Implantation of asymmetrical corneal intrastromal rings: A case series.

This case series reports eight eyes with keratoconus treated with laser implantation of one or two segments of progressive thickness corneal intrastromal ring (PT-ICRS). In this case series, it was evident that the insertion of PT-ICRS induces more pronounced corneal flattening at the thickest point, causing a reduction in distortion (coma) and lower astigmatism, resulting in a remarkable improvement in vision. Compared to the implementation of traditional intrastromal rings, the PT-ICRS variant showed superior results despite the small sample size. However, the same degree of asymmetry enhancement was not observed in cases in which a 330° PT-ICRS was implanted, despite the improvement in visual results when replacing a 320° traditional ring with a 330° PT-ICRS. These conclusions are limited as this is a case series with few cases.

A new technique to implant intracorneal ring-segments from the perilimbal region: one-year prospective pilot study report.

BACKGROUND: Recently a new surgical technique for intracorneal ring-segments (ICRS) assisted by femtosecond laser (FSL) called ByLimB was developed, involving the creation of the incision from a paralimbic region. This study aims to evaluate the safety and efficacy of the ByLimb technique following one year of follow-up. METHODS: A prospective, single-center study was conducted at the Zaldivar Institute in Buenos Aires, Argentina. Keratoconus patients with indication for ICRS-FSL assisted procedure, operated with the ByLimb technique were included. By using the ByLimb technique, the ICRS are placed without affecting the tunnel's roof, and the end of the ICRS is always away from the incision area. Visual acuity, topographic astigmatism, and the occurrence of complications were evaluated. Safety index was the main outcome and efficacy indes was a complimentary outcome. RESULTS: A total of 17 eyes completed the 12-month follow-up period. The safety index was 1.10 (mean postoperative corrected distance visual acuity (CDVA) in decimal: 0.76/preoperative CDVA: 0.69), while the efficacy index was 0.89 (mean postoperative uncorrected distance visual acuity UDVA in decimal: 0.62/preoperative CDVA: 0.69). Mean preoperative astigmatism was 5.3 ± 2.3, decreasing twelve months after surgery at 2.1 ± 1.2 (p < 0.001). No eye loss lines of vision and no intraoperative complications were observed. During the first month after surgery, an improper positioning of the ICRS based on topographic assessment was detected in five cases. A second procedure was performed, which consisted of opening the incision and introducing a Sinsky hook, through which the ICRS was mobilized and placed in its correct position. No incisional alterations, signs of infection, anterior segment anomalies, or fundus alterations were observed. CONCLUSION: FSL-assisted ICRS implantation through the perilimbal region has demonstrated an adequate safety index one year post-surgery. Additionally, this technique has facilitated accurate realignment of ICRS during secondary surgical interventions within one-month post-surgery. While the current findings are promising, continued follow-up of these cases is warranted.

Vision-Related Quality of Life in Patients With Keratoconus With Enantiomorphic Topography After Bilateral Intrastromal Corneal Ring Implantation.

PURPOSE: The aim of this study was to evaluate the quality of life (QOL) after intrastromal ring implantation in patients with keratoconus. METHODS: This was a prospective, randomized, interventional study. We analyzed 60 eyes of 30 patients aged 16 to 35 years who were treated at the Department of Ophthalmology and Visual Sciences, Federal University of São Paulo, Brazil. The Visual Function Questionnaire (VFQ-25) and Short-Form 36 Questionnaire (SF-36) were used before intracorneal ring segment (ICRS) implantation and at 3, 6, and 12 months after surgical intervention. RESULTS: The mean corrected visual acuity improved from a mean of 0.32 ± 0.2 logMAR (20/40) preoperatively to 0.14 ± 0.11 logMAR (20/25) 1 year postoperatively ( P = 0.001). The mean spherical equivalent varied from -7.24 ± 3.47 preoperatively to -4.13 ± 2.41 postoperatively ( P = 0.001). The overall composite score for the VFQ-25 improved from 55.1 preoperatively to 80.4 1 postoperatively ( P = 0.001). SF-36 showed statistically significant improvement in all scores. When analyzing the correlation between visual acuity and VFQ composite score, a significant correlation was found between both variables (Pearson correlation coefficient of -0.40, P = 0.001). CONCLUSIONS: Patients with keratoconus had increased psychological symptoms and lower QOL and improved psychosocial criteria associated with corneal remodeling and decreased visual dependence on others after surgery. Extrapolation of these data to the whole keratoconus population suggests that ICRS implantation could improve QOL in these patients.

Results of intrastromal corneal ring implantation in advanced keratoconus With the aim of postpoing or avoiding corneal transplantation.

PURPOSE: To evaluate the safety and efficacy of the surgery of intracorneal ring segment implantation with 320° of arc (320-ICRS) in patients with advanced keratoconus stage IV and maximum keratometry (Kmax) above 60 D. METHODS: A prospective, interventional case series study evaluating 25 eyes of 19 patients with keratoconus stage IV and Kmax > 60D in which 320-ICRS were implanted using VisuMax® femtosecond. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), keratometric values (mean - mean-K, flat - K1, and steep - K2), maximum keratometry (Kmax), tomographic astigmatism, refractive astigmatism and asphericity (Q) were assessed preoperatively and at 3, 6 and 12 months after the procedure. RESULTS: The UDVA improved from 1.03 ± 0.28 LogMAR (20/200) to 0.54 ± 0.21 LogMAR (20/60), (p < 0.001), the CDVA (with glasses) improved from 0.63 ± 0.29 LogMAR (20/80) to 0.31 ± 0.16 LogMAR (20/40),(p = 0.004), K1 reduced from 54.41 ± 4.46 D to 49.36 ± 4.11 D (p < 0.001), K2 reduced from 61.15 ± 4.37 D to 53.715 ± 4.05 D, (p < 0.001), mean-K reduced from 57.55 ± 4,17 D to 51.44 ± 3,94 D (p < 0.001), Kmax reduced from 69.80 ± 8.20 D to 63.43 ± 6.31 D (p < 0.001) and asphericity (Q) changed from -1.57 ± 0.35 to -0.77 ± 0.56 (p < 0.001). A total of 89.9% patients reached BCVA wearing scleral contact lens  0.2 LogMAR(20/25). CONCLUSION: 320-ICRS to treat advanced keratoconus appears to be an efficacious and safe procedure, being a surgical alternative to delay or even prevent corneal transplantation.

Corneal ectasia following photorefractive keratectomy: a confocal microscopic case report and literature review.

The occurrence of corneal ectasia after photorefractive keratectomy is a rare but serious complication of refractive surgery. Possible risk factors are not well assessed, but a probable reason is the failure to detect keratoconus preoperatively. In this report, we describe a case of corneal ectasia after photorefractive keratectomy in a patient who presented a suspicious tomography pattern preoperatively but had no degenerative alterations associated with pathologic keratoconus, as revealed by in vivo corneal confocal microscopy. We also review eligible case reports of post-photorefractive keratectomy ectasia to find similar characteristics.

Late-onset distal-apical intracorneal ring-segments keratopathy: an analysis of a large sample in a multicenter study.

PURPOSE: To review the prevalence and describe the characteristics, of cases with late-onset intracorneal ring segments (ICRS) keratopathy in a multicenter study. METHODS: A retrospective multicentric case-series study was performed in a specialized keratoconus service, from Buenos Aires, Argentina. An electronic clinical chart from patients with ICRS keratopathy between January 1999 and January 2019 was reviewed. We included cases with late-onset distal-apical ICRS keratopathy, which was defined as a persistent corneal lesion developed 12 months or later after implantation, located over, around, or closer to the ICRS. All the surgeries were performed by a manual corneal tunnel creation technique. Samples were taken to rule out infectious etiology. RESULTS: From 5217 eyes that underwent ICRS implantation, 13 cases (0.24%) were detected. The keratopathy onset was 72 ± 42.98 months (29-133) after ICRS implantation. Cultures were negative in all cases. An ICRS exchange was made for five cases in stage I and four in stage II. Four cases presented with partial ICRS extrusion in stage III. ICRS exchange was possible in two of them and a penetration keratoplasty was necessary for the rest. All cases remained stable 1 year after surgical procedures. CONCLUSIONS: A late-onset distal-apical ICRS keratopathy was detected with low prevalence (0.24%) in a large sample. It was classified into three stages according to its severity. Different treatments were selected for each stage, obtaining stable results 1 year after treatment.

Birefringence analysis of collagen supraorganization in cat corneas with tropical keratopathy.

OBJECTIVE: To evaluate the birefringent properties of the cornea and examine the supraorganizational aspects of collagen fibers in cats with tropical keratopathy. PROCEDURE: In this study, 10-micrometer-thick sections of corneal tissue from cats with tropical keratopathy were examined, both in the opaque and transparent areas of the anterior stroma. Control samples were obtained from healthy cat corneas. Polarized light microscopy was employed to evaluate the birefringent properties using two distinct methods. The first method involved measuring the optical retardation associated with corneal birefringence, while the second method assessed the alignment/waviness of the birefringent collagen fibers. Differences were significant when p < .05. RESULTS: Tropical keratopathy resulted in a significant rise (p < .05) in optical retardation in both opaque and transparent regions of the cat cornea. In the anterior stroma, both the opaque zones and transparent tissue exhibited a higher degree of collagen fiber packing than the control corneas. However, no significant differences (p > .05) in alignment were observed between the transparent tissue of the diseased cornea and the healthy corneas. CONCLUSION: Supraorganizational changes in collagen fiber packing are not restricted to lesion zones in cat corneas affected by tropical keratopathy. Such alterations also occur in the corneal tissue of the anterior stroma adjoining the lesions. Therefore, it is plausible that the transparent tissue of the anterior stroma in corneas affected by the disease may have functional abnormalities, despite its macroscopic healthy appearance. Additional investigations are required to clarify the implications of these potential defects and their conceivable contribution to tropical keratopathy.

Bilateral interstitial keratitis in a patient with presumed brain tuberculoma.

Interstitial keratitis is an inflammation of the corneal stroma without epithelium or endothelium involvement. The underlying causes are mostly infectious or immune mediated. Brazil has one of the highest incidence rates of tuberculosis in the world. Tuberculosis is considered one of the causes of interstitial keratitis. Malnutrition and anemia are risk factors of the disseminated disease. This is a case report of a 10-year-old child who presented with decreased visual acuity and a clinical diagnosis of bilateral interstitial keratitis and sclero-uveitis. The patient had been treated with topical steroids with partial improvement. Examinations revealed severe iron deficiency anemia, negative serologies for human immunodeficiency virus and syphilis, positivity for cytomegalovirus- and herpes simplex-specific IgG, and purified protein derivative of 17 mm. During the follow-up, the patient presented with tonic-clonic seizures, and magnetic resonance imaging findings suggested a central nervous system tuberculoma. Interstitial keratitis improvement was observed after specific tuberculosis treatment. This is the first case report describing the association of interstitial keratitis and central nervous system tuberculoma.

Comparação entre os resultados do implante de um segmento de arco longo versus dois segmentos de arco tradicional no tratamento de pacientes com ceratocone / Comparison between the results of implanting a long-arch segment versus two standard arch segments for treatment of keratoconus patients

RESUMO Objetivo: Analisar retrospectivamente as alterações na ceratometria e no astigmatismo corneano obtidas após cirurgia de implante de anel intraestromal, comparando o uso de um segmento de arco longo versus o implante de dois segmentos de comprimento de arco tradicional. Métodos: A partir de um estudo transversal, obtivemos os dados de 94 olhos de pacientes diagnosticados com ceratocone, que foram submetidos ao implante de anel corneano. Eles foram divididos em dois grupos, dependendo do tipo de implante recebido: Grupo A, um segmento de arco longo; Grupo B, dois segmentos tradicionais. Todos os segmentos implantados possuíam 250µ de espessura. Os dados do pré-operatório dos dois grupos foram comparados, para garantir que as amostras eram similares (as diferenças encontradas entre os dois grupos não eram estatisticamente significativas). As variáveis analisadas no pré e no pós-operatório foram acuidade visual com correção, ceratometria, astigmatismo corneano e refração. Resultados: A amostra que recebeu apenas um segmento de arco longo (Grupo A) obteve redução da ceratometria média de 4,42D (8,7%) e do astigmatismo corneano de 2,43D (40,4%). Já na amostra dos olhos que receberam dois segmentos de arco tradicional (Grupo B), houve redução média de 2,66D (5,1%) em relação à ceratometria média e redução média de 2,11D (34,8%) em relação ao astigmatismo corneano. A redução obtida na ceratometria média no Grupo A foi maior que a obtida no Grupo B (diferença estatisticamente significativa). A redução obtida no astigmatismo do Grupo A não foi estatisticamente significante, se comparada com o resultado obtido no Grupo B (considerando p≤0,05). Conclusão: Foi demonstrado que o uso de um segmento de arco longo possui maior capacidade de aplanação corneana, se comparado com o uso de dois segmentos com comprimento de arco tradicional. Em relação à redução do astigmatismo, os dois grupos mostraram resultados equivalentes.

ABSTRACT Purpose: To retrospectively analyze the changes in corneal keratometry and astigmatism after intrastromal ring surgery, comparing the use of one long arch segment versus two traditional arc length segments. Methods: A cross-sectional study obtained data from 94 eyes of patients diagnosed with keratoconus that underwent surgical treatment with corneal ring implant. They were divided into two groups according to the type of implant received: one long-arch segment (Group A) or two traditional segments (Group B), both 250 microns thick. Preoperative data from the two groups were compared to ensure that the samples were similar (the differences between the two groups were not statistically significant). The variables (pre and post-operatively) analyzed were: best corrected visual acuity, keratometry, corneal astigmatism and refraction. Results: Group A, which received one long arch segment, showed a Km decrease of 4.42D (8.7%) and a corneal astigmatism reduction of 2.43D (40.4%). Group B, where the eyes acquired two traditional arch segments, showed an average Km decrease of 2.66D (5.1%) and corneal astigmatism reduction of 2.11D (34.8%). The mean keratometry (Km) reduction obtained was statistically significant (p≤0.05) when comparing both groups (A and B). The mean corneal astigmatism reduction was not statistically significant (p≤0.05) when comparing both groups (A and B). Conclusions: One long-arch segment has been demonstrated to have a greater capacity to reduce corneal curvature when compared to the use of two traditional-sized arch segments. No significant differences were found regarding the reduction of corneal astigmatism after comparing the results obtained in both groups.

Early keratometric and refractive results after intra-corneal rings surgery in keratoconus patients.

OBJECTIVE: To evaluate early keratometric and refractive results after intra-corneal rings surgery in keratoconus patients. METHOD: 50 eyes of 25 patients with keratoconus within stage 2 and 3, underwent intra-stromal corneal rings surgery by using the femtosecond surgical laser, one month after surgery, corneal keratometries and patient refraction were compared vs pre-operative ones. RESULTS: Mean pre-operative low keratometry was 48.8 ± 3.65 D vs. 46.44 ± 3.65 D post-operative (p < 0.005). Mean pre-operative high keratometry was 53.92 ± 4.50 vs. 49.65 ± 4.15 post-operative (p < 0.005). Mean pre-operative spherical equivalent was -7.39 ± 2.42 D vs. -3.48 ± 2.47 D post-operative (p < 0.005). Mean pre-operative cylinder was -5.65 ± 2.02 D vs. -3.48 ± 2.47 D post-operative (p < 0.005). CONCLUSIONS: Corneal keratometries, spherical equivalent and corneal cylinder, significant decrease at one month after intra-stromal corneal rings surgery in keratoconus patients.

OBJETIVO: Evaluar los resultados queratométricos y refractivos tempranos de pacientes con queratocono operados con anillos intracorneales. MÉTODO: Se evaluaron 50 ojos de 25 pacientes con queratocono de grado 2 o 3, posoperados con colocación de anillos intracorneales mediante el uso de láser de femtosegundos, al mes del posoperatorio, comparando las queratometrías y las refracciones antes y después de la operación. RESULTADOS: El promedio preoperatorio de las queratometrías planas fue de 48.8 ± 3.65 D y en el posoperatorio fue de 46.44 ± 3.65 D (p < 0.005). El promedio preoperatorio de las queratometrías curvas fue de 53.92 ± 4.50 y en el posoperatorio fue de 49.65 ± 4.15 (p < 0.005). El equivalente esférico preoperatorio fue de −7.39 ± 2.42 D y en el posoperatorio fue de −3.48 ± 2.47 D (p < 0.005). El promedio del cilindro preoperatorio fue de −5.65 ± 2.02 D y en el posoperatorio fue de −3.48 ± 2.47 D (p < 0.005). CONCLUSIONES: La colocación de anillos intracorneales reduce de forma significativa tanto las queratometrías como los equivalentes esféricos y el astigmatismo en pacientes con queratocono en forma temprana.

Successful Management of Corneal Hydrops and Intrastromal Corneal Ring Segment (ICRS) Migration Following ICRS Implantation for Keratoconus.

BACKGROUND Acute corneal hydrops refers to a rare complication of keratoconus and other ectatic disorders with potentially sight-threatening sequelae. Intrastromal corneal ring segment (ICRS) implantation is a surgical procedure performed as therapy for keratoconus when there is contact lens intolerance. ICRS migration along the tunnel made for its insertion is one of its most frequent complications. We believe this is the first published case of acute corneal hydrops and ICRS migration unfolding shortly after an uneventful ICRS implantation, and successfully managed with medical treatment and ICRS reimplantation, respectively. CASE REPORT A 17-year-old male, previously diagnosed with bilateral keratoconus 4 years earlier for which he underwent cross-linking surgery for both eyes 3 years prior, presented to our department for a first-time keratoconus assessment. His best-corrected visual acuity (BCVA) was 20/25 OD and 20/40 OS with rigid gas-permeable contact lenses. Due to contact lens intolerance in the OS and lack of custom-fit scleral lenses at the time, 2 ring segments (Ferrara, AJL Ophthalmic, Inc.) with an arc length of 160 degrees and 300 µm in size were implanted at a depth of 320 µm. Within 1 week, severe hydrops and ICRS migration emerged. Medical treatment provided resolution of hydrops and then ICRS reimplantation was performed without further complications, resulting in contact lens tolerance alongside a BCVA of 20/40 OS. CONCLUSIONS Corneal hydrops is a challenging complication in ICRS implantation due to its infrequent occurrence and the severity of its potential sequelae. Prompt medical treatment and close follow-up are essential to obtain the best outcome in these instances.

Topical losartan inhibits corneal scarring fibrosis and collagen type IV deposition after Descemet's membrane-endothelial excision in rabbits.

The purpose of this study was to examine the effect of topical and/or oral angiotensin converting enzyme II inhibitor and TGF-beta signaling blocker losartan on corneal stromal fibrosis that developed in rabbit corneas after Descemetorhexis removal of central Descemet's membrane and corneal endothelium. Twenty-eight New Zealand white rabbits were included and either had 8 mm central Descemetorhexis or sham control surgery without Descemetorhexis in one eye. Groups of 4 eyes without Descemetorhexis were treated for one month with no medications, topical losartan or oral losartan. Groups of 4 eyes with Descemetorhexis were treated with topical and oral vehicle, topical losartan, oral losartan, or both topical losartan and oral losartan for one month. Standardized slit lamp photos were obtained with central opacity intensity measured with ImageJ. The posterior fibrotic zone of corneas was measured on immunohistochemistry for alpha-smooth muscle actin (SMA) and keratocan using QuPath analysis. Collagen type IV expression in the posterior cornea was quantitated with ImageJ and duplex immunohistochemistry for collagen type IV and TGF beta-1. After Descemetorhexis, topical, but not oral, losartan decreased the intensity of central stromal opacity, reduced peripheral corneal scarring, and decreased alpha-smooth muscle actin myofibroblast fibrosis area compared to corneas that had Descemetorhexis and treatment with vehicles alone. Topical losartan decreased posterior stromal cellular, non-Descemet's membrane, collagen type IV production, that is likely stimulated by TGF beta as part of a negative regulatory feedback mechanism, compared to vehicle treatment at one month after Descemetorhexis. Topical losartan is likely to be effective in reducing corneal scarring fibrosis produced by traumatic injury, microbial infection, and some corneal diseases and surgeries.

Abscesso estromal em córnea de cão / Corneal stromal abscess in a dog

Background: The eye is an important sense organ responsible for sight. The cornea is the outermost of many eye layers,being predisposed to several lesions, some of them being frequent in small animal clinics meanwhile others are unusualand seldom reported in specialized literature. The stroma abscess is a common condition in horses, but atypical in dogs,it’s a condition in which a microperforation in the corneal epithelium allows microorganisms or a foreign body to penetratethe corneal stroma, and those become inside the cornea after a re-epithelialization, producing an intense inflammatoryresponse. Therefore, this case reports a case of deep stromal abscess in a Shih Tzu dog.Case: A 4-year-old female Shih Tzu, weighing 4.6 kg, was submitted to ophthalmic examination in which the left eyepresented an opaque yellowish-white protruding structure located on the right side, in the center of the cornea (3 o´clockposition), bulbar and palpebral conjunctival hyperemia and congestion, chemosis, blepharospasm, and a moderate amountof mucous discharge. The clinical diagnosis was stromal abscess with reflex uveitis. A differential diagnosis should includeconditions affecting the anterior part of the cornea, such as an epithelial inclusion cyst and a corneal ulcer. The inclusioncyst, contrarily to the corneal abscess, doesn’t cause pain, meanwhile, the corneal ulcer was ruled out by the FluoresceinStaining Test. The recommended treatment was surgical, through lamellar keratectomy, followed by overlapping pedicledconjunctival graft and third eyelid flap. In association with the surgical treatment, oral antibiotics, anti-inflammatory,and opioids, plus topical antibiotics and autologous serum eye drop. Seventy days post-surgery, the previously observedinflammatory signs were no longer present. In the conjunctival graft insertion site perpetuated a scar leucoma with few...

Fluconazol intra-estromal - eficácia na cirurgia de abscesso estromal em equino / Intrastromal fluconazole - effectiveness in the surgery of stromal abscess in a horse

Background: Due to its ocular microflora, the equine species is predisposed to develop mycotic ulcers which, when notproperly treated, can lead to the formation of a stromal abscess. A stromal abscess occurs through the introduction ofmicroorganisms into the corneal stroma. During re-epithelialization, the foreign body is encapsulated, thus creating abarrier that protects bacteria or fungi from treatment with antimicrobial medication. This framework can end up resultingin blindness due to chronic iridocyclitis, putting the animal’s vision at risk. The current work aims to report a case of corrective surgery for stromal abscess in a mare with the administration of intraoperative intrastromal fluconazole, in orderto corroborate the effectiveness of the technique.Case: A 9-year-old mare was evaluated, with the complaint that her right eye was closed and “yellowish” and that she hadalready been treated with intramuscular injectable anti-inflammatory drugs based on flunexin meglumine (Banamine® -50 mg) for 15 days, referring to a possible ulcer in the right eye. Ophthalmic screening resulted in a negative direct reflexand no threat response in the right eye. Examination of the conjunctiva showed congestion and chemosis. Examination ofthe cornea of the right eye was negative for Fluorescein and Green Lissamine tests, and opacity and corneal neovascularization were noted. The final diagnosis was a corneal abscess of probable fungal origin secondary to a keratomycosis. Afterthe consultation, complementary blood and biochemical tests were performed, which showed normal results for the speciesin question, and treatment was started with eye drops based on atropine 1% (Fagra® - 20 mL), ciprofloxacin antimicrobialeye drops (Ciprovet Colirio® - 5 mL), and antifungal eye drops based on ketoconazole...

Abscesso estromal em córnea de cão / Corneal stromal abscess in a dog

Background: The eye is an important sense organ responsible for sight. The cornea is the outermost of many eye layers,being predisposed to several lesions, some of them being frequent in small animal clinics meanwhile others are unusualand seldom reported in specialized literature. The stroma abscess is a common condition in horses, but atypical in dogs,its a condition in which a microperforation in the corneal epithelium allows microorganisms or a foreign body to penetratethe corneal stroma, and those become inside the cornea after a re-epithelialization, producing an intense inflammatoryresponse. Therefore, this case reports a case of deep stromal abscess in a Shih Tzu dog.Case: A 4-year-old female Shih Tzu, weighing 4.6 kg, was submitted to ophthalmic examination in which the left eyepresented an opaque yellowish-white protruding structure located on the right side, in the center of the cornea (3 o´clockposition), bulbar and palpebral conjunctival hyperemia and congestion, chemosis, blepharospasm, and a moderate amountof mucous discharge. The clinical diagnosis was stromal abscess with reflex uveitis. A differential diagnosis should includeconditions affecting the anterior part of the cornea, such as an epithelial inclusion cyst and a corneal ulcer. The inclusioncyst, contrarily to the corneal abscess, doesnt cause pain, meanwhile, the corneal ulcer was ruled out by the FluoresceinStaining Test. The recommended treatment was surgical, through lamellar keratectomy, followed by overlapping pedicledconjunctival graft and third eyelid flap. In association with the surgical treatment, oral antibiotics, anti-inflammatory,and opioids, plus topical antibiotics and autologous serum eye drop. Seventy days post-surgery, the previously observedinflammatory signs were no longer present. In the conjunctival graft insertion site perpetuated a scar leucoma with few...(AU)

Intracorneal circular ring implant with femtosecond laser: Pocket versus tunnel.

PURPOSE: To evaluate and compare visual and refractive outcomes after implantation of the intracorneal continuous ring 360° arc (ICCR) versus the intracorneal ring segment 340° arc (ICRS) using femtosecond laser for central keratoconus. SETTING: Research Department, Oftalmosalud, Instituto de Ojos, Lima, Peru. METHODS: Randomized study that included 40 eyes of 32 patients diagnosed with central keratoconus between November 2014 and March 2015. Twenty eyes had an implantation of ICCR (MyoRing, Dioptex GmbH, Austria) through an intrastromal pocket and 20 eyes had an implantation of ICRS (Keraring, Mediphacos, Brazil) through an intrastromal tunnel. Both procedures were performed with a femtosecond laser (LDV Z6 model, Ziemer Ophthalmic Systems AG). Visual acuity (VA), refraction, and Scheimpflug imaging analysis were performed pre- and postoperatively at 1 month and 1 year. Comparisons of means were performed using the Student's t-test. RESULTS: At 1 year, uncorrected VA improved 0.77 LogMAR (p < 0.001) in the ICCR group and 0.79 LogMAR (p = 0.01) in the ICRS group; mean sphere improvement was 5.13 Diopters (D) in the ICCR group and 6.27 D in the ICRS group (p < 0.001 both); mean Steeper Keratometry improvement was 4.24 D in the ICCR group and 5.53 D in the ICRS group (p < 0.001 both). In the ICCR group, mean decrease in the pachymetry at the thinnest point of the cornea was 32.16 µm (p = 0.01), and in the ICRS group, mean increase was 4.2 µm at 1 year (p = 0.61). CONCLUSION: Intracorneal continuous ring 360° arc (ICCR) and intracorneal ring segment 340° (ICRS) are effective treatments for central keratoconus. No significant differences between rings were found on visual acuity, refraction, and keratometry improvement.

Birefringence Analyses Reveal Differences in Supramolecular Characteristics of Corneal Stromal Collagen Fibrils Between Falconiformes and Strigiformes.

This study aimed to assess the birefringent properties of corneal stromal collagen fibrils in birds of the orders Falconiformes (diurnal) and Strigiformes (predominantly nocturnal) to compare their supramolecular organizations. In total, 22 corneas of Falconiformes (Caracara plancus, n = 8; Rupornis magnirostris, n = 10; and Falco sparverius, n = 4) and 28 of Strigiformes (Tyto furcata, n = 16; Pseudoscops clamator, n = 6; and Athene cunicularia, n = 6) were processed histotechnically into 8-µm thick sections. Corneal optical retardation (OR) values related to the form and intrinsic fractions of the total birefringence of collagen fibrils were measured using a polarized light microscope equipped with phase compensators. In addition, the coherence coefficients that inform the local orientation of the fibrils were calculated through video image analysis. All assessments were conducted both in the anterior and posterior stroma of the cornea. Differences were significant when P < 0.05. The results showed supraorganizational differences between fibrils in the anterior stroma of Falconiformes and Strigiformes. The OR values were greater (P < 0.0001) for Falconiformes, indicating that the corneas of these birds contain more collagen fibrils or more aggregated collagen fibrils. In contrast, the coherence coefficients were higher (P = 0.016) for Strigiformes, indicating that the corneal collagen fibers in these birds are highly aligned and have few undulations. A multivariate data matrix constructed for Euclidean distance calculations showed that the dissimilarity between Falconiformes and Strigiformes corneas, in terms of the supraorganization of stromal collagen fibrils, was 4.56%. In conclusion, it is possible that the supraorganizational differences reported in this study may be sources of variation in the visual quality of Falconiformes and Strigiformes. This study provides the necessary evidence to encourage further research associating corneal optical performance to supramolecular characteristics of corneal stromal collagen.

Descemet's membrane injury and regeneration, and posterior corneal fibrosis, in rabbits.

The purpose of this investigation was to study Descemet's membrane and corneal endothelial regeneration, myofibroblast generation and disappearance, and TGF beta-1 localization after Descemet's membrane-endothelial excision (Descemetorhexis) in rabbits. Thirty-six rabbits had 8 mm Descemetorhexis and standardized slit lamp photos at 1, 2 and 4 days, 1, 2 and 4 weeks, and 2, 4 and 6 months, as well as multiplex IHC for stromal cell markers keratocan, vimentin, and alpha-smooth muscle actin (SMA); basement membrane (BM) components perlecan, nidogen-1, laminin alpha-5, and collagen type IV; and corneal endothelial marker Na,K-ATPase ß1, and TGF beta-1, with ImageJ quantitation. Stromal transparency increased from the periphery beginning at two months after injury and progressed into the central cornea by six months. At six months, central transparency was primarily limited by persistent mid-stromal neovascularization. Stromal myofibroblast zone thickness in the posterior stroma peaked at one month after injury, and then progressively decreased until to six months when few myofibroblasts remained. The regeneration of a laminin alpha-5 and nidogen-1 Descemet's membrane "railroad track" structure was accompanied by corneal endothelial closure and stromal cell production of BM components in corneas from four to six months after injury. TGF beta-1 deposition at the posterior corneal surface from the aqueous humor peaked at one day after Descemetorhexis and diminished even before regeneration of the endothelium and Descemet's membrane. This decrease was associated with collagen type IV protein production by corneal fibroblasts, and possibly myofibroblasts, in the posterior stroma. Descemet's membrane and the corneal endothelium regenerated in the rabbit cornea by six months after eight mm Descemetorhexis. Real-time quantitative RT-PCR experiments in vitro with marker-verified rabbit corneal cells found that 5 ng/ml or 10 ng/ml TGF beta-1 upregulated col4a1 or col4a2 mRNA expression after 6 h or 12 h of exposure in corneal fibroblasts, but not in myofibroblasts. Stromal cells produced large amounts of collagen type IV that likely decreased TGF beta-1 penetration into the stroma and facilitated the resolution of myofibroblast-generated fibrosis.

In vivo confocal microscopy findings after SMILE refractive surgery technique.

OBJECTIVE: To evaluate confocal microscopy finding after SMILE surgery by in vivo confocal microscopy and stromal lenticule and stromal interface accuracy planed vs measured. METHOD: Thirty eyes of 15 patients were evaluated before and 1 month after SMILE surgery by using confocal microscopy. Cellular morphology was studied. Planed stromal lenticule thickness was compared vs measured stromal lenticule thickness after surgery by comparing the total stromal corneal thickness before vs after surgery. Stromal corneal interface was evaluated and depth of this planed interface was compared vs measured post-surgery interface depth. RESULTS: Sub-epithelial nerve plexus was absent at 1 month after surgery. Activated keratocytes were found before and after stromal corneal interface depth. There was not statistical significant difference between mean planed stromal lenticule vs. post-surgery measured (102.3 ± 25.7 vs. 104.2 ± 29.9 mm; p = 0.73). There was not statistical significant difference between mean planed stromal interface depth vs. post-surgical measured (113.7 ± 8.2 vs. 120.5 ± 17.3 mm; p = 0.058). CONCLUSIONS: Confocal microscopy is useful to evaluate changes after SMILE surgery; lenticule thickness and stromal interface depth are exact.

OBJETIVO: Evaluar los hallazgos mediante microscopía confocal in vivo de pacientes operados de cirugía SMILE, la exactitud del lentículo estromal y la profundidad de la interfaz estromal planeados versus medidos. MÉTODO: Treinta ojos de 15 pacientes operados de SMILE se estudiaron mediante microscopía confocal antes y al mes de la cirugía. Se evaluaron la morfología celular, el espesor del lentículo estromal planeado versus el medido en el posoperatorio mediante la diferencia entre el espesor estromal preoperatorio y el postoperatorio, así como la interfaz estromal, y se comparó la profundidad de esta interfaz estromal planeada con la medida en el posoperatorio. RESULTADOS: Se observó la ausencia del plexo nervioso subepitelial al mes del posoperatorio y una activación de queratocitos anterior y posterior a la profundidad de la interfaz estromal. No hubo diferencia en el lentículo estromal planeado versus el medido en el posoperatorio (102.3 ± 25.7 vs. 104.2 ± 29.9 mm; p = 0.73). No hubo diferencia entre la profundidad de la interfaz estromal planeada y medida (113.7 ± 8.2 vs. 120.5 ± 17.3 mm; p = 0.058). CONCLUSIONES: Tras la cirugía SMILE se pueden evaluar los cambios mediante microscopía confocal; el espesor del lentículo y la profundidad de la interfaz son exactos.