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Abstract Bioabsorbable materials enable temporary implantation without the need for subsequent implant removal. The aim of the present experimental study was to evaluate the suitability of a fibrous bioabsorbable implant made of poly-L/D-lactide (PLDLA) 96/4 fibres as an episcleral implant. The general tissue reactions were evaluated in subcutaneous tissues in rats in follow-up periods ranging from 3 days to 48 weeks. The episcleral tissue reactions were studied in rabbits with follow-up periods of one, three, five and 48 weeks. A silicone sponge implant was used as a control material and operations were performed using similar technique with both implants. Tissue reactions were located just around the implant area and consisted of an acute inflammatory reaction in the early follow-up periods, continuing as a foreign body inflammatory reaction. With episcleral implants there were no inflammatory cells seen within the sclera or in the retinal layers, and the structure of the retina and the cornea was also normal. The biocompatibility was good in the 48 week follow-up despite the relatively high surface area of the fibrous implant. The material had not degraded by 48 weeks. The indentation effect by the PLDLA implant (diameter of 3–3.5mm) was lower than that achieved with the silicone sponge implant (diameter 4mm). The depth of indentation decreased over time in both groups with comparable rates over the follow-up period of 5 months. The duration of the indentation effect was sufficient to be used for scleral buckling in retinal detachment surgery. In conclusion, the biocompatibility of a fibrous implant made of PLDLA 96/4 placed subcutaneously and episclerally was good in the follow-up lasting 48 weeks despite the relatively high surface area of the implant. The fibrous implant made of PLDLA 96/4 seemed to be well-tolerated by ocular tissues and the indentation effect was sufficiently long.

No description available.

No description available.

PURPOSE: To investigate relationships between preoperative and intraoperative characteristics with outcome variables in patients suffering from primary rhegmatogenous retinal detachment (RRD) or traction retinal detachment (TRD) complicated by serous choroidal detachment (CD). Choroidal detachment is a rare complication of retinal detachment and the current literature cites generally poor visual outcome variables. By investigating a retrospective case series, we hope to elucidate new relationships and embolden existing ones so that future physicians can make more educated decisions regarding the care for these complicated patients. METHODS: A retrospective case series analyzed 18 patient’s medical records (18 eyes) who had been diagnosed and surgically treated for RRD or TRD associated with a CD at the Longwood Medical Eye Center at Beth Israel Deaconess Medical Center. Patients with RDCD who had undergone 23-gauge pars plana vitrectomy with silicone oil tamponade were selected. Exclusionary criteria included ocular complications such as phthisis bulbi and open globe trauma. Patients experienced a variety of surgical procedures including by not limited to relaxing retinotomy (n=12 eyes), choroidal drainage (n=10 eyes), endoscopy-assisted PPV (n=10 eyes), and ERM peeling (n=8 eyes). Primary outcome variables tabulated were primary and final anatomic success, defined as successful reattachment of the retina to the underlying choroid, and final visual acuity. RESULTS: The mean age of the sample group was 69 with 8 patients (44%) diagnosed with preoperative hypotony (IOP <= 6 mmHg). A total of 12 patients were pseudophakic (67%). With a mean follow-up of 21.6 months, patients exhibited expected visual outcomes with 6 patients (33%) improving visual acuity and 7 patients (39%) decreasing visual acuity. Final anatomic success was seen in 17 cases (94%). A significant correlation was found between decreased number of previous surgeries and better visual outcomes (change in BCVA). Another significant relationship correlates choroidal drainage with worse visual outcomes (change in BCVA). Finally, patients who received ERM peeling had better rates of primary anatomic success. CONCLUSION: The advanced age of the sample lends itself to increased risk for cataracts and thus pseudophakia. In addition, high rates of diabetes and macular degeneration follow. The pathophysiology of RDCD in relation to the risk factors of hypotony and macular holes is possibly based on the Starling forces and favorable fluid transudation into the suprachoroidal space. Although the outcomes of this study were similar to previous literature, the visual outcomes are still poor at best. Reducing the number of previous, invasive, ocular surgeries was seen to be correlated with better visual outcomes. In addition, performing ERM peels is seen to be correlated with improved rates of primary anatomic success. More research is required on the etiology of the disease process and a case-controlled longitudinal study may be helpful in determining more relationships with outcome variables.

The purpose of this project is to study the risk of cataract development in patients who had undergone pars plana vitrectomy, scleral buckle, or both. A retrospective study was performed of phakic patients who underwent pars plana vitrectomy, scleral buckle, or both at Yale University Eye Center from 1998 to 2005. Mild postoperative cataract, defined as a change in severity of 1+, developed in 32 of 53 (60%) eyes following vitrectomy, 2 of 19 (11%) post scleral buckle, and 14 of 16 (88%) after both. Moderate postoperative cataract, defined as a change in severity of 2+, developed in 14 of 53 (26%) eyes post vitrectomy, 1 of 19 (5%) post scleral buckle, and 11 of 16 (69%) after both procedures. In eyes that underwent vitrectomy, a lens change of at least 2+ occurred in 8% at 3 months, 15% at 6 months, 21% at 12 months, and 26% at 36 months. In eyes status post scleral buckle surgery, one eye (5%) experienced a 2+ change at 36 months. In eyes that underwent both vitrectomy and scleral buckle, a lens change of at least 2+ occurred in 44% at 3 months, 50% at 6 months, 63% at 12 months, and 69% at 36 months. Cataract extraction surgery was performed in 15% of eyes post vitrectomy, 0% post scleral buckling, and 50% after both. The most common type of cataract to develop was nuclear sclerotic, which accounted for 61% of cataracts after vitrectomy, 50% after scleral buckling, and 50% after combined vitrectomy and scleral buckling. Scleral buckling surgery is associated with a low risk of cataract formation. Pars plana vitrectomy and combined vitrectomy and buckle have a higher risk of cataract development.

No description available.

Η Ακετονική Τριαμσινολόνη είναι ένα συνθετικό γλυκοκορτικοειδές το οποίο έχει ευρέως χρησιμοποιηθεί στη θεραπεία ενός αριθμού φλεγμονωδών και αγγειακών / εξιδρωματικών παθήσεων του οφθαλμού, χορηγούμενη υπό μορφή ένεσης παραβόλβια, υποτενόνια ή ενδοϋαλοειδικά. Δυστυχώς έχει περιορισμένο χρόνο ημιζωής με συνέπεια να είναι συχνά αναγκαίες επανειλημμένες ενέσεις για να επιτευχθεί παρατεταμένη δράση. Αυτό αυξάνει τη συχνότητα των επιπλοκών, οι οποίες σχετίζονται τόσο με το ίδιο το φάρμακο όσο και με την οδό χορήγησης. Σκοπός της μελέτης: Η παρασκευή σκληρικών συστημάτων ελεγχόμενης αποδέσμευσης Ακετονικής Τριαμσινολόνης βασιζόμενα στο βιοδιασπόμενο πολυμερές Πόλυ[γαλακτικό] (PLA) και η αξιολόγηση των in vitro/ex vivo χαρακτηριστικών τους σε σχέση με τη δυνητική χρήση τους για παρατεταμένη διασκληρική χορήγηση ΤΑ. Υλικό και Μέθοδος: Μικροσφαίρες PLA που περιείχαν ΤΑ παρασκευάστηκαν με τη μέθοδο του απλού και του διπλού γαλακτώματος. Εξετάστηκαν η μορφολογία τους, το μέγεθός τους, η επίδραση της αρχικής ποσότητας ΤΑ και της μεθόδου παρασκευής στη φόρτιση των μικροσφαιρών καθώς και η in vitro αποδέσμευση ΤΑ από αυτές. Παρασκευάστηκαν δισκία αποτελούμενα από μικροσφαίρες καθαρού PLA και ΤΑ (με αναλογία βάρους 1:1, 2:1 και 4:1 αντίστοιχα) και εξετάστηκε η in vitro καμπύλη αποδέσμευσης ΤΑ από αυτά. Αξιολογήθηκε η καμπύλη διασκληρικής διάχυσης in vitro τοποθετώντας ένα δισκίο αναλογίας PLA:TA=1:1 σε ένα δοχείο δότη και μετρώντας τη συγκέντρωση ΤΑ σε δοχείο δέκτη. To δοχείο δότης και το δοχείο δέκτης διαχωρίζονταν διαμέσου ενός τμήματος σκληρού χιτώνα κουνελιού. Σε δύο πτωματικούς οφθαλμούς κουνελιών τοποθετήθηκε επισκληρικά ένα δισκίο 1:1 PLA-ΤΑ και καλύφθηκε με ένα σκληρικό μόσχευμα. Η συγκέντρωση της ΤΑ στο υδατοειδές υγρό και στο υαλοειδές μετρήθηκε 5, 10 και 20 ημέρες μετά από την ένθεση. Aποτελέσματα: Η μέση διάμετρος των μικροσφαιρών ήταν 2 μm. H μέθοδος του διπλού γαλακτώματος καθώς και η αύξηση της αρχικής ποσότητας του φαρμάκου οδήγησε στην αύξηση της τιμής φόρτισης και ενκαψακίωσης των μικροσφαιρών. Παρατηρήθηκε παρατεταμένη για αρκετές μέρες αποδέσμευση ΤΑ από τις μικροσφαίρες, με το ρυθμό αποδέσμευσης να εξαρτάται από την περιεκτικότητά τους σε ΤΑ. H ΤΑ αποδεσμευόμενη από δισκία PLA-TA παρουσίασε παρατεταμένη αποδέσμευση, με το ρυθμό της να εξαρτάται από το λόγο PLA:TA. H TA μπόρεσε να διαπεράσει το σκληρό χιτώνα με περίπου 21% του φαρμάκου στο δοχείο δότη να έχει διαχυθεί διαμέσου του σκληρού χιτώνα μετά από 45 ημέρες. Μετά από σκληρική χορήγηση η ΤΑ εμφάνισε συγκεντρώσεις στο υδατοειδές υγρό και στο υαλοειδές σε πτωματικούς οφθαλμούς. Συμπεράσματα: Οι μικροσφαίρες και τα δισκία PLA-TA που αναπτύχθηκαν σε αυτήν τη μελέτη παρουσιάζουν παρατεταμένη και ελεγχόμενη αποδέσμευση ΤΑ, έχουν τα πλεονεκτήματα της καθιερωμένης βιοαποικοδομησιμότητας και βιοσυμβατότητας του πολυμερούς PLA, παρέχουν ευελιξία ως προς το ρυθμό αποδέσμευσης και τη συνολική δόση ΤA και παρουσιάζουν ευκολία στους χειρουργικούς χειρισμούς. Αυτά τα συστήματα φαίνεται να είναι υποσχόμενα για την ελεγχόμενη διασκληρική χορήγηση ΤΑ και δικαιολογείται η περαιτέρω μελέτη τους. / Triamcinolone Acetonide (TA) is a synthetic glucocorticoid, which has been widely used to treat a number of inflammatory and vascular and/or exudative diseases of the eye, administered via a peribulbar, sub-tenon or intravitreal injection. Unfortunately, it has a limited half-life and thus repeated injections are often required to establish a prolonged effect. This increases the rate of complications, which are related to the drug itself as well as to the administration route. Study Purpose: To develop scleral controlled-release-systems of Τriamcinolone Αcetonide based on biodegradable Poly[lactide] (PLA) and evaluate their in vitro/ex vivo properties with regard to their possible application for the prolonged transscleral delivery of TA. Materials and Methods: PLA microspheres containing TA were prepared by a single or double emulsification-solvent evaporation method. Morphology, size, effect of drug input and method of microsphere preparation on drug loading, and in vitro TA release of the microspheres were investigated. Tablets consisting of blank PLA-microspheres and TA (weight ratios of 1:1, 2:1, and 4:1, respectively) were developed and their release profile οf TA in vitro was evaluated. The in vitro transscleral diffusion profile was evaluated by placing a PLA-TA (1:1) tablet in a donor chamber and measuring the TA concentration in a receptor chamber. Donor and receptor chambers were separated by rabbit sclera. Two cadaver rabbit eyes received a 1:1 PLA-TA tablet episclerally, which was covered by a scleral patch. TA aqueous humor and vitreous concentrations were measured 5, 10, and 20 days post implantation. Results: Microsphere average diameter was 2 μm. The double emulsification method and increasing drug input led to an increase in microsphere drug loading and encapsulation. Sustained release of TA over several days from the microspheres in vitro was observed, with the rate of release being affected by their TA content. TA exhibited sustained release profile from the PLA-TA tablets, with the rate of release being affected by the PLA:TA ratio. TA could cross the sclera tissue in vitro, with approximately 21% of the initial drug in the donor compartment having diffused through the sclera in 45 days. Following scleral administration of the PLA-TA tablets, TA accumulated in the vitreous and aqueous humor of cadaver eyes. Conclusions: The PLA-TA microspheres and tablets developed in this study provide a sustained and controlled release of TA, provide the advantages of established biodegradability and biocompatibility of the PLA polymer, demonstrate flexibility concerning their TA release rate and total TA dosage and are easy to surgically manipulate. These systems appear promising for the controlled transscleral delivery of TA and justify further investigation.

L'orientation des lentilles sclérales devient extrêmement importante pour maximiser la stabilité et la vision chez des patients qui portent des lentilles ayant une face antérieure torique. Les techniques cliniques actuelles pour déterminer la rotation d'une lentille sclérale impliquent l'utilisation de lentilles diagnostiques; cependant, ces méthodes nécessitent beaucoup de temps de chaise pour obtenir un ajustement optimal. Des appareils novateurs existent maintenant pour évaluer la forme de la surface oculaire et peuvent s’avérer utiles pour prédire la rotation des lentilles sclérales et augmenter l'efficacité globale des ajustements. Le but de cette étude comparative et randomisée était d'évaluer la rotation des lentilles sclérales en se basant sur des valeurs fournies par deux topographes. Quinze participants ont été recrutés et leurs deux yeux ont été imagés à l'aide de deux topographes: le Eye Surface Profiler (ESP) et le Cornea Sclera Profile (CSP). Les participants ont ensuite été ajustés avec la lentille OneFit MED dans un oeil et la Zenlens dans l'autre. La rotation de chaque lentille a été évaluée à l’aide de la lampe à fente et comparée à l’axe le plus cambré de l’astigmatisme conjonctival identifié par chaque topographe. Bien que les rotations des deux instruments ne soient pas comparables, l'ESP a prédit une rotation à moins de 15° de l'observation à la lampe à fente, ce qui la rend cliniquement acceptable pour les lentilles avec de faibles valeurs de puissance cylindrique. L'acuité visuelle des patients portant des lentilles avec des quantités élevées de toricité pouvant être plus affectée par la quantité de rotation, les ajustements empiriques semblent, à ce stade, être déconseillés pour ces cas. / Scleral lens orientation becomes extremely important to maximize vision and lens stability in patients who are fitted in front-toric lenses. Current clinical techniques to determine the rotation of a scleral lens involve the use of diagnostic lenses; however, these methods require a substantial amount of chair time to achieve an optimal fit. Contemporary equipment exists to evaluate ocular surface shape, which could be useful in predicting scleral lens rotation and increasing the overall efficiency of scleral lens adjustments. The goal of this comparative and randomized study was to evaluate scleral lens rotation based on the values provided by two scleral topographers. Fifteen participants were recruited and both eyes were imaged using two scleral topographers: the Eye Surface Profiler (ESP) and the Cornea Sclera Profile (CSP). Participants were fitted with the OneFit MED on one eye and the Zenlens on the other. Each lens’s rotation was evaluated at the slit lamp and compared to the steep axis of conjunctival astigmatism identified by each topographer. While the rotations from both instruments are not comparable, the ESP predicted rotation within 15˚ from slit lamp observation, which makes it clinically acceptable for lenses with low values of cylindrical power. The visual acuity of patients wearing lenses with a high amount of toricity may be affected by the amount of rotation and are not suitable for empirical fittings at this point in time.

Background: Collagen cross-linking of the sclera is a promising approach to strengthen scleral rigidity and thus to inhibit eye growth in progressive myopia. Additionally, cross-linking might inhibit degrading processes in idiopathic melting or in ocular inflammatory diseases of the sclera. Different cross-linking treatments were tested to increase resistance to enzymatic degradation of the rabbit sclera. Methods: Scleral patches from rabbit eyes were cross-linked using paraformaldehyde, glutaraldehyde or riboflavin combined with UV-A-light or with blue light. The patches were incubated with collagenase I (MMP1) for various durations up to 24 h to elucidate differences in scleral resistance to enzymatic degradation. Degraded protein components in the supernatant were detected and quantified using measurements of Fluoraldehyde o-Phthaldialdehyde (OPA) fluorescence . Results: All cross-linking methods reduced the enzymatic degradation of rabbit scleral tissue by MMP1. Incubation with glutaraldehyde (1%) and paraformaldehyde (4%) caused nearly a complete inhibition of enzymatic degradation (down to 7% ± 2.8 of digested protein compared to control). Cross-linking with riboflavin/UV-A-light reduced the degradation by MMP1 to 62% ± 12.7 after 24 h. Cross-linking with riboflavin/blue light reduced the degradation by MMP1 to 77% ± 13.5 after 24 h. No significant differences could be detected comparing different light intensities, light exposure times or riboflavin concentrations. Conclusions: The application of all cross-linking methods increased the resistance of rabbit scleral tissue to MMP1-degradation. Especially, gentle cross-linking with riboflavin and UV-A or blue light might be a clinical approach in future.