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Animals ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 132
Author(s):  
Ahmed Abdelbaset-Ismail ◽  
Mohamed Aref ◽  
Shimaa Ezzeldein ◽  
Eslam Eisa ◽  
Mudasir Bashir Gugjoo ◽  
...  

The study investigated normal macromorphological and ultrasonographic features of the eye and lacrimal gland, as well as normal dacryocystorhinography of the donkey (Equus asinus) in Egypt. A total of 36 donkeys of different ages, weights, and sexes were included in the study: 21 live animals for ultrasonography and dacryocystorhinography, and 15 cadaver skulls for morphological anatomy of the lacrimal apparatus. The ultrasound biometric values of the eye were 33.7 ± 1.7 mm for axial globe length (AGL), 39.8 ± 2.1 mm for globe diameter (GD), 10.8 ± 0.7 mm for lens thickness (LT), 3.2 ± 0.7 mm for anterior chamber depth (ACD), and 19.3 ± 1.6 mm for vitreous chamber depth (VCD). The lacrimal gland was recognized as a hypoechogenic structure with an anechoic core, located at the dorsolateral aspect of the orbit, and ovoid in shape. The mean NLD length was 193.0 ± 9.8 mm by radiography and 206.0 ± 20.4 mm by gross assessment. One NL orifice (NLO) was noticed on each side, with a diameter of 3.0 ± 0.1 mm and located 12.1 ± 2.1 mm from the dorsal commissure of the nostril. These results may act as the baseline for proper management of conditions of the eye and lacrimal apparatus in the donkey in the future.


2021 ◽  
Vol 5 (1) ◽  
pp. e32-e43
Author(s):  
Obinwanne Junior Chukwuemeka ◽  
Damian C. Echendu ◽  
Isaura Ilorena D'Alva Brito dos Santos ◽  
Sharon Onwuka ◽  
Osazee Agbonlahor

Purpose: To determine if regional variation in post lens fluid reservoir thickness (PLFT) during scleral lens wear leads to regional variation in oxygen transmissibility and corneal edema during 4 hours of non-fenestrated scleral lens wear.Methods: About 20 healthy subjects (mean age, 28.8 ± 4.2 years) were fitted with nonfenestrated rotationally symmetric scleral lenses. Anterior segment optical coherence tomography was used to measure cornea thickness before and after lens wear, PLFT 10 minutes and 4 hours after lens application, and scleral lens thickness (with the scleral lens in situ) 4 hours after scleral lens application. These measurements were limited to the central 6 mm and divided into three zones (central, mid-peripheral, and peripheral zones). In the mid-peripheral and peripheral zones, eight principal meridians were measured, generating 17 measurement points in total. Scleral lens thickness and PLFT measurements were corrected for optical distortions by a series of equations. Oxygen transmissibility was calculated by dividing the scleral lens oxygen permeability by the optically-corrected scleral lens thickness, taking into account the oxygen permeability of saline and fluid reservoir thickness.Results: A significant regional variation in PLFT (F = 12.860, P = 0. 012) was observed after 10 minutes of the lens application, PLFT was thickest and thinnest in the inferotemporal and the superonasal region of the peripheral zones( 322.6 ± 161.8 µm and 153.8 ± 96.4 µm, respectively); however, this variation was not statistically significant at 4 hours of scleral lens wear (F = 4.692; P = 0.073). Despite significant regional variation in oxygen transmissibility (F = 48.472; P = 0.001) and relatively low oxygen transmissibility through the scleral lens, induced corneal edema did not vary significantly in different regions (F = 3.346; P = 0.126). In the central corneal region, the induced corneal edema correlated moderately with PLFT (r = 0.468; P = 0.037) and oxygen transmissibility (r = -0.528; P = 0.017). This relationship was insignificant in the peripheral cornea.Conclusion: The inferotemporal peripheral region had the thickest PLFT and least oxygen transmissibility, and the superonasal region had the vice versa. Despite significant variation in PLFT and oxygen transmissibility initially, in healthy corneas, this variation does not seem to induce statistically significant regional variation in corneal edema. Increased central PLFT and decreased oxygen transmissibility moderately correlate with central corneal edema.


2021 ◽  
Vol 8 ◽  
Author(s):  
Xiaoyu Xin ◽  
Qingge Guo ◽  
Shuai Ming ◽  
Changgeng Liu ◽  
Zhongfeng Wang ◽  
...  

Purpose: To study the association between axial length (AL) and the thickness of the lens, retina, choroid, and cone density with swept-source optical coherence tomography (SS-OCT) and an adaptive optics (AO) fundus camera.Design: A prospective cross-sectional study.Methods: This study included 136 eyes in 68 subjects. SS-OCT was used to quantify the thickness of the lens, ganglion cell complex (GCC) layer, inner nuclear layer (INL), outer retinal layer (ORL), and choroid layer. Adaptive optics was used to quantify spatial features of the cone photoreceptors, including density, spacing, regularity, and dispersion. The associations among the AL and the thickness of lens, retina, choroid, and cone features were evaluated with linear regression.Results: With the severity of myopia, the increased AL was associated with thinning of the lens (P < 0.001, 95% CI: −100.42 to −49.76). The thickness of the ORL and choroid decreased significantly (all P < 0.001), whereas the thickness of the GCC and INL decreased only in the outer ring (both P < 0.01). There was a significant correlation between the cone density/spacing and AL (both P < 0.001). Although cone density was reduced from 25,160/mm2 to 19,134/mm2 in the inner region and from 17,458/mm2 to 13,896/mm2 in the outer region, the best-corrected visual acuity (BCVA) was 20/20 or greater.Conclusions: We found that the lens thickness (LT), ORL, and cone density decreased in myopia. While decreasing cone density and ORL thickness should be related to axial elongation, decreasing of LT might imply intrinsic physical accommodation. These results provide further morphological changes of myopia.


The Eye ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 7-11
Author(s):  
N. Yu. Gorbunova ◽  
A. A. Voskresenskaya ◽  
R. A. Yakovlev ◽  
N. A. Pozdeeva

Relevance. Cataract surgeries are among the most frequently performed ophthalmic surgeries in the world. Despite the fact that they become less traumatic every year, such interventions are still accompanied by post-surgery complications, one of which is cystic macular edema (CME) or Irwin–Gass syndrome. Purpose. To analyze ocular biometric parameters in patients with CME. Material and Methods. The study included 40 patients (40 eyes) with post-surgery CME. All patients underwent ultrasound biometry, axial length measurement, crystalline lens thickness measurement with Bio&Pachy Meter AL-4000 (Tomey, Japan) and optical coherence tomography (OCT) with Cirrus HD-OCT 5000 (Carl Zeiss, Germany) to assess central foveal thickness. Depending on the axial length, all eyes were divided into “long” and “short” relative to the average axial length of 23.3 mm. The data was analyzed with STATISTICA 10 software (StatSoft Inc., USA). Results. The incidence of CME after uncomplicated cataract surgery in Cheboksary branch of the S. Fyodorov Eye Microsurgery Federal State Institution amounted to 0.002%. Axial length among patients with CME ranged from 20.53 mm to 25.4 mm; the average value amounted to 22.67 ± 1.05 mm. The majority of eyes were “short” – 31 eyes (77.5%), whereas 9 eyes (22.5%) were “long”. “Short” eyes exhibited a greater crystalline lens thickness (4.81 ± 0.53 mm) compared to “long” eyes (4.42 ± 0.42 mm) (рM-U = 0.014). Conclusion. The development of CME after uncomplicated cataract surgery is more often observed in eyes with axial length smaller than 23.3 mm.


2021 ◽  
pp. 112067212110644
Author(s):  
Ayşe Yağmur Kanra ◽  
Haşim Uslu

Objective To assess the biometric features of keratoconic eyes using the Lenstar LS900 and Pentacam systems relative to healthy myopic eyes. Materials and Methods Seventy-three eyes of keratoconic subjects and 83 eyes of control subjects were enrolled. To evaluate the reproducibility of the Lenstar and Pentacam devices’ measurements, keratometric readings [in flattest meridian (Kf), in steepest meridian (Ks), and mean (Km)], central corneal thickness (CCT), and anterior chamber depth (ACD) were obtained using both systems. Axial length and lens thickness (LT) were measured by the Lenstar. The compatibility between the two devices was investigated using the Bland-Altman statistical method. Results Axial length was longer in the myopic group than in eyes with keratoconus (24.94  ±  0.7 and 23.88  ±  0.96 mm, respectively, p  <  0.001). LT and vitreous depth were also higher in the myopic group, although ACD values were similar. Compared to the Lenstar, the Pentacam measured the ACD and CCT values higher in the myopia group [with a difference of 0.07  ±  0.12 mm ( p <0.001) and 4.47  ±  11.33 µm ( p   =   0.001), respectively] and measured the CCT values higher in the keratoconus group. Pentacam found all keratometry values significantly lower than Lenstar in the keratoconus group. Conclusions Axial length was longer in the myopic eyes due to the differences starting from the lens and extending to the posterior segment. Lenstar and Pentacam can be used interchangeably for Km, Kf, and ACD in the myopic group and only for ACD in the keratoconus group.


2021 ◽  
pp. 101534
Author(s):  
Zengying Wang ◽  
Yifei Meng ◽  
Zuocheng Wang ◽  
Lili Hao ◽  
Vania Rashidi ◽  
...  

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Omnia Talaat Abd elwahab ◽  
Dina Ezzat Mansour ◽  
Maged Maher Salib Roshdy ◽  
Ahmed Taha Ismail ◽  
Omnia Talaat Abd elwahab

Abstract Objective To study the axial length (AL) and white to white (WTW) corneal diameter in keratoconus (KC) eyes and compare them to normal eyes. Methods Sixty-three eyes of 53 patients were included in this cross-sectional observational study divided into KC group comprised of 28 eyes of 18 patients and control group comprised of 35 eyes of 35 patients based on clinical and tomographic findings. All subjects were examined using rotating Scheimpflug corneal tomography (Pentacam HR; Oculyzer II) for central corneal thickness (CCT), thinnest corneal thickness (TCT), keratometric values, anterior chamber depth (ACD) and lens thickness, and by optical biometry (IOLMaster 500) for axial length (AL) measurements. Vitreous cavity length (VCL) was calculated by subtracting the values of CCT, ACD (internal), and lens thickness from the AL. White to white (WTW) corneal diameter was measured using Placido-based tomography (Topolyzer VARIO). Results The mean age was 31.27±8.65 years(30.39 ± 9.31) in the KC group and .(31.74 ± 8.38) in the non KC group. The KC group included 28 eyes their mean spherical equivalent (SE) was -3.16 ± 2.42 and the control group 35 healthy eyes including 23 ametropic eyes with mean spherical equivalent (SE) (-3.95±4.50 D) and 12 emmetropic eyes with mean SE (-0.19±0.40 D). The mean VCL was significantly greater in normal eyes (17.45 ±1.34 mm) compared with KC (16.77±1.18 mm) (P = 0.037), while the mean ACD (internal) was significantly greater in KC eyes compared to normal (P = 0.020) and the lens thickness showed no statistically significant difference. The greater VCL in the normal group was compensated by the greater ACD in the KC group causing the total AL to have no statistically significant difference (normal eyes =24.44 ±1.38 mm and KC eyes= 24.21 ±1.31 mm) (P = 0.513). There was no statistically significant difference in the WTW corneal diameter between KC and normal eyes (11.81 ±0.35 mm in the normal group compared to 11.79 ±0.35 mm in the KC group) (P = 0.835). Conclusion VCL was significantly greater in normal eyes compared with those eyes with KC. AL and WTW showed no difference between the two groups.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tailiang Lu ◽  
Jike Song ◽  
Qiuxin Wu ◽  
Wenjun Jiang ◽  
Qingmei Tian ◽  
...  

AbstractTo examine the refractive lens power (RLP) and lens thickness and their associated factors in children from North-Western China. Children from two schools (primary school and junior high school) in the North-Western Chinese province of Qinghai underwent a comprehensive ophthalmic examination including biometry and cycloplegic refractometry. The RLP was calculated using Bennett’s equation. The study included 596 (77.9%) individuals (mean age: 11.0 ± 2.8 years; range: 6–16 years) with a mean axial length of 23.65 ± 1.24 mm (range: 20.02–27.96 mm). Mean lens thickness was 3.30 ± 0.16 mm (range: 2.85–3.99 mm) and mean RLP was 24.85 ± 1.98D (range: 19.40–32.97). In univariate analysis, girls as compared to boys had a significantly thicker lens and greater RLP, shorter axial length, smaller corneal curvature radius and shorter corneal curvature radius (all P < 0.001). Both sexes did not differ significantly in refractive error (P = 0.11) and corneal thickness (P = 0.16). RLP was positively associated with refractive error (correlation coefficient r = 0.33; P < 0.001) and lens thickness (r = 0.62; P < 0.001) and negatively with axial length (r =  − 0.70; P < 0.001). In univariate analysis, RLP decreased significantly with older age in the age group from age 6–13, while it plateaued thereafter, with no significant difference between boys and girls. In multivariate regression analysis, a higher RLP was associated with younger age (P < 0.001; standard regression coefficient β =  − 0.07), female sex (P < 0.001; β =  − 0.08), shorter axial length (P < 0.001; β =  − 0.48) and higher lens thickness (P < 0.001; β = 0.42). In Chinese children, RLP with a mean of 24.85 ± 1.98D decreases with older age, male sex, longer axial length, and thinner lens thickness. Changes in RLP and axial length elongation are important players in the emmetropization and myopization.


2021 ◽  
Author(s):  
Kira Lin ◽  
Tu Tran ◽  
Soohyun Kim ◽  
Sangwan Park ◽  
Jiajia Chen ◽  
...  

Purpose: To assess age-related changes in the rhesus macaque eye and evaluate them to corresponding human age-related eye disease. Methods: Data from eye exams and imaging tests including intraocular pressure (IOP), lens thickness, axial length, and retinal optical coherence tomography (OCT) images were evaluated from 142 individuals and statistically analyzed for age-related changes. Quantitative autofluorescence (qAF) was measured as was the presence of macular lesions as related to age. Results: Ages of the 142 rhesus macaques ranged from 0.7 to 29 years (mean=16.4 years, stdev=7.5 years). Anterior segment measurements such as IOP, lens thickness, and axial length were acquired. Advanced retinal imaging in the form of optical coherence tomography and qAF were obtained. Quantitative assessments were made and variations by age groups were analyzed to compare with established age-related changes in human eyes. Quantitative analysis of data revealed age-related increase in intraocular pressure, ocular biometry (lens thickness and axial length), and presence of macular lesions. Age-related changes in thicknesses of retinal layers on OCT were observed and quantified. Age was correlated with increased qAF. Conclusions: The rhesus macaque has age-related ocular changes similar to humans. IOP increases with age while retinal ganglion cell layer thickness decreases. Macular lesions develop in some aged animals. Our findings support the concept that rhesus macaques may be useful for the study of important age-related diseases such as glaucoma, macular diseases, and cone disorders, and for development of therapies for these diseases.


2021 ◽  
Author(s):  
Tailiang Lu ◽  
Jike Song ◽  
Qiuxin Wu ◽  
Wenjun Jiang ◽  
Qingmei Tian ◽  
...  

Abstract Purpose: To examine the refractive lens power (RLP) and lens thickness and their associated factors in children from North-Western China.Methods: Children from two schools (primary school and junior high school) in the North-Western Chinese province of Qinghai underwent a comprehensive ophthalmic examination including biometry and cycloplegic refractometry. The RLP was calculated using Bennett’s equation. Results: The study included 596 (77.9%) individuals (mean age: 11.0±2.8 years; range: 6-16 years) with a mean axial length of 23.65±1.24mm (range: 20.02-27.96mm). Mean lens thickness was 3.30±0.16mm (range: 2.85-3.99mm) and mean RLP was 24.85±1.98D (range: 19.40-32.97). In univariate analysis, girls as compared to boys had a significantly thicker lens and greater RLP, shorter axial length, smaller corneal curvature radius and shorter corneal curvature radius (all P<0.001). Both sexes did not differ significantly in refractive error (P=0.11) and corneal thickness (P=0.16). RLP was positively associated with refractive error (correlation coefficient r=0.33; P<0.001) and lens thickness (r=0.62; P<0.001) and negatively with axial length (r=−0.70; P<0.001). In univariate analysis, RLP decreased significantly with older age in the age group from age 6-13, while it plateaued thereafter, with no significant difference between boys and girls. In multivariate regression analysis, a higher RLP was associated with younger age (P<0.001; standard regression coefficient β=−0.07), female sex (P<0.001; β=−0.08), shorter axial length (P<0.001; β=−0.48) and higher lens thickness (P<0.001; β=0.42). Conclusions: In Chinese children, RLP with a mean of 24.85±1.98D decreases with older age, male sex, longer axial length, and thinner lens thickness. Changes in RLP and axial length elongation are important players in the emmetropization and myopization.


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