Morphological Characteristics of Drug-Eluting Biodegradable Polymeric Thin Films Developed on the Surface of Intraocular Lenses by Three Techniques: A Comparative Study.

Background Cataract surgery is a very popular operation that requires a postoperative period of frequent instillation of antibiotic and anti-inflammatory eye drops. Modified drug-eluting intraocular lenses (IOLs) may eliminate the need for eye drops after surgery. Aim The purpose of this study is to compare the morphological characteristics of dexamethasone eluting biodegradable polymeric thin films developed on the surface of commercially available IOLs by three different methods. Method This experimental study was conducted between May and August of 2021 in the Lab for Thin Films - Nanobiomaterials - Nanosystems & Nanometrology (LTFN) of the Aristotle University of Thessaloniki. A mixture of two organic polymers [Poly (D, L-lactide-co-glycolide)(PLGA), lactide: glycolide (75:25) and Polycaprolactone (PCL)] and dexamethasone was prepared and then deposited on the surface of three-piece IOLs by spin coating, by spray coating, and by gravure printing. The modified IOLs were sterilized with the use of ultraviolet (UV) radiation and plasma treatment. Their structural properties were studied with the use of atomic force microscopy (AFM). Results Spin coating and gravure printing produced uniform thin films on the surface of the IOLs which were not damaged during the sterilization process. Spray coating led to the partial coating of the surface of the IOLs; the thin films underwent alterations following plasma treatment. Conclusions Thin films developed by spin coating and gravure printing on IOLs demonstrate the desired morphological characteristics that make them suitable candidates for further research.

Design, characterisation and drug release study of polymeric, drug-eluting single layer thin films on the surface of intraocular lenses.

To design, develop and study a novel drug delivery system for intraocular applications. The spin coating technique was applied to develop a polymeric, drug-eluting thin film consisting of a blend of organic polymers [poly (D, L lactide coglycolide) lactide: glycolide 75: 25, PLGA and polycaprolactone, PCL] and dexamethasone on the surface of intraocular lenses (IOLs). The initial durability of the IOLs during spinning was assessed. Information about the structural and optical properties of the modified IOLs was extracted using atomic force microscopy, scanning electron microscopy and spectroscopic ellipsometry. A drug release study was conducted for 8 weeks. The IOLs were durable in spinning speeds higher than the ones used to develop thin films. Single-layer thin films were successfully developed on the optics and the haptics of the lenses. The films formed nanopores with encapsulated aggregates of dexamethasone. The spectroscopic ellipsometry showed an acceptable optical transparency of the lenses regardless of the deposition of the drug-eluting films on their surface. The drug release study demonstrated gradual dexamethasone release over the selected period. In conclusion, the novel drug-eluting IOL system exhibited desired properties regarding its transparency and drug release rate. Further research is necessary to assess their suitability as an intraocular drug delivery system.

Ophthalmology Training in Greece as Perceived by Resident Ophthalmologists in the Times of Crisis: A National, Questionnaire-based Survey.

PURPOSE: To assess the level of perceived satisfaction with the current level of ophthalmology training in Greece from the perspective of residents and to identify deficiencies in the training curriculum. METHODS: This is a prospective, cross-sectional questionnaire-based study. An online, semi-structured questionnaire was designed to evaluate ophthalmology residents' extent of satisfaction with the quality of their postgraduate medical training. The survey was divided in two parts: demographics and evaluation of training. Resident ophthalmologists in all teaching hospitals in Greece were contacted and encouraged to complete it. RESULTS: A response rate of 53.8% was achieved. Two out of three participants stated their disappointment with the quality of training they received and deemed the four-year residency training program as insufficient. Surgical training was also viewed as unsatisfactory by the majority of the respondents. An interest in subspecialty training, as well as a significant participation in research activities, was noted. CONCLUSIONS: Both training and overall satisfaction with working conditions must be improved to preserve the appeal of ophthalmology for young academics. A new, structured curriculum, reduction of unnecessary bureaucracy, and improved surgical training rank among the most essential priorities in order to improve postgraduate ophthalmology training.

Bilateral identical intervals between phacoemulsification procedures performed 23 years before retinal detachment.

We aim to present a case of bilateral rhegmatogenous retinal detachment (RRD) after successful phacoemulsification procedures performed 23 years before RRD onset and surgical management. A 57-year-old female presented with blurred vision due to floaters in the left eye. The patient was followed up with dilated fundus examination. The patient underwent bilateral uneventful cataract extraction 23 years before the baseline visit with the use of phacoemulsification. Dilated fundus examination revealed RRD in the left eye that was managed with a 25G pars plana vitrectomy, cryopexy, and 16% C3F8 expandable gas. Thirty-three days following the procedure in the left eye, the patient presented with RRD in the right eye. Management included a 25G pars plana vitrectomy with cryopexy and 20% SF6 expandable gas. Phacoemulsification ultrasound energy appears to bring about changes in the peripheral vitreous and retina that may manifest several decades following uncomplicated cataract extraction.

Design and fabrication of drug-eluting polymeric thin films for applications in ophthalmology.

To study the development, characterisation, and drug release of one- and two-layered thin films based on organic polymers [poly(D,L-lactide-co-glycolide) lactide:glycolide (65:35), poly(D,L-lactide-co-glycolide) lactide:glycolide (75:25), and polycaprolactone] and dexamethasone. To examine their applicability for intraocular lenses (IOLs) and function in intraocular drug delivery systems. Four series of thin films, single and double-layer, were prepared by the spin-coating method on a silicon substrate. The films were studied using atomic force microscopy and spectroscopic ellipsometry. The release rate of dexamethasone was studied for a period of ten weeks. Series A and C demonstrated the formation of large dexamethasone aggregates. The monolayer films of series C and D formed pores, in agreement with previous findings. The spectroscopic ellipsometry study demonstrated that the samples were transparent. The drug release study demonstrated that dexamethasone was released during the first 6 weeks at a desirable rate. The films exhibited properties suitable for use in intraocular drug delivery systems. The single-layer thin films demonstrated a sufficient encapsulation of dexamethasone and appropriate release of the therapeutic substance. Further studies are necessary to investigate the possibility of developing the films directly on the surface of the IOL.

Training of Resident Ophthalmologists in Cataract Surgery: A Comparative Study of Two Approaches.

Purpose. To evaluate and compare the efficacy of two different training methods in resident-performed phacoemulsification surgery. Methods. 502 eyes of 467 patients who underwent resident-performed phacoemulsification were included in the study by reviewing their medical records. Residents were allocated into two groups according to the method applied during their training in cataract surgery; Group A included residents that were trained with the "step-by-step" method and Group B those trained with the "one-step" method. Primary outcome was the incidence of main complications, defined as posterior capsular ruptures and/or zonular dehiscence with vitreous loss. Results. Each resident performed a median of 63 phacoemulsification surgeries. A statistically significant difference (p = 0.0032) was noted in the main complications rate between the two groups, yielding a mean of 17.3% in Group A and 7.25% in Group B. Other intraoperative complications were not shown to differ statistically significantly between study groups (p > 0.05). Among the first 40 surgeries of each resident, main complications rate differed also statistically significantly (p = 0.0048) between Group A (21.67%) and Group B (8.5%), while a better surgical performance-yielding statistical significance in Group A (p = 0.017) was indicated in both groups between the 20th and the 30th procedure. Conclusions. Training in cataract surgery using the "one-step" method may lead to an improvement in surgical competency, when measured by complications rates and, therefore, to significantly better quality of training for resident ophthalmologists.

Contribution of integrated teaching in the improvement of an undergraduate ophthalmology curriculum.

PURPOSE: Conventional medical curriculum is the rule of medical teaching in Greek Medical Schools. Medical students are often taught irrelevant details with little or no reference to their potential clinical significance. Alternatively, integrated teaching warrants that the complete teaching material is covered by each faculty member not considering areas of personal expertise. The aim of this study was to evaluate the implementation of integrated teaching in ophthalmic training. METHODS: The main outcome measures of this retrospective study were a) comments and recommendations made anonymously by the fifth-year medical students in the evaluation questionnaires filled in at the end of their training, and b) scores obtained by students in their final examination at the end of their training in the 2nd Department of Ophthalmology as part of the core Curriculum of the Medical School of the Aristotle University of Thessaloniki. The latter outcome was analyzed with respect to the implementation of integrated teaching. RESULTS: The score obtained by students in the final examination, which is an objective outcome measure, increased significantly after the implementation of integrated teaching. The final grade (scores out of 10) of students who were trained with the integrated system (6.17±1.67, mean ± standard deviation) was significantly higher compared to those (5.52±2.20) trained with the conventional system (P<0.001). The positive outcome of this process was evident as there was a significant increase in the number of students satisfied with the teaching process compared to previous academic years. CONCLUSION: Based on the experience of eight academic years and as a result of interactive assessment process our department has modified its medical student teaching process from conventional to integrated; all teaching staff members are involved in the teaching process, while students are divided in small groups. In conclusion, integrated teaching in small student groups appears to be an efficient teaching method (for both theoretical and clinical skills) of ophthalmic training for medical students.

Measurements of elastic modulus for human anterior lens capsule with atomic force microscopy: the effect of loading force.

The purpose of the study was to appraise the effect of loading force magnitude on the determination of the elastic modulus of the anterior lens capsule through atomic force microscopy. Four human anterior lens capsules taken during phacoemulsification cataract surgery were studied, free of epithelial cells, with atomic force microscopy. For the experiment, five different indentation loading forces were applied to near areas of the specimen. Experimental data was exported and analyzed according to the Hertz model to obtain the Young's modulus with regards to the elastic behavior of the material. Force-distance curves were acquired by applying a load of 2, 5, 10, 20 and 30 nN. When examining the results it was evident that determination of Young's modulus of the anterior lens capsule is dependent on the loading force concerning the examined range. Loading forces of 10 and 20 nN led to results without significant difference (p > 0.05) and more reproducible (coefficients of variation 12.4 and 11.7 %, respectively).

Imaging characteristics of delayed surface calcification in hydrophilic intraocular lens models.

We report two cases of opacified explanted intraocular lenses (IOL).The first lens was explanted from a cataract patient, then treated in vitro with trypsin/ethylene-diamine-tetra-acetic acid. The second hydrophilic acrylic IOL was explanted from a patient who had undergone sulphur hexafluoride (SF6) gas endotamponade surgery to repair a retinal detachment.

Surgical outcomes in phacoemulsification after application of a risk stratification system.

BACKGROUND: The purpose of this study was to determine whether application of a risk stratification system during preoperative assessment of cataract patients and subsequent allocation of patients to surgeons with matching experience may reduce intraoperative complications. METHODS: Nine hundred and fifty-three consecutive patients (1109 eyes) undergoing phacoemulsification cataract surgery were assigned to two groups, ie, group A (n = 498 patients, 578 eyes) and group B (n = 455 patients, 531 eyes). Patients from group A were allocated to surgeons with varying experience with only a rough estimate of the complexity of their surgery. Patients from group B were assigned to three risk groups (no added risk, low risk, and moderate-high risk) according to risk factors established during their preoperative assessment and were respectively allocated to resident surgeons, low-volume surgeons, or high-volume surgeons. Data were collected and entered into a computerized database. The intraoperative complication rate was calculated for each group. RESULTS: The intraoperative complication rate was significantly lower in group B than in group A (group A, 5.88%; group B, 3.2%; P < 0.05). Patients from group B with no added risk and allocated to resident surgeons had a significantly lower rate of intraoperative complications than those from group A allocated to resident surgeons (group A, 7.2%; group B, 3.08%; P < 0.05). CONCLUSION: Our study demonstrates that allocation of cataract patients to surgeons matched for experience according to a uniform and reliable preoperative assessment of their risk of complications allows for better surgical outcomes, especially for resident surgeons.