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Luminescence of favipiravir in skin appendages and sclera. A controlled study and literature review.Photodermatology, Photoimmunology &... Jan 2024Favipiravir is an antiviral agent, recently used for COVID-19 infections. Several reports associate favipiravir intake with Wood's lamp fluorescence of hair, nails, and... (Review)
Review
BACKGROUND/OBJECTIVES
Favipiravir is an antiviral agent, recently used for COVID-19 infections. Several reports associate favipiravir intake with Wood's lamp fluorescence of hair, nails, and sclera. The present study was designed to elucidate the positivity rates, and sites of favipiravir-related fluorescence and to unravel the site-specific changes in fluorescence positivity rates by a function of time past exposure.
METHODS
The study population comprised 50 patients and 50 control individuals. All patients in the patient group had received a full dose of favipiravir for COVID-19 infection. Fifty volunteers served as the control group. Wood's lamp examination was performed in a completely darkened room, and the positivity rate, extent, pattern, and distribution of fluorescence were recorded.
RESULTS
Wood's light revealed fluorescence of the fingernails, toenails, sclera, and hair in 35 (70%), 35 (70%), 22 (44%), and 8 (16%) patients, respectively. No control individual tested positive by Wood's lamp. Statistical analysis revealed significant differences between patient and control groups in terms of Wood's light luminescence in the fingernails (p = .000), toenails (p = .000), sclera (p = .000) and hair (p = .003). Although fingernail, toenail, and hair fluorescence positivity rates declined or ceased at or after 91 days of favipiravir exposure, ocular fluorescence positivity rates were prolonged up to 188 days.
CONCLUSIONS
These findings confirm that favipiravir may produce fluorescence of nails, sclera, and hair, detectable by Wood's light starting from the initial month and peaking at second- and third months following exposure to the medication. Although nail and hair fluorescence tend to abate after 3 months, ocular fluorescence may persist even longer than 6 months after cessation of the medication.
Topics: Humans; Luminescence; Sclera; Ultraviolet Rays; COVID-19; Amides; Pyrazines
PubMed: 37882104
DOI: 10.1111/phpp.12919 -
Indian Journal of Ophthalmology Jul 2024Traboulsi syndrome is a sporadic autosomal recessive disorder. Very few cases reported and no surgical treatment has been described.
BACKGROUND
Traboulsi syndrome is a sporadic autosomal recessive disorder. Very few cases reported and no surgical treatment has been described.
PURPOSE
The purpose of the study was to describe the surgical treatment of a case of Traboulsi syndrome with intercalary staphyloma.
SYNOPSIS
Traboulsi syndrome[1-3] is a type of spontaneous filtering bleb. The case was of a 31-year-old lady with a flat anterior chamber and large intercalary staphyloma, with a subluxated clear lens. Liberal peritomy was done. The staphyloma was cut and the displaced lens was delivered through it. It was closed with 7-0 vicryl continuous suture. A cross-linked cornea was used after removing the Descemet membrane. It was modified to match the crescentic shape of the limbus by using 11 and 6 mm trephine. Two wedge-shaped defects were created and tissue was excised between them, which were then sutured to increase the arc radius. A peripheral flange at the corneal edge was created. A pocket was created in the host cornea to accommodate the donor corneal flange. The donor cornea was tucked in and the graft was sutured. The sclera was used to suture another side prophylactically, making a 360-degree encirclage. The patient got ambulatory vision postsurgery. The use of the cornea as biological encirclage has not been described previously.
HIGHLIGHTS
Using a cross-linked cornea. Creating wedge-shaped defects in crescentic corneal graft to increase arc radius. Use of cornea as encirclage.Link of video:https://youtu.be/T3b5rkvFmlc.
Topics: Humans; Adult; Female; Visual Acuity; Anterior Chamber; Syndrome; Lens Subluxation; Ophthalmologic Surgical Procedures; Suture Techniques; Intraocular Pressure
PubMed: 38905471
DOI: 10.4103/IJO.IJO_1968_23 -
Life (Basel, Switzerland) Nov 2023Considering that peripheral corneal thinning occurs in keratoconus (KC), the anterior scleral thickness (AST) profile was measured to compare thickness variations in...
PURPOSE
Considering that peripheral corneal thinning occurs in keratoconus (KC), the anterior scleral thickness (AST) profile was measured to compare thickness variations in healthy and KC eyes across several meridians.
METHODS
This cross-sectional case-control study comprised 111 eyes of 111 patients: 61 KC eyes and 50 age- and axial-length-matched healthy eyes. The AST was explored at three scleral eccentricities (1, 2, and 3 mm from the scleral spur) across four scleral zones (nasal, temporal, superior, and inferior) by using swept-source optical coherence tomography. The AST variations among eccentricities and scleral regions within and between groups were investigated.
RESULTS
The AST significantly varied with scleral eccentricity in healthy eyes over the temporal meridian ( = 0.009), whereas in KC eyes, this variation was observed over the nasal ( = 0.001), temporal ( = 0.029) and inferior ( = 0.006) meridians. The thinnest point in both groups was 2 mm posterior to the scleral spur ( < 0.001). The sclera was thickest over the inferior region (control 581 ± 52 μm, KC 577 ± 67 μm) and thinnest over the superior region (control 448 ± 48 μm, KC 468 ± 58 μm) in both populations ( < 0.001 for all eccentricities). The AST profiles were not significantly different between groups ( > 0.05). The inferior-superior thickness asymmetry was statistically different 2 mm posterior to the scleral spur between groups ( = 0.009), specifically with subclinical KC ( = 0.03). There is a trend where the asymmetry increases, although not significantly, with the KC degree ( > 0.05).
CONCLUSIONS
KC eyes presented significant thickness variations among eccentricities over the paracentral sclera. Although AST profiles did not differ between groups, the inferior-superior asymmetry differences demonstrated scleral changes over the vertical meridian in KC that need further investigation.
PubMed: 38004363
DOI: 10.3390/life13112223 -
Ophthalmology Science Dec 2023Retinitis pigmentosa (RP) is the most common cause of inherited blindness, with onset occurring as early as 4 years of age in certain rare but severe forms caused by...
PURPOSE
Retinitis pigmentosa (RP) is the most common cause of inherited blindness, with onset occurring as early as 4 years of age in certain rare but severe forms caused by mutations in the gamma subunit of phosphodiesterase 6 (PDE6). Studies in humans and mice have shown that RP pathology begins with progressive photoreceptor death, which then drives changes in downstream neurons, neighboring retinal pigment epithelium (RPE), and vasculature. Here, we present the first detailed analysis of RP disease progression in -deficient mice.
DESIGN
Experimental study of an RP mouse model.
SUBJECTS
We studied and Pde6g mice at the age of 7, 16, 30, 44, and 56 days with n = 2 to 5 per group and time point.
METHODS
Photoreceptor degeneration and retinal remodeling were analyzed in retinal sections by immunofluorescence. Retinal blood vessel degradation was analyzed in flat-mounted retinas immunolabeled for isolectin GS-IB4. Protein expression was measured by immunoblot. Acellular capillaries were assessed in trypsin-digested and hematoxylin-eosin-stained retinas at postnatal day (P) 44. Retinal pigment epithelium cells were delineated in flat-mounted RPE-choroid-sclera by immunolabeling for the cell-adhesion protein β-catenin.
MAIN OUTCOME MEASURES
Immunofluorescence and morphometry (quantitative analysis of outer nuclear layer, dendrite area, vessel area, acellular vessels, RPE cell size, number of nuclei per RPE cell, RPE cell eccentricity, and RPE cell solidity).
RESULTS
This novel RP model exhibits early onset and rapid rod degeneration, with the vast majority gone by P16. This pathology leads to retinal remodeling, including changes of inner retinal neurons, early activation of glia cells, degradation of retinal vasculature, and structural abnormalities of the RPE.
CONCLUSIONS
The pathology in our mouse model precisely mirrors human RP progression. The results demonstrate the significant role of the gamma subunit in maintaining phosphodiesterase activity and provide new insights into the disease progression due to deficiency.
FINANCIAL DISCLOSURES
Proprietary or commercial disclosure may be found after the references.
PubMed: 37363133
DOI: 10.1016/j.xops.2023.100332 -
Eye and Vision (London, England) Nov 2023Recent studies have indicated a strong correlation between endoplasmic reticulum (ER) stress and myopia and that eyedrops containing the ER stress inducer tunicamycin...
BACKGROUND
Recent studies have indicated a strong correlation between endoplasmic reticulum (ER) stress and myopia and that eyedrops containing the ER stress inducer tunicamycin (Tm) can induce myopic changes in C57BL/6 J mice. Therefore, this study aimed to create a new myopia model using Tm eyedrops and to explore the mechanism of ER stress-mediated myopia development.
METHODS
Three-week-old C57BL/6 J mice were treated with different concentrations (0, 25, 50, and 100 μg/mL) and/or number of applications (zero, one, three, and seven) of Tm eyedrops. Refraction and axial length (AL) were measured before and one week after Tm treatment. Scleral collagen alterations were evaluated under polarised light after picrosirius red staining. ER stress-related indicators, such as the expression of collagen I and cleaved collagen were detected using Western blotting.
RESULTS
Compared with the control group, mice administered eyedrops with 50 μg/mL Tm only once showed the greatest myopic shifts in refraction and AL elongation and reduced scleral expression of collagen I. Picrosirius red staining showed a lower percentage of bundled collagen in the Tm group. Expression of ER-stress indicators increased in the Tm groups. Furthermore, optimised administration of Tm induced matrix metalloproteinase-2 (MMP2) expression in the sclera, which plays a major role in collagen degradation.
CONCLUSIONS
We have demonstrated that ER stress in the sclera is involved in myopia progression. Tm eyedrops induced myopic changes, loosening of the scleral collagen and decreased expression of collagen I. This process may be associated with ER stress in the sclera, which upregulates the expression of MMP2 leading to collagen degradation.
PubMed: 37907982
DOI: 10.1186/s40662-023-00361-2 -
Clinical Ophthalmology (Auckland, N.Z.) 2023Sclerochoroidal calcification (SCC) is a rare disease which is characterized by calcium deposition in the sclera. The choroid is secondarily involved. Typical... (Review)
Review
Sclerochoroidal calcification (SCC) is a rare disease which is characterized by calcium deposition in the sclera. The choroid is secondarily involved. Typical localization is in the midperipheral region, outside the vascular arcades. SCC is mostly located in the superotemporal quadrant. Often times, the patients are referred with the diagnosis of an amelanotic tumor. SCC may be dystrophic or metastatic. Metastatic SCC lesions are associated with conditions altering calcium and phosphate metabolism including primary and secondary hyperparathyroidism, vitamin D intoxication, renal failure, hyperphosphatemia, and destructive bony lesions. SCC lesions have a characteristic appearance and appear as distinct, ill-defined, yellow-white, elevated scleral/choroidal masses funduscopically. The purpose of this literature review is to review the current knowledge on SCC, highlight the imaging features, and discuss the differential diagnosis as well as management options.
PubMed: 37720010
DOI: 10.2147/OPTH.S399058 -
Archivos de La Sociedad Espanola de... Dec 2023Nanophthalmos is a rare congenital condition of the eyeball that is characterised by a smaller size of the anterior and posterior segments without associated ocular... (Review)
Review
Nanophthalmos is a rare congenital condition of the eyeball that is characterised by a smaller size of the anterior and posterior segments without associated ocular malformations. Typical features that have traditionally been described in these eyes are short axial length, thickened sclera, cornea with a smaller diameter, narrow anterior chamber, and an increased lens to globe volume ratio. However, at present, there is still a lack of recognised diagnostic criteria for nanophthalmos and a classification of its severity. Its clinical relevance stems from the increased risk of multiple ocular conditions, such as high hyperopia, amblyopia, angle-closure glaucoma, retinal detachment, and cataracts. Likewise, in relation to surgery in these eyes, there are particularities in cataract and glaucoma surgery and with a greater risk of associated intra- and postoperative complications. In this way, the treatment of nanophthalmos focuses on controlling the associated eye conditions and reducing and controlling surgical complications. This review aims to update what has been published in recent years regarding nanophthalmos.
Topics: Humans; Microphthalmos; Glaucoma, Angle-Closure; Lens, Crystalline; Hyperopia; Vision, Ocular; Cataract
PubMed: 37813187
DOI: 10.1016/j.oftale.2023.10.003 -
Journal of AAPOS : the Official... Oct 2023Neonatal retinal hemorrhage is a common finding in newborns, but the underlying mechanisms are not fully understood. A computational simulation was designed to study the...
PURPOSE
Neonatal retinal hemorrhage is a common finding in newborns, but the underlying mechanisms are not fully understood. A computational simulation was designed to study the events taking place in the eye and orbit when the head is compressed as the neonate passes through the birth canal.
METHODS
A finite element model of the eye, optic nerve sheath, and orbit was simulated and subjected to forces mimicking rises in intracranial pressure (ICP) associated with maternal contractions during normal vaginal delivery. Resulting changes in intraocular pressure (IOP), pressure in the optic nerve sheath, and stress within the sclera and retina were measured.
RESULTS
During contractions, increased ICP was transmitted to the orbit, globe, and optic nerve sheath. IOP rose by 2.71 kPa near the posterior pole. Pressure at the center of the optic nerve sheath rose by 7.31 kPa and up to 9.30 kPa at its interface with the sclera. Stress in the retina was highest near the optic disk and reached 10.93, 10.99, and 13.28 kPa in the preretinal, intraretinal, and subretinal layers, respectively. Stress in the sclera peaked at 12.76 kPa.
CONCLUSIONS
Increasing ICP associated with natural vaginal delivery increases intraorbital pressure, which applies stress to the retina. Associated retinal deformation may cause tearing of the retinal vasculature. Increased pressure within the optic nerve sheath may occlude the central retinal vein, resulting in outflow obstruction and subsequent rupture. Forces accumulated near the optic disk, likely accounting for the tendency of neonatal retinal hemorrhage to occur posteriorly.
Topics: Female; Humans; Infant, Newborn; Retinal Hemorrhage; Optic Disk; Retina; Intraocular Pressure; Retinal Vessels
PubMed: 37722620
DOI: 10.1016/j.jaapos.2023.07.013 -
Vision Research Jul 2024Studies in animal models and humans have shown that refractive state is optimized during postnatal development by a closed-loop negative feedback system that uses... (Review)
Review
Studies in animal models and humans have shown that refractive state is optimized during postnatal development by a closed-loop negative feedback system that uses retinal image defocus as an error signal, a mechanism called emmetropization. The sensor to detect defocus and its sign resides in the retina itself. The retina and/or the retinal pigment epithelium (RPE) presumably releases biochemical messengers to change choroidal thickness and modulate the growth rates of the underlying sclera. A central question arises: if emmetropization operates as a closed-loop system, why does it not stop myopia development? Recent experiments in young human subjects have shown that (1) the emmetropic retina can perfectly distinguish between real positive defocus and simulated defocus, and trigger transient axial eye shortening or elongation, respectively. (2) Strikingly, the myopic retina has reduced ability to inhibit eye growth when positive defocus is imposed. (3) The bi-directional response of the emmetropic retina is elicited with low spatial frequency information below 8 cyc/deg, which makes it unlikely that optical higher-order aberrations play a role. (4) The retinal mechanism for the detection of the sign of defocus involves a comparison of defocus blur in the blue (S-cone) and red end of the spectrum (L + M-cones) but, again, the myopic retina is not responsive, at least not in short-term experiments. This suggests that it cannot fully trigger the inhibitory arm of the emmetropization feedback loop. As a result, with an open feedback loop, myopia development becomes "open-loop".
Topics: Humans; Myopia; Emmetropia; Retina; Refraction, Ocular; Animals; Feedback, Physiological
PubMed: 38705024
DOI: 10.1016/j.visres.2024.108402