Reversible increase of intraocular pressure in subclinical hypothyroid patients

Thyroid disorders and their role in the pathogenesis of glaucoma

The literature analysis confirms the interrelationship of thyroid gland pathology and glaucoma. Patients with diffusetoxic goiter (DTG) and endemic goiter have an especially high risk of developing glaucoma, while those with autoimmune thyroiditis face a moderate risk. The prevalence of primary open angle glaucoma (POAG) in patients over 40 with endocrine ophthalmopathy is reliably associated with the male gender and the duration of the disease longer than 60 months. An increased risk of POAG is noted in men with hypothyroidism averagely aged 69. In most cases, ophthalmic hypertension that accompanies endocrine pathology does not need any topical hypotensive treatment. The main pathogenetically validated therapy of thyroid disorders results in a reduction of IOP level and an improvement of fluid outflow from the eye.

Relationship between Alcohol Consumption and Ocular Pressure according to Facial Flushing in Korean Men with Obesity

Background

This study aimed to examine the relationship between alcohol consumption and intraocular pressure (IOP) according to facial flushing in Korean men with obesity.

Methods

The study included 479 Korean men with a body mass index of ≥25 kg/m² (75 non-drinkers, 174 with drinking-related facial flushing, and 230 without facial flushing) who underwent health check-ups between October 1, 2016 and March 31, 2017. Multivariate logistic regression was used to assess the relationship between alcohol consumption and high IOP (≥21 mm Hg).

Results

Flushers consuming ≤16 drinks per week had a significantly higher risk of high IOP than non-drinkers, depending on alcohol consumption (≤8 standard drinks: odds ratio [OR], 4.49; 95% confidence interval [CI], 1.05– 19.25; >8 but ≤16 standard drinks: OR, 8.14; 95% CI, 1.37–48.45). However, when the consumption was >16 drinks per week, the high IOP risk did not significantly increase (OR, 0.71; 95% CI, 0.05–10.69). In addition, there was no significant relationship between alcohol consumption and high IOP among non-flushers consuming ≤8 drinks per week (OR, 2.07; 95% CI, 0.52–8.19). However, a significantly increased risk of high IOP was observed among non-flushers consuming >8 drinks per week, depending on alcohol consumption (>8 but ≤16 standard drinks: OR, 4.84; 95% CI, 1.14–20.61; >16 standard drinks: OR, 4.08; 95% CI, 1.02–16.26).

Conclusion

This study suggests that obese men with alcohol flush reactions may have an increased risk of high IOP with the consumption of smaller amounts of alcohol than non-flushers.

Changes in Intraocular Pressure and Corneal and Retinal Nerve Fiber Layer Thicknesses in Hypothyroidism

Purpose

To evaluate the changes in intraocular pressure (IOP), corneal thickness (CT), and retinal nerve fiber layer thickness (RNFLT) in patients with hypothyroidism before and after treatment.

Methods

A complete ophthalmic examination including visual acuity, IOP, anterior segment, and fundus examination together with CT and RNFLT measurements were performed for each patient with newly diagnosed hypothyroidism, at the initial diagnosis and the third and ninth months of the L-thyroxine treatment. Wilcoxon signed rank test and Spearman's correlation test were used for statistical evaluation of the results.

Results

A total of 56 eyes of 28 patients were included in the study. The mean IOP and CT values were found to decrease with medical treatment (p=0.000). There was no significant change in any of the RNFLT parameters measured with scanning laser Polarimeter after L-thyroxine treatment (Wilcoxon, p>0.05). The change in IOP levels was not correlated with the change in thyroid hormone levels (Spearman's correlation test, p>0.05). The mean increase in serum free T3 and serum free T4 levels and the mean decrease in serum TSH levels at the ninth month of the therapy were found to be correlated with the decrease in CT in the left eyes (Spearman's correlation test, R>0.4 and p<0.05).

Conclusions

Hypothyroidism seems to cause a reversible increase in CT and IOP. IOP changes may be secondary to CT changes. RNFLT parameters measured with scanning laser Polarimeter do not seem to be affected by hypothyroidism. When the CT is taken into account and the IOPs corrected for CT, the prevalence of glaucoma in hypothyroidism may not be as high as previously reported. This issue should be taken into account while assessing glaucoma in patients with hypothyroidism.

The interrelation between hypothyroidism and glaucoma: a critical review and meta-analyses

Data on the association between hypothyroidism and glaucoma are conflicting. We sought to shed light on this by conducting a critical review and meta-analyses. The meta-analyses were conducted in adherence with the widely accepted MOOSE guidelines. Using the Medical Subject Heading (MeSH) terms: hypothyroidism, myxoedema and glaucoma or intraocular pressure, case-control studies, cohort studies and cross-sectional studies were identified (PubMed) and reviewed. Using meta-analysis, the relative risk (RR) of coexistence of glaucoma and hypothyroidism was calculated. Based on the literature search, thirteen studies fulfilled the inclusion criteria and could be categorized into two groups based on the exposure. The designs of the studies varied considerably, and there was heterogeneity related to lack of power, weak phenotype classifications and length of follow-up. Eight studies had glaucoma (5757 patients) as exposure and hypothyroidism as outcome. Among these, we found a non-significantly increased risk of hypothyroidism associated with glaucoma (RR 1.65; 95% confidence interval [CI]: 0.97-2.82). Based on five studies (168 006 patients) with hypothyroidism as exposure and glaucoma as outcome, we found the risk of glaucoma to be significantly increased (RR 1.33; 95% CI: 1.13-1.58). Based on these meta-analyses, there seems to be an association between hypothyroidism and glaucoma, which does not seem to be the case between glaucoma and hypothyroidism. However, larger scale studies with better phenotype classification, longer follow-up and taking comorbidity and other biases into consideration are needed to address a potential causal relationship.

Glaucomatous Optic Nerve Changes and Thyroid Dysfunction in an Urban South Korean Population

Purpose. This study was performed to evaluate the relationship between intraocular pressure (IOP) and glaucomatous optic nerve change and thyroid factors in Korean population. Materials and Methods. The study included subjects who underwent health screening in Kangbuk Samsung Hospital. Detailed history taking and systemic and ocular examination including fundus photography were performed for all participants. All fundus photographs were divided into two groups based on disc and RNFL appearance: nonglaucoma and glaucoma group. Subjects were also divided into quartiles of each thyroid function parameter, and the relationship with IOP and glaucoma were analysed. Results. In univariate analysis, free T4, T3, and TSH in normal subjects and T3 in thyroid disease group were associated with the IOP. After adjusting for age and sex, the IOP tended to slightly decrease according to the level of the quartile of free T4 and T3 in normal subjects. In terms of glaucoma, on multivariate analysis, it did not show a significant correlation with any thyroid function tests. Conclusions. In normal subjects, the IOP tended to be decreased according to the level of free T4 and T3 but the amounts were clinically insignificant. Thyroid factors are not an independent risk factor for the development of glaucoma.

Hypothyroidism and Glaucoma in The United States

PURPOSE

To investigate the association between hypothyroidism and glaucomatous disease.

METHODS

This cross-sectional study included all subjects above the age of 40 years from two nationwide surveys: the 2008 National Health Interview Survey (NHIS) as well as the 2007 and 2008 National Health and Nutrition Examination Survey (NHANES). The presence or absence of glaucoma, thyroid disease and other demographic and health-related information including comorbidities was ascertained via interview. Blood samples were collected from NHANES subjects and analyzed for thyrotropin (TSH).

RESULTS

A total of 13,599 and 3,839 NHIS and NHANES participants respectively were analyzed to assess for a possible relationship between self-reported glaucoma, and self-reported hypothyroidism as well as self-reported thyroid disease. The unadjusted odds ratio (OR) for NHIS showed a significant association between self-reported glaucoma and self-reported hypothyroidism (OR 1.46, 95% confidence interval [CI] 1.07-1.99). Multivariate logistic regression analysis adjusted for age, gender, race, comorbidities, and health-related behavior, however, showed no association between self-reported glaucoma and hypothyroidism or thyroid disease in both surveys (OR 1.60, 95%CI 0.87-2.95 for NHIS; OR 1.05, 95%CI 0.59-1.88 for NHANES).

CONCLUSION

A previously reported association between hypothyroidism and glaucomatous disease was not confirmed in two large U.S. health survey populations. While such an association was noted in the univariate analysis for the NHIS survey, such a relationship was not found in the multivariate analysis after adjustment for potential confounding variables.

Glaucoma and systemic diseases

Glaucoma management may be extremely challenging, especially in elderly patients who have a variety of systemic diseases and take multiple medications. We obtained a comprehensive medical history in patients with primary open-angle glaucoma to determine which systemic diseases are most prevalent and which systemic medications are most commonly used. We have also reviewed the literature that addresses how these concomitant diseases and medical treatments influence the management of glaucoma. Knowledge of systemic diseases and potential drug interactions, especially between various systemic and glaucoma medications, is important for the safe management of glaucoma patients.

Ocular changes in primary hypothyroidism

BACKGROUND

To determine the ocular changes related to hypothyrodism in newly diagnosed patients without orbitopathy.

FINDINGS

Thirty-three patients diagnosed to have primary overt hypothyroidism were enrolled in the study. All subjects were assigned to underwent central corneal thickness (CCT), anterior chamber volume, depth and angle measurements with the Scheimpflug camera (Pentacam, Oculus) and cup to disc ratio (C/D), mean retinal thickness and mean retinal nerve fiber layer (RNFL) thickness measurements with optical coherence tomography (OCT) in addition to ophthalmological examination preceeding the replacement therapy and at the 1(st), 3(rd )and 6(th )months of treatment. The mean age of the patients included in the study were 40.58 +/- 1.32 years. The thyroid hormone levels return to normal levels in all patients during the follow-up period, however the mean intraocular pressure (IOP) revealed no significant change. The mean CCT was 538.05 +/- 3.85 mu initially and demonstrated no statistically significant change as the anterior chamber volume, depth and angle measurements did. The mean C/D ratio was 0.29 +/- 0.03 and the mean retinal thickness was 255.83 +/- 19.49 mu initially and the treatment did not give rise to any significant change. The mean RNFL thickness was also stable during the control visits, so no statistically significant change was encountered.

CONCLUSIONS

Neither hypothyroidism, nor its replacement therapy gave rise to any change of IOP, CCT, anterior chamber parameters, RNFL, retinal thickness and C/D ratio.

Is there an association between hypothyroidism and open-angle glaucoma in an elderly population? An epidemiologic study

PURPOSE

There have been conflicting reports pertaining to the association between hypothyroidism and open-angle glaucoma (OAG). The purpose of this study was to assess the hypothesized association between preexisting hypothyroidism and development of OAG in a population-based setting.

DESIGN

Case-control study.

PARTICIPANTS

The study population and controls were taken from all patients in a large US managed care database aged >or=60 years with 4 years of continuous eligibility dating from January 1, 2001, through December 31, 2004.

METHODS

A total of 4728 newly diagnosed OAG patients were matched with 14 184 controls (3:1 matching) based on age and gender.

MAIN OUTCOME MEASURES

Conditional logistic regression was used to assess the relationship between hypothyroidism and OAG while controlling for various risk factors (ischemic heart disease, cerebrovascular disease, hyperlipidemia, hypertension, arterial disease, diabetes, and migraines).

RESULTS

Based on a diagnosis of hypothyroidism or use of a thyroid replacement therapy, prior hypothyroidism was found in 815 (17.2%) OAG subjects and in 2498 (17.6%) control subjects. After adjusting for the specified risk factors, patients with OAG were not found to be associated with a prior hypothyroid diagnosis when compared with control subjects (odds ratio, 0.93; 95% confidence interval, 0.85-1.01).

CONCLUSIONS

An association between prior hypothyroidism and OAG development was not found. The large proportion of patients receiving thyroid replacement therapy may have negated any OAG-related consequences of hypothyroidism.

High prevalence of subclinical hypothyroidism in patients with Anderson-Fabry disease

Anderson-Fabry disease is a rare lysosomal storage disorder. It results from a deficiency of the lysosomal alpha-galactosidase A and leads to progressive accumulation of globotriaosylceramide in the endothelium and tissue cells of various organs. Some of the typical clinical findings such as tiredness, dry skin, myalgia and arthralgia as well as vague gastrointestinal complaints are also symptoms of hypothyroidism. Therefore, we studied the thyroid function in patients with Anderson-Fabry disease. Thyroid function was studied in 11 patients (6 female, 5 male) with Anderson-Fabry disease by measuring thyroid-stimulating hormone (TSH) and free thyroxine serum levels. Nine patients had chronic kidney disease with stage 1 and two with stage 5. Subclinical hypothyroidism (normal serum free thyroxine concentrations along with elevated serum TSH levels) was found in 4 of 11 patients (36.4%). Subclinical hypothyroidism was observed in both male and female patients as well as in patients with stage 1 and stage 5 kidney disease. Subclinical hypothyroidism is a common finding in patients with Anderson-Fabry disease, showing an excess prevalence as compared to the normal population. The high frequency seems to be relevant regarding the potential consequences of a hypothyroid state.

[Autoimmune thyroiditis. Treatment with thyroid gland hormones in subclinical hypothyroidism or already in euthyroid state?]

In patients with subclinical hypothyroidism thyroid hormone therapy should be recommended more often with respect to analysis of effectiveness and risks. There is no cost-difference between treated patients and those who undergo thyroid hormone controls only, but thyroid hormone therapy probably induces improvement of clinical and laboratory parameters and reduction of cardiovascular risk factors. These therapeutic effects have to be elucidated in clinical prospective studies. Thyroid hormone therapy of patients with autoimmune thyroiditis and still euthyroid function obviously inhibits the autoimmune process and development of hypothyroidism. A final recommendation, however, can be given after the data of clinical studies with larger populations are available.

Hypothyroidism and glaucoma. A study of 100 hypothyroid patients

PURPOSE

To determine whether glaucoma is associated with hypothyroidism, as has previously been suggested.

METHODS

This is a cross-sectional study and a noncomparative interventional case series. One hundred consecutive patients with newly diagnosed hypothyroidism were referred for complete ophthalmologic examination, including automated perimetry and examination of the optic disks, to identify the presence of glaucoma. After correction of the hypothyroidism, reexamination was performed.

RESULTS

No patient had glaucoma and no correlation was found between intraocular pressure and either thyroid stimulating hormone or free tri-iodothyronine. No statistically significant difference was found between intraocular pressure levels before and after treatment of the hypothyroidism.

CONCLUSION

This study does not demonstrate an association between hypothyroidism and glaucoma.

When to treat mild hypothyroidism

The availability and wide acceptance of TSH assays for primary assessment of thyroid function has led to the recognition that mild thyroid hormone deficiency is characterized by elevation of the serum TSH concentration despite a normal free thyroxine level. Other conditions can also cause isolated serum TSH elevation, and these conditions can be distinguished from mild thyroid failure usually based-on clinical and circumstantial observations alone. Thyroxine treatment of patients with mild hypothyroidism has been shown in most, but not all, clinical trials to lower atherogenic lipid levels and relieve certain somatic and neuropsychiatric symptoms. Such treatment also prevents the progression to overt hypothyroidism, which is particularly likely in patients who are older, who have circulating thyroid autoantibodies, or who have a serum TSH greater than 10 mU/L. After the optimal thyroxine dose has been defined, long-term monitoring of patients with an annual clinical evaluation and serum TSH measurement is appropriate. The high prevalence of mild hypothyroidism, particularly in older women, and its subtle clinical presentation have led some authorities to recommend a low threshold for case-finding or routine population screening for the disorder.