Comparative Analysis of Corneal Wound Healing: Differential Molecular Responses in Tears Following PRK, FS-LASIK, and SMILE Procedures.

BACKGROUND/OBJECTIVES: In this study, we aimed to analyze the changes in the expression profiles of selected messenger RNAs (mRNAs) and their encoded proteins in the tears of patients undergoing photorefractive keratectomy (PRK), femtosecond-assisted laser in situ keratomileusis (FS-LASIK), and small-incision lenticule extraction (SMILE) procedures. METHODS: A total of 120 patients were divided into three groups based on the laser vision correction (LVC) procedure: PRK, FS-LASIK, or SMILE. Tear samples were collected preoperatively and at 1, 7, 30, and 180 days postoperatively. The expression levels of selected messenger RNAs (mRNAs) and proteins were analyzed by using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA), respectively. RESULTS: PRK and FS-LASIK elicited significantly stronger biological responses than SMILE. Interleukin-15 (IL-15) expression increased notably in the PRK and FS-LASIK groups, with mRNA levels reaching fold changes of 4.65 ± 0.65 and 4.99 ± 0.28, respectively, on day 1, compared with only 2.09 ± 0.23 in the SMILE group. Vascular endothelial growth factor A (VEGFA) levels were also elevated in the PRK (2.98 ± 0.23 fold change) and FS-LASIK groups (3.45 ± 1.09 fold change) on day 1, while the SMILE group showed minimal fluctuations. The protein concentration analysis based on the ELISA confirmed these trends, with IL-15 levels peaking at 54.2 ± 2.5 pg/mL in the PRK group and 52.8 ± 3.1 pg/mL in the FS-LASIK group, compared with 32.4 ± 1.9 pg/mL in the SMILE group on day 1. Similarly, VEGFA protein concentrations were the highest in the PRK (72.4 ± 4.1 pg/mL) and FS-LASIK patients (69.5 ± 3.8 pg/mL) on day 1 but remained low in the SMILE patients (45.6 ± 2.3 pg/mL). By day 180, gene expression and protein levels in all groups had stabilized, returning to near-preoperative values. CONCLUSIONS: PRK and FS-LASIK induced more pronounced molecular and protein-level changes during corneal wound healing than the less invasive SMILE procedure, indicating stronger biological responses. These findings suggest that tailored postoperative care based on the specific procedure could optimize healing and patient outcomes. However, further research with larger sample sizes and longer follow-ups is needed to confirm these observations and develop personalized treatment strategies.

Evaluating the Efficacy of Pre-Emptive Peribulbar Blocks with Different Local Anesthetics or Paracetamol Using the Adequacy of Anesthesia Guidance for Vitreoretinal Surgeries: A Preliminary Report.

BACKGROUND/OBJECTIVES: Precisely selected patients require vitreoretinal surgeries (VRS) performed under general anesthesia (GA) when intravenous rescue opioid analgesics (IROA) are administered intraoperatively, despite a risk of adverse events, to achieve hemodynamic stability and proper antinociception and avoid the possibility of intolerable postoperative pain perception (IPPP). Adequacy of anesthesia guidance (AoA) optimizes the titration of IROA. Preventive analgesia (PA) techniques and intravenous or preoperative peribulbar block (PBB) using different local anesthetics (LAs) are performed prior to GA to optimize IROA. The aim was to analyze the utility of PBBs compared with intravenous paracetamol added to AoA-guided GA on the incidence of IPPP and hemodynamic stability in patients undergoing VRS. METHODS: A total of 185 patients undergoing vitreoretinal surgery (VRS) were randomly assigned to one of several anesthesia protocols: general anesthesia (GA) with analgesia optimized through AoA-guided intraoperative remifentanil opioid analgesia (IROA) combined with a preemptive single dose of 1 g of paracetamol (P group), or PBB using one of the following options: 7 mL of an equal mixture of 2% lidocaine and 0.5% bupivacaine (BL group), 7 mL of 0.5% bupivacaine (BPV group), or 7 mL of 0.75% ropivacaine (RPV group). According to the PA used, the primary outcome measure was postoperative pain perception assessed using the numeric pain rating scale (NPRS), whereas the secondary outcome measures were as follows: demand for IROA and values of hemodynamic parameters reflecting quality or analgesia and hemodynamic stability. RESULTS: A total of 175 patients were finally analyzed. No studied PA technique proved superior in terms of rate of incidence of IPPP, when IROA under AoA was administered (p = 0.22). PBB using ropivacaine resulted in an intraoperative reduction in the number of patients requiring IROA (p = 0.002; p < 0.05) with no influence on the dose of IROA (p = 0.97), compared to paracetamol, and little influence on hemodynamic stability of no clinical relevance in patients undergoing VRS under AoA-guided GA. CONCLUSIONS: PA using paracetamol or PBBs, regardless of LAs used, in patients undergoing VRS proved no advantage in terms of rate of incidence of IPPP and hemodynamic stability when AoA guidance for IROA administration during GA was utilized. Therefore, PA using them seems no longer justified due to the potential, although rare, side effects.

Assessment of OCT and Angio-OCT Parameters in Keratoconus Patients with and without Penetrating Keratoplasty.

Background/Objectives: Keratoconus (KC) is a bilateral eye disease characterized by corneal thinning and cone-like deformation, leading to visual impairment. This study evaluated the radial peripapillary capillaries (RPCs) in keratoconus patients with and without penetrating keratoplasty (PKP) using OCT and angio-OCT, comparing the results to a control group. Methods: This retrospective study included 149 eyes, 97 from patients who underwent PKP between January 2018 and February 2023 and 52 from patients who did not undergo PKP. The control group comprised 72 patients (144 eyes) who were healthy volunteers. Measurements included the best corrected visual acuity (BCVA), the intraocular pressure (IOP), slit-lamp biomicroscopy, a fundus examination, and corneal topography, as well as OCT and angio-OCT assessments of the RPCs, retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), and central retinal thickness (CRT). Statistical analyses were performed using Student's t-test and Pearson's correlation coefficient. Results: The RNFL was significantly thinner in KC eyes after PKP compared to control eyes (p < 0.001), and the CRT was significantly thicker in KC eyes after PKP compared to control eyes (p = 0.003). However, the GCC was similar across the groups (p = 0.0885). Additionally, RPCs inside the disc were significantly reduced in KC eyes after PKP compared to control eyes (p < 0.0001). A significant positive correlation was found between RPC whole vessel density and RNFL thickness as measured via angio-OCT (r = 0.308, p < 0.0001). Conclusions: This study found that the RPC density inside the disc is significantly reduced in keratoconus patients after penetrating keratoplasty, highlighting RPCs inside the disc as a potential diagnostic tool for further assessment of keratoconus.

Efficacy of Continuous-Wave Transscleral Cyclophotocoagulation Post-Pars Plana Vitrectomy in Glaucoma Patients: A Retrospective Study from Poland.

BACKGROUND Glaucoma, a vision-threatening condition, results from optic nerve damage and affects millions of people worldwide. Often asymptomatic, it is hereditary, with risk factors like hypertension, diabetes, and steroid use. Despite its link with intraocular pressure (IOP), not everyone with high IOP develops glaucoma. After pars plana vitrectomy (PPV), patients face increased IOP risks. Traditional treatment includes pharmacotherapy, and, when ineffective, surgical interventions. Continuous-wave transscleral cyclophotocoagulation (CW-TSCPC) is an alternative for refractory glaucoma but can have complications. Our study compares the efficacy and safety of CW-TSCPC after PPV. MATERIAL AND METHODS The study group consisted of 18 patients diagnosed with glaucoma who underwent the CW-TSCP procedure as the first-choice therapy after conservative treatment of glaucoma proved ineffective. The comparison group consisted of 12 patients who underwent the CW-TSCP procedure after conservative drug treatment and in whom surgical treatment of glaucoma had been unsuccessful. All patients had inadequate control of IOP after PPV. RESULTS Study and comparison group patients showed a decrease in IOP during the follow-up, independent of the type of endotamponade used (P<0.05). When the indication for PPV was retinal detachment hemorrhage into the vitreous chamber, a significant decrease in IOP between 0 days and 180 days was only found in the study group (P<0.05). In contrast, when the indication for PPV was the state after uveitis or proliferative diabetic retinopathy, a significant decrease in IOP was found at 180 days in the study and comparison groups (P<0.05). CONCLUSIONS The analysis showed that the CW-TSCPC procedure can be recommended as the first-choice invasive treatment in patients with increased IOP after PPV.

Prospective Safety Evaluation of the Femtosecond Laser-Assisted Keratomileusis Procedure in Correcting Residual Ametropia in Patients After Deep Anterior Lamellar Keratoplasty.

BACKGROUND This prospective study, from a single center in Poland, aimed to evaluate the correction of residual ametropia, or refractive errors, after corneal grafting using femtosecond laser-assisted in situ keratomileusis (Femto-LASIK) in 60 patients (96 eyes) who had previously undergone deep anterior lamellar keratoplasty (DALK) compared with that achieved in 60 patients (108 eyes) who underwent vision correction using Femto-LASIK alone. MATERIAL AND METHODS The study group included 60 patients (96 eyes) whose residual ametropia was corrected using the Femto-LASIK procedure after having previously undergone DALK. The comparison group consisted of 60 patients (108 eyes) who underwent vision correction with the Femto-LASIK procedure without previously having undergone DALK. Uncorrected vision acuity, best-corrected vision acuity, and intraocular pressure were measured for both groups before the procedures and at 3, 6, 12, and 24 months after the procedures. Corneal endothelial cell density was evaluated by non-contact specular microscopy before the procedures and at 6, 12, and 24 months after the procedures. RESULTS In the study group, within the 24-month observation period, no transplant rejection, transplant decompensation, or corneal ectasia were noted. Statistical analysis did not show any significant differences between the best-corrected vision acuity values in the study group in the preoperative and postoperative periods (P>0.05). In contrast, uncorrected vision acuity values were significantly higher in patients during the postoperative period than the preoperative period (P>0.05). CONCLUSIONS The effects of vision correction with the Femto-LASIK procedure after DALK demonstrate the safety and effectiveness of the procedure for patients.

Assessment of the Effectiveness of Glaucoma Treatment Using MicroPulse Transscleral Cyclophotocoagulation in Patients with Glaucoma Who Have Previously Undergone Vitreoretinal Surgery.

INTRODUCTION: This retrospective study aimed to assess the effectiveness of using MicroPulse transscleral cyclophotocoagulation (µP-TSCPC) in patients who had previously undergone pars plana vitrectomy (PPV), depending on the endotamponade used. METHODS: For the study, a total of 60 patients were enrolled who underwent PPV followed by tµP-TSCPC as a result of an increase in intraocular pressure (IOP) over the norm of 21 mmHg. In this group of patients, 20 received silicone oil endotamponade during PPV, 20 received sulfur hexafluoride gas SF6, and in another 20 a differentiated balanced salt solution (BSS) was used. RESULTS: The main indications for conducting PPV were (1) retinal detachment (silicone oil endotamponade was used; n = 12); (2) dislocation/subluxation of the patient's own or artificial intraocular lens (balanced salt solution (BSS) endotamponade was used; n = 11); (3) the presence of an epiretinal membrane and/or a macular hole (BSS endotamponade was used; n = 9, or SF6; n = 20); and (4) hemorrhage into the vitreous chamber (silicone oil endotamponade was used; n = 8). CONCLUSION: The choice of endotamponade used during PPV was not found to determine the effectiveness of µP-TSCPC treatment. The effectiveness of µP-TSCPC in patients after PPV depended, above all, on the etiology of the disease, for which PPV was previously performed. The lowest effectiveness of µP-TSCPC was noted in cases where the reason for conducting PPV was hemorrhage into the vitreous chamber and silicone oil endotamponade was used, while the highest effectiveness was noted in cases where PPV was conducted owing to the presence of an epiretinal membrane and/or a macular hole and SF6 endotamponade was used.

The Effectiveness of Brolucizumab and Aflibercept in Patients with Neovascular Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) is a progressive, chronic disease of the central area of the retina, which, if untreated, leads to blindness. This study aimed to compare the effectiveness of therapy using anti-VEGF drugs, namely brolucizumab and aflibercept, in patients with neovascular AMD (nAMD) during a monitoring period lasting around 20 weeks. The analysis consisted of 40 patients diagnosed with neovascular age-related macular degeneration, with 20 patients receiving aflibercept (Eylea, Bayer) at a dose of 2 mg/50 µL into the vitreous chamber at the following intervals-3 doses, 4 weeks apart, followed by a fourth dose after 8 weeks. The remaining 20 patients received brolucizumab (Beovu, Novartis) at a dose of 6 mg/50 µL, administered in the following schedule-3 initial doses, 4 weeks apart, with the administration of a fourth dose decided for each patient individually by the doctor, depending on disease activity, assessed through imaging tests. To evaluate treatment effectiveness, the following measurements were used: 'read distance and near visual acuity' for each eye separately using the Snellen chart; and non-invasive retinal imaging techniques-optical coherence tomography (OCT) and OCT angiography (OCTA). In patients treated using brolucizumab, during the observation period, statistically significant differences were found in the following parameters: flow area (p = 0.0277); select area (p = 0.0277); FOVEA (p = 0.0073); visus (p = 0.0064). In brolucizumab-treated patients, changes in OCT and OCTA, indicating an improvement, were already visible after the first injection of the drug, whereas in the aflibercept-treated group, changes were only visible after the fourth injection. We found a higher effectiveness of brolucizumab therapy compared to aflibercept in patients with nAMD during an observations period lasting 20 weeks. Our observations are significant, although they require further research.

Ocular Surface Preparation Before Keratoprosthesis Implantation.

INTRODUCTION: This study aimed to evaluate the surgical treatment results for conjunctival limbal autograft (CLAU) and keratolimbal allograft (KLAL) in various types of limbal stem cell deficiency (LSCD) etiologies performed in order to achieve a stable ocular surface prior to KPro implantation. METHODS: We analyzed the outcomes of the surgical treatment of 43 eyes of 39 patients with LSCD as an initial treatment preparing patients' ocular surface for KPro implantation. The most common causes were ocular trauma (50.7%), mainly alkali burns (77%); autoimmune causes, mainly ocular cicatricial pemphigoid (OCP; 17.4%); infection (15.9%) including Lyell's syndrome/Stevens-Johnson syndrome (LS/SJS; 16%). In all 17 eyes operated on with CLAU, this procedure was performed once. Similarly, one uncomplicated KLAL procedure in one eye was performed in 10 women and 19 men. In another one woman and three men, KLAL was performed in both eyes. In one man with Lyell's syndrome, the KLAL operation was performed three times in one eye. Follow-up was at least 12 months. RESULTS: Visual acuity (VA) improved in 17 eyes (31%) and remained unchanged in 38 eyes (69%). VA improved from light perception to hand movements in three eyes (16%) from the CLAU group of patients and eight eyes (15%) from the KLAL group; VA improved from hand movements to finger counting in two eyes (12%) post CLAU and two eyes (4%) post KLAL operation. The most common complication of surgical treatment was persistent epithelial defect that was refractory to medical treatment in 32 eyes (58%), 5 eyes post CLAU and 27 post KLAL. Corneal conjunctivalization (19%) and neovascularization (29%) were present on the corneal edge of the graft. Symblephara recurred within 3 months in nine eyes (17.3%) after KLAL, including four eyes that had been chemically burned and five eyes with LS/SJS. DISCUSSION: Pretreatment with CLAU or KLAL procedures in severely damaged ocular surfaces allows the ocular surface to be prepared for safe KPro implantation with sufficient tissue surroundings with less conjunctivalization and deeper conjunctival fornices.

Urinary sulphated glycosaminoglycans excretion in obese patients with type 2 diabetes mellitus treated with metformin.

OBJECTIVE: The pattern of urinary excretion of total sulphated glycosaminoglycans (GAGs) and their particular types: chondroitin sulphate/dermatan sulphate (CS/DS) and heparan sulphate (HS) was analysed in obese patients with type 2 diabetes mellitus (T2DM) treated with metformin in monotherapy for the period of six months. METHODS: The urinary sulphated glycosaminoglycans were quantitated using standardised dye (1.9-dimethylmethylene blue)-binding method and normalised to creatinine level. RESULTS: Urinary total GAGs, CS/DS and HS levels were significantly higher in untreated diabetic patients in comparison to healthy subjects. Moreover, it was observed that urinary total GAGs, CS/DS and HS levels in diabetic patients after six-month metformin therapy were significantly decreased versus pre-treatment situation. CONCLUSIONS: The obtained results suggest that the six-month treatment with metformin in obese patients with T2DM has a regulating influence on the systemic changes in proteoglycans/glycosaminoglycans, resulting in a decrease in the urinary excretion of total GAGs, CS/DS and HS.

Assessment of Vascular Changes in Patients after Pars Plana Vitrectomy Surgery Due to Macula-Off Rhegmatogenous Retinal Detachment.

The aim of this study was to investigate the changes in the retinal capillary plexuses in patients after pars plana vitrectomy (PPV), which is used for the treatment of rhegmatogenous retinal detachment (RRD). In this study, we included the results of 114 patients who underwent PPV after total retinal detachment (RRD; retinal detachment group). It should be kept in mind that to qualify for the study group, there was a condition that retinal detachment be only present in one eye, allowing the fellow healthy eye to be used for the control group, and the study, therefore, did not include cases where retinal detachment occurred binocularly. Optical coherence tomography (OCT) and OCT-A images were taken at 9 ± 2 months (median 10 months) after the surgery, with the study conducted in the years 2017-2019. OCT was used to examine the external limiting membrane (ELM), central macular thickness (CMT) and retinal nerve fiber layer (RNFL), while OCT-angiography (OCT-A) was used to examine the extent of the foveal avascular zone (FAZ) in the deep and superficial capillary plexuses. Changes in the FAZ area of the superficial plexus (SCP) between the study and control groups were analyzed over 346 ± 50 days. In our study, we observed changes in the FAZ area between the RRD and control groups in the SCP (203.65 ± 31.69 µm2 vs. 215.30 ± 35.82 µm2; p = 0.28733) and DCP (284.79 ± 35.82 µm2 vs. 336.84 ± 32.23 µm2; p = 0.00924). Changes in the RNFL thickness between the study and control groups over 346 ± 50 days were as follows: 90.15 µm vs. 82.44 µm; p = 0.19773. Disruption of the external limiting membrane was observed in 78.95% (90 eyes) of the study group. In the control group, it was undamaged, and no integrity disorder was observed. In the RRD, changes occurred in the FAZ of both the SCP and the DCP, which reduced the extent of this zone, an effect that was more pronounced in DCPs. A better understanding of the anatomical and hemodynamic changes taking place in the retina after macula-off RRD might be helpful in answering the question as to why BCVA in these cases is "only" or "as much as" from 0.4 to 0.1, namely, that it might be related to changes in the neurosensory retina after macular peeling.

Comparison of Long-Term Outcomes of the Lamellar and Penetrating Keratoplasty Approaches in Patients with Keratoconus.

We compared the visual and refractive outcomes, intraocular pressure (IOP), endothelial cell loss (ECL), and adverse events in keratoconus patients after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) with the best corrected visual acuity (BCVA) below 0.3 (logMAR 0.52). This is a prospective, comparative cohort study of 90 eyes (90 patients) with a clinical diagnosis of keratoconus. Patients underwent a complete eye examination before the surgical approach, 6 and 12 months postoperatively that consisted of BCVA, refractive astigmatism (AS), central corneal thickness (CCT), IOP, and ECL. Secondary outcomes were adverse events related to the surgical procedure. With lower ECL and less adverse events, DALK was revealed to be beneficial over PK with similar visual outcomes. Results: There was no significant difference between the BCVA in the DALK and PK groups (at 6 months: 0.49 ± 0.17 vs. 0.48 ± 0.17; p = 0.48; at 12 months: 0.54 ± 0.17 vs. 0.52 ± 0.14; p = 0.41). The mean value of AS was significantly lower after the PK procedure when compared to DALK, after both 6 and 12 months of follow up (p < 0.001). The CCT in the DALK group was significantly lower when compared to the PK group (at 6 months: 452.1 ± 89.1 µm vs. 528.9 ± 69.9 µm, p < 0.0001; at 12 months: 451.6 ± 83.5 µm vs. 525.5 ± 37.1 µm). The endothelial cell loss at 12 months after surgery was significantly lower after DALK when compared to PK (p < 0.0001). DALK transplantation should be considered as an alternative procedure in the surgical treatment of keratoconus.

OCT on Anterior Segment Anomalies of the Eye in a Polish Paediatric Cohort: Diagnostic and Therapeutic Challenges.

PURPOSE: To present applications of anterior segment optical coherent tomography (AS OCT) for anomalies of the eye in a Polish paediatric cohort. MATERIALS AND METHODS: Seventy-four eyes of infants and older children were examined. The majority of them underwent general anaesthesia to allow OCT to be performed in the operating room, but a few were examined in a routine way. We focused on corneal, anterior chamber, iris, and lens disorders. Measurements included corneal morphology, anatomy of the anterior chamber, and general involvement of surrounding tissues in pathologic lesions. RESULTS: We divided the paediatric patients into several groups by considering the type of disease and involvement of particular tissues. The groups were selected based on OCT usefulness in describing their ocular disorders. CONCLUSION: The collected anterior segment disorders showed huge usefulness for paediatric diagnosis and treatment planning.

Application of Artificial Intelligence in the Analysis of Features Affecting Cataract Surgery Complications in a Teaching Hospital.

Aims: To evaluate the ocular and systemic factors involved in cataract surgery complications in a teaching hospital using artificial intelligence. Methods: One eye of 1,229 patients with a mean age of 70.2 ± 10.3 years old that underwent cataract surgery was selected for this study. Ocular and systemic details of the patients were recorded and then analyzed by means of artificial intelligence. A total of 1.25 billion simulations of artificial intelligence learning and testing were conducted on several variables and a customized model of analysis was developed. Results: A total of 73 complications were recorded in this study. According to the analysis performed, the main factors involved in cataract surgery complications were: a surgeon in training, axial length and intraocular lens power. The model predicted how long surgery would last with an error of <6 min compared to the effective time needed. Conclusions: According to the data here obtained, artificial intelligence could be an interesting option to build customized models able to prevent complications and to predict actual surgery time. The customized algorithm option allows the development of better models adaptable to different units as well as the possibility to be calibrated for the same unit along time.

Long-Term Outcomes of Allogeneic Ocular Surface Reconstruction: Keratolimbal Allograft (KLAL) Followed by Penetrating Keratoplasty (PK).

PURPOSE: Long-term results of the patients with total LSCD, who had undergone keratolimbal allograft (KLAL) for limbal reconstruction followed by penetrating keratoplasty (PK). METHODS: The study analyzes surgical treatment of 43 eyes with severe ocular surface disorders. All subjects underwent KLAL to achieve suitable conditions for consecutive PK. Due to failures of primary treatment in 17 eyes (39%), the KLAL was repeated. PK was performed in all the patients at 9-12 months after KLAL. As a retrospective study we analyzed data from the medical records including the preoperative and postoperative best corrected visual acuity, corneal clarity, surgical outcomes and complications, postoperative intraocular pressure, graft rejection, and other comorbidities and complications. RESULTS: The preoperative visual acuity ranged from light perception to 0.01. The final improvement of visual acuity within a gain of one or more lines with the Snellen chart, including the results of successive surgical treatments after PK, was achieved in 23 operated eyes (53%). Early graft rejection was observed in 4 eyes (9%). In 3 eyes, it was manifested as endothelial rejection, and in 1 eye, as combined endothelial and epithelial rejection. PK failure requiring repetitive PK was present in 14 eyes (32%). Phthisis bulbi developed in 6 eyes (14%). Glaucoma or ocular hypertension was reported in 25 eyes (58%). A majority were treated with up to 3 topical agents or referred for trabeculectomy in 3 cases, transscleral cyclophotocoagulation in 2 eyes, and EX-PRESS glaucoma shunt implantation in 3 cases. CONCLUSIONS: Successful KLAL carries a high risk of subsequent PK failure. Visual function remains the second aim of treatment; the primary one is to stabilize the surface.

Amniotic Membrane as a Main Component in Treatments Supporting Healing and Patch Grafts in Corneal Melting and Perforations.

PURPOSE: To report on surgical approaches using amniotic membrane applications and patch grafts in corneal melting and perforations. Anatomical and functional results, including advantages and disadvantages of the interventions, will also be explored. METHODS: A five-year retrospective analysis of 189 surgical treatments involving corneal melting with perforation was performed. In one evaluated treatment type, a graft of amniotic membrane, often folded one to three times, was sutured with the epithelial side facing the previously mechanically debrided corneal tissue. A larger monolayer amniotic patch was then sutured, with the epithelial side facing the top of the first membrane, to the perilimbal conjunctiva. For corneal patch grafts, the size-fitting technique of graft trephination was applied, and the donor-recipient junctions were sewn with interrupted sutures. All the procedures were evaluated, noting outcomes and complications of surgery, preoperative and postoperative visual acuities, postoperative intraocular pressures, graft rejection, and other late comorbidities and complications. RESULTS: We performed 119 amniotic membrane applications (63%) and 70 corneal patch grafts (37%). Anatomical reconstruction of the anterior chamber was achieved in 157 eyes, of which 102 eyes (86%) received an amniotic membrane and 55 eyes (79%) were treated with the patch graft technique. In 63 eyes (33%), more than one amnion or graft treatment was necessary to close the corneal perforation. CONCLUSIONS: The success of medical and surgical management depends on the cause of corneal melting, and amniotic membrane applications often require further intervention; nevertheless, patch grafts deliver better tectonic reconstruction than amniotic membrane alone.

Comparison of Methods of Endotamponade Used During 23-Gauge Pars Plana Vitrectomy and the Risk of Raised Intraocular Pressure During 24-Month Follow-Up: A Retrospective Study of 196 Patients.

BACKGROUND Pars plana vitrectomy (PPV) is used to treat retinal conditions, including retinal detachment, and involves removal of the vitreous gel from the eye. Complications following PPV include raised intraocular pressure (IOP). This retrospective study aimed to compare methods of endotamponade used during 23-gauge PPV and the risk of raised IOP during 24-month follow-up at a single center. MATERIAL AND METHODS The study included 196 patients (age, 15-86 years; mean, 63.5 years) (196 eyeballs). There were 93 patients (47.45%) with a preoperative history of type 2 diabetes mellitus and 14 patients (7.14%) with a history of myopia. IOP was measured with Goldmann applanation tonometry at one-, three-, six-, 12-, and 24-month follow-up. The outcome was compared following endotamponade with silicone oil, sulfur hexafluoride (SF6), and balanced salt solution (BSS). RESULTS Mean IOP at one-month follow-up was 17.2 mmHg (±3.61 mmHg; range, 9-45 mmHg), and at 24-month follow-up was 17.3 mmHg (±3.23 mmHg; range, 7-30 mmHg). IOP following PPV was significantly associated with the indication for PPV (P=0.023), and the type of endotamponade used (P=0.049). In patients with silicone oil endotamponade, the risk of IOP at 24 months was increased by 2.3 times compared with SF6 or BSS endotamponade. Patients with SF6 endotamponade had a risk of IOP that was 3.3 times lower than for silicone oil tamponade or BSS tamponade. CONCLUSIONS Silicone oil endotamponade in PPV was associated with an increased risk of IOP at 24-month follow-up.

A new method for detecting the outer corneal contour in images from an ultra-fast Scheimpflug camera.

BACKGROUND: The Corvis® ST tonometer is an innovative device which, by combining a classic non-contact tonometer with an ultra-fast Scheimpflug camera, provides a number of parameters allowing for the assessment of corneal biomechanics. The acquired biomechanical parameters improve medical diagnosis of selected eye diseases. One of the key elements in biomechanical measurements is the correct corneal contour detection, which is the basis for further calculations. The presented study deals with the problem of outer corneal edge detection based on a series of images from the afore-mentioned device. Corneal contour detection is the first and extremely important stage in the acquisition and analysis of corneal dynamic parameters. RESULT: A total of 15,400 images from the Corvis® ST tonometer acquired from 110 patients undergoing routine ophthalmologic examinations were analysed. A method of outer corneal edge detection on the basis of a series of images from the Corvis® ST was proposed. The method was compared with known and commonly used edge detectors: Sobel, Roberts, and Canny operators, as well as others, known from the literature. The analysis was carried out in MATLAB® version 9.0.0.341360 (R2016a) with the Image Processing Toolbox (version 9.4) and the Neural Network Toolbox (version 9.0). The method presented in this paper provided the smallest values of the mean error (0.16%), stability (standard deviation 0.19%) and resistance to noise, characteristic for Corvis® ST tonometry tests, compared to the methods known from the literature. The errors were 5.78 ± 9.19%, 3.43 ± 6.21%, and 1.26 ± 3.11% for the Roberts, Sobel, and Canny methods, respectively. CONCLUSIONS: The proposed new method for detecting the outer corneal contour increases the accuracy of intraocular pressure measurements. It can be used to analyse dynamic parameters of the cornea.

Changes in the Density of Corneal Endothelial Cells in Elderly Diabetic Patients After Combined Phacovitrectomy and Ex-PRESS Glaucoma Implants.

BACKGROUND & OBJECTIVE: Corneal endothelial cells (ECD) are characterized by limited regenerative potential, which is additionally impaired in patients with diabetes. This retrospective study included 27 patients aged 58.1±13.6, 16 female and 11 males, who underwent 23-gauge vitrectomy in combination with cataract surgery (phacovitrectomy) and further Ex-PRESS shunt implantation throughout 2013-2017 at St. Barbara Hospital in Sosnowiec, Poland. METHODS: In our study, we distinguished 4 periods: initial period; post phacovitrectomy and removal of oil tamponade; and 3 and 12 months post implantation of the Ex-PRESS shunt. Statistical analysis was performed at the level of statistical significance of p<0.05. It included an analysis of variance (ANOVA) and Tukey's post-hoc test in order to determine the differences in the density of ECD cells/mm2 between the periods of observation. The paired-samples t-Student test was also performed to determine whether the differences in visual acuity values before and after PPV and before and after Ex-PRESS shunt were statistically significant. RESULTS: The initial count of ECD cells was 2381.1±249, which decreased to 1872.8±350.7 cell/mm2 and finally to 1677.9±327 at the endpoint. Differences in the density of ECD cells/mm2 were observed to be statistically significant between the periods: after PPV vs. initial number of ECD (p = 0.000138); before 3 months after Ex-PRESS shunt vs. initial number of ECD (p = 0.000138); 12 months after Ex- PRESS shunt vs. initial number of ECD (p = 0000138). Analyzing the changes in visual acuity, we observed a deterioration both before and 3 months after Ex-PRESS shunt (p = 0.007944) and before and after PPV (p = 0.060334). In turn, correlation analysis indicated that there is a statistically significant, moderate, positive relationship. The relationship between visual acuity after Ex-PRESS shunt and ECD cells/mm2 density turned out to be statistically significant (r = +0.521381; p < 0.05). CONCLUSION: Regardless of the period of observation and the choice of ophthalmic treatment of diabetic complications, we observed a decrease in the number of ECD cells and a deterioration in visual acuity. It is, therefore, reasonable to provide the patient with complete information about the proposed procedures and to consider the risk-benefit balance.

Impact of ultrasound and optical biometry on refractive outcomes of cataract surgery after penetrating keratoplasty in keratoconus.

AIM: To analyse the impact of ultrasound and optical intraocular lens (IOL) calculation methods on refractive outcomes of cataract phacoemulsification performed after penetrating keratoplasty (PK) in keratoconus. METHODS: Phacoemulsification cataract surgery was performed on 42 eyes of 34 patients with keratoconus who had previously undergone PK. The IOL power was determined by using both standard and corneal topography-derived keratometry using the SRK/T formula. We used two independent methods-ultrasound biometry (UB) and interferometry [optical biometry (OB)] for IOL calculation. The analysed data from medical records included demographics, medical history, best corrected visual acuity (BCVA) on Snellen charts, technique of IOL calculation and calculation formula and its impact on final refractive result. RESULTS: BCVA ranged from 0.01 to 0.4 (mean 0.09±0.19) before surgery and ranged from 0.2 to 0.7 (mean 0.38±0.14) at 1mo and from 0.2 to 1.0 (mean 0.56±0.16) (P<0.05) at 3mo, postoperatively. The refractive aim differed significantly from the refractive outcome in both the UB and OB groups (P<0.05). There was no statistically significant difference in the accuracy of the two biometry methods. CONCLUSION: The refractive aim in keratoconus eyes post-PK is not achieved with either ultrasound or OB.

Corneal deformation amplitude analysis for keratoconus detection through compensation for intraocular pressure and integration with horizontal thickness profile.

BACKGROUND: The Corvis ST provides measurements of intraocular pressure (IOP) and a biomechanically-corrected IOP (bIOP). IOP influences corneal deflection amplitude (DA), which may affect the diagnosis of keratoconus. Compensating for IOP in DA values may improve the detection of keratoconus. METHODS: 195 healthy eyes and 136 eyes with keratoconus were included for developing different approaches to distinguish normal and keratoconic corneas using attribute selection and discriminant function. The IOP compensation is proposed by dividing the DA by the IOP values. The first approaches include DA compensated for either IOP or bIOP and other parameters from the deformation corneal response (DCR). Another approach integrated the horizontal corneal thickness profile (HCTP). The best classifiers developed were applied in a validation database of 156 healthy eyes and 87 eyes with keratoconus. Results were compared with the current Corvis Biomechanical Index (CBI). RESULTS: The best biomechanical approach used the DA values compensated by IOP (Approach 2) using a linear discriminant function and reached AUC 0.954, with a sensitivity of 88.2% and a specificity of 97.4%. When thickness horizontal profile data was integrated (Approach 4), the best function was the diagquadratic, resulting in an AUC of 0.960, with a sensitivity of 89.7% and a specificity of 96.4%. There was no significant difference in the results between approaches 2 and 4 with the CBI in the training and validation databases. CONCLUSIONS: By compensating for the IOP, and with the horizontal thickness profile included or excluded, it was possible to generate a classifier based only on biomechanical information with a similar result to the CBI.