Topography changes and endothelial cell loss after temporal 1.8 mm coaxial microincision cataract surgery (MICS)

INTRODUCTION. The purpose of this paper was to determine surgically-induced changes both in corneal topographic parameters and in endothelial cell loss after coaxial microincision cataract surgery (MICS) through temporal 1.8 mm incision. MATERIALS AND METHODS. Evaluation was performed in forty eyes of thirty patients who underwent cataract sur­gery. Topographic parameters including corneal astigmatism, surface regularity index (SRI), and surface asymmetry index (SAI) were estimated preoperatively and at one week, four weeks, and eight weeks after surgery. A specular microscope was also used for the measurement of the corneal endothelial density (cells/mm2). The surgically-induced astigmatism (SIA) was calculated by means of vector analysis using Alpins’ method. RESULTS. Eight weeks after surgery the final mean value of SIA was 0.42 D and the differences in topographic parameters such as corneal astigmatism, SRI, and SAI were not statistically significant. Also, the decrease in endothelial cell density eight weeks after surgery was 6.02%. CONCLUSIONS. The changes in SIA and topographic parameters after temporal coaxial 1.8 mm MICS are minimal throughout an eight-week follow up period

Living-related limbal allograft transplantation for bilateral stem cell deficiency in a patient with bilateral chemical burn

INTRODUCTION. The purpose of this paper was to report the long-term outcome of a living-related limbal allograft transplantation followed by penetrating keratoplasty in a patient with severe bilateral stem cell deficiency. MATERIALS AND METHODS. A 50-year-old woman presented with extensive bilateral stem cell deficiency secondary to ocular acid burn on both eyes. Visual acuity was counting fingers at 30 cm on the right eye and counting fingers at 1 m Snellen line on the left. Limbal allograft transplantation on the right eye from a first-degree living-related relative was performed. The recipient was prepared by removing the abnormal corneal epithelium and vascularised pannus of the right eye under general anaesthesia. Two limbal allografts (mean length of 2–3 corresponding anatomic posi­tions on the recipient). Postoperatively, the host received systemic immunosuppression (steroids and cyclosporine). RESULTS. The cornea of the right eye achieved reepithelialisation within two weeks after surgery, followed by re­duction in vascularity in eight weeks time. After one year of regular follow up, the corneal surface remained stable whereas the stroma was opaque and the vision was low. Therefore, the patient underwent penetrating keratoplasty on the same eye. After the surgery the corneal graft was clear and the visual acuity on the right eye improved to 20/50 Snellen line. No graft rejection occurred after a five-year follow-up. CONCLUSION. Living-related limbal allograft transplantation is a good alternative option in cases of total bilateral stem cell deficiency whenever a conjunctival limbal autograft transplantation is not possible

Characteristic Needle-Shaped Pattern Seen on OCT in a Patient with Ocular Amyloidosis

This article is freely available via Open Access. Click on the Publisher URL to access it via the publisher's site.published version, accepted version (12 month embargo

Phototherapeutic keratectomy for the treatment of dense subepithelial infiltrates after epidemic keratoconjunctivitis

This is a case report of a patient who developed dense subepithelial corneal infiltrates after epidemic keratoconjunctivitis and was treated with phototherapeutic keratectomy (PTK). The purpose of this case report is to explain the surgical technique and the results of PTK procedure

Ηφαιστειακά αέρια και οι επιπτώσεις τους στην υγεία και το περιβάλλον - Η περίπτωση της Σαντορίνης-

Η ηφαιστειακή δραστηριότητα αποτελεί ένα από τους βασικους κινδύνους, συνδεόμενους με φυσικά φαινόμενα, που έχουν επηρεάσει τη ζωή των ανθρώπων αλλά και όλου του έμβιου κόσμου μέσα στο γεωλογικό χρόνο. Πέρα από τις άμεσες συνέπειες μιας ηφαιστειακής έκρηξης, η ασφυξία από την εισπνοή επικίνδυνων αερίων αποτελεί την πιο κοινή αιτία θανάτου που συνδέεται με την ηφαιστειακή δραστηριότητα. Από τα ηφαιστειακά αέρια το διοξείδιο του άνθρακα είναι ιδιαίτερο τοξικό και ασφυξιογόνο σε μεγάλες συγκεντρώσεις, ενώ ακολουθεί και το μονοξείδιο του θείου, το οποίο όμως έχει πολύ μικρότερη συμμετοχή στα μίγματα αερίων. Εκτός από το διοξείδιο του άνθρακα, το διοξείδιο του θείου είναι επίσης ένα από τα πιο κοινά αέρια που συνδέονται με την ηφαιστειακή δραστηριότητα και μπορεί να προκαλέσει αναπνευστικά προβλήματα, ακόμα και θάνατο σε υψηλές συγκεντρώσεις. Άμεσα συνδεόμενα με την ηφαιστειακή δραστηριότητα είναι και το υδρόθειο που θεωρείται τοξικό και επίσης προκαλεί προβλήματα στο αναπνευστικό σύστημα,καθώς και ερεθισμό στα μάτια καθώς και το μεθάνιο που σε κλειστούς χώρους προκαλεί ασφυξία και είναι ιδιαίτερα εύφελκτο. Η ηφαιστειακή δραστηριότητα σε συνδυασμό με την απελευθέρωση των παραπάνω αερίων, επηρεάζει και το περιβάλλον καθώς το διοξείδιο του άνθρακα είναι το σημαντικότερο αέριο που συμβάλει στο φαινόμενο του θερμοκηπίου και ακολουθεί το μεθάνιο. Επίσης σε συνδυασμό με το διοξείδιο του θείου, τα δυο αυτά αέρια μπορούν να δημιουργήσουν όξινη βροχή καταστρέφοντας του υδάτινους υδροφορείς και σκοτώνοντας του υδρόβιους οργανισμούς, νεκρώνοντας τα δάση και τη βλάστηση. Επίσης η ηφαιστειακή δραστηριότητα συμβάλλει στη μείωση του όζοντος και είναι ικανή να επηρεάσει, πέρα από το τοπικό, ακόμα και το παγκόσμιο κλίμα της Γης λόγω της μετατροπής του διοξειδίου του άνθρακα σε θειικό οξύ, μειώνοντας τη θερμοκρασία του πλανήτη και κάνοντας το κλίμα ψυχρότερο. Στην Ελλάδα η ηφαιστειακή δραστηριότητα έχει έντονο ενδιαφέρον με σημαντικά ηφαιστειακά κέντρα όπως τα Μέθανα, η Μήλος, η Νίσυρος και η Σαντορίνη. Εκλύσεις αερίων έχουν καταγραφεί σε πολλά κέντρα όπως και στη Σαντορίνη, τα οποία αποτελούν επιφανειακές ενδείξεις ύπαρξης μάγματος και απελευθερώνονται από τις ατμίδες μαζί με τις θερμές πηγές. Η Σαντορίνη αποτελεί το γνωστότερο ενεργό ηφαίστειο του Ελληνικού Ηφαιστειακού Τόξου.Το ηφαιστειακό σύμπλεγμα της Σαντορίνης αποτελείται από μια ομάδα νησιών,με κυκλικό περίπου σχήμα και σχηματίζουν μια ιδιαίτερα εντυπωσιακή μορφή καλδέρας στο Μεσαγειακό χώρο.Aποτελείται από δυο ενεργά ηφαιστειακά κέντρα, αυτό της Καμένης και το Κολούμπο.Το ηφαίστειο της Σαντορίνης ανήκει στα κεντρικά πολυγενή μεικτά ηφαίστεια ή αλλιώς στρωματοηφαίστεια. Εκτός από ένα μικρό μη ηφαιστειακό υπόβαθρο αποτελείται σχεδόν εξ ολοκλήρου από ηφαιστειακά πετρώματα. Η δραστηριόητα του ηφαιστείου της Σαντορίνης και του υποθαλάσσιου Κολούμπο, παρακολουθείται στενά από την επιστημονική κοινότητα, ειδικότερα τα τελευταία χρόνια, με διάφορα τεχνολογικά μέσα και σκοπό την κατανόηση της δημιουργίας του, της δράσης του αλλά και την εκτίμηση του πιθανού ηφαιστειακού κινδύνου. Στο πλαίσιο αυτό γίνεται και η παρακολούθηση και η μέτρηση των ηφαιστειακών αερίων, οποιαδήποτε μεταβολή των οποίων μπορεί να σημάνει μέχρι και την εκ νέου ενεργοποίηση του ηφαιστείου.Volcanic activity is one of the main natural hazards that have affected human life and the entire living world in geological time. Aside from the immediate consequences of a volcanic eruption, inhalation of hazardous volcanic gases is the most common cause of death associated with volcanic activity. Of the volcanic gases, it seems that carbon dioxide is particularly toxic and suffocating in large concentrations, followed by sulfur monoxide, which, however, has much lower participation in gas mixtures. In addition to carbon dioxide, sulfur dioxide is also one of the most common gases associated with volcanic activity and can also cause breathing problems and even death in high concentrations. Directly associated with the volcanic activity is hydrogen sulfide, which is considered toxic and causes breathing problems and eye irritation, as well as methane, which indoor, can cause suffocating and can be extremely flammable. The volcanic activity in combination with the release of the above gases also affects the environment as carbon dioxide is the most important gas that contributes to the greenhouse effect, followed by methane. Also in combination with sulfur dioxide, these two gases can create acid rain destroying aquatic aquifers, killing aquatic organisms, and killing forests and vegetation. Volcanic activity also contributes to the depletion of ozone and can affect, in addition to the local, even the global climate of the Earth due to the conversion of carbon dioxide to sulfuric acid, reducing the temperature of the planet and making the climate colder. In Greece, volcanic activity is of great interest with important volcanic centers such as Methana, Milos, Nisyros, and Santorini. Gas emissions have been recorded in many centers as well as in Santorini, which are superficial signs of magma and released from the fumaroles along with the hot springs. Santorini is the most famous active volcano of the Greek Volcanic Arc. The volcanic complex of Santorini consists of a group of islands that have a circular shape and form a particularly impressive from the caldera in the Mediterranean area. It consists of two active volcano centers, Kameni and Columbo. The volcano of Santorini belongs to the central polygonal mixed volcanoes. Except for a small non-volcanic background, it consists almost entirely of volcanic rocks. The activity of the volcano of Santorini and the underwater Columbus is closely monitored by the scientific community, especially in recent years, with various technological techniques and in order to understand its creation, its action, and the assessment of potential volcanic risk. In this context, the monitoring, and measurement of volcanic gases is done, any change of which may conclude, even to the reactivation of the volcano

Partial transepithelial topography-guided PRK combined with corneal collagen crosslinking in patients with keratoconus

INTRODUCTION. The aim of this study is to identify the visual outcome and possible complications of partial transepithelial topography-guided PRK combined with collagen crosslinking in patients with keratoconus. MATERIALS AND METHODS. Twenty eyes (20 patients) were treated with partial transepithelial topography-guided PRK combined with collagen crosslinking. Patients were evaluated preoperatively for best spectacle corrected visual acuity (BSCVA), clinical signs of keratoconus via slit lamp examination, and Scheimpflug-generated corneal topography. All eyes were treated with Amaris 750s Excimer Laser and KXL system. RESULTS . Mean BCVA was improved from 20/100 to 20/25, postoperatively. Mean flat K was 46.8 ± 0.14 D preoperatively and was reduced to 45.2 ± 0.7 D postoperatively. Mean steep K was reduced from 50.2 ± 0.10 D to 47 ± 0.6 D. Total corneal astigmatism was 4.5 ± 0.14 D and decreased to 2.5 ± 0.10 D postoperatively. Average thinnest pachymetry was reduced from 465 ± 9.9 μm to 416 ± 11.3 μm. Total RMS (corneal aberrations) was 15.5 ± 7.4μm and was significantly reduced to 5.5 ± 2 μm. CONCLUSIONS. Partial transepithelial topography-guided PRK combined with collagen crosslinking can benefit patients fitting the criteria for such a procedure, by stabilising their cornea as well as improving their BSCVA.

Evaluating the safety and efficacy of photorefractive keratectomy combined with corneal collagen crosslinking for the treatment of myopia and myopic astigmatism

INTRODUCTION. The purpose of the study was to evaluate the safety and efficacy of photorefractive keratectomy (PRK) combined with corneal collagen crosslinking (CXL) in patients with potential risk of developing postoperative ectasia, who were not good candidates for LASIK. MATERIALS AND METHODS. Twenty eyes were treated with transepithelial PRK combined with CXL. Patients were evaluated preoperatively for best corrected visual acuity (BCVA), refraction, keratometry, topography, and endothelial cell count. All eyes were treated with Amaris 750s Excimer Laser and KXL system for 90 seconds at 30 mW/cm2. RESULTS. Mean BCVA was improved from 0.0075 ± 0.08 logMAR to 0.025 ± 0.05 logMAR postoperatively. Average keratometry reduced from 44.9 ± 1.9 D to 39.8 ± 3.9 D. Mean minimal corneal thickness reduced from 504 ± 16.7 μm to 405 ± 41 μm. None of the cases developed regression, corneal ectasia, or corneal haze. CONCLUSIONS. Photorefractive keratectomy combined with high-fluence corneal collagen crosslinking (PRK XTRA) appears to be a safe and effective treatment for patients who are not good candidates for LASIK