XEN45 Implant in Medically Controlled vs. Uncontrolled Eyes-Differential IOP Changes in Real-Life Conditions.

Background: To assess intraocular pressure (IOP) changes and complications after XEN45 implants in medically controlled eyes (MCE) vs. medically uncontrolled eyes (MUE). Methods: A retrospective study, in a tertiary referral hospital, on mild-to-moderate primary open-angle glaucoma (POAG) cases under topical medication, including 32 eyes with IOP < 21 mmHg (MCE group) and 30 eyes with IOP ≥ 21 mmHg (MUE group). The success criteria using Kaplan-Meier analysis was IOP < 21 mmHg without medications (complete success) or fewer drugs than preoperatively (qualified success) at the last visit, without new surgery or unresolved hypotony. Results: No significant preoperative differences were found between the groups. The mean IOP was 15.6 ± 3.8 mmHg in MCE and 15.1 ± 4.1 mmHg in the MUE group (p > 0.05; Mann-Whitney test) at the end of the follow-up (mean of 26.1 ± 15.6 months and 28.3 ± 15.3 months, respectively) (p = 0.414, Mann-Whitney Test). The device caused a significant IOP reduction at 24 h in both groups. Thereafter, the MCE group significantly tended to increase IOP, recovering baseline values at 1 month and maintaining them until the end of the follow-up. In contrast, in the MUE group, the IOP values tended to be similar after the first reduction. No relevant complications and no significant differences between the groups in the survival analysis were found. Conclusions: XEN45 provided stable IOP control in both the MCE and MUE group without important complications in the medium term. The IOP increasing in the MCE group, after a prior decrease, led to restored baseline values 1 month after surgery. The homeostatic mechanism that causes the rise in the IOP to baseline values and its relationship with failure cases remains to be clarified.

Establishing Standardization Guidelines For Finite-Element Optomechanical Simulations of Refractive Laser Surgeries: An Application to Photorefractive Keratectomy.

Purpose: Computational models can help clinicians plan surgeries by accounting for factors such as mechanical imbalances or testing different surgical techniques beforehand. Different levels of modeling complexity are found in the literature, and it is still not clear what aspects should be included to obtain accurate results in finite-element (FE) corneal models. This work presents a methodology to narrow down minimal requirements of modeling features to report clinical data for a refractive intervention such as PRK. Methods: A pipeline to create FE models of a refractive surgery is presented: It tests different geometries, boundary conditions, loading, and mesh size on the optomechanical simulation output. The mechanical model for the corneal tissue accounts for the collagen fiber distribution in human corneas. Both mechanical and optical outcome are analyzed for the different models. Finally, the methodology is applied to five patient-specific models to ensure accuracy. Results: To simulate the postsurgical corneal optomechanics, our results suggest that the most precise outcome is obtained with patient-specific models with a 100 µm mesh size, sliding boundary condition at the limbus, and intraocular pressure enforced as a distributed load. Conclusions: A methodology for laser surgery simulation has been developed that is able to reproduce the optical target of the laser intervention while also analyzing the mechanical outcome. Translational Relevance: The lack of standardization in modeling refractive interventions leads to different simulation strategies, making difficult to compare them against other publications. This work establishes the standardization guidelines to be followed when performing optomechanical simulations of refractive interventions.

Causes of intraocular pseudophakic lens explantation in Spain.

PURPOSE: To report the causes of pseudophakic intraocular lens (IOL) explantation in Spain over a 20 year period. METHODS: Multicenter observational prospective study of a consecutive series of cases corresponding to pseudophakic intraocular lenses explantations performed in 22 Spanish clinical centres from 2002 to 2021, within a national clinical research network. The clinical data of all IOL explantation patients was evaluated, and the different causes for IOL explantation were systematically analyzed. RESULTS: From a total of 1013 pseudophakic explantations, 919 cases were included in this investigation. The mean age of the patients at the time of explantation was 66.3 years, and 142 (15.45%) were women. Over the 20 years of the study, the five main reasons for explanting lenses in the last 20 years in Spain according to the Iberia RETICS database were: dislocation / decentration / misalignment (43.08%), bullous keratopathy (16.79%), neuroadaptation failure (13.85%), IOL opacification (9.71%), refractive surprise (6.87%). Other causes, less frequent, were uveitis / endophthalmitis / infection with 39 cases (4.25%); IOL substitution for reasons other than multifocal IOL neuroadaptation failure 3 cases (0.33%); and other causes, 47 cases (5.13%). Hydrophobic lenses were the most frequently explanted with a ratio of 47.1%. CONCLUSIONS: Over the 20 years of the study, the five main reasons for explanting lenses in the last 20 years in Spain according to the Iberia RETICS database were: dislocation / decentration / misalignment, bullous keratopathy, neuroadaptation failure, IOL opacification, and refractive surprise.

Titanium Boston keratoprosthesis with corneal cell adhesive and bactericidal dual coating.

The Boston keratoprosthesis (BKPro) is a medical device used to restore vision in complicated cases of corneal blindness. This device is composed by a front plate of polymethylmethacrylate (PMMA) and a backplate usually made of titanium (Ti). Ti is an excellent biomaterial with numerous applications, although there are not many studies that address its interaction with ocular cells. In this regard, despite the good retention rates of the BKPro, two main complications compromise patients' vision and the viability of the prosthesis: imperfect adhesion of the corneal tissue to the upside of the backplate and infections. Thus, in this work, two topographies (smooth and rough) were generated on Ti samples and tested with or without functionalization with a dual peptide platform. This molecule consists of a branched structure that links two peptide moieties to address the main complications associated with BKPro: the well-known RGD peptide in its cyclic version (cRGD) as cell pro-adherent motif and the first 11 residues of lactoferrin (LF1-11) as antibacterial motif. Samples were physicochemically characterized, and their biological response was evaluated in vitro with human corneal keratocytes (HCKs) and against the gram-negative bacterial strain Pseudomonas aeruginosa. The physicochemical characterization allowed to verify the functionalization in a qualitative and quantitative manner. A higher amount of peptide was anchored to the rough surfaces. The studies performed using HCKs showed increased long-term proliferation on the functionalized samples. Gene expression was affected by topography and peptide functionalization. Roughness promoted α-smooth muscle actin (α-SMA) overexpression, and the coating notably increased the expression of extracellular matrix components (ECM). Such changes may favour the development of unwanted fibrosis, and thus, corneal haze. In contrast, the combination of the coating with a rough topography decreased the expression of α-SMA and ECM components, which would be desirable for the long-term success of the prosthesis. Regarding the antibacterial activity, the functionalized smooth and rough surfaces promoted the death of bacteria, as well as a perturbation in their wall definition and cellular morphology. Bacterial killing values were 58 % for smooth functionalised and 68 % for rough functionalised samples. In summary, this study suggests that the use of the dual peptide platform with cRGD and LF1-11 could be a good strategy to improve the in vitro and in vivo performance of the rough topography used in the commercial BKPro.

Localized Refractive Changes Induced by Symmetric and Progressive Asymmetric Intracorneal Ring Segments Assessed with a 3D Finite-Element Model.

To build a representative 3D finite element model (FEM) for intracorneal ring segment (ICRS) implantation and to investigate localized optical changes induced by different ICRS geometries, a hyperelastic shell FEM was developed to compare the effect of symmetric and progressive asymmetric ICRS designs in a generic healthy and asymmetric keratoconic (KC) cornea. The resulting deformed geometry was assessed in terms of average curvature via a biconic fit, sagittal curvature (K), and optical aberrations via Zernike polynomials. The sagittal curvature map showed a locally restricted flattening interior to the ring (Kmax -11 to -25 dpt) and, in the KC cornea, an additional local steepening on the opposite half of the cornea (Kmax up to +1.9 dpt). Considering the optical aberrations present in the model of the KC cornea, the progressive ICRS corrected vertical coma (-3.42 vs. -3.13 µm); horizontal coma (-0.67 vs. 0.36 µm); and defocus (2.90 vs. 2.75 µm), oblique trefoil (-0.54 vs. -0.08 µm), and oblique secondary astigmatism (0.48 vs. -0.09 µm) aberrations stronger than the symmetric ICRS. Customized ICRS designs inspired by the underlying KC phenotype have the potential to achieve more tailored refractive corrections, particularly in asymmetric keratoconus patterns.

Bilensectomy: Safety and Visual Outcomes in Angle-Supported, Iris-Fixated, and Posterior Chamber Phakic Intraocular Lenses.

PURPOSE: To report the visual and refractive outcomes, intraoperative and postoperative complications, and main causes of bilensectomy in the different types of phakic intraocular lenses (pIOLs). METHODS: This was a retrospective multicenter study that included 234 eyes of 185 patients that underwent bilensectomy. Patients were divided into three groups depending on the pIOL that was explanted (angle-supported, iris-fixated, or posterior chamber). The main reasons leading to the indication for bilensectomy, time elapsed between pIOL implantation and bilensectomy, intraoperative and postoperative complications, uncorrected and corrected distance visual acuity (UDVA and CDVA), and endothelial cell density loss 1 year after bilensectomy were evaluated. RESULTS: There was a statistically significant improvement in UDVA and CDVA after bilensectomy in all groups. Cataract development was the main reason for bilensectomy, followed by significant endothelial cell density loss. Time between pIOL implantation and bilensectomy was significantly greater in eyes with an anterior chamber pIOL. CONCLUSIONS: Bilensectomy outcomes in general are good. Iris-fixated lenses, particularly hyperopic, are more prone to intraoperative complications and endothelial cell loss than the other pIOLs models. The results show that bilensectomy is a safe and effective procedure with a relatively low rate of intraoperative and postoperative complications and acceptable refractive predictability. [J Refract Surg. 2023;39(3):128-134.].

Analysis of visual and refractive results after wedge resection for high astigmatism after penetrating keratoplasty in keratoconus.

PURPOSE: To analyze visual and refractive results after wedge resection to correct high astigmatism after penetrating keratoplasty (PK) for keratoconus. SETTING: Cornea Unit of the Centro de Oftalmología Barraquer Barcelona, Spain. DESIGN: A retrospective quasi-experimental, before and after study. METHODS: Patients who developed high astigmatism or ectasia in the graft-host junction after PK were treated with wedge resection. The following variables were studied before the surgery, 1-year after and at the final visit: uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive and topographic astigmatism and spherical equivalent. Vectorial analysis of the astigmatism changes was performed. RESULTS: Fifty-one eyes were included with a mean follow-up of 4.19 ± 3.09 years. Mean refractive astigmatism was 11.47 ± 3.57 diopters (D) pre-operatively and 4.79 ± 3.32 D at the final follow-up (p < 0.001). The mean centroid changed from 2.65 ± 11.82 D at 23 degrees preoperatively to 0.35 ± 5.86 D at 127 degrees postoperatively. Concerning spherical equivalent, the mean preoperative value was -3.10 ± 4.15 D and the mean postoperative value was -1.55 ± 3.41 D (p = 0.002). Mean pre-operative and final follow-up UDVA were 1.25 ± 0.27 and 0.84 ± 0.50 (p < 0.001). Mean Pre-op and final follow-up CDVA were 0.27 ± 0.19 and 0.24 ± 0.24. CONCLUSIONS: Wedge resection is a useful surgical procedure to correct high astigmatism. It is a safe technique with moderate efficacy and may be considered as initial procedure of choice in high astigmatism due to long-term ectasia in the graft-host junction after PK for keratoconus.

Orbital amyloid tumor associated with myasthenia gravis.

We present a case of a 53-year-old female with an 11 year history of myasthenia gravis (MG) with palpebral ptosis in the left eye which had become more marked over the previous year. Examination revealed a painless left orbital mass causing ptosis. The tumor was surgically removed and histopathology revealed deposits of a hyaline substance which when stained with Congo Red had an apple-green birefringence with polarized light, typical of amyloid. In the absence of amyloid deposits elsewhere in the body, amyloid tumor (AT) was diagnosed. No myelo- or lymphoproliferative syndromes, systemic involvement by amyloidosis or any autoimmune disease were found. The evolution and aesthetic results where satisfactory. Only two cases of orbital AT associated with MG have been described previously; however, in one of the cases, the symptoms of the AT had led to a false diagnosis of MG.

Intraocular pressure after myopic laser refractive surgery measured with a new Goldmann convex prism: correlations with GAT and ORA.

BACKGROUND: The purpose of this study is to describe measurements using a newly developed modified Goldmann convex tonometer (CT) 1 year after myopic laser refractive surgery. Intraocular pressure (IOP) measurements were compared with IOP values obtained by Goldmann applanation tonometer (GAT), and Ocular Response Analyzer (ORA). METHODS: Prospective double-masked study performed on thirty eyes of thirty patients that underwent laser in situ keratomileusis (LASIK; n = 19) or photorefractive keratectomy (PRK; n = 11). IOP was measured before and 3 and 12 months after surgery. Intraclass correlation coefficient (ICC) and Bland-Altman plot were calculated to assess the agreement between GAT, CT, IOPg (Goldmann-correlated IOP) and IOPcc (corneal-compensated IOP) from ORA. RESULTS: Twelve months after LASIK, IOP measured with CT showed the best correlation with IOP measured with GAT before surgery (GATpre) (ICC = 0.886, 95% CI: 0.703-0.956) (15.60 ± 3.27 vs 15.80 ± 3.22; p < 0.000). However, a moderate correlation was found for IOP measured with IOPcc and CT 12 months after LASIK (ICC = 0.568, 95% CI: - 0.185 - 0.843) (15.80 ± 3.22 vs 12.87 ± 2.77; p < 0.004). Twelve months after PRK, CT showed a weak correlation (ICC = - 0.266, 95% CI: - 3.896 - 0.663), compared to GATpre (17.30 ± 3.47 vs 16.01 ± 1.45; p < 0.642), as well as poor correlation (ICC = 0.256, 95% CI: - 0.332 - 0.719) with IOPcc (17.30 ± 3.47 vs 13.38 ± 1.65; p < 0.182). CONCLUSIONS: Twelve months after LASIK, IOP measured with CT strongly correlated with GAT before surgery and could therefore provide an alternative method for measuring IOP after this surgery. More studies regarding this new convex prism are needed to assess its accuracy.

Recurrence and Visual Outcomes of Phototherapeutic Keratectomy in Lattice Corneal Dystrophy: A Cohort Study.

PURPOSE: To evaluate recurrence and visual outcomes of phototherapeutic keratectomy (PTK) in lattice corneal dystrophy. METHODS: Kaplan-Meier survival analyses were retrospectively performed. Recurrence was defined as central biomicroscopic findings of recurrence with decreased visual acuity: loss of at least two lines or visual acuity ≤ 20/40) at any time during the follow-up. RESULTS: Twenty-two virgin eyes and 10 with previous keratoplasty (20 patients; 13 women and 7 men) were studied during a mean of 4.7 ± 3.5 years (range: 11 months to 18 years). One and 5 years after the first PTK (PTK1), 1 of 32 and 12 of 32 eyes, respectively, recurred. The cumulative probabilities of recurrence were 3%, 48%, and 89% in the whole sample at 1, 5, and 10 years, respectively. All cases in the virgin group and 8 eyes in the previous keratoplasty group improved their visual acuity. There were no significant differences in recurrence probability between groups (log-rank test; P = .86). A second PTK (PTK2) was performed in 15 of 32 eyes, with 6 postoperative recurrences recorded. The cumulative probabilities of recurrence in the whole sample were 18%, 30%, and 44% at 1, 3, and 5 years, respectively. Visual acuity improved in 11 of 13 eyes in the virgin group and 2 of 2 eyes in the previous keratoplasty group. Recurrence probability after PTK1 and PTK2 was similar in the whole sample (log-rank test; P = .637). Persistent graft edema after PTK1 in one eye was the only complication found. CONCLUSIONS: PTK can be an effective, safe, and repeatable treatment to delay keratoplasty in symptomatic lattice corneal dystrophy. [J Refract Surg. 2022;38(1):43-49.].

Color LED reflection topography: validation of equivalent keratometry reading for IOL power calculation in eyes with previous corneal myopic refractive surgery.

PURPOSE: To compare the accuracy of the equivalent keratometry reading (EKR) from a color LED corneal topographer (Cassini) with that of other no-history formulas for intraocular lens (IOL) power calculation in eyes with previous myopic excimer laser surgery. SETTING: Centro de Oftalmología Barraquer, Barcelona, Spain. DESIGN: Retrospective case series. METHODS: The refractive outcomes of the Cassini EKR entered into the Haigis formula were compared with those of the Barrett True-K, Haigis-L, and Shammas-PL formulas and the Triple-S method combined with the Haigis formula. Optimized lens constants for virgin eyes were used. The mean prediction error (PE), the median absolute error (MedAE), and the percentage of eyes with a PE within ±0.25 diopter (D), ±0.50 D, ±0.75 D, and ±1.00 D were calculated. RESULTS: The study comprised 37 patients (37 eyes). The Haigis-L, Shammas-PL, and Barrett True-K no-history methods produced a myopic mean PE that was significantly different from zero (P < .001, P < .001 and P = .004, respectively), whereas the mean PEs of Cassini EKR and the Triple-S combined with the Haigis formula were not different from zero (P > .05). Repeated-measures analysis of variance disclosed a significant difference among the PE of all methods (P < .0001). The MedAE of the Cassini EKR, Barrett True-K, Haigis-L, Shammas-PL, and Triple-S was, respectively, 0.34 D, 0.34 D, 0.49 D, 0.48 D, and 0.31 D (P = .0026). CONCLUSIONS: The performance of the combination of standard Haigis formula with Cassini EKR was comparable to other no-history formulas in eyes with previous myopic excimer laser surgery.

Intraocular lens power calculation in virgin eyes: Accuracy of the Barrett Universal II formula and a Ray tracing software.

PURPOSE: To compare the accuracy of Sirius ray tracing software with the Barrett Universal II formula for intraocular lens power prediction in virgin eyes. METHODS: Retrospective case series including 86 eyes that have undergone uneventful cataract surgery with SN60WF implantation. The median absolute error, mean prediction error, variance, and the percentage of eyes within ± 0.25 D, ± 0.50 D, ± 0.75 D, and ± 1.00 D of the prediction error in refraction were calculated. The correlation of prediction error with different baseline parameters was investigated. RESULTS: No differences were found between the median absolute error of the Barrett Universal II formula (0.226 D) and the ray tracing software with different intraocular lens centerings; apex (0.331 D), limbus (0.345 D), and pupil (0.342 D) (p = 0.084). The variance, from lowest to highest, was the Barrett Universal II (0.144 D2), ray tracing-limbus (0.285 D2), ray tracing-pupil (0.285 D2), and ray tracing-apex (0.287 D2) (p = 0.027). The Barrett Universal II formula showed a higher percentage of eyes within ± 0.25 D (56.98%), ± 0.50 D (82.56%), and ± 0.75 D (93.02%) compared to ray tracing software (p < 0.01). A significant correlation between the prediction error of the Barrett Universal II formula and corneal diameter (r = 0.322, p = 0.002) and pupil diameter (r = 0.230, p = 0.033) was found. Also, a positive correlation between the prediction error of Sirius ray tracing and axial length (p < 0.001) and pupil diameter (p = 0.01) was found. CONCLUSION: There is a trend of the Barrett Universal II formula to be more accurate than Sirius ray tracing software for intraocular lens power calculation in virgin eyes. This should be confirmed in future prospective comparative studies.

Long-Term Anatomical and Functional Survival of Boston Type 1 Keratoprosthesis in Congenital Aniridia.

Purpose: To analyze the long-term anatomical survival, functional survival, and complications of Boston type 1 keratoprosthesis (KPro) in the eyes with congenital aniridia-associated keratopathy (AAK). Methods: A retrospective review of 12 eyes with congenital aniridia that underwent a Boston type 1 KPro surgery was conducted. A Kaplan-Meier analysis was performed. Anatomical and functional success criteria were KPro retention and a best corrected visual acuity (BCVA) ≤1.3 LogMAR (≥0.05 decimal) at the end of a follow-up period. Postoperative complications were recorded. Results: The mean preoperative BCVA was 2.1 ± 0.9 (range: 3.8-1) LogMAR, and glaucoma was a comorbidity in all the cases. Five years after the surgery, the overall retention rate was 10/12 (83.3%), and 50% had functional success. Only three (25%) of the 12 cases did not achieve a BCVA ≤1.3 LogMAR. The cumulative probability of anatomical success was 92, 79, and 79% after 1, 5, and 10 years, respectively. The cumulative probability of functional success was 57 and 46% after 1 and 5 years, respectively. The mean anatomical and functional survival time was 10 ± 1.3 (95% IC = 7.5-12.3 years) and 3.8 ± 0.9 years (95% IC = 1.8-5.8 years), respectively. The most common postoperative complication was retroprosthetic membrane (RPM) formation in 8/16 cases (66%). The mean number of complications per case was 2.4 ± 1.8 (0-6). Conclusions: The Boston type 1 KPro is a viable option for patients with AAK with good anatomical and functional long-term results. Glaucoma is an important preoperative condition that affects functional results. Retroprosthetic membrane formation seems to have a higher incidence in this condition.

Clinical Outcomes of Femtosecond Laser-Assisted Implantation of Asymmetric ICRS in Keratoconus With No Coincidence of Topographic and Comatic Axes.

PURPOSE: To analyze the clinical outcomes obtained with asymmetric intracorneal corneal ring segments (ICRS) of variable thickness and width in patients with keratoconus, identifying predictive parameters of the final visual outcome. METHODS: This prospective, longitudinal, non-comparative clinical trial enrolled 35 eyes of 27 patients with keratoconus with a significant difference among corneal topographic and comatic axes. All eyes underwent implantation of AJL-pro+ ICRS (AJL Ophthalmic). Visual, refractive, corneal topographic and aberrometric, and pachymetric changes were evaluated during a 3-month follow-up. RESULTS: Significant changes were detected at 3 months after surgery in manifest sphere and cylinder, spherical equivalent, overall blur strength, and corrected distance visual acuity (CDVA) (P < .001). No losses of two or more lines of CDVA were observed, whereas 94.3% (33) of eyes gained one or more lines of CDVA. Keratometric readings and the magnitude of anterior corneal astigmatism were significantly reduced with surgery (P < .001), as well as the levels of corneal coma (P < .001) and spherical aberration (P = .007). Likewise, a significant change toward less prolateness was observed (P < .001). Significant correlations were found among the change in CDVA and preoperative CDVA (r = -0.532, P = .001), and between the change in primary coma root mean square and the preoperative level of spherical aberration (r = -0.542, P = .001) and coma root mean square (r = -0.719, P < .001). CONCLUSIONS: The implantation of the ICRS evaluated in keratoconus with no coincidence between topographic and comatic axes regularizes the corneal shape and reduces the level of higher order aberrations, inducing a significant visual improvement. [J Refract Surg. 2021;37(10):693-699.].

Causes of corneal transplant failure: a multicentric study.

PURPOSE: To identify the causes of failure of the different surgical corneal graft techniques: penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK). METHODS: This multicentric retrospective study enrolled a consecutive cohort of patients who had undergone any type of keratoplasty between 2001 and 2016. The clinical data were obtained from the patient's medical records, following ethical guidelines, permissions and data protection. The main outcome measured in the study was the cause of graft failure, defined as any irreversible loss of graft transparency capable of compromising vision. The main causes of graft failure were classified as follows: (A) primary graft failure (PGF), (B) immunological rejection, (C) non-rejection (which includes endothelial decompensation without rejection, IOP elevation/glaucoma, diseases of the ocular surface, recurrence of the primary disease, wound dehiscence/hypotonia and trauma, among others) and (D) specific causes of lamellar keratoplasty failure. A descriptive study of the obtained data was carried out. The distribution of the causes of failure was evaluated according to the type of corneal transplant. RESULTS: Our research included a cohort of 571 keratoplasty failures, of which 509 met the inclusion criteria. The analysis of the causes of the PK failure showed that immunological allograft rejection represented the main cause, with 28.2% of the failures, followed by surface diseases (17.8%) and endothelial decompensation without rejection (17.3%). For the PK re-grafts group, the main cause of failure was immunological allograft rejection (34.0%), followed by diseases of the ocular surface (18.5%). For the DALK group, the failures mainly occurred due to surface diseases such as limbal stem cell insufficiency, infectious keratitis, keratolysis or persistent epithelial defect (37.8%). However, the main reason for failure in the DSAEK group was endothelial decompensation without rejection (31.9%) while primary graft failure was the main cause of failure in the DMEK group (64.1%). CONCLUSION: The main reason for failure in PK was immunological allograft rejection, both in primary and secondary transplants. The leading causes for failure were diseases of the ocular surface in the DALK population, endothelial decompensation without rejection in DSAEK and primary graft failure in DMEK.

Bilateral Boston keratoprosthesis type 1 in a case of severe Mooren's ulcer.

INTRODUCTION: Mooren's ulcer is a painful, inflammatory chronic keratitis that affects corneal periphery, progressing centripetally, ultimately ending in perforation. The first line of treatment includes systemic immunomodulators, with surgery being the last option. We present a case of bilateral Boston keratoprosthesis implantation for severe Mooren's ulcer that responded differently in each eye. CLINICAL CASE: A 32-year-old male with corneal opacification, anterior staphylomas, vision of hand movement, was started on systemic immunosuppression with cyclosporine. After two failed penetrating keratoplasties in each eye, high intraocular pressure despite diode cyclophotocoagulation, and cystic macular edema, we performed Boston keratoprosthesis type 1 in both eyes. The right eye responded initially well, with a best-corrected visual acuity of 20/80 and normal intraocular pressure. The left eye presented high intraocular pressure, which required cyclophotocoagulation, ultimately resulting in hypotony. Boston keratoprosthesis was performed but had peripheral corneal necrosis that progressed despite amniotic membrane transplantation and aggressive intensive treatment with medroxyprogesterone, autologous platelet-rich-in-growth-factors eye drops, and oral doxycycline. Thus, replacement of the semi-exposed Boston keratoprosthesis with tectonic penetrating keratoplasty was necessary. However, both eyes developed phthisis bulbi with final visual acuity of perception of light with poor localization. CONCLUSION: Mainstay treatment of Mooren's ulcer is systemic immunomodulation. Surgical treatment must be considered only when risk of perforation, preferably with inflammation under control. Penetrating keratoplasty frequently fails, and Boston keratoprosthesis may be a viable option. However, postoperative complications, especially uncontrolled high intraocular pressure, corneal necrosis, and recurrence of Mooren's ulcer may jeopardize the outcomes and need to be addressed promptly with intensive topical and systemic treatment.

Unilateral spontaneous filtering bleb dissecting into the cornea in a patient with high myopia.

PURPOSE: To report a case of a unilateral spontaneous filtering bleb dissecting into the cornea in a patient with high myopia. CLINICAL CASE: A 33-year-old woman with high myopia (-18 D) presented with discomfort in the left eye. Ocular history included pars plana vitrectomy and cataract extraction and posterior chamber intraocular lens implantation in the left eye. Best-corrected visual acuity was 0.65 and intraocular pressure was 20 mmHg. Slit-lamp examination showed a filtering bleb in the upper-temporal quadrant, which extended and dissected the proximal cornea without affecting the visual axis. The morphology and content of the bleb was studied with anterior segment optical coherence tomography, which ruled out a corneal-scleral fistulization into the subconjunctival space. The spontaneous filtering bleb was resected surgically. Due to her high myopia, two strips of fascia lata were used to strengthen the area. In the postoperative period, a complete resection of the bleb was confirmed, without apparent leaking points and with a well-vascularized conjunctiva. No complications were noted. The patient maintained the same best-corrected visual acuity and intraocular pressure than before surgery. CONCLUSION: The formation of a spontaneous filtering bleb is a rare entity in patients with high myopia, whose risk increases due to their thinned sclerae. The risk is even greater if they have undergone ocular surgeries. Resection of the filtering bleb in our case halted the progression of the corneal dissection, therefore respecting the transparency of the visual axis and preserving visual acuity.

Challenges in using both eyes of the same patient when evaluating the results after implantation of intrastromal corneal ring segments.

PURPOSE: To assess correlation between results from both eyes of the same patient after implantation of intrastromal corneal ring segments (ICRS) and define whether they can be used together in clinical studies. METHODS: A review of medical records of 74 patients with keratoconus implanted with bilateral Ferrara ICRS at Centro de Oftalmología Barraquer from January 2005 until December 2014. Data were collected on uncorrected visual acuity, best-corrected visual acuity and subjective refractive values (sphere, cylinder and axis). RESULTS: A total of 39 patients were male (53%), and 35 were female (47%). Mean age at the time of implantation was 32.5 ± 10 years. No major complications occurred. A significant correlation between the results from right and left eyes was found (p < 0.0043), indicating that both eyes significantly resembled each other. No significant interaction in the magnitude of change between eye and surgery was observed under classic and mixed models. CONCLUSION: Based on our data, whenever application is not possible under mixed-model analyses, we recommend the use of a first eye operated only, either right or left, in order to avoid bias and errors derived from autocorrelation and guarantee the independence of the registered observations.

Corneal graft failure: an update.

Corneal graft surgery is one of the most successful forms of human solid-tissue transplantation, and nowadays, there is a worldwide expansion of the surgical volume of corneal grafts. This surgery is continuously evolving, with new surgical techniques and postoperative treatments that have considerably increased the chance of survival for the grafts. Despite the high rate of success, corneal transplantation is still complicated by a relevant risk of graft failure. This study investigates the causes that lead to the failure of the different corneal graft surgical techniques and provides an updated synthesis on this topic. A comprehensive review of the main pathological pathways that determine the failure of corneal grafts is provided, analysing the main risk factors and disclosing the survival rates of the principal form of corneal grafts. Our results revealed that penetrating keratoplasty has higher failure rates than lamellar keratoplasty, with immunological rejection being the leading cause of graft failure, followed by late endothelial failure (LEF) and ocular surface disorders. Postoperative glaucoma and dehiscence of the surgical wound represent other important causes of failure. Endothelial keratoplasty showed the lowest rates of failure in the mid-term, with LEF, detachment of the graft and primary graft failure representing the most common pathological reasons for failure.

Safety and visual outcomes following posterior chamber phakic intraocular lens bilensectomy.

BACKGROUND: To evaluate the safety, efficacy, refractive outcomes and causes for bilensectomy (phakic intraocular lens - pIOL - explantation with cataract surgery and pseudophakic intraocular lens implantation) in patients previously implanted with posterior chamber pIOLs. METHODS: This multi-center retrospective study included 87 eyes of 55 patients who underwent bilensectomy for posterior chamber pIOL with a follow up time of 12 months. The uncorrected and best corrected distance visual acuities (UDVA, CDVA), endothelial cell density before and after bilensectomy were assessed, as well as the cause of bilensectomy and intra or postoperative complications. RESULTS: There was a statistically significant improvement in uncorrected and best corrected visual acuities after bilensectomy (p = 0.00). The main reason for bilensectomy was cataract development (93.1% of the cases), followed by miscalculation of lens size, and corneal edema. The endothelial cell count remained stable without a statistically significant change after surgery (p = 0.67). The refractive efficacy index was 0.8, none of the patients lost lines of CDVA after surgery, 73% of the patients were within ±1 D (spherical equivalent) of the target refraction. Intraoperative complications were one posterior capsule rupture with the intraocular lens (IOL) implanted in the sulcus, and 3 eyes required the use of pupil expanders for adequate pupil dilation. Postoperatively, one eye developed retinal detachment. The three pIOLs models explanted were the Implantable Collamer Lens (ICL), Implantable Phakic Contact Lens (IPCL) and the Phakic Refractive Lens (PRL). CONCLUSIONS: Good safety and visual outcomes were observed 1 year after bilensectomy for posterior chamber phakic intraocular lenses (PC pIOLs). There were few intra and postoperative complications and there was no significant endothelial cell loss after the bilensectomy procedure.