Keratoconus: imaging modalities and management

Background: Keratoconus (KCN) is characterized by gradual thinning and steepening of the cornea, which can lead to significant vision problems owing to high astigmatism, corneal scarring, or even corneal perforation. The detection of KCN in its early stages is crucial for effective treatment. In this review, we describe current advances in the diagnosis and treatment of KCN.   Methods: This narrative review focuses on recent advancements in the diagnosis and treatment of KCN, especially evolving approaches and strategies. To ensure the inclusion of the most recent literature, relevant publications discussing advanced imaging techniques and treatment options for KCN were extensively gathered from the PubMed/MEDLINE and Google Scholar databases. The following index terms and keywords were used for the online search: keratoconus, diagnosis of keratoconus, advances in the diagnosis of keratoconus, topography or tomography, anterior segment optical coherence tomography, treatment of keratoconus, advances in the treatment of keratoconus, collagen crosslinking, intrastromal ring, keratoplasty, and new techniques in keratoconus.   Results: Various screening methods such as corneal topography, tomography, anterior segment optical coherence tomography, and assessment of corneal biomechanics have been developed to identify KCN in its early stages. After diagnosis, KCN management focuses on preventing disease progression. Corneal collagen crosslinking is a minimally invasive treatment that can slow or stop the progression of the condition. Recent research has also explored the use of copper sulfate eye drops (IVMED-80) as a noninvasive treatment to prevent the progression of KCN. Current treatment options for visual improvement include scleral lenses, intracorneal ring segments, corneal allogeneic intrastromal ring segments, and deep anterior lamellar keratoplasty. Recently, novel alternative procedures, such as isolated Bowman layer transplantation, either as a corneal stromal inlay or onlay, have demonstrated encouraging outcomes. Artificial intelligence has gained acceptance for providing best practices for the diagnosis and management of KCN, and the science of its application is contentiously debated; however, it may not have been sufficiently developed.   Conclusions: Early detection and advancements in screening methods using current imaging modalities have improved diagnosis of KCN. Improvement in the accuracy of current screening or diagnostic tests and comparison of their validities are achievable by well-designed, large-scale, prospective studies. The safety and effectiveness of emerging treatments for KCN are currently being investigated. There is an ongoing need for studies to track progress and evaluate clinicians’ knowledge and practices in treating patients with KCN. Artificial intelligence capabilities in management approach considering the currently available imaging modalities and treatment options would best benefit the patient

Fatty acids as biological markers for symbiotic bacteria in Phyllidia varicosa and Phyllidiella pustulosa

The fatty acid (FA) composition of Phyllidia varicosa and Phyllidiella pustulosa (notum and viscera) was investigated. Samples were collected from coastal water of Balok - Pahang - Malaysia. This study was conducted to test the hypothesis that nudibranchs species host symbiotic bacteria by using fatty acids as biological markers. A high level of fatty acids group specific to the bacteria were detected in the selected species that called odd- branched chain fatty acids. Among them, high levels of iso- anteiso-C15:0, C15:0, iso-C16:0, C17:0, iso-C17:0, iso C17:1(n-5), iso C18:0, 14-methyl-C18:0 and iso-C18:0) were found and their percentages in the notum are significantly different compared to viscera. The total odd- branched chain fatty acids were 29.64% in P. varicosa and 30.66% in P. pustulosa compared to another group of fatty acids such as saturated FA, monounsaturated FA and polyunsaturated FA. The present study deals with the identification of cyclopropane FA in the nudibranch tissue for the first time which cyclopropaneoctanoic acid 2-hexyl and cyclopropaneoctanoic acid 2-octyl were detected. We suggest that symbiotic bacteria associated with the nudibranchs tissue originate these fatty acids

Extrinsic factors influencing internal auditors’ effectiveness in Jordanian public sector

This study focuses on the extrinsic factors, namely, top management support, complexity, independence, and internal audit department’s size that are out of internal auditors' control affecting their effectiveness in the Jordanian public sector. The current study also tries to improve understanding of the extrinsic factors affecting internal auditors’ ability to achieve the assigned goals in order to highlight internal auditors’ effectiveness. Resource-based and agency theories were used in developing the research model. Two sets of questionnaires were distributed among the financial managers and internal audit managers. The results reveal that top management support, independence, and the size of internal audit department play a significant and positive role on the effectiveness of internal auditors, whereas complexity of the task has been found to make a negative impact on the level of their performance. Given the significance of the public sector within the Jordanian economy, the findings are valuable for the internal audit function, regulators, and decision-makers in proposing new legislation and regulations of an internal audit function. Future studies may look into other factors that may restrict internal audit performance, such as organizational culture and pay satisfaction

Identification and phylogenetic inference in different mollucs nudibranch species via mitochondrial 16S rDNA

The molecular analysis of marine life is an essential approach to discover new classes of natural products and to improve the management and sustainable utilization of these useful genetic resources. Mitochondrial DNA markers are frequently utilized to identify any organism up to the species level. This study provides insight into the significant role of species discrimination based on 16S rDNA, and this method could be a powerful tool for the identification of animal species. 16S rDNA sequences of each studied species (Phyllidia varicosa (Lamarck, 1801) and Phyllidiella pustulosa (Cuvier, 1804)) from two locations in the coastal waters of Balok in Pahang State and Bidong Island in Terengganu State were aligned to identify the phylogenetic relationships among them. The phylogenetic tree produced in this study is consistent with those previously presented in the literature. The divergence of sequences was adequate to identify the samples at the species level with the assistance of the GenBank database and the BLAST tool. The results presented here provide useful information for a better understanding of this marine genetic resource. This genetic approach could simplify the identification of the species accurately for further analysis

Fatty acids as biological markers for symbiotic bacteria in Phyllidia varicosa and Phyllidiella pustulosa

The fatty acid (FA) composition of Phyllidia varicosa and Phyllidiella pustulosa (notum and viscera) was investigated. Samples were collected from coastal water of Balok - Pahang - Malaysia. This study was conducted to test the hypothesis that nudibranchs species host symbiotic bacteria by using fatty acids as biological markers. A high level of fatty acids group specific to the bacteria were detected in the selected species that called odd- branched chain fatty acids. Among them, high levels of iso- anteiso-C15:0, C15:0, iso-C16:0, C17:0, iso-C17:0, iso C17:1(n-5), iso C18:0, 14-methyl-C18:0 and iso-C18:0) were found and their percentages in the notum are significantly different compared to viscera. The total odd- branched chain fatty acids were 29.64% in P. varicosa and 30.66% in P. pustulosa compared to another group of fatty acids such as saturated FA, monounsaturated FA and polyunsaturated FA. The present study deals with the identification of cyclopropane FA in the nudibranch tissue for the first time which cyclopropaneoctanoic acid 2-hexyl and cyclopropaneoctanoic acid 2-octyl were detected. We suggest that symbiotic bacteria associated with the nudibranchs tissue originate these fatty acids

Identification and phylogenetic inference in different mollucs nudibranch species via mitochondrial 16S rDNA

Abstract. The molecular analysis of marine life is an essential approach to discover new classes of natural products and to improve the management and sustainable utilization of these useful genetic resources. Mitochondrial DNA markers are frequently utilized to identify any organism up to the species level. This study provides insight into the significant role of species discrimination based on 16S rDNA, and this method could be a powerful tool for the identification of animal species. 16S rDNA sequences of each studied species (Phyllidia varicosa (Lamarck, 1801) and Phyllidiella pustulosa (Cuvier, 1804)) from two locations in the coastal waters of Balok in Pahang State and Bidong Island in Terengganu State were aligned to identify the phylogenetic relationships among them. The phylogenetic tree produced in this study is consistent with those previously presented in the literature. The divergence of sequences was adequate to identify the samples at the species level with the assistance of the GenBank database and the BLAST tool. The results presented here provide useful information for a better understanding of this marine genetic resource. This genetic approach could simplify the identification of the species accurately for further analysis

Observations on nudibranch behaviour patterns under laboratory conditions

Phyllidiid Nudibranchs Phyllidia varicosa and Phyllidiella pustulosa were observed under laboratory conditions and abnormal behaviours were recorded. This study described the manoeuvering, mating behaviour, egg laying and abnormal activities. Some abnormal behaviours were recorded while retaining the sample in the aquarium such as emitting noxious chemicals, lifting up the mantle edge to expose the gills and crawling towards the water surface and lie there. Maneuvering behaviour was distinguished when two individuals were interacting with each other before the mating. Mating behaviour started by extending and joining the reproductive organs followed by gamete exchange for several minutes. During the mating behaviour, there was a limited movement like contracting of the body and hiding the rhinophores into the rhino-tube. Egg deposition was observed in the aquarium as natural behavior after mating and as a stress response after placing the sample in the captivity