Trasplante de membrana amniotica en la reconstrucción de superficie ocular.

RESUMEN Las indicaciones del empleo de placenta para el tratamiento de patología oftálmica están reevaluándose y redefiniéndose. Esta tesis ha desarrollado su investigación en una doble vertiente, una experimental y otra clínica, para valorar la utilidad de la membrana amniótica en la reconstrucción de la superficie ocular. En la primera parte, se ha aplicado un modelo experimental de causticación corneal con compromiso límbico a 40 ojos de conejo albinos de la raza New Zealand, estableciéndose dos grupos de estudio (control y trasplante de membrana). La evolución espontánea de las lesiones provocadas en el grupo control es hacia la opacidad corneal, neovascularización y tendencia a la conjuntivalización de la córnea. Se demuestra la utilidad del trasplante de membrana amniótica en la regeneración de la superficie ocular en el modelo experimental propuesto, mejorando tanto la opacidad y úlcera corneales como la menor tendencia a la neovascularización de los ojos de conejo trasplantados respecto a los no trasplantados. El estudio clínico se ha realizado en 64 ojos de 63 pacientes con diversas alteraciones de la superficie ocular. De los pacientes intervenidos incluidos en este estudio a los que se les ha practicado trasplantes de membrana amniótica, concluimos que hemos obtenido mejores resultados, especialmente con 2 patologías: descompensaciones corneales (queratopatía bullosa) y microperforaciones corneales. Sin embargo, en otras patologías de la superficie ocular con mayor implicación conjuntival, hemos encontrado ligeramente superior a la membrana amniótica, el empleo de injertos conjuntivales libres tanto del ojo contralateral como del mismo ojo afecto. ____________________________________________________________________________________________________Current indications for amniotic membrane transplantation in ophthalmic pathology are stablishing. We have developed this thesis doctoralis in a double way: one investigative and one clinic, to evaluate the usefullness of amniotic membrane transplantation for the reconstruction of the ocular surace. In the first way, we have applied an experimental model of coneal alkali injury wth limbus compromise in 40 rabbit eyes. Spontaneous evolution of lesions in control group without amniotic membrane is to corneal opacity, neovascularization and corneal conjunctivalization. We have demostrated amniotic membrane transplantation in ocular surface regenaration in the experimental model we have proposed, improving both corneal opacity and neovascularization in rabbit eyes with amniotic membrane transplantation comparing with control group. Clinical study was developed in 64 eyes of 63 patients with various ocular surface pathologies. Among patientes included in this study that we have operated with amniotic membrane, we conclude we have obtained best results especially in two pathologies: corneal decompensation (bullous keratopathy) and corneal microperforations. However, in other ocular surface diseases with more conjunctival implication, we have found that conjunctival implants, are more effective than amniotic membrane transplantation

Lentes de contato corneoesclerais adaptadas em córneas irregulares após cirurgia LASIK

Purpose: We aimed to describe the outcomes of corneoscleral contact lens fitting with multi-aspherical geometry designs in patients with irregular corneas after laser-assisted in situ keratomileusis (LASIK). Methods: This was a retrospective series of 18 patients (age, 26-38 years) selected from an eye clinic database. Participants were required to have unsatisfactory visual acuity with their current contact lenses or spectacles after LASIK for myopia correction. All patients were fitted with corneoscleral contact lenses designed to correct corneal surface irregularities. A diagnostic trial set was used for fitting, and assessments were performed according to a standardized methodology. Subjective comfort, visual acuity, central corneal thickness, endothelial cell count, and corneal-compensated intraocular pressure were evaluated. The follow-up period was one year. Results: Contact lens use was discontinued in 3 patients, thus leaving 24 eyes from 8 females and 7 males for analysis. The fitting characteristics were optimal in terms of lens position and movement. Statistically significant improvements were found in the best spectacle-corrected vision from before fitting to the visual acuity after fitting (p<0.001). Moreover, the patients reported high subjective comfort ratings and usage times (12.98 ± 2.3 hours/day). After one year of wear, visual acuity, subjective comfort, and usage time were maintained. No statistically significant adverse changes developed in the corneas over this period. Conclusion: Corneoscleral contact lenses with a multi-aspherical geometry design provide optimal visual acuity, improved comfort, and prolonged usage times in patients with irregular corneas after LASIK.Objetivo: Descrever os resultados do ajuste de lentes de contato corneoesclerais com geometria multiasférica em pacientes com córneas irregulares após cirurgia de ceratomileuse in situ assistida por laser (LASIK). Métodos: Esta foi uma série retrospectiva de 18 pacientes (idade, 26-38 anos) selecionados a partir de um banco de dados de uma clínica oftalmológica. Os participantes foram escolhidos ao manifestaram acuidade visual insatisfatória com suas lentes de contato ou óculos atuais depois de terem sido submetidos à LASIK para correção de miopia. Todos os pacientes receberam lentes de contato corneoesclerais projetadas para corrigir irregularidades na superficie da córnea. Um conjunto diagnóstico de prova foi usado para a adaptação e as avaliações foram feitas de acordo com uma metodologia padronizada. O conforto subjetivo, a acuidade visual, a espessura central da córnea, a contagem de células endoteliais e a pressão intraocular compensada da córnea foram avaliados. O período de acompanhamento foi de um ano. Resultados: O uso de lentes de contato foi descontinuado em 3 pacientes, deixando 24 olhos de 8 mulheres e 7 homens para análise. As características de adaptação foram ótimas em termos de posição e movimento da lente. Melhorias estatisticamente significativas foram encontradas na melhoria da visão corrigida por óculos antes de se ajustar a acuidade visual após a adaptação (p<0,001). Além disso, os pacientes relataram altos índices subjetivos de conforto e tempo de uso (12,98 ± 2,3 horas/dia). Após um ano de uso, a acuidade visual, o conforto subjetivo e o tempo de uso foram mantidos. Não houve alterações adversas estatisticamente significativas nas córneas ao longo deste período. Conclusão: As lentes de contato corneoesclerais com projeto geométrico multiasférico proporcionam acuidade visual ideal, maior conforto e tempo de uso prolongado em pacientes com córneas irregulares após o LASIK.Medicin

Treatment of Interface Fluid Syndrome after Laser-Assisted In Situ Keratomileusis with Descemet Membrane Endothelial Keratoplasty in Three Patients with Corneal Endothelial Dysfunction

Descemet Membrane Endothelial Keratoplasty (DMEK) has become a first-line treatment in corneal endothelial diseases owing to its exceptional clinical outcomes and low complication rates. Thanks to its refractive predictability and the ability to reshape the superficial cornea, DMEK is now also considered for managing cases with endothelial decompensation following previous refractive procedures. This article reviews the clinical outcomes of DMEK in three patients with Interface Fluid Syndrome (IFS), a complication of laser-assisted in situ keratomileusis (LASIK) in which endothelial failure can play a major role

Characterization and Prediction of the Clinical Outcome of Intense Pulsed Light-Based Treatment in Dry Eye Associated to Meibomian Gland Dysfunction

This non-comparative prospective case series was conducted to characterize the clinical impact of intense pulsed light (IPL)-based treatment in dry eyes associated to Meibomian gland dysfunction (MGD), defining the predicting factors for a successful outcome with this therapy in a large case series. A total of 390 eyes (195 patients, range: 23–93 years) received four sessions of Optima IPL system (Lumenis, Yokneam, Israel). Significant changes were observed in tear film osmolarity in both eyes (p < 0.001) and in meibum quality (p < 0.001), with more eyes showing clear or yellow secretions after therapy. Mean change in the ocular surface disease index (OSDI) was −8.61, ranging from −27.00 to 11.00. This change was significantly correlated with the baseline value of OSDI (r = −0.489, p < 0.001). The change in osmolarity correlated significantly with the baseline osmolarity in both eyes (right r = −0.636, left r = −0.620, p < 0.001). A linear predicting model of the change in OSDI with therapy was obtained: change OSDI = 10.99 − 0.35 × OSDI − 1.03 × NIBUTRE-LE (mean non-invasive break up time of right and left eye) −2.03 × Meibum quality grade (p = 0.001; R2: 0.325). In conclusion, the improvement in symptomatology achieved with an IPL-based therapy can be predicted at baseline using a linear model considering the level of MGD and the magnitude of OSDI and NIBUT (non-invasive break-up time).The author David P Piñero has been supported by the Ministry of Economy, Industry and Competitiveness of Spain within the program Ramón y Cajal, RYC‐2016‐20471

The Efficacy and Patient Satisfaction with a Mini-Scleral Lens after penetrating Keratoplasty

Background: To analyse the efficacy and patient satisfaction of fitting a mini-scleral lens (SL) after keratoplasty surgery in patients unsatisfied with their visual outcomes. Material and Methods: A retrospective chart review of 22 consecutive patients was performed between 2018 and 2019. Demographic data, indications for keratoplasty, ocular parameters, and visual results were evaluated. In addition, subjective visual quality (SVQ) and comfort, complications, daily wear time, and the reason for discontinuing SL wear during the 6-month follow-up were analysed. Results: Twenty-two eyes of 22 patients (6 females and 16 males; mean age 48.82 ± 17.19 years) were assessed. Keratoconus was the main indication for keratoplasty (9 eyes, 40.9%), followed by corneal opacities (5 eyes), and Fuchs endothelial dystrophy (4 eyes). High refractive anisometropia was found in 14 eyes (63.6%) and 6 eyes presented significant irregular astigmatism. LogMAR visual acuity improved significantly with SL when compared with the best spectacle-correction (mean, 0.12 ± 0.12 vs 0.52 ± 0.33, respectively; p < 0.01). Six patients discontinued SL wear (27.3%). Among the other 16 patients, the mean daily wear time was 11.47 ± 1.52 h; of these, 14 (87.5%) were successfully fitted and enjoyed favourable SVQ and comfort. No significant complications were found during the follow-up period. Conclusions: Mini-scleral lenses may be a safe and effective alternative for treating complicated eyes after keratoplasty; they may provide optimal visual rehabilitation and/or restore binocular vision with significant efficacy and patient satisfaction

Evaluation of a new nomogram for Ferrara ring segment implantation in keratoconus

AIM: To evaluate the short-term clinical outcomes of Ferrara rings in keratoconus using an optimized nomogram developed after several years of research and retrospective analysis of clinical data. METHODS: This prospective longitudinal non-comparative clinical trial evaluated 88 eyes of 88 patients (age 18-62y) with keratoconus diagnosis from two Spanish centers. Ferrara ring segment (AJL Ophthalmic) implantation was performed in all cases, using the mechanical procedure in 25 eyes (28.4%) and a femtosecond laser-assisted procedure in 63 eyes (71.6%). The ring segments implanted in each case were selected using a new optimized nomogram that considered variables such as anterior corneal asphericity and astigmatism or the discrepancy among astigmatism and coma orientations. Visual, refractive, corneal topographic, aberrometric, and pachymetric changes after surgery were evaluated during a 3-month follow-up. RESULTS: The implants induced a significant refractive change as well as an improvement in uncorrected (UDVA) and corrected distance visual acuity (CDVA; P<0.001). Postoperative CDVA of 0.10 logMAR or better was achieved in 28.4% and 46.5% of eyes, respectively. Two eyes (2.3%) lost two or more lines of CDVA whereas a total of 53.5% of eyes gained lines of CDVA. A significant central anterior and posterior corneal flattening was induced (P≤0.003), with a significant reduction of anterior (P<0.001) and posterior corneal astigmatisms (P=0.048), and a change in anterior asphericity (P<0.001). Total primary coma (6 mm pupil) change was also statistically significant (preoperative 3.66±3.04 ?m vs postoperative 2.33±2.26 ?m, P<0.001). No significant differences were found in the effect of ring segments between cases implanted using the mechanical and femtosecond techniques (P≥0.101). CONCLUSION: The implantation of Ferrara rings based on the nomogram evaluated is safe and effective for promoting a visual rehabilitation in keratoconus, with a relevant control of primary coma aberration.Supported by the Ministry of Economy, Industry and Competitiveness of Spain within the program Ramón y Cajal (RYC-2016-20471)

Antioxidant and Anti-Inflammatory Effects of Oral Supplementation with a Highly-Concentrated Docosahexaenoic Acid (DHA) Triglyceride in Patients with Keratoconus: A Randomized Controlled Preliminary Study

A prospective, randomized, single-center preliminary study was performed in patients with keratoconus stages I-III (Amsler-Krumeich), who received a high rich docosahexaenoic acid (DHA) (1000 mg/day) supplement for 3 months versus untreated patients. One eye per patient was evaluated. Thirty-four patients were recruited (75% men, mean age 31 years), with 15 randomized to the control group and 19 to the DHA-treated group. Corneal topography variables and plasma biomarkers of oxidative stress and inflammatory status were evaluated. A panel of fatty acids in blood samples was also assessed. There were significant between-group differences in the astigmatism axis, asphericity coefficient, and intraocular pressure in favor of the DHA group. Additionally, between-group significant differences in total antioxidant capacity (TAC), malondialdehyde (MDA), free glutathione (GSH) and GSH/GSSG ratio, as well as reduced values of inflammatory markers, including interleukin (IL)-4, IL-6, and vascular endothelial growth factor (VEGF-A) were found. These preliminary findings support the usefulness of the antioxidant and anti-inflammatory effects of DHA supplementation for targeting underlying pathophysiological mechanisms of keratoconus. Prolonged duration of DHA supplementation may be needed to detect more noticeable clinical changes in corneal topography

Corneal biomechanical parameters and central corneal thickness in glaucoma patients, glaucoma suspects, and a healthy population

Purpose: To evaluate and compare corneal hysteresis (CH), corneal resistance factor (CRF), and central corneal thickness (CCT), measurements were taken between a healthy population (controls), patients diagnosed with glaucoma (DG), and glaucoma suspect patients due to ocular hypertension (OHT), family history of glaucoma (FHG), or glaucoma-like optic discs (GLD). Additionally, Goldmann-correlated intraocular pressure (IOPg) and corneal-compensated IOP (IOPcc) were compared between the different groups of patients. Methods: In this prospective analytical-observational study, a total of 1065 patients (one eye of each) were recruited to undergo Ocular Response Analyzer (ORA) testing, ultrasound pachymetry, and clinical examination. Corneal biomechanical parameters (CH, CRF), CCT, IOPg, and IOPcc were measured in the control group (n = 574) and the other groups: DG (n = 147), FHG (n = 78), GLD (n = 90), and OHT (n = 176). We performed a variance analysis (ANOVA) for all the dependent variables according to the different diagnostic categories with multiple comparisons to identify the differences between the diagnostic categories, deeming p < 0.05 as statistically significant. Results: The mean CH in the DG group (9.69 mmHg) was significantly lower compared to controls (10.75 mmHg; mean difference 1.05, p < 0.001), FHG (10.70 mmHg; mean difference 1.00, p < 0.05), GLD (10.63 mmHg; mean difference 0.93, p < 0.05) and OHT (10.54 mmHg; mean difference 0.84, p < 0.05). No glaucoma suspects (FHG, GLD, OHT groups) presented significant differences between themselves and the control group (p = 1.00). No statistically significant differences were found in the mean CRF between DG (11.18 mmHg) and the control group (10.75 mmHg; mean difference 0.42, p = 0.40). The FHG and OHT groups showed significantly higher mean CRF values (12.32 and 12.41 mmHg, respectively) than the DG group (11.18 mmHg), with mean differences of 1.13 (p < 0.05) and 1.22 (p < 0.001), respectively. No statistically significant differences were found in CCT in the analysis between DG (562 μ) and the other groups (control = 556 μ, FHG = 576 μ, GLD = 569 μ, OHT = 570 μ). The means of IOPg and IOPcc values were higher in the DG patient and suspect groups than in the control group, with statistically significant differences in all groups (p < 0.001). Conclusion: This study presents corneal biomechanical values (CH, CRF), CCT, IOPg, and IOPcc for diagnosed glaucoma patients, three suspected glaucoma groups, and a healthy population, using the ORA. Mean CH values were markedly lower in the DG group (diagnosed with glaucoma damage) compared to the other groups. No significant difference was found in CCT between the DG and control groups. Unexpectedly, CRF showed higher values in all groups than in the control group, but the difference was only statistically significant in the suspect groups (FHG, GLD, and OHT), not in the DG group

Study of stereopsis using a depth sensation detection platform equipped with computer vision technology (DALE3D)

[EN] Background and objectives: The invention described herein is a prototype based on computer vision technology that measures depth perception and is intended for the early examination of stereopsis. Materials and methods: The prototype (software and hardware) is a depth perception measurement system that consists on: (a) a screen showing stereoscopic models with a guide point that the subject must point to; (b) a camera capturing the distance between the screen and the subject's finger; and (c) a unit for recording, processing and storing the captured measurements. For test validation, the reproducibility and reliability of the platform were calculated by comparing results with standard stereoscopic tests. A demographic study of depth perception by subgroup analysis is shown. Subjective comparison of the different tests was carried out by means of a satisfaction survey. Results: We included 94 subjects, 25 children and 69 adults, with a mean age of 34.2 18.9 years; 36.2 % were men and 63.8 % were women. The DALE3D platform obtained good repeatability with an interclass correlation coefficient (ICC) between 0.94 and 0.87, and coefficient of variation (CV) between 0.1 and 0.26. Threshold determining optimal and suboptimal results was calculated for Randot and DALE3D test. Spearman's correlation coefficient, between thresholds was not statistically significant (p value > 0.05). The test was considered more visually appealing and easier to use by the participants (90 % maximum score). Conclusions: The DALE3D platform is a potentially useful tool for measuring depth perception with optimal reproducibility rates. Its innovative design makes it a more intuitive tool for children than current stereoscopic tests. Nevertheless, further studies will be needed to assess whether the depth perception measured by the DALE3D platform is a sufficiently reliable parameter to assess stereopsis. (c) 2023 Published by Elsevier Espana, S.L.U. on behalf of Spanish General Council of Optometry. This is an open access article under the CC BY -NC -ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).The project was funded by a UPV-FISABIO grant (Ref. UPV- FISABIO-2017-002-939) for the realization of preparatory activities to support the exploration and development of Research/Innovation Projects and by a UPV-FISABIO grant (Ref. UPV-FISABIO-2019-B19) to support the development of innovation projects, provided by the Polytechnic University of Valencia (UPV) and the FISABIO Foundation of the Ministry of Health and Public Health.Porcar Plana, CA.; Campos Mollo, E.; Boronat, F.; Lledo Riquelme, MD.; Marfil Reguero, D.; Silvestre Beneito, C.; Peris Martínez, C. (2024). Study of stereopsis using a depth sensation detection platform equipped with computer vision technology (DALE3D). Journal of Optometry. 17(3). https://doi.org/10.1016/j.optom.2023.10049117

Oxidative stress in keratoconus

PURPOSE. The purpose of this study was to establish the alterations of oxidative stress-related markers in keratoconus (KC) corneas. METHODS. A total of 6 healthy and 11 ectatic corneas (7 KC and 4 post-LASIK) were studied. Different oxidative stress-related markers were determined to assess their implication in the KC pathophysiology. Total antioxidant capacity and total nitrites present in the samples were assayed. Furthermore, lipid peroxidation products and the glutathione contents were determined, together with 4-hydroxynonenal (4-HNE) immunohistochemistry, to establish the relationship between KC and oxidative stress. RESULTS. The antioxidant capacity and glutathione content in KC corneas were decreased significantly when compared with healthy corneas. Moreover, the total nitrites and lipid peroxidation were significantly elevated in the corneas with KC when compared with the controls. There was a statistically significant difference in the amount of HNE-positive cells in KC corneas when compared with healthy corneas by immunohistochemistry. Post-LASIK ectatic corneas and KC corneas showed similar results. CONCLUSIONS. The increased levels of oxidative stress markers and the decreased antioxidant capacity and antioxidant defenses in KC corneas, as well as in the post-LASIK ectatic corneas, indicate that oxidative stress might be involved in the development of this disease and may provide new insights for its prevention and treatment in the future. (Invest Ophthalmol Vis Sci. 2011;52:8592-8597