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Translational Vision Science &... Aug 2020To use second harmonic generation imaging and fluorescence recovery after photobleaching to demonstrate alterations in scleral collagen structure and permeability after...
PURPOSE
To use second harmonic generation imaging and fluorescence recovery after photobleaching to demonstrate alterations in scleral collagen structure and permeability after crosslinking in rat and human eyes.
METHODS
Excised rat and human scleras were imaged ex vivo with an inverted two-photon excitation fluorescence microscope before and after photochemical crosslinking using riboflavin and 405-nm laser light. Fluorescence recovery after photobleaching was applied to measure the diffusion of fluorescein isothiocyanate-dextran across the sclera.
RESULTS
Crosslinking caused scleral collagen fibers to become wavier and more densely packed, with surface collagen being more affected than deeper collagen fibers. Crosslinked sclera showed significantly decreased permeability in the irradiation zone and also extended as far as 250 µm outside the irradiation zone.
CONCLUSIONS
Photochemical crosslinking induced changes in scleral structure and permeability that extended to tissue even outside the irradiation zone.
TRANSLATIONAL RELEVANCE
Ultrastructural changes associated with the emerging clinical technique of photochemical scleral crosslinking have not been well characterized. We demonstrate not only changes in scleral collagen by second harmonic generation imaging but also the associated functional changes in tissue permeability by fluorescence recovery after photobleaching. We report the novel finding of reduced permeability extending well beyond the direct irradiation zone. This has implications for control in the clinical setting.
Topics: Animals; Collagen; Humans; Light; Permeability; Rats; Riboflavin; Sclera
PubMed: 32934895
DOI: 10.1167/tvst.9.9.45 -
PloS One 2022To evaluate corneo-scleral junction (CSJ) using anterior segment optical coherence tomography (AS-OCT) and describe the pattern of cornea and sclera interfusion based on... (Observational Study)
Observational Study
PURPOSE
To evaluate corneo-scleral junction (CSJ) using anterior segment optical coherence tomography (AS-OCT) and describe the pattern of cornea and sclera interfusion based on tissue reflectivity.
METHODS
This prospective observational study enrolled candidates for vision correction. Eyes with previous ocular surgery or irregular corneas were excluded. Temporal and nasal CSJ width and reflectivity patterns were assessed with AS-OCT horizontal scans. Correlations between manual and automated variables and multivariate linear regression analyses with age and spherical equivalent were performed.
RESULTS
101 right eyes were analysed. Temporal CSJ was wider (median 1.62; 1.13 to 2.22 mm) compared to the nasal side (median 1.18; 0.73 to 1.80 mm) (p<.0001). The temporal CSJ width showed negative correlation with ipsilateral anterior chamber angle measurements and positive correlation with horizontal visible iris diameter (HVID). These relationships were not statistically significant for the nasal CSJ width. No significant correlations with age or refractive error were observed at both sides. The pattern of temporal CSJ reflectivity was mostly V- or U-shaped. The eyes with V-shaped temporal CSJ had significantly larger HVID than the eyes with irregular temporal CSJ. The nasal CSJ presented irregular reflectivity in 47% of cases.
CONCLUSIONS
The temporal CSJ was wider and had regular (V or U-shaped) reflectivity patterns, while nasal CSJ was narrower and more irregular. The CSJ width was independent of age and refractive error and could not be predicted from other parameters. The HVID measurement accuracy may benefit from CSJ analysis based on AS-OCT.
Topics: Humans; Tomography, Optical Coherence; Sclera; Cornea; Anterior Chamber; Refraction, Ocular; Refractive Errors
PubMed: 36490278
DOI: 10.1371/journal.pone.0278884 -
Journal of Plastic, Reconstructive &... Oct 2022To explore the clinical effect of allogeneic sclera transplantation combined with tarso-conjunctival flap in total excision of divided eyelid nevus.
OBJECTIVE
To explore the clinical effect of allogeneic sclera transplantation combined with tarso-conjunctival flap in total excision of divided eyelid nevus.
METHODS
Eleven patients (three male and eight female patients) who experienced divided nevus of the eyelids between January 2014 and April 2020 were recruited to this retrospective study. All lesions were thick, darkly pigmented, presented with a wart-like appearance, and invaded the eyelid margin and tarsal conjunctiva. The surgical method involved a full-thickness lesion excision; then, the posterior defect was reconstructed by sliding the residual tarso-conjunctival flap forward and allogeneic sclera transplantation, and the anterior defect was reconstructed with sliding flaps, rotating flaps, and free skin grafts.
RESULTS
Neither malignant transformations nor recurrences were observed after a follow-up of more than one year. The eyelid shape was normal, the rim of the eyelid was smooth, there was no dissolution or rejection of the allogeneic sclera, and the eyelid had good mobility. All the flaps used were viable, soft, and thin. The most frequent complication was the loss of eyelashes in the reconstructed area.
CONCLUSION
For divided nevus of the eyelids invaded the eyelid margin and tarsal conjunctiva, total excision is a better decision, regardless of tumor recurrence or aesthetic considerations. The posterior defect reconstruction through sliding residual tarso-conjunctival flaps combined with allogeneic sclera transplantation is simple and effective.
Topics: Conjunctiva; Disease Progression; Eyelid Neoplasms; Eyelids; Female; Hematopoietic Stem Cell Transplantation; Humans; Male; Neoplasm Recurrence, Local; Nevus; Nevus, Pigmented; Retrospective Studies; Sclera; Skin Neoplasms
PubMed: 36045014
DOI: 10.1016/j.bjps.2022.06.028 -
Eye & Contact Lens May 2021This case reports on the use of scleral lens therapy for a patient with a descemetocele secondary to exposure and neurotrophic keratopathy. (Review)
Review
OBJECTIVES
This case reports on the use of scleral lens therapy for a patient with a descemetocele secondary to exposure and neurotrophic keratopathy.
METHODS
Case report and literature review.
RESULTS
A 31-year-old man had undergone emergency surgery to repair a ruptured arteriovenous malformation resulting in left facial and trigeminal nerve palsies. The patient reported to our clinic with a central descemetocele secondary to exposure and neurotrophic keratopathy. Given the poor prognosis of a therapeutic penetrating keratoplasty in this case, the descemetocele was treated with therapeutic scleral lens wear. After 1 year, the patient has remained stable without corneal perforation.
CONCLUSIONS
This case illustrates the use of extended scleral lens wear, followed by maintenance with daily scleral lens wear, to manage a descemetocele in a patient with neurotrophic and exposure keratopathy. For patients at high risk of postsurgical complications, therapeutic scleral lens wear may be used as an alternative or as a supplement to corneal transplantation and tarsorrhaphy in patients with descemetocele formation.
Topics: Adult; Contact Lenses; Corneal Perforation; Eyelids; Humans; Keratoplasty, Penetrating; Male; Sclera
PubMed: 33273266
DOI: 10.1097/ICL.0000000000000765 -
Current Eye Research Dec 2019Although trabeculectomy, and to a less extent glaucoma drainage devices are currently the gold standard in glaucoma surgery, there is a rising interest in addressing... (Review)
Review
Although trabeculectomy, and to a less extent glaucoma drainage devices are currently the gold standard in glaucoma surgery, there is a rising interest in addressing the more physiological pathway of aqueous outflow through surgeries that target Schlemm's canal (SC). These surgeries have the advantage of a lower risk of hypotony and bleb-related complications commonly associated with conventional glaucoma surgery.In this article we review new developments and the different techniques of circumferential angle surgery in adult and pediatric glaucoma, as well as procedures which target the canal circumferentially without incising it, such as canaloplasty and Visco360. A comprehensive literature search of various electronic databases was performed. Angle surgery, namely goniotomy and trabeculotomy, have been well established as standard procedures in pediatric glaucoma, yet their results in the management of adult glaucoma have not been as promising. In recent years, ab-interno trabeculectomy using Trabectome and Kahook dual blade have yielded variable results in adult glaucoma. As growing evidence suggests that bigger extent incisions into SC result in increased lowering of intraocular pressure than conventional 120 to 180-degree incisions, several procedures have been developed to create a circumferential incision into SC. Circumferential SC incision using sutures, microcatheters, TRAB360 or the rigid probe trabeculotome, through an ab-interno or ab-externo approach, have yielded promising results in both adult and pediatric glaucoma by reducing the resistance to aqueous outflow through the inner wall of SC over 360 degrees of the angle. Various techniques of circumferential Schlemm's canal surgery is effective in management of different adult and pediatric glaucomas. Further long-term comparative studies would be useful in evaluating safety and efficacy of these procedures.
Topics: Adult; Child; Filtering Surgery; Glaucoma; Glaucoma Drainage Implants; Humans; Intraocular Pressure; Microsurgery; Sclera; Sutures
PubMed: 31438743
DOI: 10.1080/02713683.2019.1659975 -
Ocular Immunology and Inflammation 2022To investigate the safety and efficacy of topical erythropoietin for the treatment of scleral necrosis.
PURPOSE
To investigate the safety and efficacy of topical erythropoietin for the treatment of scleral necrosis.
METHODS
This study enrolled eight consecutive patients with scleral necrosis due to previous ocular surgery, rheumatoid arthritis-associated necrotizing anterior scleritis, and thermal and chemical burns. Conventional treatments failed to heal avascular scleral lesions in all eyes. Patients were treated with topical erythropoietin (3000 IU/mL) four times a day.
RESULTS
The mean patient age was 37.6 ± 15.5 years. The interval between the development of scleral necrosis and initiation of topical erythropoietin was 25.6 ± 12.0 days. The necrotic sclera completely healed within 31.9 ± 16.9 days in all patients. The avascular lesions did not recur, and there was no evidence of side effects during the study.
CONCLUSION
Our results showed that topical erythropoietin could be safely used to manage scleral necrosis. Randomized clinical trials are needed to further explore the efficacy of this intervention in patients with avascular scleral lesions.
Topics: Adult; Humans; Middle Aged; Young Adult; Necrosis; Sclera
PubMed: 34124987
DOI: 10.1080/09273948.2021.1934485 -
Ophthalmology. Retina Mar 2021To evaluate scleral thickness in central serous chorioretinopathy (CSC) using anterior segment (AS) OCT.
PURPOSE
To evaluate scleral thickness in central serous chorioretinopathy (CSC) using anterior segment (AS) OCT.
DESIGN
Retrospective, comparative study.
PARTICIPANTS
Forty-seven eyes of 40 patients with CSC and 53 eyes of 47 age- and gender-matched normal control participants.
METHODS
Spherical equivalent, axial length, subfoveal choroidal thickness, and scleral thickness were compared between the CSC and control groups. Scleral thickness was measured by AS OCT 6 mm posterior to the scleral spur in 4 directions.
MAIN OUTCOME MEASURE
Scleral thickness in CSC eyes.
RESULTS
No differences were found between the 2 groups in age, gender, spherical equivalent, or axial length. Subfoveal choroidal thickness was significantly greater in CSC eyes than in normal control eyes (424.0 ± 101.4 μm vs. 324.3 ± 91.8 μm; P < 0.001). Scleral thickness was significantly greater in CSC eyes than in normal control eyes at the superior (429.4 ± 50.3 μm vs. 395.2 ± 55.4 μm; P = 0.005), temporal (447.7 ± 45.7 μm vs. 396.5 ± 64.1 μm; P < 0.001), inferior (455.7 ± 81.2 μm vs. 437.8 ± 46.9 μm; P = 0.022), and nasal (454.9 ± 44.7 μm vs. 416.6 ± 51.2 μm; P = 0.001) points.
CONCLUSIONS
Scleral thickness measured by AS OCT was significantly greater in CSC eyes than in normal control eyes, although no differences were found in spherical equivalent or axial length. Thick sclera may have a role in the pathogenesis of CSC.
Topics: Central Serous Chorioretinopathy; Female; Fluorescein Angiography; Fundus Oculi; Humans; Male; Middle Aged; Retrospective Studies; Sclera; Tomography, Optical Coherence
PubMed: 32683110
DOI: 10.1016/j.oret.2020.07.011 -
Retinal Cases & Brief Reports May 2023To present a surgical technique that allows rescue (repositioning) of a dislocated Crystalens model intraocular lens using scleral sutures.
PURPOSE
To present a surgical technique that allows rescue (repositioning) of a dislocated Crystalens model intraocular lens using scleral sutures.
METHODS
The surgical technique is described with supplemental video.
RESULTS
The technique was used in one patient with 3 months of follow-up information. The intraocular lens was well-positioned, and the visual acuity is 20/20, without adverse events.
CONCLUSION
Scleral suture techniques for repositioning of the Crystalens offer a suitable alternative to intraocular lens exchange.
Topics: Humans; Drug Repositioning; Lenses, Intraocular; Visual Acuity; Sclera; Suture Techniques; Sutures; Retrospective Studies
PubMed: 34048379
DOI: 10.1097/ICB.0000000000001169 -
Indian Journal of Ophthalmology Jun 2022The video shows the meticulous repair of the corneoscleral tear along with management of the choroidal prolapse.
BACKGROUND
The video shows the meticulous repair of the corneoscleral tear along with management of the choroidal prolapse.
PURPOSE
The video demonstrates the steps to establish the anatomical integrity of the globe and tips to avoid suture bites through the choroid in a corneo-scleral tear repair.
SYNOPSIS
Identification of important landmarks helps in the establishment of anatomical integrity. Therefore, the limbal area of tear is first sutured with 10-O nylon. The extent of wound onto the sclera is checked on the other end of the tear. Second limbal suture at the opposite end of the tear is taken, followed by dividing the corneal extent of tear by rule of half and segmental suturing with 10-O nylon. Then conjunctival peritomy is done to explore the scleral extent and the uveal tissue prolapse. Blunt and atraumatic back tip of Weckel sponge is used perpendicular to the plane of the sclera to push the choroid back aiding the scleral bite. Sclera is sutured with 9-O nylon suture taking care not to include the choroidal tissue. Air injection is done to check for any wound leak. Side port is hydrated, and corneal sutures are buried. The conjunctiva is secured with fibrin glue. Anterior chamber is formed with air bubble. Povidone iodine is instilled and BCL placed.
HIGHLIGHTS
1. Suturing the landmark areas first; 2. Exploring the extent of wound; 3. Segmental suturing of the cornea; 4. Pushing the choroid back to avoid bites through it while suturing sclera; 5. Air injection to check for wound leaks; 6. Anterior chamber formation with air at the end.
VIDEO LINK
https://youtu.be/e5lEyLsQR3U.
Topics: Choroid; Eye Injuries; Humans; Lacerations; Nylons; Prolapse; Sclera; Suture Techniques
PubMed: 35648030
DOI: 10.4103/ijo.IJO_1260_22 -
Indian Journal of Ophthalmology Jul 2022Management of posterior scleral perforation is commonly done with cryotherapy/laser or scleral patch graft depending on the size of perforation. However, for large...
BACKGROUND
Management of posterior scleral perforation is commonly done with cryotherapy/laser or scleral patch graft depending on the size of perforation. However, for large perforations, the availability of donor sclera is always an issue. To overcome this problem, we tried using absorbable gelatin sponge to plug the perforation as an alternative.
PURPOSE
To evaluate the efficacy of gelatin foam as an alternative to scleral patch graft in cases with perforation of posterior sclera.
SYNOPSIS
Here we report the case of a 27-year-old male, who sustained penetrating injury to right eye with two metallic intraocular foreign bodies with visual acuity of hand movement close to face. Primary wound repair was done, followed by retrieval of the first piece of metallic foreign body that measured 11X3mm in size. The second foreign body visualized at posterior pole adjascent to the disc was removed using Machemar forceps and it measured 10X3 mmin size. Leakage of PFCL at the site confirmed a posterior scleral perforation. Cryotherapy was avoided due to its proximity to optic nerve head, and donor sclera was not readily available at that moment. We managed the case by plugging the defect with absorbable gelatin foam, followed by silicone oil injection into the vitreous cavity. Post operative outcome was good with restoration of anatomical integrity of the globe along with improvement in visual acuity upto 6/18.
HIGHLIGHTS
Gelatin foam being absorbable and inciting less reaction aids in sealing the perforation and maintenance of globe contour with the advantage being readily available, cost-effective and it can be left in situ without the need for additional surgery for its removal. This would be of use in situations where the donor sclera is not readily available, and thus can be a potential alternative. However, further studies with larger sample size need to be done to evaluate and compare its effectiveness over donor scleral grafts.
ONLINE VIDEO LINK
https://youtu.be/fkardnkMQQo.
Topics: Adult; Foreign Bodies; Gelatin; Humans; Male; Optic Disk; Sclera; Tissue Donors
PubMed: 35791255
DOI: 10.4103/ijo.IJO_1431_22