Dysfunction of the Salivary and Lacrimal Glands After Radioiodine Therapy for Thyroid Cancer: Results of the START Study After 6-Months of Follow-Up

Background: Understanding of changes in salivary and lacrimal gland functions after radioactive iodine therapy (131I-therapy) remains limited, and, to date, no studies have evaluated dose-response relationships between absorbed dose from 131I-therapy and dysfunctions of these glands. This study investigates salivary/lacrimal dysfunctions in differentiated thyroid cancer (DTC) patients six months after 131I-therapy, identifies 131I-therapy-related risk factors for salivary/lacrimal dysfunctions, and assesses the relationships between 131I-therapy radiation dose and these dysfunctions. Methods: A cohort study was conducted involving 136 DTC patients treated by 131I-therapy of whom 44 and 92 patients received 1.1 and 3.7 GBq, respectively. Absorbed dose to the salivary glands was estimated using a dosimetric reconstruction method based on thermoluminescent dosimeter measurements. Salivary and lacrimal functions were assessed at baseline (T0, i.e., immediately before 131I-therapy) and six months later (T6) using validated questionnaires and salivary samplings, with and without stimulation of the salivary glands. Statistical analyses included descriptive analyses and random-effects multivariate logistic and linear regressions. Results: There was no difference between T0 and T6 in the level of parotid gland pain, nor was there difference in the number of patients with hyposalivation, but there were significantly more patients with dry mouth sensation and dry eyes after therapy compared with baseline. Age, menopause, depression and anxiety symptoms, history of systemic disease, and not taking painkillers in the past three months were found to be significantly associated with salivary or lacrimal disorders. Significant associations were found between 131I-exposure and salivary disorders adjusted on the previous variables: for example, per 1-Gy increase in mean dose to the salivary glands, odds ratio = 1.43 [CI 1.02 to 2.04] for dry mouth sensation, ß = -0.08 [CI -0.12 to -0.02] mL/min for stimulated saliva flow, and ß = 1.07 [CI 0.42 to 1.71] mmol/L for salivary potassium concentration. Conclusions: This study brings new knowledge on the relationship between the absorbed dose to the salivary glands from 131I-therapy and salivary/lacrimal dysfunctions in DTC patients six months after 131I-therapy. Despite the findings of some dysfunctions, the results do not show any obvious clinical disorders after the 131I-therapy. Nevertheless, this study raises awareness of the risk factors for salivary disorders, and calls for longer follow-up. Clinical Trials Registration: Number NCT04876287 on the public website (ClinicalTrials.gov).

[Lacrimal dysfunction syndrome in patients with COVID-19 as an indicator of the severity of ocular ischemia]

PURPOSE

To assess the state of lacrimal function of the organ of vision in patients suffering from COVID-19 at the time of manifestation of the disease.

MATERIAL AND METHODS

The study included 112 (224 eyes) patients without concurrent ophthalmic pathologies suffering from COVID-19 infection, they were examined at the time of manifestation of the disease. Study patients were divided into two groups depending on the presence or absence of concomitant somatic diseases. In addition to a comprehensive ophthalmological examination, all patients underwent Schirmer's test (I and II) to measure tear production rate.

RESULTS

Analysis of the results of the study revealed that impaired tear production correlates with insufficient oxygenation of ocular tissues, regardless of patient's comorbid background. Active oxygen therapy performed in severe cases of the disease further exacerbates the process on the ocular surface.

CONCLUSION

The decrease in tear production observed at the height of the COVID-19 disease in patients with severe and moderately severe course correlates with indicators of blood saturation and index of ischemia, allowing this parameter - the rate of tear production - to be considered as a criterion for the severity of ocular ischemia.

Risk factors for ocular surface damage in Mexican patients with dry eye disease: a population-based study

PURPOSE

To analyze potential risk factors for ocular surface damage in a representative population of Mexican patients with dry eye disease (DED).

PATIENTS AND METHODS

A prospective and cross-sectional population-based epidemiologic cohort study was conducted through a survey of patients with symptoms, signs, known preexisting diagnosis, and clinical conditions related to DED. Fluorescein staining, tear break-up time (TBUT), and Oxford lissamine green staining were performed on both eyes of patients enrolled in the study.

RESULTS

A total of 2,725 surveys including 1,543 (56.6%) women and 1,182 (43.3%) men were analyzed. Most common pre-existing diagnosis included dry eye (58%), chronic blepharitis (17%), and ocular allergy (15%). More than 70% of patients had a positive fluorescein test, and this prevalence increased proportionally to the number of reasons for consultation. The same was true for gender (P<0.001) and age (P<0.0001), with women showing a strong correlation with age (R2=0.93912, P=0.001). The association between positive fluorescein staining and diagnosis was significant for dry eye (P<0.0001), Sjögren's syndrome (P<0.0001), and glaucoma (P<0.05). No significant association between TBUT and age or gender was found, but the shorter the TBUT, the larger the prevalence of fluorescein staining. Reduced TBUT was seen more frequently in patients with dry eye (57%), ocular allergy (16%), and chronic blepharitis (15%). Most patients (39%) with Oxford grades III and IV were older, complained of red eye (51.0%), foreign body sensation (47.0%), burning (46.0%), and were using eye drops (67%) and systemic medications (47%).

CONCLUSION

The Mexican profile of patients with significant ocular surface damage related to DED includes women at older ages, complaining of red eye, foreign body, and burning sensation. Diagnoses of dry eye, Sjögren's syndrome, and glaucoma were also risk factors for significant ocular surface damage, along with long-term use of preserved eyes drops and systemic medications.