Identification of a novel partial deletion of STS associated with pre-Descemet corneal dystrophy and X-linked ichthyosis.

Purpose: Pre-Descemet corneal dystrophy (PDCD) with X-linked ichthyosis (XLI) is associated with mutations in or deletions of the steroid sulfatase gene (STS). As only three cases of genetically confirmed PDCD associated with XLI have been reported, we sought to expand our understanding of the genetic basis of PDCD by screening STS in two previously unreported families. Materials and Methods: The affected individuals underwent cutaneous and slit-lamp examinations. Saliva samples collected from each affected individual served as a source of DNA for the amplification of the 10 coding exons of STS and flanking DNA markers. Results: The slit-lamp examination of three affected men (two of whom were brothers) from two families revealed bilateral punctate posterior corneal stromal opacities anterior to the Descemet membrane. Cutaneous examination demonstrated dry, coarse, scaly ichthyotic changes characteristic of XLI in all individuals. Genetic examination of the STS locus on the X chromosome in Case 1 revealed a deletion that spanned across DNA markers DXS1130-DXS237, which includes all the coding exons (exons 1-10) of STS. Genetic screening of Cases 2 and 3 revealed a partial deletion of the STS locus involving exons 1-7 and flanking DNA marker DXS1130 on the X chromosome. Conclusions: PDCD with XLI may be associated with either partial or complete deletion of STS. Despite the identification of point mutations, partial deletion, and complete deletion of STS in different affected families reported to date, there was no apparent difference in the affected phenotype between the families, suggesting that the identified variants likely all resulted in loss of function of steroid sulfatase.

Cataract surgery considerations in patients with prior history of keratoconus and ectasia.

PURPOSE OF REVIEW: Preoperative workup for cataract surgery in patients with keratoconus poses certain challenges, particularly in patients with moderate-to-severe disease. This review aims to outline the appropriate preoperative, intraoperative, and postoperative considerations and provides an algorithm to help guide the workup prior to surgery. RECENT FINDINGS: A new system for keratoconus progression and staging has been proposed and additional studies comparing intraocular lens (IOL) formulas calculations and biometry devices have been conducted. SUMMARY: Patients with severe keratoconus have unpredictable results and have an increased risk of a hyperopic refraction postoperatively. Although studies have compared IOL calculation formulas, there is no consensus on management. Clinical considerations and an approach to the workup are presented; however, additional studies are required to determine the most appropriate management of cataracts in severe keratoconus.

Light adjustable intraocular lenses: an updated platform for cataract surgery.

PURPOSE OF REVIEW: Light adjustable intraocular lenses (LALs) are a relatively new platform for cataract surgery that is shifting the paradigm for intraocular lens placement following cataract removal. RECENT FINDINGS: LALs may have additional utility in patients with prior refractive surgery and complex ocular conditions, as they give the surgeon greater latitude in preoperative intraocular power calculations to meet postoperative refractive goals. SUMMARY: Further study of best candidates for LALs is warranted. Current best candidates are patients who can comply with treatment and have decreased accuracy in calculating the preoperative intraocular power requirement.

The Impact of Antiviral Resistance on Herpetic Keratitis.

ABSTRACT: Herpes simplex keratitis resistance to antiviral treatment presents a growing concern. The herpes simplex virus has many different mechanisms of resistance to antiviral treatment, which have been well described. Resistance to acyclovir occurs because of mutations in the viral thymidylate kinase and DNA polymerase that decrease this enzyme's affinity for its substrate. This article discusses factors that explain the prevalence of this resistance, the ability for recurrences in immunocompromised populations, current treatments for acyclovir-resistant herpes simplex keratitis, and novel therapies for this growing concern.

Cutibacterium (Formerly Propionibacterium ) acnes Keratitis: A Review.

ABSTRACT: Infectious keratitis is a devastating cause of vision loss worldwide. Cutibacterium acnes ( C. acnes ), a commensal bacterium of the skin and ocular surface, is an underrecognized but important cause of bacterial keratitis. This review presents the most comprehensive and up-to-date information for clinicians regarding the risk factors, incidence, diagnosis, management, and prognosis of C. acnes keratitis (CAK). Risk factors are similar to those of general bacterial keratitis and include contact lens use, past ocular surgery, and trauma. The incidence of CAK may be approximately 10%, ranging from 5% to 25% in growth-positive cultures. Accurate diagnosis requires anaerobic blood agar and a long incubation period (≥7 days). Typical clinical presentation includes small (<2 mm) ulcerations with deep stromal infiltrate causing an anterior chamber cell reaction. Small, peripheral lesions are usually resolved, and patients recover a high visual acuity. Severe infections causing VA of 20/200 or worse are common and often do not significantly improve even after treatment. Vancomycin is considered the most potent antibiotic against CAK, although other antibiotics such as moxifloxacin and ceftazidime are more commonly used as first-line treatment.

Cataract surgery and intraocular lens placement in patients with Fuchs corneal dystrophy: a review of the current literature.

PURPOSE OF REVIEW: Late-onset Fuchs endothelial corneal dystrophy (FECD) is seen in approximately 4% of individuals over the age of 40. With the growing population of adults over the age of 65, ophthalmologists need to be aware of the preoperative, perioperative, and postoperative considerations involved in cataract surgery in Fuchs patients. RECENT FINDINGS: Management of cataract patients with FECD requires preoperative assessment of endothelial cell size, density, and morphology. Considerations for perioperative endothelial cell loss include patients with hyperopia and shallow anterior chambers, phacoemulsification technique, transfer of ultrasonic energy to the cornea, corneal-protective perioperative agents, as well as thermal and mechanical damage. SUMMARY: Ophthalmologists performing cataract surgery on patients with FECD must carefully consider the risks of endothelial cell loss during surgery and minimize the risk of corneal decompensation after surgery. Preoperative management should evaluate the severity of the FECD as well as individual factors such as cataract density, the health and thickness of the cornea, and the anterior chamber depth. Perioperative techniques, adjustments to biometry calculations, and intraocular lens (IOL) selection may help optimize visual outcomes and recovery time.

Phakic intraocular lenses: an update and review for the treatment of myopia and myopic astigmatism in the United States.

PURPOSE OF REVIEW: To review all phakic intraocular lenses (pIOLs) available in the United States for the correction of myopia or myopic astigmatism and offer a clinical approach to their proper use, postoperative follow-up, and analysis of visual and adverse outcomes. RECENT FINDINGS: In March 2022, the FDA approved the EVO/EVO+ Visian ICL for widespread use, adding this lens to the two others available (Verisyse, Visian ICL). Cataract formation, endothelial cell loss (ECL) and surgical reintervention remain the most common adverse events. There are discrepancies between studies on ECL following implantation with pIOLs, although trends can be deduced with meta-analysis. Posterior Chamber-pIOLs (PC-pIOLs), especially the EVO/EVO+, have an overall lower mean adverse effect and subjective patient symptom profile when compared to Iris Fixated-pIOLS (IF-pIOLs). Advancements in PC-pIOL sizing have provided a noticeable difference in visual and safety outcomes. SUMMARY: All pIOLs available in the United States provide high-quality visual correction of moderate to high myopia and/or myopia with astigmatism. Proper follow-up for ECL and cataract formation is warranted.

Thygeson Superficial Punctate Keratitis: A Clinical and Immunologic Review.

ABSTRACT: Thygeson superficial punctate keratitis (TSPK) is clinically characterized by exacerbations and remissions of gray-white opacities within the corneal epithelium, most often bilateral but may be asymmetric. Symptoms typically include photophobia, tearing, blurring, and eye irritation. Although disease progression and prognosis are well described, the exact cause is unknown. Hypotheses exist implicating virus-mediated immunity as the cause of TSPK following cases of viral keratitis; however, several polymerase chain reaction studies refute the infectious process concurrently with symptomatic TSPK. This is further supported by the consistent lack of response to antiviral and antibacterial treatment. A subset of dendritic cells known as Langerhans cells (LC) found within the corneal epithelium has been positively correlated with exacerbations of TSPK. Langerhans cells proliferate to protect and mitigate the cornea's inflammatory response, but the inflammatory triggers and relapses associated with TSPK are not well understood. Several topical drugs exist to treat inflammation related to TSPK; however, drug delivery is a major barrier to treatment because of the tear film and epithelial barrier. Drug-eluting contact lenses that target intermediates of inflammation could serve as a more effective treatment modality because of the increased bioavailability of the drugs. This review is an in-depth survey of the literature regarding the relationship between the origin and pathophysiology of LC and TSPK at the immunologic level. We also discuss potential pharmacotherapeutic interventions for TSPK prevention and treatment.

Refractive enhancements for residual refractive error after cataract surgery.

PURPOSE OF REVIEW: Advances in cataract surgery have allowed surgeons to achieve superior refractive outcomes but have also led to higher patient expectations. Despite ever-evolving technology, residual refractive errors still occur. Postcataract refractive enhancements may be required to deliver satisfactory visual outcomes. This review aims to discuss the potential causes of residual refractive errors and the various enhancement modalities to correct them. RECENT FINDINGS: A thorough preoperative workup to detect and address underlying pathologic causes of impaired vision should be performed prior to enhancement or corrective procedures. Corneal-based procedures are the safest and most accurate methods of correcting mild cases of residual refractive error. Hyperopic, high myopic, and high astigmatic errors are best managed with lens-based enhancements. Piggyback intraocular lenses (IOLs) are safer and more effective compared with IOL exchange. Toric IOL rotation and IOL exchange are ideally performed in the early postoperative period. SUMMARY: A multitude of options exist for effective correction of residual refractive errors. The choice on how to best manage these patients depends on many factors such as the cause of refractive error, type of IOL used, ocular comorbidities, and patient preference.

Use of presbyopia-correcting intraocular lenses in patients with prior corneal refractive surgery.

PURPOSE OF REVIEW: Corneal refractive surgery has achieved spectacle-free vision for millions of patients, but this aging population is now developing cataracts. Many of these patients may wish to avoid reliance on glasses after cataract surgery. Presbyopia-correcting intraocular lenses (IOLs) offer a solution, but corneal changes after refractive surgery may compound higher order aberrations and dysphotopic symptoms associated with these IOLs. This review aims to discuss potential factors that could aid in determining suitable postkeratorefractive candidates for presbyopia-correcting IOLs. RECENT FINDINGS: Studies investigating which preoperative measures influence outcomes are lacking. The few studies that have examined presbyopia-correcting IOLs in postkeratorefractive patients report that satisfactory outcomes are possible. However, recommendations for preoperative thresholds appear limited to expert opinion and studies involving virgin corneas. SUMMARY: As the number of presbyopia-correcting IOLs and postkeratorefractive patients grows, continued investigation into relevant preoperative factors and appropriate IOLs is required to make evidence-based decisions. The current literature shows that with rigorous counseling and appropriate patient selection, presbyopia-correcting IOLs can provide postkeratorefractive patients with satisfactory results and spectacle independence. In addition, the development of postoperative modifiable IOLs may prove to be the preferred option.

The impact of vaping on ocular health: a literature review.

PURPOSE: Vaping, or the use of electronic cigarettes, was initially introduced as a step toward smoking cessation, but has become an increasingly popular option for smokers. Though advertised as safer than conventional cigarettes, these devices have been found to contain carcinogenic chemicals, air pollutants, and heavy metals. The purpose of this article is to shed light on the known effects of vaping on the ocular setting and raise the discussion about additional potential effects that may call for further investigation. METHODS: A comprehensive literature search was conducted for publications pertaining to the effects of vaping on the eye. Relevant studies and findings were summarized in this article. RESULTS: It was found that aldehydes and free radicals present in electronic cigarettes may induce a disturbance in tear film stability, and vape flavorings may damage the lipid layer through peroxidation. Corneal staining has been shown to appear following exposure to e-cigarette vapor, with nicotine and acrolein potentially inducing an inflammatory response in corneal epithelial cells. In addition, nicotine has been shown to induce nystagmus, exert vasoconstrictive effects on ocular blood flow, and may interfere with retinal light-adapted vision. Vape-related explosions, though unpredictable, may also result in decreased visual acuity along with long-term ocular trauma. CONCLUSION: Research discussing both the short-term and long-term effects of vaping on the eye is limited. However, the potential harms of substances such as nicotine and aldehydes warrant additional investigation and increased education about the detriment that electronic cigarettes may inflict on sensitive organs.

Management of cataract in the setting of uveitis: a review of the current literature.

PURPOSE OF REVIEW: This review aims to cover the preoperative planning, intraoperative considerations, and postoperative management that aids in successful outcomes of patients with cataract and uveitis. Disease-specific management and pediatric management will also be addressed. RECENT FINDINGS: Dexamethasone implants appear to be a safe and effective addition to standard steroid treatment in decreasing the incidence of postoperative cystoid macular edema (CME). Intravitreal steroids and topical difluprednate have shown utility in CME treatment. SUMMARY: Cataract surgery in eyes with uveitis is generally safe and effective if inflammation is well controlled; however, complication rates are still higher than in eyes without uveitis. Future investigations should delineate outcomes for eyes with different etiologies of uveitis, and further research is needed to adequately control inflammation and avoid postoperative complications.

Biometry in cataract surgery: a review of the current literature.

PURPOSE OF REVIEW: To review the literature in 2017 and 2018 pertaining to biometry for cataract surgery and report pertinent findings. RECENT FINDINGS: New devices using swept-source ocular coherence tomography can measure axial length in dense cataracts more frequently than common biometers. Computer-assisted registration may be superior to intraoperative aberrometry for toric intraocular lens (IOL) placement. Soft contact lenses may not require removal as long before biometry as previously thought. The Barrett Universal II IOL formula has been found to perform well at all axial lengths. SUMMARY: New swept-source ocular coherence tomography biometers are more frequently successful at measuring axial length in dense cataracts which promises to improve refractive outcomes. Accuracy in toric IOL placement is likely to increase with improved devices. It may not be necessary to have patients remove soft contact lens any more than 2 days prior to biometry. The Barrett Universal II IOL formula may be used confidently for most eyes. Advancements acknowledged, purchasing new equipment will not be necessary for all surgeons.

Hyperopic small-incision lenticule extraction.

PURPOSE OF REVIEW: Small-incision lenticule extraction (SMILE) has shown great promise in the treatment of myopia; however, the literature is less extensive in its hyperopic counterpart. The purpose of this review is to detail the recent advancements and outcomes of SMILE in the treatment of hyperopic eye disease. RECENT FINDINGS: SMILE has demonstrated similar visual outcomes, regression rates, centration ability, safety profiles, and wound healing as hyperopic laser-assisted in situ keratomileusis (LASIK). Lenticule preservation and implantation show further promise in the correction of higher degrees of hyperopia. SUMMARY: Based on the current literature, SMILE represents a viable surgical alternative to LASIK in the correction of hyperopia. Lenticule intrastromal keratoplasty and small-incision lenticule intrastromal keratoplasty may be able to correct severe hyperopia in patients who would not otherwise be candidates for refractive surgery.

Cataract surgery in eyes with keratoconus: a review of the current literature.

PURPOSE OF REVIEW: There are an increasing number of keratoconic eyes, requiring cataract surgery. We review the preoperative planning, intraoperative options, and postoperative management that aid in successful outcomes. RECENT FINDINGS: Management of keratoconic eyes requiring cataract surgery requires a multifaceted approach. Preoperatively, corneal crosslinking and intrastromal corneal ring segments can be considered in order to provide stable keratometry values for intraocular lens (IOL) calculations. Deciding between toric and monofocal IOLs requires a thorough evaluation. Intraoperatively, the decision of clear corneal incisions with or without sutures versus scleral incisions is important to mitigate postoperative complications. Postoperatively, irregular astigmatism should be evaluated and updated rigid gas permeable or scleral lenses provided. Patients needing irregular astigmatism correction postoperatively should not have toric IOL implantation; however, in select cases of keratoconus, it is an option. SUMMARY: The use of stabilizing procedures prior to optical biometry can aid in preoperative lens selection and provide predictable surgical outcomes. Decisions on intraoperative wound construction and toric versus monofocal lenses should be based on the severity, regularity, and central nature of the keratoconus. Postoperative use of rigid gas permeable or scleral lenses can help patients achieve their best visual potential.

Intraoperative management of anterior capsular tear.

PURPOSE OF REVIEW: The article reviews the current literature on intraoperative techniques to properly manage anterior capsular tears during cataract surgery. RECENT FINDINGS: Femtosecond laser-assisted cataract surgery creates a more consistent capsulorhexis than traditional capsulotomies, but can also present with new challenges. Irregularities, like microadhesions and tags, can lead to anterior tears if not properly treated. New technology, like the Zepto (Mynosys, Fremont, CA, USA) pulse precision capsulotomy, may produce a smoother edge and reduce the incidence of capsular tears. However, there are novel rescue techniques in the case that a tear-out does occur. SUMMARY: Anterior capsular tears can occur at any stage of cataract surgery. The proper management of these tears will prevent them from extending into the posterior capsule and compromising the structural integrity of the capsular bag. This is essential for endocapsular placement of artificial lenses and for optimal visual outcomes for the patient.

Ocular dominance, coexistent retinal disease, and refractive errors in patients with cataract surgery.

PURPOSE OF REVIEW: The purpose of this article is to highlight some common issues when planning cataract surgery in patients with preexisting ocular pathologies and to assess the role of ocular dominance in cataract surgery. RECENT FINDINGS: In addition to routine ocular examination, determination of ocular dominance and orthoptic evaluation for tropias, phorias, amblyopia, and diplopia can be helpful in planning for cataract surgery as these factors can affect postoperative outcomes. Although once controversial, cataract surgery by phacoemulsification is often a well tolerated and effective option for patients with coexistent retinal conditions including epiretinal membrane, age-related macular degeneration, diabetic retinopathy, and macular holes. SUMMARY: It is mandatory to recognize phorias, tropias, anisometropia, and amblyopia when planning cataract surgery. Visual potential, ocular dominance, refractive errors, and other retinal comorbidities influence cataract surgery planning and outcome.

Current options in the management of pellucid marginal degeneration.

PURPOSE: To review and evaluate current and future directions in the diagnosis and surgical management of pellucid marginal degeneration (PMD), including penetrating keratoplasty, full-thickness crescentic wedge resection (FTCWR), deep anterior lamellar keratoplasty (DALK), crescentic lamellar wedge resection (CLWR), crescentic lamellar keratoplasty, tuck-in lamellar keratoplasty (TILK), toric phakic intraocular lens (PIOL) implantation, intrastromal corneal ring segment implantation (ICRS), corneal collagen cross-linking (CXL), and combined therapies. This is the first review article looking at the literature specific to PMD. METHODS: Review of published studies. RESULTS: Reported data for each treatment is presented. Penetrating keratoplasty is the treatment of last resort in PMD and is effective, but with considerable complications. DALK provides visual outcomes similar to penetrating keratoplasty without the risk of immune-mediated graft rejection, but its complexity and relative novelty limit its acceptance. FTCWR has good visual outcomes, but with significant astigmatic drift. CLWR is effective, but lacks long-term results. Crescentic lamellar keratoplasty and TILK are effective, but technically difficult and without long-term results. Toric PIOL implantation is effective, but ectasia progression is a concern. ICRS implantation can delay penetrating keratoplasty and improve contact lens tolerance, but does not treat the underlying process. CXL demonstrates effectiveness without complications, although data are limited and long-term results are needed. Combining treatments such as ICRS, CXL, toric PIOL implantation, and refractive surgery is promising, but additional studies are needed to investigate their efficacy and safety. CONCLUSIONS: Although little is understood about the etiology, pathophysiology, epidemiology, and genetics of PMD, new treatments are improving visual outcomes and reducing complications. Corneal collagen cross-linking is especially exciting because it halts disease progression. Combined treatments and improved screening could eliminate the need for surgical management in most cases of PMD.

Implication of Corneal Refractive Surgery in Duchenne Muscular Dystrophy.

Duchenne muscular dystrophy (DMD) is an X-linked disorder due to a dystrophin mutation and is the leading cause of muscular dystrophy. DMD presents with characteristic systemic effects, including severe muscular atrophy, cardiomyopathy, and ocular manifestations. Performing corneal refractive surgeries in patients with DMD raises concerns regarding patient positioning, risk of cataracts, and other comorbid conditions. Published reports of photorefractive keratectomy, laser-assisted in situ keratomileuses, and small incision lenticule extraction are lacking in this population. Here, we discuss a patient being evaluated for a corneal refractive surgery. This article also discusses the current understanding of DMD, known ocular manifestations, and factors to consider when evaluating a patient for potential corrective vision laser surgery.

Merging PRK and Collagen Crosslinking: An Analysis of Literature and a Guide to Prevalent Protocols.

PURPOSE: The purpose of this review was to summarize the different surgical approaches combining photorefractive keratectomy (PRK) and corneal crosslinking (CXL), present each protocol template in a simple format, and provide an overview of the primary outcomes and adverse events. METHODS: A literature review was conducted as outlined by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Eight different databases were searched. Papers were included if PRK was immediately followed by CXL. RESULTS: Thirty-seven papers met the inclusion criteria of a total yield of 823. The latest research into simultaneous PRK and CXL has been shown to not only stabilize the cornea and prevent keratoconus progression but also improve the visual acuity of the patient. Improvements in uncorrected distance visual acuity and (spectacle) corrected distance visual acuity were found to be significant when considering all protocols. There were also significant reductions in K1, K2, mean K, Kmax, sphere, cylinder, and spherical equivalent. Random-effects analysis confirmed these trends. Corrected distance visual acuity was found to improve by an average of 0.18 ± 1.49 logMAR (Cohen's D [CD] 0.12; P <0.02). There was also a significant reduction of 2.57 ± 0.45 D (CD 5.74; P <0.001) in Kmax. Cylinder and spherical equivalent were also reduced by 1.36 ± 0.26 D (CD 5.25; P <0.001) and 2.61 ± 0.38 D (CD 6.73; P <0.001), respectively. CONCLUSIONS: Combining the 2 procedures appears to be of net benefit, showing stabilization and improvement of ectatic disease, while also providing modest gains in visual acuity. Since customized PRK and CXL approaches appear superior, a combination of these would likely be best for patients.