Elevated Neutrophils and reduced NK cells are associated with altered tear molecular signatures and clinical sequelae of chronic ocular Stevens-Johnson Syndrome

PURPOSE

Stevens-Johnson syndrome (SJS) is characterised as an immuno-inflammatory condition with potentially blinding ocular sequelae. Therefore, we have investigated the ocular surface immune cell profile and correlated it with secreted tear molecular factors and clinical ocular sequelae in SJS patients.

METHODS

21 patients (42 eyes) with chronic ocular SJS and 16 healthy controls (20 eyes) were included in the study. Severity, types of keratopathies and ocular surface(OS) manifestations were determined. OS wash samples from study subjects were used to determine the status of 13 immune cell subsets using flow cytometry. Levels of 42 secreted immuno-inflammatory factors were measured by flow cytometry-based multiplex ELISA in tear samples.

RESULTS

Neutrophils (Total, activated), neutrophils/NK cells ratio, neutrophils/T cells ratio were significantly (p<0.05) elevated in SJS, while, proportions of T cells and NKT cells were significantly lower in SJS patients. Positive association between neutrophils and chronic ocular surface complication score (COCS) was observed, whereas, a negative association was noted between NK cells and COCS. Tear fluid levels of IL-6, IL-8, IL-18, IFNα/β/γ, TNFα, LIF, IL-8, HGF, sTNFR-I, NGAL, Granzyme, Perforins, MMP9/TIMP1 ratio were significantly higher in SJS. Loss of Limbal niche correlated significantly with immune profile and clinical sequelae. Increased neutrophils, decreased NK cells and specific set of altered secreted immuno-inflammatory mediators including bFGF, and IL-8 were observed in SJS patients with different types of keratopathies compared to those without keratopathy.

CONCLUSION

Distinct ocular surface immune profile variations were observed to correlate with clinical stages of chronic ocular SJS. Our findings uncover novel mechanisms and potential for targeted therapy in chronic ocular SJS patients.

Spike sign - To predict the formation of big bubble in deep anterior lamellar keratoplasty in advanced keratoconus

Lamellar surgeries have revolutionized our understanding and practice of keratoplasties. However, the learning curve in deep anterior lamellar keratoplasty (DALK) makes it daunting for novice surgeons. This paper describes a unique intraoperative sign - the radial "spike sign," which heralds the commencement of a big bubble in some cases of advanced keratoconus in eyes that have not undergone any previous surgery. The spike sign was noted during big bubble DALK surgery and was then retrospectively looked for in recorded DALK surgical videos and correlated with the formation of a big bubble. The movement of air after injection was classified into the direct formation of a big bubble, stromal emphysema with no big bubble, and emphysema with the spike sign followed by a big bubble. In total, 104 surgical videos of big bubble attempts were evaluated and classified as such. The spike sign helps reduce the number of unnecessary attempts at big bubble formation during DALK, thus improving surgical outcomes.

Bilateral retinal vasculitis due to presumed sarcoidosis with rickettsial retinitis

OBJECTIVE

To describe a case of bilateral retinal vasculitis due to presumed sarcoidosis and rickettsial retinitis complicated with neovascularization with tear biomarker analysis.

METHODS

A retrospective case report.

RESULTS

A 16-year-old male presented with bilateral retinal vasculitis and retinitis in both eyes with inferotemporal quadrant neovascularization in the right eye. Multimodal imaging revealed the presence of active inflammation in both eyes. Weil Felix test was positive with raised ACE levels. This patient was treated with local and systemic steroids, doxycycline, and laser photocoagulation followed by oral methotrexate therapy which resulted in clinical resolution with recovery of visual acuity. Tear biomarker analysis showed raised sICAM-1 and MMP-9 levels in both eyes which significantly reduced following treatment.

CONCLUSION

Ocular sarcoidosis with rickettsial infection is a rare association. Tear biomarkers correlated well with clinical and imaging manifestations. High index of suspicion and aggressive anti-inflammatory therapy can help control inflammation and restore good vision.

Vitamin D and tear fluid cytokines in predicting outcomes in viral conjunctivitis - A new outlook

PURPOSE

To determine the association between systemic vitamin D (VD) and immunoglobulin E (IgE) levels with severity and ocular surface inflammatory profile in patients with epidemic keratoconjunctivitis (EKC).

METHODS

210 eyes of 105 patients who were clinically diagnosed with EKC were included in the study. The levels of serum VD and serum IgE were measured. Schirmer's strip-based tear fluid (TF) was used to determine levels of IL-1β, IL-6, IL-10, IL-17A, TNFα, MMP9, sICAM1, and VEGF-A in a subset of patients.

RESULTS

Levels of VD were significantly ( P < 0.05) lower and levels of IgE were significantly higher in patients with severe forms of conjunctivitis compared to those with nonsevere forms. Majority of the patients with severe forms of the disease exhibited VD deficiency and/or abnormally high IgE. A negative correlation (r = -0.682; P < 0.0001) was observed between VD and IgE levels. TF levels of IL-1β, IL-6, TNFα, and sICAM1 were significantly higher in eyes with severe forms of conjunctivitis compared to those with nonsevere forms and controls. These factors showed a positive correlation ( P < 0.05) with IgE levels and a negative correlation ( P < 0.05) with VD levels.

CONCLUSION

Patients with severe forms of EKC exhibited VD deficiency and higher levels of IgE. Increased TF inflammatory factors demonstrated a disease causal relationship with VD and IgE. Hence, restoring the altered levels of VD and IgE to normal range would be pivotal in the prevention and management of severe conjunctivitis.

Quantitative and comparative analysis of thermography parameters in posterior scleritis, choroiditis, and controls

PURPOSE

To compare various ocular thermography parameters in posterior scleritis (PS), choroiditis (choroidal granuloma [CG], Vogt-Koyanagi-Harada [VKH] syndrome), central serous chorioretinopathy (CSCR), and healthy controls.

METHODS

This retrospective, observational, comparative study evaluated cases undergoing ocular thermography between April 2017 and October 2023. The study groups included cases of PS, CG, and VKH, while the control group comprised CSCR cases and healthy individuals. Various thermography parameters were assessed, which were as follows: Ocular surface temperature (OST), central corneal temperature (CCT), average scleral temperature (ST), nasal scleral temperature (nST), temperature difference between both the eyes (Dt), and difference between scleral and corneal temperatures (ST - CCT, nST - CCT).

RESULTS

It was found that Dt was significantly higher in the PS group compared to the CG (P = 0.005), CSCR (P = 0.0001), and control groups (dilated control: P =0.006, undilated control: P = 0.0001). ST - CCT and nST - CCT were significantly higher in the undilated control and CSCR groups and significantly lower in the PS group. ST - CCT and nST - CCT showed less difference in the affected eyes compared to contralateral healthy eyes of PS and CG cases. OST, CCT, ST, and nST displayed statistically insignificant differences across all groups.

CONCLUSION

It is advisable to focus on temperature differences between the affected and healthy eyes, or the difference between the central corneal and scleral temperature of the affected eye, utilizing parameters such as ∆t, ST - CCT, and nST - CCT. These composite parameters offer a more effective approach than individual measurements like OST, CCT, ST, and nST. Thermography can serve as a screening tool to suspect and differentiate PS.

Recommendations for diabetic macular edema management by retina specialists and large language model-based artificial intelligence platforms

PURPOSE

To study the role of artificial intelligence (AI) in developing diabetic macular edema (DME) management recommendations by creating and comparing responses to clinicians in hypothetical AI-generated case scenarios. The study also examined whether its joint recommendations followed national DME management guidelines.

METHODS

The AI hypothetically generated 50 ocular case scenarios from 25 patients using keywords like age, gender, type, duration and control of diabetes, visual acuity, lens status, retinopathy stage, coexisting ocular and systemic co-morbidities, and DME-related retinal imaging findings. For DME and ocular co-morbidity management, we calculated inter-rater agreements (kappa analysis) separately for clinician responses, AI-platforms, and the "majority clinician response" (the maximum number of identical clinician responses) and "majority AI-platform" (the maximum number of identical AI responses). Treatment recommendations for various situations were compared to the Indian national guidelines.

RESULTS

For DME management, clinicians (ĸ=0.6), AI platforms (ĸ=0.58), and the 'majority clinician response' and 'majority AI response' (ĸ=0.69) had moderate to substantial inter-rate agreement. The study showed fair to substantial agreement for ocular co-morbidity management between clinicians (ĸ=0.8), AI platforms (ĸ=0.36), and the 'majority clinician response' and 'majority AI response' (ĸ=0.49). Many of the current study's recommendations and national clinical guidelines agreed and disagreed. When treating center-involving DME with very good visual acuity, lattice degeneration, renal disease, anaemia, and a recent history of cardiovascular disease, there were clear disagreements.

CONCLUSION

For the first time, this study recommends DME management using large language model-based generative AI. The study's findings could guide in revising the global DME management guidelines.

Recurrent Third Nerve Paresis with Migraine: A Case Report and Review of the Literature

Ophthalmoplegic migraine (OM), first described by Charcot in 1870, is a disorder characterised by recurrent episodes of migraine associated with ophthalmoplegia. It has been extensively described in children and is rarer in adults. Commonly, the third nerve is affected with pupillary involvement and, more rarely, the fourth or the sixth nerve. OM is now believed to be an inflammatory demyelinating neuropathy. However, in the largest series of OM so far, by Lal et al. it most commonly involved the sixth nerve, started with a crescendo migraine and was accompanied by no enhancement of the cranial nerves. This has led to a rethink about the role of migraine, in the pathogenesis of OM. We describe a 14-year-old boy, with a 10-year history of intermittent headache followed by drooping of right eyelid and diplopia. The current episode started with a migrainous headache, which increased in severity over 3 days, followed by right third nerve paresis with pupillary involvement. Contrast-enhanced magnetic resonance imaging (MRI) of the brain with contrast showed nodular thickening at the root entry zone of the right oculomotor nerve with bright enhancement. The child responded to oral prednisolone, which was tapered over a month. Migraine prophylaxis with propranolol was concurrently added. His repeat MRI brain showed complete disappearance of enhancement of the lesion at 1 year.

Evolving Fuchs' uveitis - A diagnostic challenge

PURPOSE

To study cases of Fuchs' uveitis (FU) diagnosed as uveitis other than FU at initial visits.

METHODS

A retrospective, observational chart review. Details of clinical presentation, initial diagnosis, treatment details, and follow-up before and after the diagnosis of FU was studied.

RESULT

Twenty eyes of 19 patients finally diagnosed with FU. Mean total follow-up was 39 months (range: 3-120 months, median: 30 months) and follow-up after diagnosis of FU was 18 months (range: 0-84 months, median: 11 months). Most of the cases were diagnosed with anterior plus intermediate uveitis at the presentation (n = 8, 42.1%) and received steroid treatment. Keratic precipitates (KPs) typical of FU developed after mean 5.4 months of presentation (range: 1-18 months, median: 2 months). Altered iris pattern was noted after 17 months of presentation (range: 2-70 months, median: 8.5). Vitritis of grades 1-2 was present in all eyes. Overlap of uveitis of other etiology (retinal vasculitis, presumed tubercular intermediate uveitis) was found in three patients. Systemic immune disease (systemic lupus erythematosus, pulmonary sarcoidosis) was present in two patients. No treatment for the ocular inflammation was given after the diagnosis of FU in any patient and no change in the pattern of FU was observed during further follow-up.

CONCLUSION

Evolving FU may lead to misdiagnosis and mismanagement. We suggest a conservative approach, withholding steroid treatment, allowing FU to evolve, in otherwise asymptomatic patients with white eye, mild to moderate anterior chamber (AC) and vitreous inflammation, absent posterior synechiae and normal fundus examination or fundus examination suggestive of resolved uveitis.

Recommendations for initial diabetic retinopathy screening of diabetic patients using large language model-based artificial intelligence in real-life case scenarios

PURPOSE

To study the role of artificial intelligence (AI) to identify key risk factors for diabetic retinopathy (DR) screening and develop recommendations based on clinician and large language model (LLM) based AI platform opinions for newly detected diabetes mellitus (DM) cases.

METHODS

Five clinicians and three AI applications were given 20 AI-generated hypothetical case scenarios to assess DR screening timing. We calculated inter-rater agreements between clinicians, AI-platforms, and the "majority clinician response" (defined as the maximum number of identical responses provided by the clinicians) and "majority AI-platform" (defined as the maximum number of identical responses among the 3 distinct AI). Scoring was used to identify risk factors of different severity. Three, two, and one points were given to risk factors requiring screening immediately, within a year, and within five years, respectively. After calculating a cumulative screening score, categories were assigned.

RESULTS

Clinicians, AI platforms, and the "majority clinician response" and "majority AI response" had fair inter-rater reliability (k value: 0.21-0.40). Uncontrolled DM and systemic co-morbidities required immediate screening, while family history of DM and a co-existing pregnancy required screening within a year. The absence of these risk factors required screening within 5 years of DM diagnosis. Screening scores in this study were between 0 and 10. Cases with screening scores of 0-2 needed screening within 5 years, 3-5 within 1 year, and 6-12 immediately.

CONCLUSION

Based on the findings of this study, AI could play a critical role in DR screening of newly diagnosed DM patients by developing a novel DR screening score. Future studies would be required to validate the DR screening score before it could be used as a reference in real-life clinical situations.

CLINICAL TRIAL REGISTRATION

Not applicable.

Using adaptive optics to optimize the spherical aberration of eyes implanted with EDOF and enhanced monofocal intraocular lenses

PURPOSE

To assess the effect of change in ocular spherical aberration (SA) with adaptive optics on visual acuity (VA) at different defocus after implantation of extended depth-of-focus (EDOF) and enhanced monofocal intraocular lenses (IOLs).

SETTINGS

Narayana Nethralaya Eye Hospital, Bangalore, India.

DESIGN

Prospective, longitudinal, observational.

METHODS

80 eyes (40 patients) that had cataract surgery were included in the study. 40 eyes were implanted with Eyhance EDOF IOLs and the remaining with Vivity EDOF IOLs. Baseline ocular aberrations were measured with a visual adaptive optics aberrometer, then the optimal SA was determined by increasing it in steps of -0.01 μm up to -0.1 μm until the maximum improvement in near distance VA was observed for a given eye. Then the defocus curve for each eye was measured after modifying the ocular SA by magnitude equal to optimal SA.

RESULTS

Most of the eyes accepted a negative induced SA of -0.05 μm (Eyhance group: 67.6%; Vivity group, 45.2%). In the Eyhance group (dominant eyes), VA improved at -2 diopters (D) ( P < .02) only and degraded at 0 D, +0.5 D, and +1 D defocus ( P < .05). In the Vivity group, the VA remained unchanged at all defocus ( P > .05). In the Eyhance group (nondominant eyes), VA improved at -3.5 D defocus only and degraded at +1.5 D and +2 D defocus ( P < .05). In the Vivity group, VA improved at -2.5 D defocus ( P < .05) only.

CONCLUSIONS

A negative induced SA of -0.05 μm in implanted eyes was optimal for a slight improvement in distance-corrected near and intermediate VA without any significant decrease in baseline distance-corrected VA.

Inadvertent triple globe penetration during peribulbar anesthesia

Inadvertent globe perforation following peribulbar anesthesia can lead to unpleasant experiences if not identified early and managed appropriately. We present the case of a 75-year-old female who came with decreased vision in the left eye (LE) following cataract surgery under peribulbar block. Her visual acuity in the right eye (RE) was 6/24 and LE was 6/75. Fundus examination of LE showed vitreous hemorrhage with localized subretinal hemorrhage along the inferotemporal arcade suggestive of globe perforation. Optical coherence tomography (OCT, Spectralis. Heidelberg imaging, Germany) scan across the perforation site showed subretinal hemorrhage and full-thickness retinal tear. On follow-up, two more focal points of retinal whitening were noted in the inferotemporal equatorial region. The patient was kept under close monitoring, and 4 weeks later, vision improved to 6/9 and barrage laser was done around the perforation sites. Serial OCT scans and close follow-up in iatrogenic globe perforation can result in good visual outcomes.

Hyperglycemia-induced miR182-5p drives glycolytic and angiogenic response in Proliferative Diabetic Retinopathy and RPE cells via depleting FoxO1

PURPOSE

Diabetic Retinopathy (DR) is associated with metabolic dysfunction in cells such as retinal pigmented epithelium (RPE). Small molecular weight microRNAs can simultaneously regulate multiple gene products thus having pivotal roles in disease pathogenesis. Since miR182-5p is involved in regulating glycolysis and angiogenesis, two pathologic processes of DR, we investigated its status in DR eyes and in high glucose model in vitro.

METHOD

ology: Total RNA was extracted from vitreous humor of PDR (n = 48) and macular hole (n = 22) subjects followed by quantification of miR182-5p and its target genes. ARPE-19 cells, cultured in DMEM under differential glucose conditions (5 mM and 25 mM) were used for metabolic and biochemical assays. Cells were transfected with miRNA182 mimic or antagomir to evaluate the gain and loss of function effects.

RESULTS

PDR patient eyes had high levels of miR182-5p levels (p < 0.05). RPE cells under high glucose stress elevated miR182-5p expression with altered glycolytic pathway drivers such as HK2, PFKP and PKM2 over extended durations. Additionally, RPE cells under high glucose conditions exhibited reduced FoxO1 and enhanced Akt activation. RPE cells transfected with miR182-5p mimic phenocopied the enhanced basal and compensatory glycolytic rates observed under high glucose conditions with increased VEGF secretion. Conversely, inhibiting miR182-5p reduced Akt activation, glycolytic pathway proteins, and VEGF while stabilizing FoxO1.

CONCLUSION

Glycolysis-associated proteins downstream of the FoxO1-Akt axis were regulated by miR182-5p. Further, miR182-5p increased expression of VEGFR2 and VEGF levels, likely via inhibition of ZNF24. Thus, the FoxO1-Akt-glycolysis/VEGF pathway driving metabolic dysfunction with concurrent angiogenic signaling in PDR may be potentially targeted for treatment via miR182-5p modulation.

Minimum Corneal Diameter and Anterior Steep Axis Curvature Share the Same Meridian: A Novel Finding

PURPOSE

To define the external scleral sulcus (ESS) on a Scheimpflug image and use it for a morphometric analysis of corneal diameter (CD).

DESIGN

Retrospective, cross-sectional study of pediatric Asian-Indian eyes.

METHODS

One random eye of 353 subjects between 5 and 18 years underwent 25-scan Pentacam HR imaging. For all scans, densitometry values along the anterior corneal edge were recorded and differentiated. The peaks on the differentiated curve were chosen as the ESS points, and this distance between them was called CD. Vertical (vCD), maximum (maxCD), minimum (minCD) CD and their meridians were defined. Multiple regression models (MRMs) with CD and other Pentacam parameters were built to predict astigmatism and its axis, mean keratometry (Kmean), and Belin/Ambrósio enhanced ectasia display deviation (BAD-D). MRMs were validated using intraclass correlation coefficient (ICC). Estimated horizontal CD (hCD) was validated against digital caliper measurement using ICC.

RESULTS

The ICC (95% CI) between caliper and hCD was 0.96 (0.93, 0.97). MRM predictions (P < .001) used CD parameters, anterior chamber depth, corneal volume and distance from the corneal thinnest location to apex. These predictions achieved an ICC of 0.34 (0.18, 0.46), 0.82 (0.78, 0.86), 0.87 (0.84, 0.89), and 0.81 (0.76, 0.84), respectively. The astigmatism axis prediction depended on the minCD and maxCD meridians. Its within-subject SD (4.97°) was less than 2 consecutive Pentacam scan angles (7.2°).

CONCLUSIONS

The CD metric strongly correlated with the astigmatism axis, keratometry, and BAD-D. Its spatial description may be significant in corneal treatment planning and disease diagnoses.

Corneal stromal regeneration-keratoconus cell therapy: a review

BACKGROUND

Keratoconus is a corneal ectatic disease caused by stromal thinning leading to astigmatism and progressive loss of vision. Loss of the keratocytes and excessive degradation of collagen fibres by matrix metalloproteinases are the molecular signatures of the disease. Despite several limitations, corneal collagen cross-linking and keratoplasty are the most widely used treatment options for keratoconus. In the pursuit of alternative treatment modalities, clinician scientists have explored cell therapy paradigms for treating the condition.

METHODS

Articles pertaining to keratoconus cell therapy with relevant key words were used to search in PubMed, Researchgate, and Google Scholar. The articles were selected based on their relevance, reliability, publication year, published journal, and accessibility.

RESULTS

Various cellular abnormalities have been reported in keratoconus. Diverse cell types such as mesenchymal stromal cells, dental pulp cells, bone marrow stem cells, haematopoietic stem cells, adipose-derived stem cells apart from embryonic and induced pluripotent stem cells can be used for keratoconus cell therapy. The results obtained show that there is a potential for these cells from various sources as a viable treatment option.

CONCLUSION

There is a need for consensus with respect to the source of cells, mode of delivery, stage of disease, and duration of follow-up, to establish a standard operating protocol. This would eventually widen the cell therapy options for corneal ectatic diseases beyond keratoconus.

Simultaneous Topography-guided Custom Ablation With Corneal Cross-linking for Keratoconus: 10-Year Prospective Outcomes

PURPOSE

To assess 10-year visual and tomographic outcomes of topography-guided custom ablation (T-CAT) with corneal cross-linking (CXL) in eyes with keratoconus.

METHODS

T-CAT with CXL was performed in 600 eyes (522 patients). Based on the T-CAT ablation plan, the theoretical maximum ablation depth was 50 µm after epithelium removal. After ablation, accelerated corneal cross-linking (CXL) was performed in the central 8-mm zone (9 mW/cm2 for 10 minutes in "epi-off" mode). The visual acuity and tomography were assessed.

RESULTS

There was significant improvement in uncorrected (P = .001) and corrected (P = .001) distance visual acuity after the procedure. Keratometry, root mean square lower order aberrations and higher order aberrations, defocus, coma 90°, and spherical aberration reduced significantly after surgery at 10 years of follow-up (P < .005). All Pentacam (Oculus Optikgerate GmbH) tomographic variables showed significant changes indicating regularization after T-CAT (P < .005). Flattening of greater than 5.00 diopters in maximum keratometry was noted in 6 eyes (1%). Two of 600 eyes progressed postoperatively and required repeat CXL.

CONCLUSIONS

T-CAT plus CXL is a safe and effective technique even in the long term for regularizing the anterior corneal surface with significant visual improvement and reduction in higher order corneal aberrations. [J Refract Surg. 2023;39(11):759-766.].

Early detection and correlation of tear fluid inflammatory factors that influence angiogenesis in premature infants with and without retinopathy of prematurity

Purpose

To measure the levels of inflammatory factors in tear fluid of pre-term infants with and without retinopathy of prematurity (ROP).

Methods

The cross-sectional pilot study included 29 pre-term infants undergoing routine ROP screening. Pre-term infants were grouped as those without ROP (no ROP; n = 14) and with ROP (ROP; n = 15). Sterile Schirmer's strips were used to collect the tear fluid from pre-term infants. Inflammatory factors such as interleukin (IL)-6, IL-8, MCP1 (Monocyte Chemoattractant Protein 1; CCL2), RANTES (Regulated on Activation, Normal T Cell Expressed and Secreted; CCL5), and soluble L-selectin (sL-selectin) were measured by cytometric bead array using a flow cytometer.

Results

Birth weight (BW) and gestation age (GA) were significantly (P < 0.05) lower in pre-term infants with ROP compared with those without ROP. Higher levels of RANTES (P < 0.05) and IL-8 (P = 0.09) were observed in the tear fluid of pre-term infants with ROP compared with those without ROP. Lower levels of tear fluid IL-6 (P = 0.14) and sL-selectin (P = 0.18) were measured in pre-term infants with ROP compared with those without ROP. IL-8 and RANTES were significantly (P < 0.05) higher in the tear fluid of pre-term infants with stage 3 ROP compared with those without ROP. Tear fluid RANTES level was observed to be inversely associated with GA and BW of pre-term infants with ROP and not in those without ROP. Furthermore, the area under the curve and odds ratio analysis demonstrated the relevance of RANTES/BW (AUC = 0.798; OR-7.2) and RANTES/MCP1 (AUC = 0.824; OR-6.8) ratios in ROP.

Conclusions

Distinct changes were observed in the levels of tear inflammatory factors in ROP infants. The status of RANTES in ROP suggests its possible role in pathobiology and warrants further mechanistic studies to harness it in ROP screening and management.

Depleted hexokinase1 and lack of AMPKα activation favor OXPHOS-dependent energetics in retinoblastoma tumors

Lack of retinoblastoma (Rb) protein causes aggressive intraocular retinal tumors in children. Recently, Rb tumors have been shown to have a distinctly altered metabolic phenotype, such as reduced expression of glycolytic pathway proteins alongside altered pyruvate and fatty acid levels. In this study, we demonstrate that loss of hexokinase 1(HK1) in tumor cells rewires their metabolism allowing enhanced oxidative phosphorylation-dependent energy production. We show that rescuing HK1 or retinoblastoma protein 1 (RB1) in these Rb cells reduced cancer hallmarks such as proliferation, invasion, and spheroid formation and increased their sensitivity to chemotherapy drugs. Induction of HK1 was accompanied by a metabolic shift of the cells to glycolysis and a reduction in mitochondrial mass. Cytoplasmic HK1 bound Liver Kinase B1 and phosphorylated AMP-activated kinase-α (AMPKα Thr172), thereby reducing mitochondria-dependent energy production. We validated these findings in tumor samples from Rb patients compared to age-matched healthy retinae. HK1 or RB1 expression in Rb-/- cells led to a reduction in their respiratory capacity and glycolytic proton flux. HK1 overexpression reduced tumor burden in an intraocular tumor xenograft model. AMPKα activation by AICAR also enhanced the tumoricidal effects of the chemotherapeutic drug topotecan in vivo. Therefore, enhancing HK1 or AMPKα activity can reprogram cancer metabolism and sensitize Rb tumors to lower doses of existing treatments, a potential therapeutic modality for Rb.

Retinal organoids in disease modeling and drug discovery: Opportunities and challenges

Diseases leading to retinal cell loss can cause severe visual impairment and blindness. The lack of effective therapies to address retinal cell loss and the absence of intrinsic regeneration in the human retina leads to an irreversible pathological condition. Progress in recent years in the generation of human three-dimensional retinal organoids from pluripotent stem cells makes it possible to recreate the cytoarchitecture and associated cell-cell interactions of the human retina in remarkable detail. These human three-dimensional retinal organoid systems made of distinct retinal cell types and possessing contextual physiological responses allow the study of human retina development and retinal disease pathology in a way animal model and two-dimensional cell cultures were unable to achieve. We describe the derivation of retinal organoids from human pluripotent stem cells and their application for modeling retinal disease pathologies, while outlining the opportunities and challenges for its application in academia and industry.

Correlation between tear levels of vascular endothelial growth factor and vitamin D at retinopathy of prematurity stages in preterm infants

Deregulation of vascular endothelial growth factor (VEGF) levels leads to retinopathy of prematurity (ROP). Vitamin D (VIT-D) is known to regulate VEGF in an oxygen dependent manner. The purpose of this study was to correlate tear levels of VEGF and VIT-D with different ROP stages in preterm infants. In this prospective cross-sectional study, we enrolled 104 pre-term infants. They were grouped into: Group-1 (Classical ROP) and Group-2 (Aggressive ROP), which were further subdivided into Group-1A (progressing), Group-1B (regressing), Group-2A (pre-treatment), and Group-2B (post-treatment). Tear VEGF and VIT-D levels and their association with different ROP stages were assessed. Stage 1 and stage 2 had higher whereas stage 3 had lower VEGF levels in Group-1B compared to Group-1A. Stage 1 and stage 3 showed higher levels of VIT-D with no difference in stage 2 in Group-1B compared to Group-1A., Group-2B showed higher VEGF and lower VIT-D levels compared to Group-2A. Presence of a positive correlation at an early stage (stage 1) of ROP and a negative correlation at a more advanced stage (stage 3) of ROP with VIT-D and VEGF implies stage-specific distinct signaling crosstalk. These findings suggest that VIT-D supplementation may have the potential to modify the course and outcome of ROP.

Ocular manifestations following COVID-19 vaccination

BACKGROUND

Immunologic and inflammatory adverse effects following vaccination against COVID-19 are being reported. While some reactions may develop denovo others concern its immunogenic effect in patients with pre-existing inflammatory conditions.

METHODS

Retrospective consecutive patients diagnosed with ocular inflammatory manifestations within 8 weeks of receiving COVID-19 vaccination who presented to a tertiary eye care centre in South India.

RESULTS

Ninety-eight eyes of 67 patients presenting with ocular inflammatory manifestations within 8 weeks following COVID-19 vaccination were studied. The mean age was 43 years (+/- 14.82; range 19-80 years). The most common presentations were anterior uveitis (n = 31, 31.7%), followed by panuveitis (n = 24, 24.5%). The mean time to onset of symptoms was 25 days (+/- 15.48; range 2-55 days) following a dose of vaccine. Among all patients, 39 (58.2%) had a previous history of ocular inflammation. Mean presenting visual acuity was 0.4 (0-4) logMAR units and mean final visual acuity was 0.2 (0-4) logMAR units. The causes for reduced vision included of cystoid macular edema (n=2, 2%), chorioretinal atrophy (n=2.2%), optic atrophy (n=1.1%), retinal vascular occlusion (n=1.1%) and acute retinal necrosis (n=1.1%).

CONCLUSION

Infective and immunogenic adverse events should be watched out for after COVID-19 vaccination. It is difficult to establish causality for such manifestations, nevertheless, most of them were mild and had good final visual outcomes.

Comparison of intraocular lens power prediction accuracy of formulas in American Society of Cataract and Refractive Surgery post-refractive surgery calculator in eyes with prior radial keratotomy

Purpose

To evaluate the accuracy of intraocular lens (IOL) power prediction of the formulas available on the American Society of Cataract and Refractive Surgery (ASCRS) post-refractive calculator in eyes with prior radial keratotomy (RK) for myopia.

Methods

This retrospective study included 25 eyes of 18 patients whose status was post-RK for treatment of myopia, which had undergone cataract extraction with IOL implantation. Prediction error was calculated as the difference between implanted IOL power and predicted power by various formulae available on ASCRS post-refractive calculator. The formulas compared were Humphrey Atlas method, IOLMaster/Lenstar method, Barrett True-K no-history formula, ASCRS Average power, and ASCRS Maximum power on ASCRS post-refractive calculator.

Results

Median absolute errors were the least for Barrett True-K and ASCRS Maximum power, that is, 0.56 (0.25, 1.04) and 0.56 (0.25, 1.06) D, respectively, and that of Atlas method was 1.60 (0.85, 2.28) D. Median arithmetic errors were positive for Atlas, Barrett True-K, ASCRS Average (0.86 [-0.17, 1.61], 0.14 [-0.22 to 0.54], and 0.23 [-0.054, 0.76] D, respectively) and negative for IOLMaster/Lenstar method and ASCRS Maximum power (-0.02 [-0.46 to 0.38] and - 0.48 [-1.06 to - 0.22] D, respectively). Multiple comparison analysis of Friedman's test revealed that Atlas formula was significantly different from IOLMaster/Lenstar, Barrett True-K, and ASCRS Maximum power; ASCRS Maximum power was significantly different from all others (P < 0.00001).

Conclusion

In post-RK eyes, Barrett True-K no-history formula and ASCRS Maximum power given by the ASCRS calculator were more accurate than other available formulas, with ASCRS Maximum leading to more myopic outcomes when compared to others.

Visual Fields in Epidemic Retinitis

AIM

The aim of the study is to analyze visual fields defects (VFDs) in epidemic retinitis (ER).

METHODS

Patients with ER and Humphrey's visual field (HFA) 30-2 performed after resolution were studied. VFD severity grading was performed. Patients treated with oral doxycycline (Group-A) versus doxycycline-steroids (group-B) were compared.

RESULTS

Thirty-five eyes of 25 patients were studied. Nasal, inferior, temporal and central VFD were seen in 19 (54.2%), 13 (37.1%), 7 (20%) and 6 (17.1%) eyes, respectively. Grade 0, 1, 2 and 3 VFDs were seen in 4 (11.4%), 15 (42.8%), 12 (34.2%) and 4 (11.4%) eyes respectively. Seven eyes with ≥1 year of follow-up post-resolution also showed grade 0-3 scotomas. Mean severity of scotoma was grade 1.15 (Median: 1) and 1.42 (Median: 1.5) in groups A (n = 13) and B (n = 14), respectively (p = .637).

CONCLUSION

ER can cause VFD persisting long after resolution. Treatment with oral doxycycline without steroids was non-inferior to combined treatment with respect to VFD.

Hemophagocytic Lymphohistiocytosis After Dengue Fever and Its Ocular Features

This case report discusses a diagnosis of hemophagocytic lymphohistiocytosis in a man aged 40 years with a history of dengue fever.

Scleritis and Episcleritis following Coronavirus Disease (COVID-19) Vaccination

INTRODUCTION

Coronavirus disease (COVID-19) vaccines have been reported to have ocular side effects including scleritis and episcleritis.

PURPOSE

To report scleritis and episcleritis within a month following administration of COVID-19 vaccine.

METHODS

Retrospective case series.

RESULTS

15 eyes of 12 consecutive patients with scleritis and episcleritis from March 2021 to September 2021 were included. The mean time of onset of symptoms in patients with scleritis was 15.7 days (range, 4-30) and for episcleritis it was 13.2 days (range 2-30). Patients received COVISHIELD™ (10 patients) and COVAXIN™ (2 patients). Five patients had denovo inflammation and seven had recurrent inflammation. Episcleritis patients were treated with topical steroids and systemic COX2 inhibitors while patients with scleritis were treated with topical steroids/oral steroids/antiviral medications depending on the aetiology.

CONCLUSION

Scleritis and episcleritis following COVID-19 vaccination are milder and do not require intensive immunosuppression except in rare cases.

Coronavirus disease 19 (COVID-19) and viral keratouveitis - unraveling the mystery

To demonstrate viral proteins/inflammatory cytokines in a patient with unilateral keratouveitis. Retrospective case report. A 70-year-old Asian-Indian male presented with acute onset of blurring of vision in the left eye (OS) of 2 days duration. He had was coronavirus disease 2019 (COVID-19)-positive 3 months earlier. He had undergone cataract surgery/retinal laser photocoagulation in both the eyes. The corrected distance visual acuity (CDVA) (Snellen) in the right eye (RE) (OD) and left eye (LE) (OS) was 20/20 and 20/80, respectively. OS showed decreased corneal sensation, Descemet's folds, mild stromal edema, and fine and pigmented keratic precipitates with anterior chamber 1+ flare and 1+ cells. Fundus evaluation showed scattered laser marks in the OD and temporal sectoral laser marks in OS. He was diagnosed with viral keratouveitis in OS. Tear samples were collected on Schirmer's strips and tear wash for mass spectrometry and cytokines, which had 368 and 451 viral proteins in the RE and LE, respectively, using nano liquid chromatography-mass spectrometry, which were more than controls. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and varicella zoster virus proteins were detected. Cytokine analysis using flow cytometer analysis showed higher inflammation in OS as compared to OD. The patient was treated with oral acyclovir and topical steroids and resulted in resolution of his keratouveitis. SARS-CoV-2 proteins were present in the tear sample 3 months after COVID-19. The presence of viral proteins does not indicate causality.

Choroidal Involvement and Chronic Macular Edema in Acute Retinal Necrosis: A Novel Finding and a Novel Treatment

Acute retinal necrosis (ARN) as the term suggests is recognized as necrotic inflammation of retina, in contrast to toxoplasma retinochoroiditis where involvement of choroid can be appreciated as choroidal thickening on optical coherence tomography scan during active stage. Secondly, sequelae of ARN, such as chronic anterior uveitis and cystoid macular edema, could be challenging to manage as steroid use in various forms poses a risk of virus reactivation. We present a case of ARN caused by varicella zoster virus with an initial confusing clinical picture with toxoplasma retinochoroiditis, documented with choroidal involvement. The patient also developed a chronic anterior uveitis with macular edema after resolution of ARN which was treated with topical interferon (IFN) alfa 2b therapy with successful outcome. This report supports the recently described choroidal involvement in ARN and suggests topical IFN as a novel treatment in management of chronic macular edema post ARN.

New simulation software to predict postoperative corneal stiffness before laser vision correction

PURPOSE

To develop a new virtual surgery simulation platform to predict postoperative corneal stiffness (Kc mean ) after laser vision correction (LVC) surgery.

SETTING

Narayana Nethralaya Eye Hospital and Sankara Nethralaya, India; Humanitas Clinical and Research Center, Italy.

DESIGN

Retrospective observational case series.

METHODS

529 eyes from 529 patients from 3 eye centers and 10 post-small-incision lenticule extraction (SMILE) ectasia eyes were included. The software (called AcuSimX) derived the anisotropic, fibril, and extracellular matrix biomechanical properties (using finite element calculation) of the cornea using the preoperative Corvis-ST, Pentacam measurement, and inverse finite element method assuming published healthy collagen fibril orientations. Then, the software-computed postoperative Kc mean was adjusted with an artificial intelligence (AI) model (Orange AI) for measurement uncertainties. A decision tree was developed to classify ectasia from normal eyes using the software-computed and preoperative parameters.

RESULTS

In the training cohort (n = 371 eyes from 371 patients), the mean absolute error and intraclass correlation coefficient were 6.24 N/m and 0.84 (95% CI, 0.80-0.87), respectively. Similarly, in the test cohort (n = 158 eyes from 158 patients), these were 6.47 N/m and 0.84 (0.78-0.89), respectively. In the 10 ectasia eyes, the measured in vivo (74.01 [70.01-78.01]) and software-computed (74.1 [69.03-79.17]) Kc mean were not statistically different ( P = .96). Although no statistically significant differences in these values were observed between the stable and ectasia groups ( P ≥ .14), the decision tree classification had an area under the receiver operating characteristic curve of 1.0.

CONCLUSIONS

The new software provided an easy-to-use virtual surgery simulation platform for post-LVC corneal stiffness prediction by clinicians and was assessed in post-SMILE ectasia eyes. Further assessments with ectasia after surgeries are required.

Efficacy of customized corneal crosslinking versus standard corneal crosslinking in patients with progressive keratoconus (C-CROSS study): study protocol for a randomized controlled trial

BACKGROUND

Keratoconus is a degenerative disorder of the cornea leading to a protrusion and thinning with loss of visual acuity. The only treatment to halt the progression is corneal crosslinking (CXL), which uses riboflavin and UV-A light to stiffen the cornea. Recent ultra-structural examinations show that the disease is regional and does not affect the entire cornea. Treating only the affected zone with CXL could be as good as the standard CXL, that treats the entire cornea.

METHODS

We set up a multicentre non-inferiority randomized controlled clinical trial comparing standard CXL (sCXL) and customized CXL (cCXL). Patients between 16 and 45 years old with progressive keratoconus were included. Progression is based on one or more of the following changes within 12 months: 1 dioptre (D) increase in keratometry (Kmax, K1, K2); or 10% decrease of corneal thickness; or 1 D increase in myopia or refractive astigmatism, requiring corneal crosslinking.

DISCUSSION

The goal of this study is to evaluate whether the effectiveness of cCXL is non-inferior to sCXL in terms of flattening of the cornea and halting keratoconus progression. Treating only the affected zone could be beneficial for minimalizing the risk of damaging surrounding tissues and faster wound healing. Recent non-randomized studies suggest that a customized crosslinking protocol based on the tomography of the patient's cornea may stop the progression of keratoconus and result in flattening of the cornea.

TRIAL REGISTRATION

This study was prospectively registered at ClinicalTrials.gov on August 31^st, 2020, the identifier of the study is NCT04532788.

Distinct gene expression profiles underlie morphological and etiological differences in pediatric cataracts

Purpose

Pediatric cataract is a major cause of preventable childhood blindness worldwide. Although genetic mutations or infections have been described in patients, the mechanistic basis of human cataract development remains poorly understood. Therefore, gene expression of structural, developmental, profibrotic, and transcription factors in phenotypically and etiologically distinct forms of pediatric cataracts were evaluated.

Methods

This cross-sectional study included 89 pediatric cataract subjects subtyped into 1) prenatal infectious (cytomegalovirus, rubella, and combined cytomegalovirus with rubella infection), 2) prenatal non-infectious, 3) posterior capsular anomalies, 4) postnatal, 5) traumatic, and 6) secondary, and compared to clear, non-cataractous material of eyes with the subluxated lenses. Expression of lens structure-related genes (Aqp-0, HspA4/Hsp70, CrygC), transcription factors (Tdrd7, FoxE3, Maf, Pitx 3) and profibrotic genes (Tgfβ, Bmp7, αSmA, vimentin) in surgically extracted cataract lens material were studied and correlated clinically.

Results

In cataract material, the lens-related gene expression profiles were uniquely associated with phenotype/etiology of different cataracts. Postnatal cataracts showed a significantly altered FoxE3 expression. Low levels of Tdrd7 expression correlated with posterior subcapsular opacity, whereas CrygC correlated significantly with anterior capsular ruptures. The expression of Aqp0 and Maf was elevated in infectious cataracts, particularly in CMV infections, compared to other cataract subtypes. Tgfβ showed significantly low expression in various cataract subtypes, whereas vimentin had elevated gene expression in infectious and prenatal cataracts.

Conclusion

A significant association between lens gene expression patterns in phenotypically and etiologically distinct subtypes of pediatric cataracts suggests regulatory mechanisms in cataractogenesis. The data reveal that cataract formation and presentation is a consequence of altered expression of a complex network of genes.

Choroidal lesions in varicella zoster virus uveitis

Purpose

To evaluate choroidal lesions with spectral domain optical coherence tomography (SD-OCT) scan in varicella zoster virus (VZV) uveitis.

Methods

VZV-uveitis cases which underwent OCT scan for choroidal lesions were studied. SD-OCT scan passing through these lesions was studied in detail. Subfoveal choroidal thickness (SFCT) during active and resolved stages was studied. Angiogaphic features were studied where available.

Results

Thirteen out of 15 cases had same-sided herpes zoster ophthalmicus skin rashes. All except three patients had old or active kerato-uveitis. All eyes demonstrated clear vitreous and a single or multiple hypopigmented orangish-yellow choroidal lesions. The number of lesions remained unchanged during the follow-up on clinical examination. SD-OCT over lesions (n = 11) showed choroidal thinning (n = 5), hyporeflective choroidal elevation during active inflammation (n = 3), transmission effects (n = 4), and ellipsoid zone disruption (n = 7). The mean change in SFCT (n = 9) after resolution of the inflammation was 26.3 μm (range: 3-90 μm). Fundus fluorescein angiography showed iso-fluorescence over lesions in all (n = 5), but indocyanine green angiography (n = 3) showed hypofluorescence at lesions. Mean follow-up was 1.38 years (range: 3 months-7 years). De-novo appearance of choroidal lesion during the first relapse of VZV-uveitis was captured in one case.

Conclusion

VZV-uveitis can cause focal or multifocal hypopigmented choroidal lesions with thickening or scarring of choroidal tissue, depending on the disease activity.

Artificial intelligence-based stratification of demographic, ocular surface high-risk factors in progression of keratoconus

Purpose

The purpose of this study was to identify and analyze the clinical and ocular surface risk factors influencing the progression of keratoconus (KC) using an artificial intelligence (AI) model.

Methods

This was a prospective analysis in which 450 KC patients were included. We used the random forest (RF) classifier model from our previous study (which evaluated longitudinal changes in tomographic parameters to predict "progression" and "no progression") to classify these patients. Clinical and ocular surface risk factors were determined through a questionnaire, which included presence of eye rubbing, duration of indoor activity, usage of lubricants and immunomodulator topical medications, duration of computer use, hormonal disturbances, use of hand sanitizers, immunoglobulin E (IgE), and vitamins D and B12 from blood investigations. An AI model was then built to assess whether these risk factors were linked to the future progression versus no progression of KC. The area under the curve (AUC) and other metrics were evaluated.

Results

The tomographic AI model classified 322 eyes as progression and 128 eyes as no progression. Also, 76% of the cases that were classified as progression (from tomographic changes) were correctly predicted as progression and 67% of cases that were classified as no progression were predicted as no progression based on clinical risk factors at the first visit. IgE had the highest information gain, followed by presence of systemic allergies, vitamin D, and eye rubbing. The clinical risk factors AI model achieved an AUC of 0.812.

Conclusion

This study demonstrated the importance of using AI for risk stratification and profiling of patients based on clinical risk factors, which could impact the progression in KC eyes and help manage them better.

Cold bandage contact lens use reduces post-photorefractive keratectomy or corneal collagen-crosslinking pain perception in patients

Purpose

To compare post-operative pain perception using bandage contact lens (BCL) stored at 2-8°C (Cold BCL, CL-BCL) or room temperature (23 - 25°C, RT-BCL) after photorefractive keratectomy (PRK) or corneal collagen-crosslinking (CXL) and determine status of nociception associated factors.

Methods

In this prospective interventional study, 56 patients undergoing PRK for refractive correction and 100 keratoconus (KC) undergoing CXL were recruited following approval from the institutional ethics committee with informed consent. Patients undergoing bilateral PRK received RT-BCL on one eye and CL-BCL on the other. Pain was graded by Wong-Baker scoring on the first post-operative day (PoD1). Expression of transient receptor potential channels (TRPV1, TRPA1, TRPM8), calcitonin gene-related peptide (CGRP) and IL-6 was measured in cellular content from used BCLs collected on PoD1. Equal number of KC patients received RT-BCL or CL-BCL post-CXL. Pain was graded by Wong-Baker scoring on PoD1.

Results

Pain scores on PoD1 were significantly (P < 0.0001) reduced in subjects receiving CL-BCL (Mean ± SD: 2.6 ± 2.1) compared to RT-BCL (6.0 ± 2.4) post-PRK. 80.4% of subjects reported reduced pain scores with CL-BCL. 19.6% reported no change or increased pain scores with CL-BCL. TRPM8 expression was significantly (P < 0.05) increased in BCL of subjects reporting reduced pain with CL-BCL compared to those who did not. Pain scores on PoD1 were significantly (P < 0.0001) reduced in subjects receiving CL-BCL (3.2 ± 2.1) compared to RT-BCL (7.2 ± 1.8) post-CXL.

Conclusion

The simple approach of using a cold BCL post-operatively substantially reduced pain perception and could overcome post-operative pain-related limited acceptance of PRK/CXL.

Corneal Regeneration Using Gene Therapy Approaches

One of the most remarkable advancements in medical treatments of corneal diseases in recent decades has been corneal transplantation. However, corneal transplants, including lamellar strategies, have their own set of challenges, such as graft rejection, delayed graft failure, shortage of donor corneas, repeated treatments, and post-surgical complications. Corneal defects and diseases are one of the leading causes of blindness globally; therefore, there is a need for gene-based interventions that may mitigate some of these challenges and help reduce the burden of blindness. Corneas being immune-advantaged, uniquely avascular, and transparent is ideal for gene therapy approaches. Well-established corneal surgical techniques as well as their ease of accessibility for examination and manipulation makes corneas suitable for in vivo and ex vivo gene therapy. In this review, we focus on the most recent advances in the area of corneal regeneration using gene therapy and on the strategies involved in the development of such therapies. We also discuss the challenges and potential of gene therapy for the treatment of corneal diseases. Additionally, we discuss the translational aspects of gene therapy, including different types of vectors, particularly focusing on recombinant AAV that may help advance targeted therapeutics for corneal defects and diseases.

Automatic segmentation and quantified analysis of meibomian glands from infrared images

Purpose

An algorithm for automated segmentation of meibomian glands from infrared images obtained using a novel prototype infrared hand-held imager has been proposed in this study. Meibomian gland dysfunction (MGD) is quantified in terms of five clinically relevant metrics. A comparison of these metrics in patients with MGD has been presented against a sample of the normative healthy population.

Methods

This is a prospective cross-sectional observational study. Patients presenting to the clinics were enrolled after written informed consent. The everted eyelids of 200 eyes of patients (of which 100 were healthy and 100 were diagnosed with MGD) were imaged using a prototype hand-held camera. The proposed algorithm was used to process the images using enhancement techniques and the glands were automatically segmented. A comparison of glands of normal eyes versus MGD-affected eyes is performed using five metrics presented in this study: (i) drop-out, (ii) length, (iii) width, (iv) the number of glands, and (v) the number of tortuous glands.

Results

The 95% confidence interval for the metrics did not show any overlap between the two groups. In MGD patients, the drop-out ratio was higher than normal. The length and number of glands were significantly lesser than normal. A number of tortuous glands were more in the MGD group. The metrics for MGD versus healthy and cut-off ranges were computed in the results.

Conclusion

The prototype infrared hand-held meibographer and the proposed automatic algorithm for gland segmentation and quantification are effective aids in MGD diagnosis. We present a set of five metrics, which are clinically relevant for guiding clinicians in the diagnosis of MGD.

Type 1-type 2 interferon imbalance in dry eye disease

Purpose

Dry eye disease (DED) is characterized by altered ocular surface proinflammatory and antiinflammatory factors. Interferons (IFNs) are a class of pleiotropic cytokines well known for their antimicrobial, inflammatory, and immunomodulatory roles. Hence, this study investigates the ocular surface expression of different types of IFNs in patients with DED.

Methods

The cross-sectional, observational study included patients with DED and normal subjects. Conjunctival impression cytology (CIC) samples were obtained from the study subjects (controls, n = 7; DED, n = 8). The mRNA expression levels of type 1 IFN (IFNα, IFNβ), type 2 IFN (IFNγ), and type 3 IFN (IFNλ1, IFNλ2, IFNλ3) were measured by quantitative PCR (polymerase chain reaction) in CIC samples. IFNα and IFNγ expression under hyperosmotic stress was also studied in human corneal epithelial cells (HCECs) in vitro.

Results

The mRNA expression levels of IFNα and IFNβ were significantly lower and that of IFNγ was significantly higher in DED patients compared to healthy controls. The mRNA levels of IFNα, IFNβ, and IFNλ were significantly lower compared to IFNγ in DED patients. An inverse association between tonicity-responsive enhancer-binding protein (TonEBP; hyperosmotic stress maker) and IFNα or IFNβ expression and a positive association between TonEBP and IFNγ expression was observed in CIC samples. The expression of IFNα was lower than IFNγ in HCECs undergoing hyperosmotic stress compared to HCECs without the stress.

Conclusion

The presence of an imbalance between type 1 and type 2 IFNs in DED patients suggests newer pathogenic processes in DED, plausible ocular surface infection susceptibility in DED patients, and potential therapeutic targets in the management of DED.

Effect of maqui-berry extract in dry eye disease - A clinical and molecular analysis

Purpose

This study aims to investigate the effects of maqui-berry extract (MBE) in improving signs and symptoms of dry eye disease (DED) along with ocular surface inflammation in patients with DED.

Methods

Twenty patients were randomly assigned to a MBE or a placebo group (PLC). DED parameters including Schirmer's test 1 (ST1), tear film break-up time (TBUT), ocular surface disease index (OSDI), and corneal staining were assessed before treatment and 2 months post-treatment. Tear fluid samples before and after treatment from a subset of these patients were collected from the study subjects using sterile Schirmer's strips, and the levels of interleukin (IL)-1β, IL-10, IL-6, IL-17A, tumor necrosis factor-α (TNFα), matrix metalloproteinase-9 (MMP9), soluble intercellular adhesion molecule-1 (sICAM1), and vascular endothelial growth factor-A (VEGF-A) were measured using a microfluidic cartridge-based multiplex ELISA.

Results

The MBE group demonstrated a significant (p < 0.05) decrease in OSDI scores along with a significant increase in Schirmer's test 1 compared to the PLC group. No significant change in TBUT and corneal staining was observed between the study groups. Levels of proinflammatory factors such as IL-1β, IL-6, IL-17A, TNFα, and MMP9 were observed to be significantly reduced, along with a significant increase in IL-10 levels following treatment in the MBE group compared with the PLC group.

Conclusion

Consumption of MBE resulted in the resolution of DED signs and symptoms, along with a reduction in ocular surface inflammation.

Autophagy in dry eye disease: Therapeutic implications of autophagy modulators on the ocular surface

Dry eye disease (DED) is a chronic ocular surface disorder, associated with inflammation, which can cause severe morbidity, visual compromise, and loss of quality of life, affecting up to 5-50% of the world population. In DED, ocular surface damage and tear film instability due to abnormal tear secretion lead to ocular surface pain, discomfort, and epithelial barrier disruption. Studies have shown the involvement of autophagy regulation in dry eye disease as a pathogenic mechanism along with the inflammatory response. Autophagy is a self-degradation pathway in mammalian cells that reduces the excessive inflammation driven by the secretion of inflammatory factors in tears. Specific autophagy modulators are already available for the management of DED currently. However, growing studies on autophagy regulation in DED might further encourage the development of autophagy modulating drugs that reduce the pathological response at the ocular surface. In this review, we summarize the role of autophagy in the pathogenesis of dry eye disease and explore its therapeutic application.

Vitamin D and eye: Current evidence and practice guidelines

Vitamin D is a steroid hormone that has widespread role in human physiology, not only in the maintenance of calcium homeostasis but also in immunomodulation, cellular differentiation, and proliferation. The immunomodulatory effects of vitamin D are well known and are applicable to the ocular surface immune cells and structural cells. The role of vitamin D in ocular surface conditions such as dry eye disease (DED), keratoconus (KC), and post-surgical outcomes has received widespread and well-deserved attention. Vitamin D supplementation is shown to improve DED clinically as well as in experimental models. The anti-inflammatory properties may be crucial in the treatment of ocular surface conditions such as DED and KC. Vitamin D plays a multifaceted role in corneal wound healing with its anti-inflammatory and extracellular matrix remodeling properties. In this review, we discuss how to approach patients with DED and those undergoing refractive surgery with the available basic and clinical knowledge on the role of vitamin D in these conditions. We aim to highlight the importance of clinically harnessing vitamin D-mediated natural immuno-inflammatory modulation in combination with currently available standard of care strategies to reduce the morbidity and disease duration associated with ocular surface diseases.

Nexus of ocular motility and dry eye

Purpose

To evaluate the effectiveness of vision therapy (VT) in patients with chronic presumed refractory dry eye disease (DED) and concurrent nonstrabismic binocular vision anomalies (NSBVAs). To propose an algorithmic approach to manage patients with refractory DED.

Methods

Thirty-two patients with chronic (>1 year) presumed refractory DED and NSBVA were prospectively evaluated. The baseline dry eye evaluation and comprehensive orthoptic evaluation were done. VT was administered by a trained orthoptist for 2 weeks. The binocular vision (BV) parameters and percentage subjective improvement were assessed after the VT.

Results

On evaluation, 12 patients (37.5%) had both DED and NSBVA, and 20 patients (62.5%) had only NSBVA. Twenty-nine patients (90.62%) showed significant improvement in BV parameters following VT. Binocular near point of accommodation (median, range) improved from 17 (8-40) to 12 (5-26) mm (P value < 0.0001), and near point of convergence (median, range) improved from 6 (3-33) to 6 (5-14) (P value 0.004) with VT. Thirty-one patients (96.87%) reported symptomatic improvement after VT, and 62.5% of these showed more than 50% improvement in symptoms.

Conclusion

The present study confirms the beneficial role of VT in the treatment of patients with DED with concurrent NSBVA. It is essential to diagnose and treat NSBVA in patients with DED to ensure complete relief of symptoms and patient satisfaction. As there is a significant overlap between symptoms of dry eye disease and that of NSBVA, a complete orthoptic evaluation is recommended in all patients presenting with refractory dry eye disease related symptoms.

Tear biomarkers in dry eye disease: Progress in the last decade

Dry eye disease (DED) is a commonly occurring, multifactorial disease characterized by reduced tear film stability and hyperosmolarity at the ocular surface, leading to discomfort and visual compromise. DED is driven by chronic inflammation and its pathogenesis involves multiple ocular surface structures such as the cornea, conjunctiva, lacrimal glands, and meibomian glands. The tear film secretion and its composition are regulated by the ocular surface in orchestration with the environment and bodily cues. Thus, any dysregulation in ocular surface homeostasis causes an increase in tear break-up time (TBUT), osmolarity changes, and reduction in tear film volume, all of which are indicators of DED. Tear film abnormalities are perpetuated by underlying inflammatory signaling and secretion of inflammatory factors, leading to the recruitment of immune cells and clinical pathology. Tear-soluble factors such as cytokines and chemokines are the best surrogate markers of disease severity and can also drive the altered profile of ocular surface cells contributing to the disease. Soluble factors can thus help in disease classification and planning treatment strategies. Our analysis suggests increased levels of cytokines namely interleukin-1β (IL-1β), IL-2, IL-4, IL-6, IL-9, IL-12, IL-17A, interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α); chemokines (CCL2, CCL3, CCL4, CXCL8); MMP-9, FGF, VEGF-A; soluble receptors (sICAM-1, sTNFR1), neurotrophic factors (NGF, substance P, serotonin) and IL1RA and reduced levels of IL-7, IL-17F, CXCL1, CXCL10, EGF and lactoferrin in DED. Due to the non-invasive sample collection and ease of quantitively measuring soluble factors, tears are one of the best-studied biological samples to molecularly stratify DED patients and monitor their response to therapy. In this review, we evaluate and summarize the soluble factors profiles in DED patients from the studies conducted over the past decade and across various patient groups and etiologies. The use of biomarker testing in clinical settings will aid in the advancement of personalized medicine and represents the next step in managing DED.

Ion channels in dry eye disease

Dry eye disease (DED) which affects millions of people worldwide is an ocular surface disease that is strongly associated with pain, discomfort, and visual disturbances. Altered tear film dynamics, hyperosmolarity, ocular surface inflammation, and neurosensory abnormalities are the key contributors to DED pathogenesis. The presence of discordance between signs and symptoms of DED in patients and refractoriness to current therapies in some patients underpin the need for studying additional contributors that can be modulated. The presence of electrolytes or ions including sodium, potassium, chloride, bicarbonate, calcium, and magnesium in the tear fluid and ocular surface cells contribute to ocular surface homeostasis. Ionic or electrolyte imbalance and osmotic imbalance have been observed in DED and feed-forward interaction between ionic imbalances and inflammation alter cellular processes in the ocular surface resulting in DED. Ionic balances in various cellular and intercellular compartments are maintained by dynamic transport via ion channel proteins present in cell membranes. Hence, alterations in the expression and/or activity of about 33 types of ion channels that belong to voltage-gated channels, ligand-gated channels, mechanosensitive ion channel, aquaporins, chloride ion channel, sodium-potassium-chloride pumps or cotransporters have been investigated in the context of ocular surface health and DED in animal and/or human subjects. An increase in the expression or activity of TRPA1, TRPV1, Nav1.8, KCNJ6, ASIC1, ASIC3, P2X, P2Y, and NMDA receptor have been implicated in DED pathogenesis, whereas an increase in the expression or activity of TRPM8, GABA_A receptor, CFTR, and NKA have been associated with resolution of DED.

Patient stratification using point of care biomarkers in dry eye disease

With changes in lifestyle, such as the increasing use of digital screens and rising demand for refractive surgery, dry eye disease has become increasingly prevalent in recent times. While we are equipped with a number of diagnostic modalities and a myriad of treatment forms, ranging from topical medication to procedural therapies, the condition remains an enigma in terms of varied patient satisfaction. An understanding of the molecular basis of a disease may open up new avenues in the customization of its treatment. We attempt to simplify this in the form of a stepwise protocol to incorporate biomarker assays in dry eye management.

Assessing clinical and molecular outcomes of prophylactic thermal pulsation therapy on ocular surface health following refractive surgery

Purpose

To study ocular surface signs, symptoms, and tear film composition following prophylactic thermal pulsation therapy (TPT) prior to refractive surgery, and to compare these outcomes with those who underwent TPT after refractive surgery.

Methods

Patients with mild-to-moderate evaporative dry eye disease (DED) and/or meibomian gland dysfunction (MGD) undergoing refractive surgery were included. Group 1 patients received TPT (LipiFlow) prior to laser-assisted in situ keratomileusis (LASIK; n = 32, 64 eyes), and Group 2 patients received TPT three months after LASIK (n = 27, 52 eyes). Ocular Surface Disease Index (OSDI) score, Schirmer's test (ST1, ST2), Tear Breakup Time (TBUT), meibography, and tear fluid were obtained preoperatively and at three months postoperatively in Groups 1 and 2. Additional postoperative evaluation was performed three months after TPT in Group 2. Tear soluble factor profile was measured by multiplex enzyme-linked immunosorbent assay (ELISA) using flow cytometry.

Results

Postoperative OSDI score was significantly lower and TBUT was significantly higher when compared with matched preoperative values of Group 1 participants. On the other hand, the postoperative OSDI score was significantly higher and TBUT significantly lower when compared with matched preoperative values of Group 2 participants. TPT significantly reduced the postoperative elevation in OSDI and significantly reduced the postoperative reduction in TBUT in Group 2 participants. Tear Matrix metalloproteinase-9/ Tissue inhibitor matrix metalloproteinase 1 (MMP-9/TIMP1) ratio was significantly higher, postoperatively, when compared with matched preoperative levels in Group 2. However, MMP9/TIMP1 ratio remained unaltered in Group 1 participants.

Conclusion

TPT prior to refractive surgery improved postsurgical ocular surface signs and symptoms and reduced tear inflammatory factors, thereby suggesting the plausibility of reduced post-refractive surgery DED in patients.

Tear proteomics in dry eye disease

Dry eye disease (DED) is a multi-factorial ocular surface condition driven by compromised ocular lubrication and inflammation which leads to itching, dryness, and vision impairment. The available treatment modalities primarily target the acquired symptoms of DED including tear film supplements, anti-inflammatory drugs, mucin secretagogues, etc., However, the underlying etiology is still an area of active research, especially in regard to the diverse etiology and symptoms. Proteomics is a robust approach that has been playing major role in understanding the causative mechanism and biochemical changes in DED by identifying the changes in protein expression profile in tears. Tears are a complex fluid composed of several biomolecules such as proteins, peptides, lipids, mucins, and metabolites secreted from lacrimal gland, meibomian gland, cornea, and vascular sources. Over the past two decades, tears have emerged as a bona-fide source for biomarker identification in many ocular conditions because of the minimally invasive and simple sample collection procedure. However, the tear proteome can be altered by several factors, which increases the complexity of the approach. The recent advancements in untargeted mass spectrometry-based proteomics could overcome such shortcomings. Also, these technological advancements help to distinguish the DED profiles based on its association with other complications such as Sjogren's syndrome, rheumatoid arthritis, diabetes, and meibomian gland dysfunction. This review summarizes the important molecular profiles found in proteomics studies to be altered in DED which have added to the understanding of its pathogenesis.

Role of in vivo confocal microscopy in dry eye disease and eye pain

Dry eye disease is known to have a lot of variability in presentation with overlapping subtypes. Understanding the pathology of this condition will guide therapeutic options. In vivo confocal microscopy is a diagnostic and imaging modality that provides high magnification and high-resolution images of all layers of the cornea and ocular surface. Various structures in the cornea and their alterations due to dry eye have been imaged. The impact of the tear film instability, inflammation, and altered homeostasis on the corneal epithelium, nerves, keratocytes, and dendritic cells have been evaluated across different studies. In addition, key features of IVCM in patients with neuropathic pain have been highlighted in this paper.

A randomized controlled study evaluating outcomes of intense pulsed light and low-level light therapy for treating meibomian gland dysfunction and evaporative dry eye

Purpose

This randomized, controlled, blinded study evaluates the efficacy of intense pulsed light (IPL) therapy with low-level light therapy (LLLT) in the treatment of meibomian gland dysfunction (MGD) and evaporative dry eye (EDE) compared to a control group.

Methods

Hundred patients with MGD and EDE were randomized into control (50 subjects, 100 eyes) and study group (50 subjects, 100 eyes). The study group underwent three sittings of IPL with LLLT 15 days apart and were followed up 1 month and 2 months after the last treatment sitting. The control group underwent sham treatment and was followed up at the same intervals. The patients were evaluated at baseline and 1 month and 3 months (post 1^st treatment) for dry eye. Schirmer's test and tear breakup time (TBUT), OSDI, meibomian gland expression, and meibography.

Results

The study group showed significant improvement in OSDI scores (P < 0.0001) compared to the control group and a significant improvement in TBUT (P < 0.005) compared to the control group. There was no change in schirmer's test and an improvement in the meibomian gland expression but not significant.

Conclusion

The results show that a combined therapy of IPL with LLT is effective in treating MGD with EDE compared to controls, and repeated treatment sessions have a cumulative effect on the disease outcomes.