Blood-aqueous barrier integrity in patients with Graves' ophthalmopathy (GO), before and after rehabilitative surgery

Evaluation of Aqueous Flare in Graves' Ophthalmopathy and its Relationship with Thyroid Hormones, Antibodies, and Clinical Activity Score

Objectives

The aim of this study was to assess intraocular inflammation in patients with active and inactive Graves' ophthalmopathy (GO) using an aqueous laser flash meter and to assess its relationship with thyroid hormones, antibodies, and clinical activity score (CAS).

Methods

Forty patients (29 females and 11 males) were included in the study. The patients were divided into two groups according to CAS; patients with CAS <3 (inactive) were included in Group 1 and patients with CAS ≥3 (active) were included in Group 2. The laser flare meter was used to measure the flare of aqueous humor. Each patient's ocular findings, thyroid hormone, and antibody levels were also recorded.

Results

The mean age of patients was 46.88±11.79 years in Group 1 and 44.50±12.59 years in Group 2 (p=0.555). The mean CAS was 0.88±0.65 in Group 1 and 3.57±0.85 in Group 2 (p<0.001). The mean aqueous flare was 6.5±2.2 ph/ms in Group 1 and 7.0±6.4 ph/ms in Group 2 (p=0.73). Hertel exophthalmometry, intraocular pressure (IOP), antithyroglobulin antibody, and thyroid stimulating hormone receptor antibody (TRAb) levels were similar in both groups (each p>0.05). There was no correlation between aqueous flare value and CAS, Hertel exophthalmometry, IOP, thyroid hormone, and antibody levels (each p>0.05). There was a significant correlation between CAS and antibody levels (each p<0.05).

Conclusion

Flare values that are not much above the normal range may be an indication that intraocular inflammation is not elevated in GO patients. This suggests that the damage to the blood-aqueous barrier in these patients is not severe enough to increase intraocular inflammation.

The effect of one- and two-rectus muscle strabismus surgery on anterior chamber flare

PURPOSE

To investigate the effect of the most commonly performed strabismus surgery procedures on the blood-aqueous barrier using laser flare photometry (LFP).

METHODS

Patients who underwent unilateral or bilateral strabismus surgery between January 2020 and May 2021 were included. Eyes were grouped according to the number of rectus muscles operated: one rectus muscle procedure (recession) with or without inferior oblique anterization (IOA), ipsilateral two rectus muscle procedure (recession and resection) with or without IOA, and unoperated fellow eyes of patients undergoing unilateral surgery. Anterior chamber flare values were measured by LFP for each eye the day before the surgery and day 1, week 1, and month 1 postoperatively.

RESULTS

A total of 66 eyes of 33 patients (21 females) were included. There were 29 eyes in the one-muscle group, 22 in the two-muscle group, and 15 in the fellow-eye group. The mean flare values of the two-muscle group were significantly higher than those of the other groups at postoperative day 1 and week 1 (P = 0.001, for both). The mean postoperative day 1, week 1, and month 1 flare values of the two-muscle group were significantly higher than the mean preoperative flare value. There were no significant differences between pre- and postoperative flare values of the one-muscle or fellow-eye groups (P > 0.05, for both).

CONCLUSIONS

In our study cohort, LFP provided evidence of subclinical changes in the blood-aqueous barrier up to the first month postoperatively in otherwise healthy patients undergoing two-muscle surgery compared with those undergoing one-muscle surgery and unoperated fellow eyes.

Using 24-h intraocular pressure-related patterns to identify open-angle glaucoma in thyroid eye disease

PURPOSE

Our study aims to develop a diagnostic model using 24-h intraocular pressure (IOP) patterns to differentiate between open-angle glaucoma (OAG) and dysthyroid optic neuropathy (DON) in thyroid eye disease (TED) patients with glaucoma-like symptoms.

METHODS

TED patients with elevated IOP, abnormal optic disc, and/or visual fields were prospectively recruited. The subjects whose symptoms were relieved by DON first-line treatments were divided into the DON group, and the subjects with previous diagnosis of OAG before TED onset were divided into the OAG group. The 24-h IOP was monitored by Tono-Pen in a sitting position during awake time and in a supine position during sleep time. All subjects were divided into a training set and a testing set. The diagnostic models were generated from training set by using either IOP curve-derived parameters or principal component (PC) factors. The discrimination ability was tested in training set based on area under curve (AUC), and the calibration ability was verified in testing set by Hosmer-Lemeshow goodness-of-fit. The sensitivity and specificity were calculated by two-by-two table with the cutoff value determined by Youden's index.

RESULTS

Thirty-two cases were recruited in each group. The 24-h IOP curves revealed a nocturnal pattern in both groups, with the acrophase moving slightly forward in the DON group (21:00 pm-24:00 pm) compared to the OAG group (22:00 pm-3:00 am). Several IOP curve-derived parameters differed between the two groups, with larger amplitude during sleep time (P < 0.000) and longer duration of IOP ≥ 21 mmHg at awake time (P = 0.004) in the DON group than the OAG group. However, the diagnostic model generated from IOP parameters showed poor reliability (P = 0.001) in calibration test and was rejected. The other model built on PC factors achieved good performance of discrimination (AUC = 0.943) and calibration (P = 0.139) with a sensitivity of 87.50% and a specificity of 95.83% at cutoff value of 0.538 to identify OAG cases.

CONCLUSION

The diagnostic model facilitates discrimination between OAG and DON in TED patients based on 24-h IOP-related patterns.

TRIAL REGISTRATION

This work was registered on Chinese Clinical Trial Registry (ChiCTR1900025394).

Laser flare-cell photometer: principle and significance in clinical and basic ophthalmology

A slit-lamp examination is an indispensable and essential clinical evaluation method in ophthalmology, but, it is qualitative subjective. To complement its weaknesses in making a quantitative evaluation of flare intensity and number of cells in the aqueous humor in the eye, we invented the laser flare-cell photometer in 1988. The instrument enables a non-invasive quantitative evaluation of flare intensity and number of cells in the aqueous with good accuracy and repeatability as well as maneuverability equal to slit-lamp microscopy. The instrument can elucidate the pathophysiology in the blood-aqueous barrier (BAB) function in a variety of ocular disorders. The accuracy of the instrument makes it possible to investigate not only the pathophysiology of intraocular disorders but also the effects of various drugs and surgical procedures in BAB. The instrument does not only lighten the burden on patients in clinical examinations and study but it also helps minimize the sacrifice of experimental animals and improves the reliability of the results by minimizing inter-individual variations through its good repeatability. Here I shall relate how the instrument has been applied to clinical and basic studies in ophthalmology and what novel knowledge its application contributed to pathophysiology in ophthalmology.