Corneal Disease Research Articles

Update on corneal crosslinking for keratoconus and corneal ectasia.

To review corneal crosslinking for keratoconus and corneal ectasia, and recent developments in the field. This study will review the mechanism of crosslinking, clinical approaches, current results, and potential future innovations. Corneal crosslinking for keratoconus was first approved by U.S. FDA in 2016. Recent studies have confirmed the general long-term efficacy of the procedure in decreasing progression of keratoconus and corneal ectasia. New types of crosslinking protocols, such as transepithelial treatments, are under investigation. In addition, adjunctive procedures have been developed to improve corneal contour and visual function in these patients. Crosslinking has been found to be well tolerated and effective with the goal of decreasing progression of ectatic corneal diseases, keratoconus and corneal ectasia after refractive surgery. Studies have shown its long-term efficacy. New techniques of crosslinking and adjunctive procedures may further improve treatments and results.

Comparison of Air Puff Tonometer with Gold Standard Applanation Tonometer for Measurement of Intraocular Pressure in Adult Population

Detecting and treating glaucoma early is vital to prevent vision loss. Two main instruments, the Air Puff Tonometer and the Gold Standard Applanation Tonometer, are used to measure Intraocular Pressure (IOP). However, there is ongoing debate among ophthalmologists regarding the accuracy and reliability of these devices. Objective: To evaluate and contrast the measurements of intraocular pressure obtained through Air puff tonometry and Goldmann applanation tonometry. Methods: A cross-sectional comparative study was conducted upon 900 patients of Glaucoma, selected through purposive sampling technique, attending the Eye OPD of Isra University Hospital, Hyderabad. Patients with age more than 18 years, of both genders who provided consent for eye examination and treatment, were included in the study while patients with corneal disease or prior surgery, ocular trauma, or those presenting with active infection or ocular disease were excluded from the study. Results: 396 (44.0%) of patients were males and 504 (56.0%) were females. The results indicate that the mean IOP measurement for air puff tonometry (17.43 mm Hg) is significantly higher (p-value=0.0001) than the mean measurement obtained by Goldman tonometry (13.84 mm Hg). Overall, the distribution of IOP was similar for both types of tonometry, with a slightly higher proportion having high IOP values (19-22 mmHg) with Goldman tonometry compared to air puff tonometry. Conclusions: The findings of this research demonstrated a noteworthy contrast between the two techniques, where the air puff tonometry produced noticeably elevated intraocular pressure measurements in comparison to the widely accepted applanation tonometry

Herpes Simplex Keratitis after PRK

Background: Herpes simplex virus (HSV) is a double stranded DNA virus that infects much of the world’s population. The World Health Organization estimates 67% of people under the age of 50 have HSV-1 and 11% of people under the age of 50 have HSV-2. While most systemic infections remain inactive and do not cause symptoms, the activation and appearance of ocular HSV can be a destructive and vision-threatening issue. HSV keratitis can be epithelial, stromal or a combination. Patients who have recently undergone photorefractive keratectomy (PRK) have a higher risk of HSV keratitis. Because of this, HSV keratitis should be considered in any PRK post-op patient that presents with unusual signs and symptoms such as decreased vision, increased IOPs, ocular pain, photophobia, iritis and corneal haze. When diagnosed in a timely manner, the prognosis is generally favorable. Current treatments for HSV keratitis include antiviral coverage as well as immunosuppression with topical steroids. Case Report: This case involves a patient that developed HSV keratitis while on topical steroid therapy following PRK. The weeks following the initial presentation were spent battling corneal haze, iritis, pain, increased IOPs and decreased visual acuity. After close monitoring and treatment changes based on each clinical presentation, the patient recovered with good vision and minimal corneal scarring. The findings and recommended treatment options are discussed. Conclusion: HSV affects much of the world’s population. Reactivation of the latent virus can lead to vision threatening corneal disease. HSV is capable of causing inflammation and pathology throughout most of the anterior segment of the eye, and therefore should be considered when managing any new or recalcitrant anterior pathology. Although the diagnosis is usually clinical, laboratory testing can be used to confirm a diagnosis. Treatment aims to decrease the viral load and to limit stromal scarring.

Herpes Simplex Keratitis after PRK

Background: Herpes simplex virus (HSV) is a double stranded DNA virus that infects much of the world’s population. The World Health Organization estimates 67% of people under the age of 50 have HSV-1 and 11% of people under the age of 50 have HSV-2. While most systemic infections remain inactive and do not cause symptoms, the activation and appearance of ocular HSV can be a destructive and vision-threatening issue. HSV keratitis can be epithelial, stromal or a combination. Patients who have recently undergone photorefractive keratectomy (PRK) have a higher risk of HSV keratitis. Because of this, HSV keratitis should be considered in any PRK post-op patient that presents with unusual signs and symptoms such as decreased vision, increased IOPs, ocular pain, photophobia, iritis and corneal haze. When diagnosed in a timely manner, the prognosis is generally favorable. Current treatments for HSV keratitis include antiviral coverage as well as immunosuppression with topical steroids. Case Report: This case involves a patient that developed HSV keratitis while on topical steroid therapy following PRK. The weeks following the initial presentation were spent battling corneal haze, iritis, pain, increased IOPs and decreased visual acuity. After close monitoring and treatment changes based on each clinical presentation, the patient recovered with good vision and minimal corneal scarring. The findings and recommended treatment options are discussed. Conclusion: HSV affects much of the world’s population. Reactivation of the latent virus can lead to vision threatening corneal disease. HSV is capable of causing inflammation and pathology throughout most of the anterior segment of the eye, and therefore should be considered when managing any new or recalcitrant anterior pathology. Although the diagnosis is usually clinical, laboratory testing can be used to confirm a diagnosis. Treatment aims to decrease the viral load and to limit stromal scarring.

EYE DISEASE RECOGNITION SYSTEM

This paper presents an innovative system for detecting eye diseases utilizing advanced machine learning techniques. Given the increasing prevalence of eye disorders, early detection and intervention are of utmost importance. The proposed system integrates a diverse dataset comprising medical images and patient information. Deep learning algorithms are employed to extract intricate features from the dataset. These features are then input into a predictive model, facilitating accurate identification of potential eye diseases. Rigorous testing and validation demonstrate the system's performance and its ability to provide reliable predictions. The early diagnosis enabled by this system has the potential to significantly impact patient outcomes and contribute to the advancement of ophthalmic healthcare. The Eye Disease Detection System serves as a valuable tool for the early detection and management of various eye conditions. Through the integration of advanced technologies such as machine learning and medical imaging, this system enhances the accuracy and efficiency of the diagnostic process. Index Terms : Vision disorders, Glaucoma, Macular degeneration, Eye diseases, Ophthalmology, Corneal diseases.

CORNEAL TRANSPLANTATION

Corneal transplantation is an ophthalmic surgery that aims to restore vision in patients with corneal diseases. Advances in transplantation techniques and in the treatment of rejection have improved the results of this procedure, making it more effective and safer. This paper seeks to analyze the latest developments in transplantation techniques and treatments for rejection in corneal transplantation, highlighting not only scientific advances, but also the emotional and social aspects involved in this procedure, providing a comprehensive overview of the latest innovations in the field of corneal transplantation, highlighting improvements in surgical techniques and post-operative treatments, which are helping to transform the lives of thousands of patients around the world. This is a bibliographical review, using qualitative premises, with the PubMed, Scopus, Web of Science and Scielo databases. The health descriptors “corneal transplantation”, “corneal graft rejection” and “penetrating keratoplasty” were used to better refine the research. Corneal transplantation is indicated for various conditions, such as keratoconus, corneal dystrophies, corneal opacities, among others. The most common transplant techniques include complete (penetrating) corneal transplantation, anterior lamellar transplantation and endothelial transplantation (DSAEK/ DMEK). In recent years, there have been significant advances in lamellar transplantation techniques, which allow specific layers of the cornea to be replaced while preserving the healthy layers. This has resulted in better success rates and faster visual recovery compared to penetrating transplantation. Treatment of corneal graft rejection includes the use of topical and systemic corticosteroids, immunosuppressants and anti-inflammatory agents. New approaches, such as biological and immunomodulatory therapies, are also being investigated to improve results in cases of refractory graft rejection. In conclusion, corneal transplantation remains an important option for restoring vision in patients with corneal diseases. Updates in transplantation techniques and advances in the treatment of rejection have improved the results of this procedure, providing patients with a better quality of life and faster and more effective visual recovery.

Corneal Complications Related to Dupilumab Use.

The aim of this report is to describe atypical corneal complications associated with dupilumab use. This is a series of four cases of adult patients with infiltrative or ulcerative keratitis secondary to dupilumab use. All four patients in this series were prescribed dupilumab for the treatment of atopic dermatitis and developed infiltrative or ulcerative corneal lesions. In all cases, corneal disease was successfully managed with immediate discontinuation of dupilumab and topical steroid treatment. In two cases, the patient also received antibiotic eye drops for infection precautions. Although dupilumab is most commonly associated with conjunctivitis, physicians should be aware of potential severe corneal complications for early identification and intervention.

Evaluation of dynamic corneal response parameters and the biomechanical E-staging after Intacs® SK implantation in keratoconus.

This retrospective longitudinal study evaluated the biomechanical E-staging in KC corneas before and after intracorneal ring segment (ICRS) implantation (Intacs® SK, Addition Technology, Illinois, United States). Biomechanical E-staging for ectatic corneal diseases was applied retrospectively on 49 KC corneas of 41 patients who underwent ICRS implantation. The main outcome parameters included the Corvis Biomechanical Factor (CBiF, the linearized Corvis Biomechanical Index and the biomechanical parameters included), the resulting biomechanical E-staging, the stress-strain index, thinnest corneal thickness (TCT), maximal anterior keratometry (Kmax), and the anterior radius of curvature (ARC). They were evaluated at 1.9 ± 1.1 months preoperatively and postoperatively after 2.8 ± 0.7, 5.8 ± 1.0, and 10.6 ± 2.3 months. The CBiF decreased (4.9 ± 0.5 | 4.7 ± 0.5, P = 0.0013), and the E-staging increased significantly (2.8 ± 0.8 | 3.1 ± 0.9, P = 0.0012, paired t-test) from preoperatively to the first postoperative follow-up. The difference remained significant after 6 months; however, there was no more difference after 11 months. TCT was stable, whereas Kmax and ARC significantly decreased after ICRS implantation (TCT: 464 ± 49, 470 ± 51, 467 ± 38, 461 ± 48; Kmax: 56.3 ± 4.5, 54.7 ± 4.5, 54.2 ± 4.8, 54.1 ± 4.3; ARC: 51.5 ± 3.4, 48.3 ± 3.8, 48.6 ± 3.0, 48.6 ± 3.2 preoperatively and 3, 6, and 11 months postoperatively, respectively). Besides Kmax and ARC, Ambrósio's relational thickness to the horizontal profile (ARTh) was the only parameter that was significantly lower than preoperatively at any follow-up (P ≤ 0.0024, Wilcoxon matched-pairs test). Intacs® SK implantation results in an increasing biomechanical E-staging in the first postoperative months with stabilization near preoperative values after 1 year. Significantly lower ARTh values at any follow-up document the ICRS effect and contribute to a slightly higher postoperative biomechanical E-staging value.

Mimicking the Physicochemical Properties of the Cornea: A Low-Cost Approximation Using Highly Available Biopolymers.

Corneal diseases represent a significant global health challenge, often resulting in blindness, for which penetrating keratoplasty is the clinical gold standard. However, in cases involving compromised ocular surfaces or graft failure, osteo-odonto keratoprosthesis (OOKP) emerges as a vital yet costly and complex alternative. Thus, there is an urgent need to introduce soft biomaterials that mimic the corneal tissue, considering its translation's physicochemical, biological, and economic costs. This study introduces a cross-linked mixture of economically viable biomaterials, including gelatin, chitosan, and poly-D-lysine, that mimic corneal properties. The physicochemical evaluation of certain mixtures, specifically gelatin, chitosan, and poly-D-lysine cross-linked with 0.10% glutaraldehyde, demonstrates that properties such as swelling, optical transmittance, and thermal degradation are comparable to those of native corneas. Additionally, constructs fabricated with poly-D-lysine exhibit good cytocompatibility with fibroblasts at 72 h. These findings suggest that low-cost biopolymers, particularly those incorporating poly-D-lysine, mimic specific corneal characteristics and have the potential to foster fibroblast survival. While further studies are required to reach a final corneal-mimicking solution, this study contributes to positioning low-cost reagents as possible alternatives to develop biomaterials with physicochemical properties like those of the human cornea.

A New Biomechanical Deformation Response Parameter: Change in Central Corneal Thickness During Air Puff Induced Corneal Deformation

Purpose To investigate the percent change in central corneal thickness (%ΔCCT) during air-puff-induced deformation as an indicator of corneal biomechanical response. Methods Forty ex vivo human eyes from forty donors were imaged using the CorVis ST at experimentally controlled intraocular pressure (IOP) of 10, 20, 30, and 40 mmHg, followed by uniaxial strip testing to calculate tensile modulus. The CorVis ST research software tracked the anterior and posterior cornea edges and determined the dynamic corneal response (DCR) parameters. Eyes were excluded if image quality or posterior tracking issues were present. Custom algorithms were used to calculate CCT during deformation using a ray-tracing method to correct for Scheimpflug and optical distortion within each image. Correlation and stepwise regression analyses between the shape-related DCR parameters and %ΔCCT were conducted. A mixed model analysis was performed to test the effect of IOP and the strongest significant predictors of the stepwise regression on %ΔCCT. The significance threshold was set to p < 0.05. Results Thirty eyes were ultimately analyzed and CCT increased significantly from the pre-deformation state to the highest concavity state at each IOP level (p < 0.001). IOP and multiple shape DCRs were found to be significantly related to %ΔCCT (p < 0.0001). The strongest predictor of %ΔCCT was integrated inverse radius (IIR) (p < 0.0001; partial R2 = 0.4772) with no other parameter having a partial R2 value greater than 0.04. The mixed model analysis showed that IIR was the sole predictor (p = 0.0098) and IOP was no longer significant as a single predictor. However, the interaction of IIR with IOP (p = 0.0023) had a significant effect on %ΔCCT. Conclusion Percent change in CCT is influenced by corneal stiffness as indicated by the significant relationship with IIR. The %ΔCCT may be a potential biomarker for determining differences in corneal deformation response with corneal diseases.

Methylation in cornea and corneal diseases: a systematic review.

Corneal diseases are among the primary causes of blindness and vision loss worldwide. However, the pathogenesis of corneal diseases remains elusive, and diagnostic and therapeutic tools are limited. Thus, identifying new targets for the diagnosis and treatment of corneal diseases has gained great interest. Methylation, a type of epigenetic modification, modulates various cellular processes at both nucleic acid and protein levels. Growing evidence shows that methylation is a key regulator in the pathogenesis of corneal diseases, including inflammation, fibrosis, and neovascularization, making it an attractive potential therapeutic target. In this review, we discuss the major alterations of methylation and demethylation at the DNA, RNA, and protein levels in corneal diseases and how these dynamics contribute to the pathogenesis of corneal diseases. Also, we provide insights into identifying potential biomarkers of methylation that may improve the diagnosis and treatment of corneal diseases.

Advances in Organoid Technology: A Focus on Corneal Limbal Organoids.

Organoid technology provides a versatile platform for simulating organogenesis, investigating disease pathogenesis, and exploring therapeutic interventions. Among various types of organoids that have been developed, corneal limbal organoids, the three-dimensional miniaturized corneas which are derived from either pluripotent stem cells or limbal epithelial stem cells, are particularly promising for clinical translation. This narrative review summarized the state-of-the-art in corneal limbal organoids research including the cultivation methods, clinical relevance and its limitations and challenges. The potential of corneal limbal organoids in mimicking corneal development, disease modelling, drug screening, and regenerative medicine was discussed. Technical improvements in cultivation techniques, imaging modalities, and gene editing tools are anticipated to overcome current limitations and further promote its clinical potential. Despite challenges and difficulties, the development of corneal limbal organoids opens a new era of regenerative medicine and provides a potential source of stem cell replacement therapies for challenging corneal diseases with the establishment of an in vitro corneal limbal organoid bank.

Extracellular vesicles from Candida albicans modulate immune cells function and play a protective role in fungal keratitis

Fungal keratitis (FK) is a highly blinding infectious corneal disease caused by pathogenic fungi. Candida albicans (C. albicans) is one of the main pathogens of fungal keratitis. Extracellular vesicles (EVs), lipid bilayer compartments released by almost all living cells, including fungi, have garnered attention for their role in pathogenic microbial infection and host immune responses in recent years. Studies have reported that pretreating the host with fungal EVs can reduce the inflammatory response of the host when attacked by fungi and reduce the lethality of fungal infection. However, there are no studies that have evaluated whether C. albicans EVs can modulate the inflammatory response associated with C. albicans keratitis. Our study revealed that C. albicans EVs could activate the polymorphonuclear cells (PMNs) and promote their secretion of proinflammatory cytokines and nitric oxide (NO), enhance their phagocytic and fungicidal abilities against C. albicans. C. albicans EVs also induced a proinflammatory response in RAW264.7 cells, which is characterized by increased production of inflammatory cytokines and elevated expression of the chemokine CCL2. Similarly, stimulation of C. albicans EVs to RAW264.7 cells also enhanced the phagocytosis and killing ability of cells against C. albicans. Besides, in vivo experiments, after receiving subconjunctival injection of C. albicans EVs, C57BL/6 mice were infected with C. albicans. The results demonstrated that pre-exposure to C. albicans EVs could effectively diminish the severity of keratitis, reduce fungal load and improve prognosis. Overall, we conclude that C. albicans EVs can modulate the function of immune cells and play a protective role in C. albicans keratitis.

Peripheral hypertrophic subepithelial corneal opacification - Role of tear secretion, medication and systemic diseases.

Peripheral hypertrophic subepithelial corneal opacification (PHSCO) is a corneal disease that may severely affect vision. The major goal of this study was to test the hypothesis that tear secretion, medication and systemic diseases are associated with PHSCO. This is a retrospective, case-control study conducted at the Department of Ophthalmology, University Medical Center of the Johannes Gutenberg University Mainz. We analysed medical records of patients diagnosed with PHSCO. Sex, age, Schirmer's test II, general medication and medical history were assessed and compared to an age- and sex-matched control group from the Gutenberg Health Study (GHS). One hundred ninety-five eyes of 112 patients with PHSCO were included. Eighty-eight patients were female with a mean age of 55.3 ± 14.7 years (23-89 years) and 24 patients were male with a mean age of 59.3 ± 12.6 years (38-84 years). In 83 patients (74.1%) both eyes were involved. The Schirmer's test II was significantly reduced in patients with PHSCO compared to the GHS control group (p < 0.001). Patients with PHSCO were more frequently administered artificial tears and steroid eye drops (p < 0.001) and were more hyperopic than healthy controls (p = 0.01). Systemic diseases or medication did not differ markedly between PHSCO and healthy controls. Reduced tear secretion and more frequent use of artificial tears in patients with PHSCO suggest a link between PHSCO and dry eye disease. The results of the study do not support our hypothesis that PHSCO is associated with systemic diseases. Interestingly, patients with PHSCO were less frequently on β-blockers than control subjects.

Artificial-Intelligence-Enhanced Analysis of In Vivo Confocal Microscopy in Corneal Diseases: A Review.

Artificial intelligence (AI) has seen significant progress in medical diagnostics, particularly in image and video analysis. This review focuses on the application of AI in analyzing in vivo confocal microscopy (IVCM) images for corneal diseases. The cornea, as an exposed and delicate part of the body, necessitates the precise diagnoses of various conditions. Convolutional neural networks (CNNs), a key component of deep learning, are a powerful tool for image data analysis. This review highlights AI applications in diagnosing keratitis, dry eye disease, and diabetic corneal neuropathy. It discusses the potential of AI in detecting infectious agents, analyzing corneal nerve morphology, and identifying the subtle changes in nerve fiber characteristics in diabetic corneal neuropathy. However, challenges still remain, including limited datasets, overfitting, low-quality images, and unrepresentative training datasets. This review explores augmentation techniques and the importance of feature engineering to address these challenges. Despite the progress made, challenges are still present, such as the "black-box" nature of AI models and the need for explainable AI (XAI). Expanding datasets, fostering collaborative efforts, and developing user-friendly AI tools are crucial for enhancing the acceptance and integration of AI into clinical practice.

Chemical, Physical, and Biological Corneal Decellularization Methods: A Review of Literature.

The cornea is one of the most commonly transplanted tissues worldwide. It is used to restore vision when severe visual impairment or blindness occurs in patients with corneal diseases or after trauma. Due to the global shortage of healthy donor corneas, decellularized corneal tissue has significant potential as an alternative to corneal transplantation. It preserves the native and biological ultrastructure of the cornea and, therefore, represents the most promising scaffold. This article discusses different methods of corneal decellularization based on the current literature. We searched PubMed.gov for articles from January 2009 to December 2023 using the following keywords: corneal decellularization, decellularization methods, and corneal transplantation. Although several methods of decellularization of corneal tissue have been reported, a universal standardised protocol of corneal decellularization has not yet been introduced. In general, a combination of decellularization methods has been used for efficient decellularization while preserving the optimal properties of the corneal tissue.

Topical Insulin for Ocular Surface Disease.

Background: Insulin and insulin-like growth factor (IGF)-1 receptors are present in ocular tissues such as corneal epithelium, keratocytes, and conjunctival cells. Insulin plays a crucial role in the growth, differentiation, and proliferation of corneal epithelial cells, as well as in wound healing processes in various tissues. Purpose: This review explores the potential role of topical insulin in the treatment of ocular surface diseases. Specifically, it examines its impact on corneal nerve regeneration, sub-basal plexus corneal nerves, and its application in conditions like corneal epithelial defects, dry eye disease, and diabetic keratopathy. Methods: The review analyzes studies conducted over the past decade that have investigated the use of topical insulin in ocular surface diseases. It focuses on indications, drug preparation methods, side effects, efficacy outcomes, and variations in insulin concentrations and dosages used. Results: While off-label use of topical insulin has shown promising results in refractory corneal epithelial defects, its efficacy in dry eye disease is yet to be demonstrated. Variations in concentrations, dilutions, and dosing guidelines have been reported. However, limited data on ocular penetration, ocular toxicity, and systemic side effects pose challenges to its widespread utility. Conclusion: This review synthesizes findings from ocular investigations on topical insulin to assess its potential applicability in treating ocular surface and corneal diseases. By highlighting indications, preparation methods, side effects, and efficacy outcomes, it aims to provide insights into the current status and future prospects of using topical insulin in ophthalmic practice.

UVB induced reactivation leads to HSV1 in the corneas of virtually all latently infected mice and requires STING to develop corneal disease

Reactivation of latent herpes simplex type 1 results in virus returning to the cornea leading to recurrent herpetic stromal keratitis (rHSK). We compare two competing models to reactivate viruses from latency, UV-B irradiation and cyclophosphamide (CP). Results revealed that while both result in corneal recrudescence, only UV-B irradiation results in rHSK. To better understand the dynamics of reactivation, we analyzed corneas for both the presence of infectious viruses and the dynamics of exposure to multiple reactivations using UV-B. We noted that multiple reactivations result in progressively worse corneal disease. We also noted that expression of IFNα and STING, surragate markers for the presence of virus, are induced by the presence of reactivated virus. Studies to determine the importance of STING to the development of HSK revealed that in the absence of STING, mice do not develop significant HSK and the magnitude of the infiltrate of CD45+ cells in these corneas is significantly reduced. The resulting paucity of CD45+CD11b+GR-1+F4/80-neutrophils, and to a lesser extent CD45+CD11b+GR-1-F4/80+ macrophages in B6-STING KO mice following reactivation is likely the underlying cause for lack of rHSK as has been noted by ourselves and others. These results underscore the critical importance of STING’s role in developing rHSK.

Corneal nerves and amyotrophic lateral sclerosis: an in vivo corneal confocal imaging study.

Amyotrophic lateral sclerosis (ALS) is a severe motor neuron disorder. Diagnosis is challenging due to its clinical heterogeneity and the absence of definitive diagnostic tools, leading to delays averaging between 9.1 and 27months. In vivo corneal confocal microscopy, assessing the sub-basal nerve plexus of the cornea, has been proposed as a potential biomarker for ALS. We aimed to determine whether the assessment of corneal nerves using in vivo confocal microscopy can serve as an imaging biomarker for ALS. A single-centre prospective case-control study was conducted in France from September 2021 to March 2023 including patients with ALS according to the revised EI Escorial criteria. The corneal sub-basal nerve plexus was analysed using in vivo confocal microscopy. An automated algorithm (ACCMetrics) was used to evaluate corneal parameters: nerve fibre density, nerve branch density, nerve fibre length, nerve fibre area, nerve total branch density, nerve fibre width, and nerve fractal dimension. Twenty-two patients with ALS and 30 controls were included. No significant differences were found between ALS and control groups for all corneal parameters (p > 0.05). Corneal sensitivity did not differ between groups, and no correlation was identified between corneal nerve parameters and ALS disease duration, severity and rate of progression (p > 0.05). The present study does not support the use of in vivo corneal confocal microscopy as an early diagnostic or prognostic tool for ALS. Further research, especially longitudinal investigations, is needed to understand any potential corneal innervation changes as ALS progresses.

Applications of photodynamic therapy in keratitis.

Keratitis is corneal inflammatory disease which may be caused by several reason such as an injury, allergy, as well as a microbial infection. Besides these, overexposure to ultraviolet light and unhygienic practice of contact lenses are also associated with keratitis. Based on the cause of keratitis, different lines of treatments are recommended. Photodynamic therapy is a promising approach that utilizes light activated compounds to instigate either killing or healing mechanism to treat various diseases including both communicable and non-communicable diseases. This review focuses on clinically-important patent applications and the recent literature for the use of photodynamic therapy against keratitis.