Physical Characteristics, Clinical Application, and Side Effects of Viscoelastics in Ophthalmology.

Purpose: To explain the physical properties of ophthalmic viscoelastic devices (OVDs), covering their structural units, optimal features, existing viscoelastic materials, clinical applications, and potential side effects.

Methods: This is a narrative review on the OVDs. A literature review was conducted in PubMed, Google Scholar, and Scopus databases.

Comparison of two different 360-degree intrastromal corneal rings combined with simultaneous accelerated-corneal cross-linking.

Purpose: to compare five-year outcomes of two complete intracorneal implants (MyoRing versus annular-shaped intracorneal implant [AICI]) combined with accelerated corneal cross-linking (A-CXL) in progressive KCN.

Methods: In this historical cohort study, preoperative and postoperative visual, refractive, tomographic, biomechanical, and aberrometric parameters of 27 eyes of 27 patients who underwent implantation of two complete rings (13 AICI and 14 MyoRing) combined with A-CXL were recorded.

Results: The mean age of patients in "AICI plus A-CXL" and "MyoRing plus A-CXL" groups were 28.

Corneal layer thickness in keratoconus using optical coherence tomography.

Clinical Relevance: Accurate thickness measurement of corneal layers using anterior segment OCT can be used to improve visual outcomes. Understanding its applications is essential for optometric practices to enhance eye care procedures.

Background: To evaluate the thicknesses of different corneal layers for identifying keratoconus (KCN) and subclinical keratoconus (SKCN) using spectral-domain optical coherence tomography (SD-OCT).

Topical Minoxidil Solution-Induced Central Toxic Keratopathy following Photorefractive Keratectomy: A Case Study.

Purpose: To report the clinical findings of unilateral central toxic keratopathy (CTK) associated with inadvertent exposure to topical minoxidil 5% solution 1 day after bilateral photorefractive keratectomy (PRK).

Methods: Anterior segment slit-lamp photography, anterior segment optical coherence tomography (AS-OCT), pachymetry map, epithelial map, and manifest refractions were recorded.

Results: This is a case of a 27-year-old male who underwent bilateral PRK and presented 5 days after surgery with the complaint of acute decreased visual acuity in the left eye (LE).

Herpetic endotheliitis and stromal keratitis following inactivated COVID-19 vaccination.

Given the scarcity of data regarding ocular complications following COVID-19 vaccination, the approach toward patients with suggestive symptoms and established clinical practice is lacking. Herein, we report the first case of herpetic endotheliithis and secondary stromal keratitis following inactivated COVID-19 vaccination who experienced a relapse due to poor adherence.

Best indices of dual Scheimpflug/Placido tomographer for keratoconus detection.

Purpose: To evaluate the accuracy of different corneal parameters in detecting keratoconus using a dual Scheimpflug/Placido system (Sirius, CSO, Italy).

Methods: Sixty-eight eyes of 68 keratoconus patients and 77 eyes of 77 normal subjects were prospectively assessed in a diagnostic test study. The mean differences of the corneal parameters were compared using the independent t-test.

Distribution Pattern of Total Corneal Thickness in Keratoconus versus Normal Eyes Using an Optical Coherence Tomography.

Purpose: To evaluate the total corneal thickness distribution pattern using a high-resolution spectral-domain optical coherence tomography (HR SD-OCT) for distinguishing normal eyes from keratoconus (KCN).

Methods: One hundred and forty-four patients were enrolled in three groups (55 normal, 45 mild KCN, and 44 moderate-to-severe KCN eyes) in this prospective diagnostic test study. Total corneal thickness was measured in 8 semi-meridians using HR SD-OCT (Heidelberg Engineering, Heidelberg, Germany) in 5 and 7 mm zones.

Modified big bubble technique for deep anterior lamellar keratoplasty in keratoconus.

We describe a modified technique for deep anterior lamellar keratoplasty with three modifications in big bubble pneumodissection technique; including two staged stromal trephination to avoid inadvertent full-thickness trephination, deep bevel-up needle air injection for better visualization and deeper air injection and, vicoseperation by refilling the pre-Descemet space with a viscoelastic after removing the air bubble for safe removal of the deep stromal layers. Patients with advanced keratoconus underwent deep anterior lamellar keratoplasty with pneumodissection by two-staged trephination followed by bevel-up needle deep air injection and viscoseperation. The big bubble was successfully formed in all cases and there was no case with the rupture of the Descemet's membrane (DM) during air injection or baring of DM.

Comparison of Artificial Intelligence-Based Machine Learning Classifiers for Early Detection of Keratoconus.

Purpose: To compare the agreement between artificial intelligence (AI)-based classifiers and clinical experts in categorizing normal cornea from ectatic conditions.

Methods: Prospective diagnostic test study at Noor Eye Hospital. Two hundred twelve eyes of 212 patients were categorized into three groups of 92 normal, 52 subclinical keratoconus (SKCN), and 68 KCN eyes based on clinical findings by 3 independent expert examiners.

Post-LASIK keratectasia in the context of a thicker than intended flap detected by anterior segment optical coherence tomography.

The corneal flap created in LASIK is responsible for most of its advantages in comparison with surface ablation. However, lamellar dissection of the corneal layers in LASIK can also result in serious complications such as corneal ectasia. A 23-year-old man underwent LASIK for correction of -4.

Update on Pain Management After Advanced Surface Ablation.

Purpose: To provide an update for postoperative pain control strategies to help ophthalmic surgeons establish a more effective management plan for patients who underwent advanced surface ablation surgeries.

Methods: Google Scholar, Scopus, ScienceDirect, and PubMed were the main resources used to search the medical literature.

Results: The postoperative cornea's healing process is accompanied by intense pain as the chief complaint in the first days after the operation.

Seven-year follow-up of a novel 360-degree implant (annular intracorneal inlay) plus accelerated corneal cross-linking: A case study.

Aim: to report late visual, refractive, and tomographic findings of a patient with progressive keratoconus (KCN) over 7-year follow-up examinations after treatment with an advanced intrastromal implant known as annular intracorneal inlay (AICI) combined with accelerated corneal cross-linking (ACXL).

Methods: Slit-lamp photography of anterior segment, corneal tomography maps, and manifest refractions were recorded.

Results: A 30-year-old female presented with the complaint of gradual decreased visual acuity in recent years that was remarkable in her left eye (LE).

Role of artificial tears with and without hyaluronic acid in controlling ocular discomfort following PRK: a randomized clinical trial.

Aim: To compare outcomes of applying preservative free artificial tears (PFAT) with and without hyaluronic acid (HA) in early postoperative course following photorefractive keratectomy (PRK).

Methods: In this triple-blinded randomized clinical trial, PRK procedure was performed on both eyes of 230 patients. Following PRK, patients were divided into three groups: the HA group, 44 patients PFAT containing HA; the HA group, 71 patients PFAT without HA were administered 5 times per day (every 4h); the third group, 115 patients received no PFAT before lens removal.

Comparison of Postoperative Symptoms of Alcohol-Assisted Versus Mechanical Epithelial Removal in Photorefractive Keratectomy: A Contralateral Double Blind Clinical Trial.

Purpose: To compare the short-term complaints of postoperative pain, and other ocular discomfort symptoms in patients who underwent photorefractive keratectomy (PRK) with alcohol-assisted epithelial removal in one eye versus mechanical debridement in the other eye.

Method: A prospective, interventional, contralateral double blind clinical trial was performed on 164 eyes of 82 candidates of PRK surgery. The patients were divided into two groups.

Synthesis and evaluation of antioxidant activity of some novel hydroxypyridinone derivatives: a DFT approach for explanation of their radical scavenging activity.

Background And Purpose: Reactive oxygen species (ROSs) are continuously produced as byproducts of cell metabolism. Free radicals are an unstable form of ROSs with the tendency to react readily with biomolecules such as amino acids, lipids and DNA. These reactions lead to oxidative damages to the cell.

Quantitative real-time polymerase chain reaction analysis in herpes simplex virus keratitis with and without epithelial involvement.

Purpose: To evaluate the quantitative real-time polymerase chain reaction (qRT-PCR) analysis in herpes simplex virus (HSV) keratitis with and without epithelial involvement.

Methods: This cross-sectional study was performed on 70 patients with different HSV types and an active ocular lesion in Farabi Eye Hospital, Tehran, Iran. From these 70 patients, 171 samples were collected, including seventy tear samples and 33 scraping samples from involved eyes; and 68 samples from uninvolved fellow eyes.

Evaluation of corneal topographic, tomographic and biomechanical indices for detecting clinical and subclinical keratoconus: a comprehensive three-device study.

Aim: To evaluate the diagnostic ability of topographic and tomographic indices with Pentacam and Sirius as well as biomechanical parameters with Corvis ST for the detection of clinical and subclinical forms of keratoconus (KCN).

Methods: In this prospective diagnostic test study, 70 patients with clinical KCN, 79 patients with abnormal findings in topography and tomography maps with no evidence on clinical examination (subclinical KCN), and 68 normal control subjects were enrolled. The accuracy of topographic, tomographic, and biomechanical parameters was evaluated using the area under the receiver operating characteristic curve (AUC) and cross-validation analysis.

Comparison of Visual, Tomographic, and Biomechanical Outcomes of 360 Degrees Intracorneal Ring Implantation With and Without Corneal Crosslinking for Progressive Keratoconus: A 5-Year Follow-up.

Purpose: To evaluate the long-term (5 years) results of 360 degrees intracorneal ring (ICR) implantation with and without corneal crosslinking (CXL) in patients with progressive keratoconus (KCN).

Method: This historical cohort study was performed on 35 eyes with progressive KCN, which was randomly divided into 2 groups. Fourteen patients were implanted only with ICR, and 21 patients with KCN were treated with ICR plus CXL simultaneously.

MyoRing Implantation with and without Corneal Collagen Crosslinking for the Management of Keratoconus.

Purpose: To evaluate the safety and efficacy of femtosecond laser-assisted MyoRing implantation with concurrent corneal collagen crosslinking (CXL) compared to MyoRing alone for the treatment of progressive keratoconus.

Methods: A total of 60 patients were enrolled in this randomized controlled trial. The patients were randomly allocated into two groups.

Simultaneous photorefractive keratectomy and accelerated collagen cross-linking in high-risk refractive surgery (Tehran protocol): 3-year outcomes.

Purpose: To evaluate safety and efficacy of performing simultaneous photorefractive keratectomy (PRK) and collagen cross-linking (CXL) in myopic patients with preoperative risk factors for developing keratectasia.

Methods: Seventeen eyes of 15 patients with at least one of the following risk factors were recruited: central keratometry (K) between 48 and 50, difference between inferior, superior corneal power (I-S value) between 1.4 and 1.

Anterior Uveitis with Posterior Synechia and Iris Atrophy Following Implantation of a Phakic Intraocular Lens.

Purpose: To describe a case with acute postoperative uveitis, posterior synechia and iris atrophy following iris-claw phakic intraocular lens (pIOL) implantation.

Methods: A case report.

Results: A 26-year-old man with high myopia had implantation of a -14.

Early diagnosis of subclinical keratoconus by wavefront parameters using Scheimpflug, Placido and Hartmann-Shack based devices.

Purpose: To compare the accuracy of three devices (Pentacam, Sirius and OPD-Scan III) to differentiate subclinical keratoconus from normal corneas by wavefront parameters.

Methods: Two hundred and seventeen patients were enrolled in three groups [68 normal, 79 subclinical keratoconus (SKCN) and 70 KCN eyes] in this prospective diagnostic test study. Wavefront indices were evaluated between the groups using Pentacam, Sirius and OPD-Scan III.

Stop and Flip: A Simple and Safe Phacoemulsification Technique.

We introduce a simple, easy to learn, fast and safe technique to facilitate nucleus management in patients with zonular weakening in uncomplicated cases. The surgery begins with a temporal 3.2 mm clear corneal incision under topical anesthesia.