Covalent crosslinking chemistry for controlled modulation of nanometric roughness and surface free energy.

Smooth interfaces embedded with low surface free energy allow effortless sliding of beaded droplets of selected liquids-with homogeneous wettability. Such slippery interfaces display low or moderate contact angles, unlike other extremely liquid repellent interfaces (e.g. superhydrophobic). These slippery interfaces emerged as a promising alternative to extremely liquid repellent hierarchically rough interfaces that generally suffer from instability under severe conditions, scattering of visible light because of the hierarchically rough interface, entrapment of fine solid particulates in their micro-grooves and so on. However, a controlled and precise modulation of surface free energy and nanometric roughness is essential for designing a more compelling solid and dry antifouling interface. Here, we have unprecedentedly demonstrated the ability of covalent cross-linking chemistry for precise and simultaneous modulation of both essential surface free energy (∼49 mN m-1 to ∼22 mN m-1) and roughness (root mean square roughness from 30 nm to 3 nm) of a solid interface for achieving liquid, substrate, and process independent, robust slippery properties. The strategic selection of ß-amino-ester linkage through a 1,4-conjugated addition reaction between amine and acrylate groups of a three component reaction mixture (dominated by a 61% (w/w) crosslinker) under ambient conditions provided a facile basis for associating various important and relevant properties-including self-cleaning ability, anti-smudge properties (against both water and oil-based inks), thermal stability (>300 °C), chemical stability, physical durability, optical transparency (∼95%) and so on. The embedded slippery properties of the coating remained unaffected at both low (0 °C) and high (100 °C) temperatures. Thus, the prepared coating would be appropriate to maintain the unperturbed performance of commercially available solar cell modules and other relevant objects under outdoor conditions.

Comparative posterior corneal profile of keratoconus hydrops versus Haab's striae in congenital glaucoma.

Keratoconus eyes develop corneal decompensation more often compared to eyes with primary congenital glaucoma (PCG) following Descemet's membrane (DM) tear. This study was conducted to compare the posterior corneal morphology in areas with DM breaks with regards to DM and pre-Descemet's layer (PDL) between the two. In this cross-sectional comparative study, anterior segment optical coherence tomography (AS-OCT) scans of the posterior cornea of advanced keratoconus eyes with hydrops ( n = 12), PCG eyes with Haab's striae ( n = 15), and healthy control eyes ( n = 14) were compared for DM-PDL morphology. These were further corroborated by the histopathology of corneal buttons from keratoconus ( n = 14) and PCG ( n = 13) cases obtained following penetrating keratoplasty and compared with controls (enucleated retinoblastoma globes, n = 6) on light microscopy and collagen IV immunostaining. AS-OCT showed a thicker median DM/PDL complex in PCG (80 µm) versus keratoconus eyes (36 µm, P = 0.01; Kruskal-Wallis test). The median height and length of detached DM-PDL were significantly more in keratoconus versus PCG (145 µm, 1766.1 ± 1320.6 µm vs. 26.5 µm, 453.3 ± 303.2 µm, respectively, P = 0.012; Kruskal-Wallis test). Type-1 DM/PDL detachment (seen as a characteristic taut chord) in keratoconus (90%) was the most common morphological pattern versus intracameral twin protuberance (92%) following DM breaks in PCG. Histopathology confirmed thicker DM in PCG (median: 63.4 µm) versus keratoconus eyes (median: 33.2 µm) or controls (27.1 µm) ( P = 0.001; Kruskal-Wallis test). Greater height/length of DM/PDL detachment compounded by poor healing response (lower DM/PDL thickness) probably causes more frequent corneal decompensation in keratoconus eyes when compared to PCG eyes following DM tears.

Gene Therapy for Inherited Retinal Diseases: From Laboratory Bench to Patient Bedside and Beyond.

This comprehensive review provides a thorough examination of inherited retinal diseases (IRDs), encompassing their classification, genetic underpinnings, and the promising landscape of gene therapy trials. IRDs, a diverse group of genetic conditions causing vision loss through photoreceptor cell death, are explored through various angles, including inheritance patterns, gene involvement, and associated systemic disorders. The focal point is gene therapy, which offers hope for halting or even reversing the progression of IRDs. The review highlights ongoing clinical trials spanning retinal cell replacement, neuroprotection, pharmacological interventions, and optogenetics. While these therapies hold tremendous potential, they face challenges like timing optimization, standardized assessment criteria, inflammation management, vector refinement, and raising awareness among vision scientists. Additionally, translating gene therapy success into widespread adoption and addressing cost-effectiveness are crucial challenges to address. Continued research and clinical trials are essential to fully harness gene therapy's potential in treating IRDs and enhancing the lives of affected individuals.

Characterization of retinal hemorrhages delimited by the internal limiting membrane.

Clinically, hemorrhages at the vitreoretinal interface have been termed as 'pre-retinal' in location. However, there is a careful distinction to be made between sub-hyaloid and sub-internal limiting membrane (ILM) planes of blood collection. In the past half-century, a body of literature has accrued on sub-internal limiting membrane hemorrhage. We characterize the etiopathological, clinical, anatomical, and imaging characteristics of this entity (often misconstrued as sub-hyaloid hemorrhage). Management decisions are briefly described, and a unifying term of sub-internal limiting membrane macular hemorrhage is proposed to aid in further research.

Management and prevention of corneal graft rejection.

The management of an episode of corneal graft rejection (CGR) is primarily by corticosteroids. Immunomodulators are useful for long-term immunosuppression and in dealing with cases of high-risk (HR) corneal grafts. The classical signs of CGR following penetrating keratoplasty (PKP) include rejection line, anterior chamber (AC) reaction, and graft edema. However, these signs may be absent or subtle in cases of endothelial keratoplasty (EK). Prevention of an episode of graft rejection is of utmost importance as it can reduce the need for donor cornea significantly. In our previous article (IJO_2866_22), we had discussed about the immunopathogenesis of CGR. In this review article, we aim to discuss the various clinical aspects and management of CGR.

Bilateral post-LASIK exacerbation of granular corneal dystrophy with epithelial ingrowth.

A male patient in his 30s, with a history of bilateral microkeratome-assisted myopic laser-assisted in situ keratomileusis (LASIK) 8 years ago at another centre, presented to us with gradually progressive diminution of vision and glare in both eyes for the last 4 years. On presentation, uncorrected distance visual acuity (UDVA) was 6/24 and 6/15 in the right eye and left eye, respectively, with normal intraocular pressures. Slit-lamp examination and anterior segment optical coherence tomography revealed well-defined white deposits, limited to an area within the LASIK flap. The deposits were confluent, at the level of the LASIK flap interface, and few discrete opacities were present in the posterior stroma. His father also had a similar clinical picture in both eyes. A diagnosis of both eyes post-LASIK exacerbation of granular corneal dystrophy with epithelial ingrowth was made. He underwent right eye femtosecond laser-assisted sutureless superficial anterior lamellar keratoplasty. At 6-month follow-up, UDVA improved to 6/12 with graft clarity of 4+ and coexistent grade 1 epithelial ingrowth.

Immunopathogenesis of corneal graft rejection.

The most common cause of corneal graft failure is corneal graft rejection (CGR). Although cornea is one of the immune-privileged sites, it can still get a rejection episode due to a breach in its natural protective mechanism. Both anatomical and structural properties of cornea and anterior chamber contribute toward its immune tolerance. Clinically, every layer of the transplanted cornea can get a rejection episode. A proper understanding of immunopathogenesis will help in understanding the various mechanism of CGR and the development of newer strategies for the prevention and management of such cases.

Design of a self-cleanable multilevel anticounterfeiting interface through covalent chemical modulation.

Counterfeit products have posed a significant threat to consumers safety and the global economy. To address this issue, extensive studies have been exploring the use of coatings with unclonable, microscale features for authentication purposes. However, the ease of readout, and the stability of these features against water, deposited dust, and wear, which are required for practical use, remain challenging. Here we report a novel class of chemically functionalizable coatings with a combination of a physically unclonable porous topography and distinct physiochemical properties (e.g., fluorescence, water wettability, and water adhesion) obtained through orthogonal chemical modifications (i.e., 1,4-conjugate addition reaction and Schiff-base reaction at ambient conditions). Unprecedentedly, a self-cleanable and physically unclonable coating is introduced to develop a multilevel anticounterfeiting interface. We demonstrate that the authentication of the fluorescent porous topography can be verified using deep learning. More importantly, the spatially selective chemical modifications can be read with the naked eye via underwater exposure and UV light illumination. Overall, the results reported in this work provide a facile basis for designing functional surfaces capable of independent and multilevel decryption of authenticity.

Cataract surgery outcomes in pediatric patients with systemic comorbidities.

Purpose: The aim of the study was to evaluate the outcomes of cataract surgery in patients of the pediatric age group with systemic comorbidities. Methods: Medical records of 54 eyes (30 patients) of the pediatric age group with systemic comorbidities who had undergone cataract surgery in a tertiary-care center were reviewed. The following parameters were recorded: systemic comorbidity; toxoplasmosis, rubella, cytomegalovirus, herpes simplex, HIV (TORCH) profile, best spectacle-corrected visual acuity (BSCVA), strabismus, nystagmus, and cataract morphology. Results: Thirty patients with a mean age of 55 months (9 months-14 years) were included. On average, every child was seen by three physicians, and the mean duration between the first visit to a physician and presentation to our center was 2.23 ± 0.67 years. The various causes for delay in referral include multiple referrals due to a lack of general anesthesia services in 78% of cases, a long waiting list at the referral hospital in 35% of cases, and a lack of awareness at the primary-care physician level in 50% of cases. The mean BSCVA at presentation was 1.4 logMAR (0.3 to 3 logMAR). The most common cataract morphology was that of zonular cataract (31.48%; 17/54). Strabismus and abnormal eye movements were observed in 27.7% (15/54) and 33.3% (18/54) of eyes, respectively. Various systemic associations were periventricular leukomalacia (12/30), Down's syndrome (6/30), seizure disorder (6/30), cardiac valvular anomalies (6/30), Marfan's syndrome (4/30), hypothyroidism (4/30), rubella (3/20), cytomegalovirus (3/20), cerebral palsy (2/30), nephrotic syndrome (2/30), Type 1 diabetes mellitus (1/30), microcephaly (1/30), cryptogenic West syndrome (1/30), congenital rubella syndrome (1/30), and Tourette syndrome (1/30). The mean postoperative corrected distance visual acuity (CDVA) at 2-year follow-up improved to 1.0 logMAR (0 to 3 logMAR). No postoperative complications were reported at the final follow-up. Around 70% of the parents reported improvement in their child's psychomotor skills. Conclusion: Intellectually impaired pediatric patients with cataract should be operated upon whenever there is a presence of infrastructure, and unnecessary delay in surgery should be avoided by referring the patient to higher centers. Even though objective improvement in visual acuity was suboptimal, there was definitely an improvement in the psychomotor skills of the patients.

A review of techniques and outcomes of endothelial keratoplasty in congenital hereditary endothelial dystrophy.

Congenital hereditary endothelial dystrophy affects the Descemet membrane and endothelium, resulting in corneal decompensation. Penetrating keratoplasty (PKP) has been the gold-standard surgical management until recently; however, at present, endothelial keratoplasty (DSEK/DSAEK/n-DSEK: Descemet-stripping or non-Descemet stripping endothelial keratoplasty and DMEK/n-DMEK: Descemet membrane endothelial keratoplasty) is being preferred due to lesser intraoperative and postoperative complications, early visual recovery, and comparable visual outcomes. Endothelial keratoplasty (EK) can be challenging, especially in pediatric eyes with CHED due to smaller eyeballs, shallow anterior chambers, phakic status, and poor intraoperative visibility due to thick and hazy corneas. A total of 198 articles matched our search strategy. After screening for duplication and going through the titles and abstracts, 12 relevant original articles, one case series, and six case reports were included in this review. Various surgical modifications have to be adopted in comparison to adult eyes to overcome the aforementioned difficulties. Regardless, studies have shown favorable visual outcomes with better graft survival and fewer complications in eyes that underwent EK compared to PKP. Hence, timely surgical intervention and strict amblyopia management can result in better final visual outcomes. The purpose of this review is to summarize various intraoperative difficulties and the surgical modifications required, different surgical techniques, visual and graft-related outcomes, and various complications of EK in CHED eyes.

Outcomes of surgical intervention in cases of ectopia lentis.

Purpose: To evaluate the outcomes of surgical intervention in cases of ectopia lentis. Methods: This retrospective study included all cases of ectopia lentis that presented between June 2015 and March 2019 in a tertiary care center. They were reviewed retrospectively. The corrected distance visual acuity (CDVA), severity of lens subluxation, type of surgery, intra-operative and post-operative complication, and specular count were recorded. Results: Seventy-eight eyes of 57 cases with a mean age at surgery of 14.73 years were analyzed. Intra-lenticular lens aspiration was the most common (n-62/78; 79.5%) surgical procedure followed by lens aspiration, intra-capsular cataract extraction, phaco-aspiration, and pars-plana lensectomy. Simultaneous intra-ocular lens (IOL) implantation was performed in 46.2% (n-32/78) of the eyes. The mean CDVA improved from 0.85 ± 0.55 logMAR to 0.44 ± 0.29 logMAR at 6 weeks follow-up. The post-operative CDVA was significantly better in the pseudo-phakic group compared to the aphakic group (p-0.02). The patient's age at the time of surgery and the degree of subluxation did not impact the final visual outcome. Intra-operative complication included vitreous hemorrhage (n-1) and lens matter drop (n-1). Post-operative complications were noted in 26.9% of the eyes (n-21/78) with a higher complication rate in the pseudo-phakic group (p-0.00). A second intervention was required in 7.7% of the eyes (n-6/78). Conclusion: Age and degree of subluxation at the time of surgery do not influence the final visual outcome in cases of ectopia lentis undergoing lens extraction surgery. IOL implantation results in better visual outcomes but is associated with a high complication rate.

Ocular manifestations in Kindler syndrome.

We aimed describe the chronic ocular sequelae of Kindler syndrome. All cases of Kindler syndrome with ocular involvement that presented to a tertiary eye care center were included. Three cases of Kindler syndrome with ocular changes were reviewed. Case 1 (10 years, female) had recurrent epithelial breakdown with severe dry eye and corneal opacity secondary to keratitis. Case 2 (28 years, male) had symblepharon , ocular surface keratinization , and severe dry eye. Case 3 (16 years , female ) had partial limbal stem cell deficiency with dry eye. All cases were treated with topical lubricants, short course of low-potency steroids and immuno-modulators. Attention must be paid to the eye in addition to the oro-an-genital mucosa to avoid longterm ocular sequelae.

Early onset unilateral Terrien's marginal degeneration.

A young man in his first decade of life presented with insidious onset, gradually progressive diminution of vision in right eye since 2 months associated with foreign body sensation. Slit-lamp examination revealed superior arcuate band of corneal stromal thinning extending from 9-3 o' clock. There was associated corneal vascularisation and presence of lipid deposition at the leading edge of the furrow formation with intact epithelium without any apparent signs of inflammation. There was no previous history of ocular or systemic disease, trauma, ocular surgery, collagen vascular disease or contact lens wear. Serological tests for rheumatic diseases did not show any abnormalities. Scheimpflug imaging showed high against the rule astigmatism with a 'reverse crab claw' pattern. A provisional diagnosis of right eye Terrien's marginal corneal degeneration was made. On a 1-month follow-up visit, there was significant symptomatic relief with lubricants alone and with spectacles the visual acuity improved to 20/60 in the right eye.

Ethambutol-induced optic neuropathy: Functional and structural changes in the retina and optic nerve.

BACKGROUD: Ethambutol hydrochloride (EMB) is used in the treatment of tuberculosis and is used as first line modality in combination with other medications. Ethambutol optic neuropathy (EON) is a rare but well-recognised adverse ocular event in patients who receive ethambutol for the treatment of mycobacterial infections and may be potentially devastating with reversible to irreversible changes in visual acuity. KEY FINDINGS: Optical coherence tomography has been used to evaluate the thickness of retinal nerve fibre and ganglion cell layers to look for degenerative changes and early markers. Electrophysiological tests like multifocal electroretinogram, visual evoked potentials and visual fields have been used to understand the functional changes associated with established EON and also whether these can be used to detect subclinical EON and correlate them with the structural changes. In this review, we have summarised evidence published till December 2021 related to evaluation of structural and functional changes in the retina and optic nerve in eyes with EON.

Deep blue dot corneal degeneration: a rare corneal degeneration.

A female patient in the age group 55-60 years presented to us with blurring of vision in both eyes. On slit-lamp examination, numerous circular to oval fleck-like discrete blue opacities at the level of deep corneal stroma and Descemet's membrane was observed. These lesions were predominantly seen in the central two-thirds of the cornea. Considering the age of presentation and the clinical features, the probable diagnosis of 'deep blue dot corneal degeneration' was made.

Complications following implantation of posterior chamber phakic intraocular lens (pIOL).

A male patient in his 20s presented with right eye aphakic corneal decompensation and left eye intumescent cataract with phakic intraocular lens (pIOL) lenticular touch. He had a history of pIOL implantation in both eyes 6 months ago. On first postoperative day, uncorrected distance visual acuity was 20/400 and 20/20 in right and left eye, respectively. Postoperatively, a diagnosis of right eye toxic anterior segment syndrome (TASS) was made and pIOL was explanted. Subsequently, the patient developed intumescent cataract for which lens aspiration with posterior chamber intraocular lens (PCIOL) implantation was performed in the right eye. Ongoing uveitis with membrane formation warranted PCIOL explantation. The patient developed aphakic corneal decompensation in the right eye and underwent penetrating keratoplasty with intrascleral haptic fixation of an intraocular lens. Central pIOL-lenticular touch with intumescent cataract was diagnosed in the left eye for which pIOL explant with lens aspiration and PCIOL was done. TASS and post-pIOL cataract are rare but vision-threatening complications require judicious management for visual rehabilitation.

Preserving posterior capsular integrity in post-endothelial keratoplasty posterior capsular opacification.

Endothelial keratoplasty (EK) with pseudophakia often presents with late-onset proliferative after-cataract with posterior capsule distension. We performed a modified technique of capsular bag lavage in 11 eyes with late-onset PCO after EK (4 cases: post-DSAEK, 7 cases: post-DMEK). Anterior capsular rim was separated from the underlying IOL optic using MVR blade. Circumferential relaxing radial nicks were made on the capsular rim to create space for the passage of irrigation-aspiration (IA) probes behind the IOL. Bimanual IA of the flocculent cortical material was performed without damaging the posterior capsule. Air was injected at end of surgery to ensure graft apposition. All cases gained 1-3 lines of Snellen's acuity and no case developed graft failure, rejection, or endothelial decompensation. An intact posterior capsule is associated with better outcomes post a repeat graft, if required. Our technique helps avoid complications related to a disturbed anterior hyaloid phase and minimizes postoperative inflammation.