Alex H Brown

Mr. Alex H Brown

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Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

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

Representative Publications

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1 September 2023 in Clinical Ophthalmology
Verified
Journal Article
Open access
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Majid MoshirfarMajid Moshirfar
Majid Moshirfar
CSChristian A Sulit
Christian A Sulit
ABAlex H Brown
Alex H Brown
CIChase Irwin
Chase Irwin
YRYasmyne Castillo Ronquillo
Yasmyne Castillo Ronquillo
PHPhillip Hoopes
Phillip Hoopes
Purpose: To assess the accuracy of five new-generation intraocular lens (IOL) power formulas: Barrett Universal II (BUII), Emmetropia Verifying Optical (EVO) Formula, Hill-Radial Basis Function (Hill-RBF), Kane Formula, and Ladas Super Formula (LSF). Patients and Methods: This is a retrospective single-surgeon study from a refractive clinic and clinical research center in Draper, UT, USA. The primary outcome measures were mean absolute error (MAE) and median absolute error (MedAE). Secondary outcome measures were the standard deviation (SD) of each formula’s refractive prediction errors (RPE) and the percentage of eyes within ± 0.50D. Refractive predictions were compared to the postoperative spherical equivalent to determine the RPE for each formula. RPEs were optimized, and MAE, MedAE, SD of the AME, and percent of eyes achieving RPEs within the specified ranges of ± 0.125 D, ± 0.25 D, ± 0.50 D, ± 0.75 D, ± 1.0 D were calculated. Subgroup analysis between different axial lengths was attempted but yielded insufficient statistical power to draw meaningful conclusions. Results: A total of 103 eyes of 103 patients were included in our study after applying inclusion and exclusion criteria to 606 eyes from 2019 to 2021. Formulas ranked in ascending order by MAE were Kane, EVO, BUII, Hill-RBF, and LSF. The ascending rankings of MedAE were Kane, BUII, Hill-RBF, EVO, Ladas. Kane had a significantly lower MAE than Hill-RBF (p< 0.001). EVO had the lowest SD of AMEs and the highest percentage of eyes within ± 0.50 D. According to heteroscedastic testing, EVO also had a statistically significant lower SD than Hill-RBF. Conclusion: Kane was the most accurate formula in terms of MAE and MedAE. EVO and BUII achieved marginally higher MAEs than Kane, suggesting these three formulas are comparable in performance. With the exception EVO and Hill-RBF, the heteroscedastic test yielded no significant differences in SD between the formulas. Although there were multiple statistically significant differences between the formulas in terms of MAE, MedAE, and SD, these differences may not be appreciable clinically. Lastly, there were no statistically significant differences in the percent of eyes with RPEs within ± 0.50 D, suggesting similar clinical performance between formulas.

Verified
Journal Article
Open access
PDF file
NRNorma Del Risco
Norma Del Risco
CTChad L. Talbot
Chad L. Talbot
KMKayvon A. Moin
Kayvon A. Moin
GMGarrett N Manion
Garrett N Manion
ABAlex H Brown
Alex H Brown
Majid MoshirfarMajid Moshirfar
Majid Moshirfar
Background/Objectives: This retrospective case series analyzed visual outcomes in patients with a prior history of implantable collamer lens (ICL) implantation who underwent cataract extraction (CE). A secondary aim was to investigate the relationship between vault height and the rate of cataract development. Methods: Visual acuity and refraction measurements were collected after CE at one week, one month and six months. Vault height measurements were correlated to the time until symptomatic cataracts were removed. Results: A total of 44 eyes were analyzed at six months after CE with efficacy and safety indexes of 1.20 ± 1.11 and 1.50 ± 1.06, respectively. In addition, 70% of eyes had a post-operative uncorrected distance visual acuity (UDVA) within one line of pre-operative corrected distance visual acuity (CDVA). Refractive predictability at six months demonstrated that 43% and 69% of eyes were within ±0.25 D and ±0.50 D of SEQ target, respectively. Astigmatism measured by refractive cylinder was ≤0.25 D in 17% and ≤0.50 D in 34% of eyes pre-operatively compared to 40% and 60% of eyes, respectively, at six months post-operatively. Vault heights one week after ICL (p < 0.0081) and one week before CE (p < 0.0154) demonstrated a positive linear regression with the time until CE. Conclusions: This sample population achieved favorable visual outcomes six months after CE, similar to six months after ICL implantation. Patients with a history of ICL implantation will similarly have a good visual prognosis after CE.

1 July 2024 in International Medical Case Reports Journal
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Journal Article
Open access
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Majid MoshirfarMajid Moshirfar
Majid Moshirfar
ABAlex H Brown
Alex H Brown
GMGarrett N Manion
Garrett N Manion
KMKayvon Moin
Kayvon Moin
PHPhillip Hoopes
Phillip Hoopes
Posterior capsular opacification (PCO), also known as “secondary cataract”, is a common complication following cataract surgery that can significantly impair visual acuity. The incidence of PCO varies widely in the literature, influenced by intraocular lens (IOL) type and patient risk factors. Neodymium-doped yttrium-aluminum-garnet (YAG) laser posterior capsulotomy is the standard treatment for PCO-related visual impairment. Recurrence of PCO after initial treatment with YAG capsulotomy, though more common in children, is rare in adults. Its underlying pathophysiological mechanisms are similar to that of primary PCO, which includes proliferation, migration, and/or clustering of lens epithelial cells (LECs), with subsequent reclosure of the posterior aperture. Potential risk factors for PCO recurrence that have been speculated through a comprehensive search of the current literature include younger age, female sex, high myopia, diabetes, vitrectomized status, uveitis, low-diopter IOLs, and certain IOL types with higher water content. We present a case of recurrent PCO in a highly myopic 48-year-old male following cataract surgery and implantable collamer lens (ICL) explantation who received a hydrophobic acrylic lens with 4% water content. Surgical techniques that may reduce recurrent PCO occurrence and appropriate postoperative care are emphasized to assist surgeons in their approach to patients at high-risk for this complication.

9 November 2022 in International Medical Case Reports Journal
Verified
Journal Article
Open access
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Majid MoshirfarMajid Moshirfar
Majid Moshirfar
ABAlex H Brown
Alex H Brown
CSChristian A Sulit
Christian A Sulit
WCWyatt Mitchell Corbin
Wyatt Mitchell Corbin
YRYasmyne Castillo Ronquillo
Yasmyne Castillo Ronquillo
PHPhillip Hoopes
Phillip Hoopes
This article discusses common ocular manifestations of cystic fibrosis (CF) and cystic fibrosis transmembrane conductance regulator-related disorders (CFTR-RD). A structured approach for assessing and treating patients with CF/CFTR-RD seeking corneal refractive surgery is proposed, as well as a novel surgical risk scoring system. We also report two patients with various manifestations of CFTR dysfunction who presented for refractive surgery and the outcomes of the procedures. Surgeons seeking to perform refractive surgery on patients with CF/CFTR-RD should be aware of mild to severe clinical manifestations of CFTR dysfunction. Specific systemic and ocular manifestations of CF include chronic obstructive pulmonary disease (COPD), bronchiectasis, recurrent pulmonary infections, CF-related diabetes and liver disease, pancreatic insufficiency, conjunctival xerosis, night blindness, meibomian gland dysfunction (MGD), and blepharitis. Corneal manifestations include dry eye disease (DED), punctate keratitis (PK), filamentary keratitis (FK), xerophthalmia, and decreased endothelial cell density and central corneal thickness. Utilization of the appropriate review of systems (ROS) and screening tests will assist in determining if the patient is a suitable candidate for refractive surgery, as CF/CFTR-RD can impact the health of the cornea. Collaboration with other medical professionals who care for these patients is encouraged to ensure that their CF/CFTR-RD symptoms are best controlled via systemic and other treatment options. This will assist in reducing the severity of their ocular manifestations before and after surgery.