control group (p = 0.52). Significant thinning of nerve fiber thickness was found statistically significant in all and especially the inferior quadrants of the healthcare workers exposed to radiation compared to the control group.

CONCLUSION

After at least 5 years of radiation exposure, the thickness of the peripapillary retinal nerve fibers may decrease in healthcare workers.

Orbital metastasis: Clinical presentation and survival in a series of 11 cases

BACKGROUND AND OBJECTIVE

Orbital metastases are an uncommon condition. They may be the clinical presentation of a previously unknown malignancy. Depending on the series, the rate of orbital metastasis as a first manifestation of a malignant tumour is 20%-42%. The clinical presentation and survival is presented in a series of 11 cases of orbital metastasis corresponding to 10 patients.

MATERIAL AND METHODS

Descriptive retrospective study of a series of 10 adult patients diagnosed with orbital metastasis from solid tumours during a 9-year period. Metastasis involving the orbit was included, and lymphomas and contiguity invasions from adjacent structures were excluded. A note was made on whether the clinical picture was the first sign of tumour onset. Signs and symptoms at clinical debut were registered, as were primary tumour location, distance seeding, orbital structures involved, and survival time since the diagnosis was established.

RESULTS

One-half (50%) of the patients were women. Mean age at diagnosis was 60.9 years (range 42-82). In nine cases (90%), the metastasis was unilateral, while in the remaining one the involvement was bilateral. The most frequent primary tumour location was the breast (36% of the cases); followed by the bladder (27%), lung (18%), and ovary and cavum (9%). Seventy percent of the patients had a previously diagnosed neoplasm; in 3 cases the metastasis was the first malignancy manifestation. Most frequent symptoms were diplopia (60%), visual impairment (40%), and pain (30%). The most common signs were resistance to ocular retropulsion (60%), presence of a mass on orbital palpation, and ocular dystopia (50%), and bulbar hyperaemia and proptosis (40%). The most employed management modality was clinical observation (5 patients). In 3 patients radiotherapy was administered, combining chemotherapy plus hormonal therapy in one case, and orbital exenteration in another one. In 2 cases, chemotherapy was administered as an isolated regime. Median survival time was 4.8 months since the diagnosis. There was a statistically significant difference between the survival time in the observation group (median 2.5 months) and in the active treatment group (median 29.2 months), p=.034.

CONCLUSIONS

In the series presented, 27% of the cases established the clinical debut of the malignant neoplasm. The ophthalmologist plays an essential role when this condition is suspected, diagnosing it, and proposing its management together with the Oncology Service.

Contour Variability in Thyroid Eye Disease with Compressive Optic Neuropathy Treated with Radiation Therapy

Purpose

Few studies have evaluated the methodology by which radiation therapy (RT) for thyroid eye disease and compressive optic neuropathy is performed. The objective of this study was to retrospectively review our experience from a radiation planning standpoint and to determine whether current treatment methods provide adequate dose to target and collateral structures.

Methods

A retrospective review of 52 patients (104 orbits) with bilateral thyroid eye disease and compressive optic neuropathy treated with RT (20 Gy in 10 fractions) at our institution. RT plans were analyzed for target volumes and doses. Visual fields, color plates, and visual acuity were assessed pretreatment and at last available follow-up post RT. A standardized, anatomic contour of the retro-orbital space was applied to these retrospective plans to determine dose to the entire space, rather than the self-selected target structure.

Results

Compared with the anatomic retro-orbital space, the original contour overlapped by only 68%. Maximum and mean dose was 2134 cGy and 1910 cGy to the anatomic retro-orbital space. Consequently, 39.8% of the orbits had a mean dose <19 Gy (<17 Gy 16.4%, <18 Gy 27.6% <19 Gy 37.8%, <20 Gy 59.2%, 20-21 Gy 35.8%, >21 Gy 5%). There was no significant association of improvement in color plates (P = .07), visual fields (P = .77), and visual acuity (P = .62), based on these dose differences. When beam placement was retrospectively adjusted to include a space of 0.5 cm between the lens and the anterior beam edge, there was a 39.4% and 20.3% decrease in max and mean dose to the lens.

Conclusions

Without a standardized protocol for contouring in thyroid eye disease, target delineation was found to be rather varied, even among the same practitioner. Differences in dose to the anatomic retro-orbital space did not affect outcomes in the follow-up period. Although precise contouring of the retro-orbital space may be of little clinical consequence overall, a >0.5 cm space from the lens may significantly reduce or delay cataractogenesis.

Orbital metastasis: Clinical presentation and survival in a series of 11 cases

BACKGROUND AND OBJECTIVE

Orbital metastases are an uncommon condition. They may be the clinical presentation of a previously unknown malignancy. Depending on the series, the rate of orbital metastasis as a first manifestation of a malignant tumour is 20-42%. The clinical presentation and survival are presented in a series of 11 cases of orbital metastasis corresponding to 10 patients.

MATERIAL AND METHODS

Descriptive retrospective study of a series of 10 adult patients diagnosed with orbital metastasis from solid tumours during a 9-year period. Metastases involving the orbit were included, and lymphomas and contiguity invasions from adjacent structures were excluded. A note was made on whether the clinical picture was the first sign of tumour onset. Signs and symptoms at clinical debut were registered, as were primary tumour location, distance seeding, orbital structures involved, and survival time since the diagnosis was established.

RESULTS

One-half (50%) of the patients were women. Mean age at diagnosis was 60.9years (range 42-82). In nine cases (90%), the metastasis was unilateral, while in the remaining one the involvement was bilateral. The most frequent primary tumour location was the breast (36% of the cases), followed by the bladder (27%), lung (18%), and ovary and cavum (9%). Seventy percent of the patients had a previously diagnosed neoplasm; in 3 cases the metastasis was the first malignancy manifestation. Most frequent symptoms were diplopia (60%), visual impairment (40%), and pain (30%). The most common signs were resistance to ocular retropulsion (60%), presence of a mass on orbital palpation and ocular dystopia (50%), and bulbar hyperaemia and proptosis (40%). The most employed management modality was clinical observation (5 patients). In 3 patients radiotherapy was administered, combining chemotherapy plus hormonal therapy in one case, and orbital exenteration in another one. In 2 cases, chemotherapy was administered as an isolated regime. Median survival time was 4.8months since the diagnosis. There was a statistically significant difference between the survival time in the observation group (median 2.5months) and in the active treatment group (median 29.2months), P=.034.

CONCLUSIONS

In the series presented, 27% of the cases established the clinical debut of the malignant neoplasm. The ophthalmologist plays an essential role when this condition is suspected, diagnosing it, and proposing its management together with the Oncology Service.

Radiation-Induced Cerebro-Ophthalmic Effects in Humans

Exposure to ionizing radiation (IR) could affect the human brain and eyes leading to both cognitive and visual impairments. The aim of this paper was to review and analyze the current literature, and to comment on the ensuing findings in the light of our personal contributions in this field. The review was carried out according to the PRISMA guidelines by searching PubMed, Scopus, Embase, PsycINFO and Google Scholar English papers published from January 2000 to January 2020. The results showed that prenatally or childhood-exposed individuals are a particular target group with a higher risk for possible radiation effects and neurodegenerative diseases. In adulthood and medical/interventional radiologists, the most frequent IR-induced ophthalmic effects include cataracts, glaucoma, optic neuropathy, retinopathy and angiopathy, sometimes associated with specific neurocognitive deficits. According to available information that eye alterations may induce or may be associated with brain dysfunctions and vice versa, we propose to label this relationship "eye-brain axis", as well as to deepen the diagnosis of eye pathologies as early and easily obtainable markers of possible low dose IR-induced brain damage.