Evaluating the long-term biological stability of cytokine biomarkers in ocular fluid samples

PURPOSE

The quality of biological fluid samples is vital for optimal preanalytical procedures and a requirement for effective translational biomarker research. This study aims to determine the effects of storage duration and freeze-thawing on the levels of various cytokines in the human aqueous humour and vitreous samples.

METHODS AND ANALYSIS

Human ocular aqueous humour and vitreous samples were obtained from 25 eyes and stored at -80°C for analysis. All samples were assayed for 27 cytokine biomarker concentrations (pg/mL) using a multiplex assay. Four sample storage durations following sample collection were evaluated (1 week, 3 months, 9 months and 15 months). Additionally, samples underwent up to three freeze-thaw cycles within the study period.

RESULTS

Among the 27 cytokine biomarkers, concentrations of four cytokines (Interleukin (IL)-2, IL-10, IL-12 and platelet-derived growth factor-BB) were significantly decreased by storage duration at all time points, as early as 3 months following sample collection (range of 9%-37% decline between 1 week and 15 months, p<0.001). Freeze-thawing of up to three cycles did not significantly impact the cytokine biomarker concentrations in aqueous humour or vitreous. Separability of patient-specific cytokine biomarker profiles in the principal component analysis remained relatively the same over the 15 months of storage duration.

CONCLUSION

The findings from this study suggest that several intraocular cytokine biomarkers in human aqueous humour and vitreous samples may be susceptible to degradation with long-term storage, as early as 3 months after collection. The overall patient-specific cytokine biomarker profiles are more stable than concentrations of individual cytokines. Future studies should focus on developing guidelines for optimal and standardised sample handling methods to ensure correct research findings about intraocular biomarkers are translated into clinical practice.

Prospective evaluation of medical student accuracy conducting direct ophthalmoscopy with an unmodified iPhone X

Purpose

To evaluate fundus examination accuracy of medical students when using an unmodified iPhone X or a direct ophthalmoscope in comparison to a staff ophthalmologist’s retinal examination.

Methods

In this prospective comparative analysis, patients underwent dilated fundus examination by novice medical trainees using either an unmodified iPhone X or standard direct ophthalmoscope. The primary outcome was the mean difference and degree of agreement in cup-to-disc ratio between student examination and the staff ophthalmologist’s cup-to-disc observation.

Results

A total of 18 medical students conducted 230 retinal examinations, 117 with the iPhone X and 113 with the direct ophthalmoscope. A greater proportion of students were unable to report cup-to-disc ratio using the iPhone X (81.2%) vs direct ophthalmoscope (30.1%). Student examination of cup-to-disc ratio led to a systematic bias (95% limits of agreement) of + 0.16 (−0.22 to + 0.54) and + 0.10 (−0.36 to + 0.56) with the iPhone X and direct ophthalmoscope, respectively. iPhone X and direct ophthalmoscope student observation concordance for optic disc colour (88.7 and 82.4%, respectively) and contour (68.3 and 74.2%, respectively) demonstrated low agreement with staff ophthalmologist findings. Student iPhone X observations demonstrated lower agreement with staff findings compared to direct ophthalmoscope observations for spontaneous venous pulsations (Cohen’s Kappa = −0.044 vs 0.099).

Conclusion

Amongst medical trainees, optic disc visualization using an unmodified iPhone X was inferior to the direct ophthalmoscope. When able to visualize the optic nerve head, there was no significant difference in reported cup-to-disc ratio between modalities. However, both modalities demonstrated poor reliability in comparison to staff ophthalmologist findings.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10792-022-02377-4.

Orbital myositis in systemic lupus erythematosus: A case report and literature review

Orbital myositis is a rare manifestation of systemic lupus erythematosus (SLE). Herein, we report a case of orbital myositis in a patient with SLE, along with a literature review. A 45-year-old female patient presented with pain in the right eye, chemosis, proptosis, and limited abduction. Computed tomography of her orbits revealed thickening of her right lateral rectus muscle. She had no other systemic symptoms. There was no elevation in the biomarkers of inflammation or disease activity. She was treated with high-dose steroids, and her symptoms resolved rapidly. It is important to maintain a high index of suspicion for orbital myositis in patients with SLE even when there are no systemic disease activities, such that early treatment can be initiated. It is also important to rule out other mimickers such as orbital cellulitis and thyroid eye disease.

Design and rationale of the atrial fibrillation occurring transiently with stress (AFOTS) incidence study

BACKGROUND

Atrial fibrillation (AF) is often detected for the first time in patients hospitalized for medical illness or non-cardiovascular surgery. AF occurring transiently with stress (AFOTS) describes this manifestation of AF, which may either be the result of a non-cardiac stressor, or existing paroxysmal AF that was not previously detected. Current estimates of AFOTS incidence are imprecise: ranging from 1 to 44%, owing to the marked heterogeneity in patient populations, identification and methods used to detect AFOTS.

METHODS

The prospective, two-centre epidemiological AFOTS Incidence study will enroll 250 consecutive participants without a history of AF but with at increased risk of AF (Age ≥ 65 or >50 with one risk factor for AF) admitted to intensive care units (ICUs) for medical illness or non-cardiac surgery. Upon admission, participants will wear an ECG patch monitor that will remain in place for 14 days, or until discharge from hospital. Patients' consent to participation is deferred for up to 72 h after admission. The primary endpoint is the incidence of AF lasting ≥30 s. The study is powered to detect an AF incidence of 17% ± 5%.

RESULTS

We conducted a vanguard feasibility study, and 55 participants have completed participation. The median duration of monitoring was seven days. AF was detected by the clinical team in 8 participants (14%; 95% Confidence Interval 7-26%).

CONCLUSIONS

The AFOTS Incidence study will employ a systematic and highly sensitive protocol for detecting AFOTS in medical illness and non-cardiac surgery ICU patients. This study is feasible and will provide a reliable estimate of the true incidence of AFOTS in this population.

Comparison of the Ahmed and Baerveldt glaucoma shunts with combined cataract extraction

OBJECTIVE

To compare the surgical outcomes of combined phacoemulsification with either Ahmed glaucoma valve (AGV) or Baerveldt glaucoma implant (BGI).

DESIGN

Retrospective cohort study.

PARTICIPANTS

A total of 104 eyes that underwent combined phacoemulsification with either AGV (PhacoAGV; n = 57) or BGI (PhacoBGI; n = 47) implantation.

METHODS

Failure was defined as uncontrolled intraocular pressure (IOP; <5 mm Hg, ≥18 mm Hg, or <20% reduction), additional glaucoma surgery, vision-threatening complications, or progression to no-light-perception vision.

RESULTS

The PhacoAGV group was older (p = 0.03), had poorer baseline visual acuity (VA; p = 0.001), and had fewer previous glaucoma surgeries (p = 0.04). Both groups had similar baseline IOP (PhacoAGV: 26.4 ± 8.3 mm Hg; PhacoBGI: 25.7 ± 7.3; p = 0.66) and glaucoma medications (PhacoAGV: 3.8 ± 1.0; PhacoBGI: 3.6 ± 1.5; p = 0.54). At 2 years, failure rates were 44% in the PhacoAGV group and 23% in the PhacoBGI group (p = 0.02). Both groups had similar mean IOP reduction (PhacoAGV: 45%; PhacoBGI: 47%, p = 0.67) and medication use reduction (PhacoAGV: 47%; PhacoBGI: 58%, p = 0.38). The PhacoBGI group had higher IOP and medication use up to 1 month (p < 0.05). Both groups improved in VA from baseline (p < 0.05) and had similar overall complication rates (p = 0.31). The PhacoBGI group required more overall interventions (p < 0.0005).

CONCLUSIONS

This comparative study found no difference in IOP, glaucoma medications, or complication rates between PhacoAGV and PhacoBGI at 2 years, despite BGIs being implanted in patients at higher risk for failure. The PhacoAGV group had higher failure rates at 2 years. Both groups had significant improvements in VA due to removal of their cataracts. The PhacoBGI group required more interventions, but most of these were minor slit-lamp procedures.

Proportion of undetected narrow angles or angle closure in cataract surgery referrals

OBJECTIVE

To determine the proportion of patients referred for cataract surgery consultation who had undetected narrow angles (primary angle closure suspect [PACS], primary angle closure [PAC], or primary angle closure glaucoma [PACG]).

DESIGN

Retrospective chart review.

PARTICIPANTS

Phakic patients referred by eye care providers (optometrists and ophthalmologists) to a tertiary centre for cataract management between July 1, 2010 and June 30, 2012 were identified and reviewed.

METHODS

Demographic, referral, and specialist assessment information, as well as biometric data, including anterior segment optical coherence tomography, were collected. Patients with undetected narrow angles were identified. Univariate tests and multivariable analyses were performed to determine risk factors for narrow angles or angle closure.

RESULTS

A total of 1229 patients were included. The mean patient age was 67.8 ± 13.0 years, 53.9% of patients were female, and 26.8% were Asian or South Asian. Of the sample population, 139 (11.3%) patients had PACS, 7 (0.6%) had PAC, and 12 (1.0%) had PACG. Overall, 158 (12.9%) patients had narrow angles or angle closure. Multivariable logistic regression using generalized estimating equations confirmed 3 independent predictors of PACS/angle closure: Asian race (odds ratio 2.82, p < 0.001), shorter axial length (AL) (odds ratio 1.25, p = 0.03), and smaller anterior chamber depth (ACD; odds ratio 33.3, p < 0.001). A patient of Asian race referred for cataract surgery with ACD <2.8 mm and AL <23 mm had a 52% probability of having PACS/angle closure (range 42%-62%) versus 3% if these 3 factors were not present.

CONCLUSIONS

Of patients referred for cataract surgery, 1.5% were found to have undetected narrow angles or angle closure, implying that gonioscopy may not be adequately performed in this patient population.

Undetected angle closure in patients with a diagnosis of open-angle glaucoma

OBJECTIVE

The aim of this study was to identify the proportion of patients referred to a tertiary glaucoma centre with a diagnosis of open-angle glaucoma (OAG) who were found to have angle closure glaucoma.

DESIGN

Retrospective chart review.

METHODS

Consecutive new patients referred for glaucoma management to a tertiary centre between July 2010 and December 2011 were reviewed. Patients whose referrals for glaucoma assessment specified angle status as "open" were included. The data collected included glaucoma specialist's angle assessment, diagnosis, and glaucoma severity. The status of those with 180 degrees or more Shaffer angle grading of 0 was classified as "closed."

RESULTS

From 1234 glaucoma referrals, 179 cases were specified to have a diagnosis of OAG or when angles were known to be open. Of these, 16 (8.9%) were found on examination by the glaucoma specialist to have angle closure. Pseudoexfoliation was present in 4 of 16 patients (25%) in the missed angle-closure glaucoma (ACG) group and 22 of 108 patients (13.5%) in the remaining OAG group. There was no difference found in demographic or ocular biometric parameters between those with confirmed OAG versus those with missed ACG.

CONCLUSIONS

Almost 1 in 11 patients referred by ophthalmologists to a tertiary glaucoma centre with a diagnosis of OAG were in fact found to have angle closure. Given the different treatment approaches for ACG versus OAG, this study suggests a need to strengthen angle evaluations.

Needs assessment of ophthalmology education for primary care physicians in training: comparison with the International Council of Ophthalmology recommendations

BACKGROUND

This cross-sectional survey assessed the adequacy of ophthalmology teaching in undergraduate medical education and evaluated the comfort level of family medicine residents in diagnosing and managing common ophthalmic conditions.

METHODS

Postgraduate year 1 and 2 family medicine residents at the University of Western Ontario were recruited for this study. The main outcome measures were hours of classroom and clinic-based instruction on ophthalmology during undergraduate medical education, and the comfort level in ophthalmic clinical skills and managing various ophthalmic conditions.

RESULTS

In total, 54 (33.3%) of 162 family medicine residents responded to the survey. Residents reported an average of 27.1 ± 35.1 hours and 39.8 ± 47.1 hours of classroom and clinical ophthalmology instruction, respectively. However, most residents (80%) responded as feeling only "somewhat comfortable" or "not at all comfortable" in assessing and managing common ophthalmic conditions, including ocular emergencies, such as acute angle closure glaucoma and ocular chemical burn. A positive correlation was seen between overall comfort level and hours of classroom instruction (P < 0.05).

CONCLUSION

The number of hours of ophthalmology training received by family medicine residents during medical school meets the International Council of Ophthalmology Task Force recommendations. However, family medicine residents appear to be uncomfortable in handling treatable but potentially sight-threatening ocular conditions. Standardizing the undergraduate medical education ophthalmology curriculum and increasing hours of ophthalmology training during postgraduate family medicine residency may be useful in bridging this gap in knowledge.

Congenital abnormalities of the urogenital tract in association with congenital vertebral malformations

There is a close link between the embryological development of the musculoskeletal system and all other main organ systems. We report a prospective series of 202 patients with congenital vertebral abnormalities and document the associated abnormalities in other systems. There were 100 boys and 102 girls. In 153 there were 460 associated abnormalities, a mean of 2.27 abnormalities for each patient. Intravenous pyelography was carried out on 173 patients (85.6%) and ultrasonography on the remaining 29 (14.4%). Patients with genitourinary anomalies were more likely to have musculoskeletal (p = 0.002), gastrointestinal (p = 0.02) and cardiac abnormalities (p = 0.008) than those without genitourinary involvement. A total of 54 (26.7%) had at least one genitourinary abnormality, the most frequent being unilateral renal agenesis. There was urinary obstruction in six (3%). There was no association between genitourinary abnormality and the place of birth, parental age, birth order, level of spinal curvature, or the number, type and side of spinal anomaly. There was, however, a statistically significant association (p = 0.04) between costal and genitourinary abnormalities. The incidence of genitourinary abnormalities (26.7%) was similar to that of previously reported series. The diagnosis of a congenital vertebral abnormality should alert the clinician to a wide spectrum of possible associated anomalies most of which are of clinical importance.

Acute mood and thyroid stimulating hormone effects of transcranial magnetic stimulation in major depression

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has recently been demonstrated to have antidepressant effects. Some work suggests that rTMS over prefrontal cortex administered to healthy individuals produces acute elevations of mood and serum thyroid-stimulating hormone (TSH). We sought to determine whether single rTMS sessions would produce acute mood and serum TSH elevations in subjects with major depressions.

METHODS

Under double-blind conditions et al 14 medication-free subjects with major depression received individual sessions of either active or sham rTMS. rTMS was administered over the left prefrontal cortex at 10 Hz et al 100% of motor threshold, 20 trains over 10 min. Immediately before and after rTMS sessions, subjects' mood was rated with the Profile of Mood States (POMS) and the 6-Item Hamilton Depression Scale, and blood was drawn for later analysis of TSH. Subjects and raters were blind to treatment assignment.

RESULTS

The group receiving active stimulation manifested significantly greater improvement on the POMS subscale of Depression (p < or = .0055) and a trend toward greater improvement on the modified Hamilton Rating (.05 < p < or =.1). No hypomania was induced. The change in TSH from pre- to post-rTMS was significantly different between active and sham sessions.

CONCLUSIONS

This blinded, placebo-controlled trial documents that individual rTMS sessions can acutely elevate mood and stimulate TSH release in patients experiencing major depressive episodes.

Urine acid output as a test of completeness of vagotomy

Peak acid output in response to sham feeding and changes in urine acid output 2 and 3 hours after a test meal have been measured in 20 normal volunteers, 17 asymptomatic patients after vagotomy, six patients with recurrent duodenal ulcer after vagotomy and ten normal subjects given a 48-h course of ranitidine, 150 mg 12-hourly. Gastric peak acid output in normal volunteers ranged from 6.9 to 22.1 mmol/h. All asymptomatic patients after vagotomy had a peak acid output less than 7 mmol/h, consistent with complete vagotomy. Five patients with recurrent ulcer had a peak acid output greater than 8 mmol/h, suggesting an incomplete vagotomy. Urine acid output after a test meal, expressed as the change from the basal rate of acid output, was always in a negative direction in normal subjects (fall in acid output = postprandial alkaline tide). This change was abolished in patients with complete vagotomy, in whom urine acid output increased after a meal. In five patients with incomplete vagotomy (and one other with recurrent ulcer and unknown vagal status) the urine acid output changed in a negative direction after a test meal. The relationship of urine acid output to gastric secretion was confirmed by the abolition of the postprandial alkaline tide in normal subjects given ranitidine. The results in patients with incomplete vagotomy did not overlap with those from patients with complete vagotomy. This suggests that this test could be used for the routine postoperative assessment of completeness of vagotomy.