Sandra F Sieminski

Dr. Sandra F Sieminski


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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PHPatrice Hicks
Patrice Hicks
EAElizabeth Au
Elizabeth Au
WSWilliam Self
William Self
BHBenjamin Haaland
Benjamin Haaland
MFMichael Feehan
Michael Feehan
Margaret DeAngelisMargaret DeAngelis
Margaret DeAngelis
The Mayan population of Guatemala is understudied within eye and vision research. Studying an observational homogenous, geographically isolated population of individuals seeking eye care may identify unique clinical, demographic, environmental and genetic risk factors for blinding eye disease that can inform targeted and effective screening strategies to achieve better and improved health care distribution. This study served to: (a) identify the ocular health needs within this population; and (b) identify any possible modifiable risk factors contributing to disease pathophysiology within this population. We conducted a cross-sectional study with 126 participants. Each participant completed a comprehensive eye examination, provided a blood sample for genetic analysis, and received a structured core baseline interview for a standardized epidemiological questionnaire at the Salama Lions Club Eye Hospital in Salama, Guatemala. Interpreters were available for translation to the patients’ native dialect, to assist participants during their visit. We performed a genome-wide association study for ocular disease association on the blood samples using Illumina’s HumanOmni2.5-8 chip to examine single nucleotide polymorphism SNPs in this population. After implementing quality control measures, we performed adjusted logistic regression analysis to determine which genetic and epidemiological factors were associated with eye disease. We found that the most prevalent eye conditions were cataracts (54.8%) followed by pseudoexfoliation syndrome (PXF) (24.6%). The population with both conditions was 22.2%. In our epidemiological analysis, we found that eye disease was significantly associated with advanced age. Cataracts were significantly more common among those living in the 10 districts with the least resources. Furthermore, having cataracts was associated with a greater likelihood of PXF after adjusting for both age and sex. In our genetic analysis, the SNP most nominally significantly associated with PXF lay within the gene KSR2 (p < 1 × 10−5). Several SNPs were associated with cataracts at genome-wide significance after adjusting for covariates (p < 5 × 10−8). About seventy five percent of the 33 cataract-associated SNPs lie within 13 genes, with the majority of genes having only one significant SNP (5 × 10−8). Using bioinformatic tools including PhenGenI, the Ensembl genome browser and literature review, these SNPs and genes have not previously been associated with PXF or cataracts, separately or in combination. This study can aid in understanding the prevalence of eye conditions in this population to better help inform public health planning and the delivery of quality, accessible, and relevant health and preventative care within Salama, Guatemala.

14 February 2022 in Case Reports in Ophthalmology
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ASAdam Siedlecki
Adam Siedlecki
BKBhumi Kinariwala
Bhumi Kinariwala
SSSandra F Sieminski
Sandra F Sieminski
Minimally invasive glaucoma surgery (MIGS) is a subset of glaucoma surgery that is known for its low rate of complications both intraoperatively and postoperatively compared to traditional filtering surgery. We present a case of a patient who, after receiving uncomplicated cataract extraction with posterior chamber intraocular lens implantation and concurrent iStent trabecular bypass stent implantation, experienced recurrent episodes of spontaneous microhyphema and inflammation in the late postoperative period. The patient, who had a history of mild asymmetric exfoliative glaucoma but no identifiable sources of trauma, underwent extensive examination to investigate causes of his episodic anterior segment bleeding and mild inflammation with concurrent elevated intraocular pressure. Given the circumstances of the patient’s recurrent symptoms and a negative workup for conventional causes of recurrent hyphema, it was suspected that the patient’s iStent was interacting with the patient’s peripheral iris, causing microtrauma and hyphema. We hypothesized that this contact was potentially exacerbated by pre-existing exfoliation syndrome, which caused zonular weakness and subsequent anterior movement of the lens-iris diaphragm. After the patient’s third recurrence of microhyphema and inflammation, the patient underwent removal of iStent and concurrent OMNI canaloplasty for glaucoma. Six months post-iStent explantation, the patient has had complete resolution of symptoms without recurrence of hyphema. In this case report, we outline the course of this patient’s symptoms and diagnosis, discuss the potential of MIGS devices such as iStent to cause recurrent hyphema, and explore treatment options following removal.

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JBJulie L Barr
Julie L Barr
MFMichael Feehan
Michael Feehan
TCTak Casey
Tak Casey
LOLeah Owen
Leah Owen
RFRobert Finley
Robert Finley
Margaret DeAngelisMargaret DeAngelis
Margaret DeAngelis
Glaucoma is the leading cause of irreversible blindness, affecting 76 million globally. It is characterized by irreversible damage to the optic nerve. Pharmacotherapy manages intraocular pressure (IOP) and slows disease progression. However, non-adherence to glaucoma medications remains problematic, with 41–71% of patients being non-adherent to their prescribed medication. Despite substantial investment in research, clinical effort, and patient education protocols, non-adherence remains high. Therefore, we aimed to determine if there is a substantive genetic component behind patients’ glaucoma medication non-adherence. We assessed glaucoma medication non-adherence with prescription refill data from the Marshfield Clinic Healthcare System’s pharmacy dispensing database. Two standard measures were calculated: the medication possession ratio (MPR) and the proportion of days covered (PDC). Non-adherence on each metric was defined as less than 80% medication coverage over 12 months. Genotyping was done using the Illumina HumanCoreExome BeadChip in addition to exome sequencing on the 230 patients (1) to calculate the heritability of glaucoma medication non-adherence and (2) to identify SNPs and/or coding variants in genes associated with medication non-adherence. Ingenuity pathway analysis (IPA) was utilized to derive biological meaning from any significant genes in aggregate. Over 12 months, 59% of patients were found to be non-adherent as measured by the MPR80, and 67% were non-adherent as measured by the PDC80. Genome-wide complex trait analysis (GCTA) suggested that 57% (MPR80) and 48% (PDC80) of glaucoma medication non-adherence could be attributed to a genetic component. Missense mutations in TTC28, KIAA1731, ADAMTS5, OR2W3, OR10A6, SAXO2, KCTD18, CHCHD6, and UPK1A were all found to be significantly associated with glaucoma medication non-adherence by whole exome sequencing after Bonferroni correction (p < 10−3) (PDC80). While missense mutations in TINAG, CHCHD6, GSTZ1, and SEMA4G were found to be significantly associated with medication non-adherence by whole exome sequencing after Bonferroni correction (p < 10−3) (MPR80). The same coding SNP in CHCHD6 which functions in Alzheimer’s disease pathophysiology was significant by both measures and increased risk for glaucoma medication non-adherence by three-fold (95% CI, 1.62–5.8). Although our study was underpowered for genome-wide significance, SNP rs6474264 within ZMAT4 (p = 5.54 × 10–6) was found to be nominally significant, with a decreased risk for glaucoma medication non-adherence (OR, 0.22; 95% CI, 0.11–0.42)). IPA demonstrated significant overlap, utilizing, both standard measures including opioid signaling, drug metabolism, and synaptogenesis signaling. CREB signaling in neurons (which is associated with enhancing the baseline firing rate for the formation of long-term potentiation in nerve fibers) was shown to have protective associations. Our results suggest a substantial heritable genetic component to glaucoma medication non-adherence (47–58%). This finding is in line with genetic studies of other conditions with a psychiatric component (e.g., post-traumatic stress disorder (PTSD) or alcohol dependence). Our findings suggest both risk and protective statistically significant genes/pathways underlying glaucoma medication non-adherence for the first time. Further studies investigating more diverse populations with larger sample sizes are needed to validate these findings.

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ASAdam R Siedlecki
Adam R Siedlecki
PHPatrice Hicks
Patrice Hicks
BHBenjamin Haaland
Benjamin Haaland
Margaret DeAngelisMargaret DeAngelis
Margaret DeAngelis
SSSandra F Sieminski
Sandra F Sieminski
IStent implantation is thought to augment the trabecular outflow channel in the anterior segment of the eye. We hypothesized that iStent with subsequent selective laser trabeculoplasty (SLT) would better control the intraocular pressure (IOP) compared to standalone SLT in patients with primary open-angle glaucoma (POAG). We, therefore, determined if the presence of an iStent combined with SLT was statistically associated with IOP lowering compared to standalone SLT. Through retrospective electronic medical record review, records of 824 eyes from 440 patients who received primary SLT without a history of iStent were considered. Additionally, 42 eyes from 28 patients who received SLT after combined phacoemulsification and iStent implantation that failed to control intraocular pressure (IOP) and/or the progression of the disease were retrospectively reviewed. IOP and number of medications, which were tracked in each patient for up to 12 months post laser, were also examined. Successful outcome was defined as a statistically significant reduction in IOP or number of medications at 6 months. As defined in univariate analysis (p ≤ 0.01), multivariate analysis included iStent, age, sex, race, and initial IOP as variables. IOP reduction was statistically associated with patients pre-SLT IOP (p < 0.001) but not with patients with iStent (p = 0.222). Medication reduction was statistically associated with the pre-SLT number of medications (p < 0.001) and iStent (p < 0.001). In eyes that received SLT, iStent was not statistically associated with a greater reduction in IOP compared to controls, but was associated with a higher reduction in the overall number of medications used 6 months after receiving SLT. The work presented should guide clinicians to consider SLT as an effective therapy after iStent implantation, in terms of glaucoma medication reduction in iStent patients, but clinicians should know that the presence of an iStent does not necessarily make subsequent SLT more effective at lowering IOP.

7 November 2020 in Journal of Clinical Medicine
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PHPatrice Hicks
Patrice Hicks
BHBenjamin Haaland
Benjamin Haaland
MFMichael Feehan
Michael Feehan
ACAlan S. Crandall
Alan S. Crandall
JPJeff H. Pettey
Jeff H. Pettey
Margaret DeAngelisMargaret DeAngelis
Margaret DeAngelis
Background: The American Indian Navajo and Goshute peoples are underserved patient populations residing in the Four Corners area of the United States and Ibupah, Utah, respectively. Methods: We conducted a cross-sectional study of epidemiological factors and lipid biomarkers that may be associated with type II diabetes, hypertension and retinal manifestations in tribal and non-tribal members in the study areas (n = 146 participants). We performed multivariate analyses to determine which, if any, risk factors were unique at the tribal level. Fundus photos and epidemiological data through standardized questionnaires were collected. Blood samples were collected to analyze lipid biomarkers. Univariate analyses were conducted and statistically significant factors at p < 0.10 were entered into a multivariate regression. Results: Of 51 participants for whom phenotyping was available, from the Four Corners region, 31 had type II diabetes (DM), 26 had hypertension and 6 had diabetic retinopathy (DR). Of the 64 participants from Ibupah with phenotyping available, 20 had diabetes, 19 had hypertension and 6 had DR. Navajo participants were less likely to have any type of retinopathy as compared to Goshute participants (odds ratio (OR) = 0.059; 95% confidence interval (CI) = 0.016–0.223; p < 0.001). Associations were found between diabetes and hypertension in both populations. Older age was associated with hypertension in the Four Corners, and the Navajo that reside there on the reservation, but not within the Goshute and Ibupah populations. Combining both the Ibupah, Utah and Four Corners study populations, being American Indian (p = 0.022), residing in the Four Corners (p = 0.027) and having hypertension (p < 0.001) increased the risk of DM. DM (p < 0.001) and age (p = 0.002) were significantly associated with hypertension in both populations examined. When retinopathy was evaluated for both populations combined, hypertension (p = 0.037) and living in Ibupah (p < 0.001) were associated with greater risk of retinopathy. When combining both American Indian populations from the Four Corners and Ibupah, those with hypertension were more likely to have DM (p < 0.001). No lipid biomarkers were found to be significantly associated with any disease state. Conclusions: We found different comorbid factors with retinal disease outcome between the two tribes that reside within the Intermountain West. This is indicated by the association of tribe and with the type of retinopathy outcome when we combined the populations of American Indians. Overall, the Navajo peoples and the Four Corners had a higher prevalence of chronic disease that included diabetes and hypertension than the Goshutes and Ibupah. To the best of our knowledge, this is the first study to conduct an analysis for disease outcomes exclusively including the Navajo and Goshute tribe of the Intermountain West.

20 September 2025 in Lasers in Medical Science
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BSBaltaj S. Sandhur
Baltaj S. Sandhur
MJMohit Jethi
Mohit Jethi
NGNatasha Gautam
Natasha Gautam
SESinan Ersan
Sinan Ersan
LJLogan Jay
Logan Jay
SSSandra F Sieminski
Sandra F Sieminski
Slow-coagulation continuous wave cyclophotocoagulation (SC-CWCPC) is a promising treatment option for refractory glaucoma. However, its efficacy following a failed MicroPulse transscleral cyclophotocoagulation (MP-TSCPC) procedure remains unexplored. This study evaluates the efficacy of SC-CWCPC in patients with uncontrolled intraocular pressure (IOP) after undergoing MP-TSCPC. A retrospective case series of patients with uncontrolled glaucoma who underwent SC-CWCPC following MP-TSCPC failure was conducted. All procedures were performed by a single glaucoma surgeon between January 2022 And October 2024. Patients with < 3 months follow-up were excluded. SC-CWCPC was performed using 1250-milliwatt power and 4-second applications. Surgical success was defined as IOP between 6 and 21 mmHg with a ≥ 20% reduction from baseline on topical medication, no incisional reoperation for glaucoma, and no loss of light perception vision. Eight patients (10 eyes) with a mean age of 43.75 ± 24.59 years were included. 90% (9/10) had prior Tube/Trabeculectomy procedures. Mean preoperative IOP was 26.10 ± 15.80 mmHg on 3.1 ± 1.20 antiglaucoma medications (AGM). At a mean follow up time of 10.97 ± 3.42 months, IOP decreased to 15.80 ± 5.31 mmHg ( p = 0.002) with 2.30 ± 1.49 AGM ( p = 0.070) with an overall success rate of 80%. One eye required Ahmed Glaucoma Valve implantation one year postoperatively while another had prolonged inflammation that resolved medically. No cases of persistent hypotony or significant visual acuity loss occurred. SC-CWCPC is an effective and safe surgical intervention in patients with refractory glaucoma following failed MP-TSCPC. The results of our study are helpful in expanding the role of the SC-CWCPC technique in the management of glaucomatous patients.