Eye Cataract Research Articles

Ocular disorders in a tertiary Hospital in South East Nigeria

The object of this study was to determine the pattern of ocular disease patients that presented to the Enugu State University of Science and Technology Teaching Hospital, Park Lane, Enugu, Nigeria. A retrospective study was conducted, where the medical case notes of patients who had ocular examinations, other clinical examinations, and investigations from April 2022 through December 2022 were retrieved. There were a total of 1145 patients, with a male population of 476 (41.6%), while females were 669 (58.4%). The mean age of the study population was 40.8 years, with a Standard Deviation (SD) of 22.4. A total of 924 (80.7%) participants were adults while children (aged 16 years and below) were 221 in number and constituted 19.3% of the study population. The most common eye disease was refractive error, which occurred in 266 (23.2%) of the participants; it was followed by allergic eye diseases, 201 (17.6%), cataract, 170 (14.9%), glaucoma, 111 (9.7%), and trauma to the eye, 94 (8.2%). Among the children, the most common eye disease seen were allergic eye diseases, 78 (35.3%), followed by refractive error, 70 (31.7%), trauma, 21 (9.5%), cataract, 11 (5.0%), while infections of the eye were 10 (4.5%). The most common eye disease among the adult participants was refractive error, 196 (21.1%), and then cataract, 159 (17.2%), allergic eye diseases, 123 (13.3%), glaucoma, 105 (11.4%), and retinal pathologies, 82 (8.9%). The most common causes of eye diseases in this study were refractive error, allergic eye diseases, cataracts, glaucoma, and trauma. Health education at community and primary health care level could help to reduce the number of people with avoidable causes of visual impairment.

Trace Element Concentration in the Blood and Aqueous Humor of Subjects with Eye Cataract.

Cataract, characterized by the opacification of the lens, is the leading cause of reversible blindness and visual impairment globally. The study aims to investigate the role of trace elements such as Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn in the development and severity of cataract. Elements were quantified by inductively coupled plasma mass spectrometry in blood and aqueous humor of 32 cataract cases and 27 controls living in the Latium region, Italy. The association between element concentration in blood and aqueous humor and cataract severity, gender, and age of subjects were also assessed. Results showed Cr levels significantly elevated in both blood and aqueous humor of cataract cases, with concentrations that increased with cataract severity. In addition, blood Pb levels were significantly higher in older cases and positively correlated with the age of cataract cases, while blood Co and Cu levels negatively correlated with cataract severity, suggesting changes in the levels of these elements. In conclusion, this study provides evidence of the involvement of specific elements in cataract development and severity, and the findings highlighted important avenues for future research. Understanding the biological mechanism underlying element-induced cataract may contribute to preventing cataractogenesis and providing targeted interventions.

Rationale for the application of modern magnetotherapy technologies for dry eye syndrome, glaucoma and cataract

Abstract. Purpose of the study. The article outlines the basic terms and concepts of information interactions of structures and systems of living organisms, provides a modern approach to the problems of optimizing medical rehabilitation through various methods of magnetic therapy, taking into account the biological effect and characteristics of the impact of various types of magnetic fields, and presents the pathogenetic conditionality of the use of magnetic techniques by means of the Ophthalmag device for the treatment of dry eye syndrome, glaucoma, and cataract.

Effect of Long-Acting Diquafosol Sodium on Astigmatism Measurement Repeatability in Preoperative Cataract Cases with Dry Eyes: A Multicenter Prospective Study.

Dry eye can compromise corneal astigmatism measurement repeatability during preoperative cataract surgery examination. No previous studies have analyzed the effectiveness of long-acting 3% diquafosol sodium (LA-DQS) on astigmatism measurement repeatability. This research assessed the effect of LA-DQS on astigmatism measurement repeatability in preoperative patients with cataract and short tear break-up time (TBUT) type dry eyes in both eyes of the same patient. Correlations between repeatability and TBUT, corneal high-order aberrations (HOAs), and corneal astigmatism magnitude were also analyzed. In total, 122 eyes (61 patients) with short TBUT-type dry eye were enrolled. Preoperatively, only one eye of all patients was treated with LA-DQS for 4 weeks. TBUT and corneal HOAs were checked using CASIA 2 before and 4 weeks post-treatment. The cylindrical power and meridian of astigmatism were measured at 3- and 4-week post-treatment using IOLMaster 700. Power vectors J0 and J45 were used for astigmatism calculations. Repeatability of astigmatism measurements was assessed as the within-subject standard deviation (Sw). The relative effects of TBUT and HOAs on J0 Sw and J45 Sw were also analyzed. Comparative changes in these variables were evaluated between treated and non-treated eyes, with additional analysis of their correlations. Treated eyes exhibited significant improvements in TBUT, HOAs, and post-treatment measurements of J0 Sw and J45 Sw at 3 and 4 weeks. In non-treated eyes, J0 Sw and J45 Sw showed significant correlation with TBUT and corneal HOAs. HOAs showed stronger relative associations with J0 Sw and J45 Sw than TBUT. In non-treated eyes, no significant correlation was found between cylindrical power and astigmatism measurement repeatability. In short TBUT-type dry eye, preoperative treatment with LA-DQS significantly improved astigmatism measurement repeatability. This may improve the precision of intraocular lens (IOL) power calculations regardless of the magnitude of corneal astigmatism, especially when toric IOLs are used.

Comparison of B-Scan ultrasonography, ultra-widefield fundus imaging, and indirect ophthalmoscopy in detecting retinal breaks in cataractous eyes.

To evaluate the diagnostic performance of B-scan kinetic ultrasonography (USG), standard ultra-widefield (UWF) imaging, and indirect ophthalmoscopy (IDO) in retinal break detection in cataractous eyes. We consecutively enrolled 126 cataract patients (including 246 eyes) with no comorbidities that could decrease best corrected visual acuity (BCVA). Three index tests (USG, nonmydriatic UWF, and mydriatic IDO) were performed preoperatively to screen for retinal breaks. One week after cataract extraction, a dilated IDO examination was repeated for the definitive diagnosis of retinal break as the reference standard. The sensitivity, specificity, Youden index (YI), and predictive values of each index test were calculated according to postoperative ophthalmoscopic findings. A deep-learning nomogram was developed to quantify the risk of retinal break presence using patients' baseline data and findings reported from preoperative ophthalmic tests. Fifty-two eyes (21%) were excluded from appropriate preoperative UWF imaging because of massive lens opacity. The BCVA cutoff point with maximum YI indicating UWF applicability was 0.6 logMAR (YI = 0.3; area under curve [AUC] = 0.7). Among all 246 eyes, preoperative IDO, USG, and UWF showed fair interobserver agreement (all κ > 0.2). According to postoperative IDO findings, the index tests with the highest sensitivity and specificity were USG (100%) and preoperative IDO (99%), respectively. For cataractous eyes without vision-impairing comorbidities, a BCVA better than 0.6 logMAR (Snellen acuity, 20/80) allows for appropriate nonmydriatic standard UWF imaging. In a high-volume clinic equipped with skilled ophthalmic examiners, screening with USG followed by directed IDO allows the efficient identification of retinal breaks in cataractous eyes.

Effectiveness of toric intraocular lens implantation for correcting irregular corneal astigmatism in cataract eyes

A retrospective cohort study was conducted to observe the correction effect of Toric intraocular lens (IOL) implantation in cataract eyes with specific types of irregular corneal astigmatism. Thirty-four eyes with either the "asymmetric bow-tie" pattern (Type I) or the "angled bow-tie" pattern (Type II) were included. Corneal topography was assessed using Pentacam HR, and changes in preoperative corneal astigmatism, visual acuity, manifest refraction, and objective visual quality were measured and compared. The average uncorrected distance visual acuity improved significantly from 0.86 ± 0.40 logMAR to 0.22 ± 0.15 logMAR (P < 0.001). Preoperative corneal astigmatism of 2.05 ± 0.90 D was corrected to a postoperative residual astigmatism of 0.78 ± 0.57 D (P < 0.001), with 32% of eyes within 0.50 D. The residual astigmatism prediction errors in Type I and Type II cases were (0.97 ± 0.68 D) and (0.66 ± 0.37 D), respectively (P = 0.100). The mean spherical equivalent prediction error in Type II cases (0.07 ± 0.36 D) was significantly smaller than that in Type I cases (− 0.29 ± 0.52 D) (P = 0.030). This study concludes that Toric IOL implantation effectively corrects specific types of irregular corneal astigmatism in cataract surgery. Eyes with the "angled bow-tie" pattern show higher accuracy in refractive predictions compared to eyes with the "asymmetric bow-tie" pattern.

CHEMICAL OCULAR INJURY BY POTASSIUM PERMANGANATE

Abstract Introduction &amp; Objectives : Chemical ocular injury is an emergency case and commonly occured among children. Alkaline chemical ocular injury is more destructive especially due to saponification. One of the rare chemical ocular injury is alkaline trauma by Potassium Permanganate (KMNO4) Methods : A case of a three-year-old boy patient brought by his mother in emergency department at Cicendo Eye Hospital with severe pain, redness, and swelling of the left eye. Ten hours earlier, the patient was playing and accidentally exposed to KMNO4. Visual acuity of the right eye was 6/6 and the left eye was difficult to examine. Ophthalmological examination revealed superior and inferior palpebra are swelling, KMNO4 adhered tightly on conjunctival tarsal superior, inferior, and conjunctival bulbi inferior until fornix and temporal area. Cornea was hazed and iris shadow test positive so he was diagnosed with Chemical Trauma Ropper Hall grade II OS. Treatment begins with irrigation 2 litres of normal saline until pH 7 along with debridement of KMNO4 from conjunctival tarsal superior inferior and bulbi. The patient underwent installation of transplanted amniotic membrane and debridement under anasthesia Results : Management in the initial phase is irrigation. The definitive therapy requires surgery to speed up the healing process. Complications that often occur are corneal limbal cell deficiency, dry eye, symblepharon formation, secondary glaucoma, and complicated cataracts Conclusion : Alkali chemical injury is hazardous and can lead to severe vision threatening complications because of saponification. Prompt and aggressive management is required in such cases to give them the best chance of a more favourable outcome

Dynamic Changes of Capsular-Intraocular Lens Adhesion in Plate-Haptic Hydrophilic and Loop-Haptic Hydrophobic Eyes.

The aim of this work is to investigate the dynamic changes of capsular-intraocular lens (IOL) adhesion in plate-haptic hydrophilic and loop-haptic hydrophobic eyes. Cataract eyes that met the inclusion criteria were randomly assigned to receive implantation of a plate-haptic hydrophilic or loop-haptic IOL. The anterior capsular adhesion, posterior capsular adhesion, and the configurations of the capsular bend were evaluated using swept-source optical coherence tomography at 1day, 1week, 1month, and 3months postoperatively. In total, 66 eyes of 66 patients were eligible for the analysis: 33 in the plate-haptic group and 33 in the loop-haptic group. The contact between the anterior capsule and IOL in the plate-haptic group was earlier than that in the loop-haptic group upon comparing the measurements taken at 1day and 1week (p = 0.001, p = 0.003, respectively). The complete attachment of the posterior capsule and IOL in the plate-haptic group was significantly greater at 1week, 1month, and 3months (p = 0.001, p = 0.000, p = 0.001, respectively). The capsular bend index of the plate-haptic group was significantly greater than that of the loop-haptic group at each time points except at 1day (p = 0.007, p = 0.049, p = 0.005, respectively). Furthermore, a new type of capsular bend, "cocked adhesion," was observed in the plate-haptic eyes. The plate-haptic IOL demonstrated excellent capsular adhesion compared to the loop-haptic IOL, which was probably attributed to haptic compressibility. A special cocked configuration of the capsular bend in plate-haptic IOL was observed for the first time. Further studies are warranted to confirm the effect of the new type of capsular bend.

Functional Approach to IOL Selection in Eyes With Combined Cataract and Keratoconus With an Option for Refractive Lens Exchange.

To evaluate spherical intraocular lens (IOL) implantation for cataracts in keratoconic eyes followed by optional refractive toric lens exchange to improve uncorrected visual acuity. This retrospective study evaluated cataract surgery outcomes in keratoconic eyes. Eyes treated with a spherical IOL targeted for -2.00 diopters (D) either achieved acceptable manifest refraction and desired exchange with a toric IOL (Group 1); achieved satisfactory manifest refraction and chose to use spectacles or contact lenses (Group 2); or did not achieve acceptable refraction and used contact lenses (Group 3). Group 4 had single-stage toric IOL implantation with plano target. Corrected and uncorrected distance visual acuity (CDVA and UDVA) and keratometry were analyzed. Groups 1 to 4 had 18, 23, 18, and 26 eyes, respectively. A staged toric exchange resulted in significantly better (P = .02) UDVA (mean: 0.15 logMAR; 20/25 Snellen) than initial toric IOL implantation (0.24 logMAR; 20/30 Snellen). All toric IOL exchange eyes achieved 20/30 or better CDVA and 94% had 20/40 or better UDVA. Mean manifest cylinder significantly decreased from 3.39 D before lens exchange to 1.10 D postoperatively. Initial implantation of a spherical IOL in keratoconic eyes allows basing toric calculations on the manifest refraction, which may be more reliable than keratometry measurements in keratoconic eyes. UDVA after staged toric IOL exchange was significantly better than after initial toric IOL implantation. Importantly, by staging use of toric lenses, the authors avoided cases where patients required a rigid contact lens after a toric IOL was implanted. [J Refract Surg. 2024;40(4):e207-e217.].

Comparison of the effect of 2 mL versus 3 mL sub-Tenon xylocaine injection on akinesia and analgesia in cataract patients at the University of Ilorin Teaching Hospital, Nigeria.

Sub-Tenon anesthesia is a form of local anesthetic techniques used in ophthalmic procedures, especially in cataract surgery. Few studies in our environment have reported the effects of sub-Tenon anesthesia on akinesia and analgesia as well as optimum volumes of anesthetic agents that are required for effective analgesia and akinesia. The objective of this study is to determine and compare the level of analgesia and akinesia and the effect of ocular compressions after sub-Tenon injection of 2 mL versus 3 mL of xylocaine among patients booked for cataract surgery in the University of Ilorin Teaching Hospital (UITH). A cross-sectional comparative study among cataract patients booked for surgery in the Department of Ophthalmology at UITH was carried out from March 2017 to August 2017. A total of 200 cataract patients that met the inclusion criteria were recruited into the study over 6 months. Lists of cataract patients booked for surgery formed the sampling frame. Questionnaires were administered to obtain information on sociodemographic, ocular symptoms, and other histories. Visual acuity was checked, and ocular examination was done with a pen-torch, ophthalmoscope, and slit-lamp examination with 78D. Tonometry and optic nerve assessments were done to exclude any patient with preexisting glaucoma or suspicious disc. About 200 patients were randomly allocated into one of two volume groups (Group 1 had 2 mL sub-Tenon xylocaine injection whereas Group 2 had 3 mL); level of analgesia and akinesia was checked 12 min and 15 min, respectively. The age range was 20-107 years; mean age for Group 1 was 63.8 ± 12.64, whereas the mean age of Group 2 was 64.14 ± 14.14. There was a slight female preponderance given a M:f of 1:1.4 and more than half of the patients presented with right eye (RE) cataract. Levels of analgesia 12 min after sub-Tenon injections in both groups were similar. However, two patients were found to have severe pain in Group 1, and no patients had severe pain in Group 2. The level of akinesia which was assessed 15 min after injection in both groups was found to be significantly better in Group 2. There was a slight female preponderance with about two-third of the total patients being female and the percentage of females who had no pain was more than the male, more than 50% of the patients had RE cataracts. Sub-Tenon anesthesia whether with 2 mL or 3 mL led to a statistically significant rise in intraorbital pressure (IOP); however, with ocular compression, the IOP was found to decrease below the preinjection pressure in both groups. Levels of analgesia were similar in the two groups, whereas akinesia was statistically better in the group that had 3 mL injection.

Risk Factor of Neovascular Age­related Macular Degeneration Progression after Cataract Surgery

The prevalence of late AMD, including neovascular AMD or geographic atrophy, and cataract in the same eye after age 80 years is estimated to be 12 and 68 %, respectively. There is currently no consensus on whether cataract surgery is beneficial or harmful for people with dry AMD. Although cataract surgery has been reported to provide better visual outcomes in eyes with AMD 6 months after surgery compared with previously followed eyes, it is unclear whether the timing of surgery relative to the start of AMD treatment influences long-term outcomes. The question of risk factors predisposing to the occurrence of exudation after cataract surgery in people with nAMD remains controversial.

Reduced Aqueous Humor Outflow Pathway Arborization in Childhood Glaucoma Eyes.

To compare aqueous humor outflow (AHO) pathway patterns between eyes of childhood glaucoma patients and non-glaucomatous patients receiving cataract surgery. Aqueous angiography was performed in childhood glaucoma eyes (n = 5) receiving glaucoma surgery and in pediatric (n = 1) and healthy adult (n = 5) eyes receiving cataract surgery. Indocyanine green (0.4%) was introduced into the anterior chamber, and AHO was imaged using an angiographic camera (SPECTRALIS HRA+OCT with Flex Module). Images were acquired and analyzed (ImageJ with Analyze Skeleton 2D/3D plugin) from the nasal sides of the eyes, the usual site of glaucoma angle procedures. Image analysis endpoints included AHO vessel length, maximum vessel length, number of branches, number of branch junctions, and vessel density. Qualitatively, childhood glaucoma eyes demonstrated lesser AHO pathway arborization compared to pediatric and adult eyes without glaucoma. Quantitatively, childhood glaucoma and healthy adult cataract eyes showed similar AHO pathway average branch lengths and maximum branch lengths (P = 0.49-0.99). However, childhood glaucoma eyes demonstrated fewer branches (childhood glaucoma, 198.2 ± 35.3; adult cataract, 506 ± 59.5; P = 0.002), fewer branch junctions (childhood glaucoma, 74.6 ± 13.9; adult cataract, 202 ± 41.2; P = 0.019), and lower vessel densities (childhood glaucoma, 8% ± 1.4%; adult cataract, 17% ± 2.5%; P = 0.01). Childhood glaucoma patients demonstrated fewer distal AHO pathways and lesser AHO pathway arborization. These anatomical alternations may result in a new source of trabecular meshwork-independent AHO resistance in this disease cohort. Elevated distal outflow pathway resistance due to decreased AHO pathway arborization may explain some cases of failed trabecular bypass surgery in childhood glaucoma.

Improving Accuracy of In-The-Bag Intraocular Lens Power Calculation in Adult Eyes with Unilateral Subluxated Lenses by Using the Anterior Chamber Depth of the Unaffected Eye

Introduction: This study aimed to determine the interchangeability of bilateral anterior chamber depth (ACD) in intraocular lens (IOL) power calculations for cataractous eyes and refractive outcomes using the unaffected fellow eye’s ACD in subluxated crystalline lenses. Methods: The predicted postoperative spherical equivalent (SE) calculated using the Kane formula with and without fellow eye’s ACD in 202 cataract patients was compared. Refractive outcomes of the newer formulas (the Kane, Barrett Universal II [BUII], and Pearl-DGS formulas) with affected eye’s ACD and with unaffected fellow eye’s ACD were compared in 33 eyes with lens subluxation (the affected eye) undergoing in-the-bag IOL implantation. The SD of the prediction error (PE) was assessed using the heteroscedastic method. Results: In 202 paired cataractous eyes, no marked ACD difference was found bilaterally; the predicted SE obtained without the fellow eye’s ACD was comparable with that calculated with the fellow eye one (p = 0.90), with a mean absolute difference of 0.03 ± 0.03 D. With the affected eye AL, keratometry, and ACD, the median absolute error (MedAE) was 0.38–0.64 D, and the percentage of PE within ±0.50 D was 30.30–57.58%. The unaffected eye’s ACD improved the results (MedAE, 0.35–0.49 D; the percentage of PE within ±0.50 D, 54.55–63.64%). The SDs of the BUII (0.82 D) and Pearl-DGS formulas (0.87 D) with the affected eye’s ACD were significantly larger than those of the Kane and Pearl-DGS formulas (both 0.69 D) with the unaffected eye’s ACD. Conclusion: Bilateral ACD was interchangeable in IOL power calculation for cataractous eyes when using the Kane formula. Unaffected eye’s ACD in lieu of affected eye’s ACD can enhance the accuracy of newer formulas in patients with unilateral subluxated lenses undergoing in-the-bag IOL implantation.

Effects and potential mechanisms of exercise and physical activity on eye health and ocular diseases.

In the field of eye health, the profound impact of exercise and physical activity on various ocular diseases has become a focal point of attention. This review summarizes and elucidates the positive effects of exercise and physical activities on common ocular diseases, including dry eye disease (DED), cataracts, myopia, glaucoma, diabetic retinopathy (DR), and age-related macular degeneration (AMD). It also catalogues and offers exercise recommendations based on the varying impacts that different types and intensities of physical activities may have on specific eye conditions. Beyond correlations, this review also compiles potential mechanisms through which exercise and physical activity beneficially affect eye health. From mitigating ocular oxidative stress and inflammatory responses, reducing intraocular pressure, enhancing mitochondrial function, to promoting ocular blood circulation and the release of protective factors, the complex biological effects triggered by exercise and physical activities reveal their substantial potential in preventing and even assisting in the treatment of ocular diseases. This review aims not only to foster awareness and appreciation for how exercise and physical activity can improve eye health but also to serve as a catalyst for further exploration into the specific mechanisms and key targets through which exercise impacts ocular health. Such inquiries are crucial for advancing innovative strategies for the treatment of eye diseases, thereby holding significant implications for the development of new therapeutic approaches.

К вопросу расчета ИОЛ у пациентов с витреоретинальной патологией

Purpose. To estimate the probability of a change in the calculated IOL after microinvasive vitrectomy 25G in patients with operated macular rupture. Methods. A retrospective analysis of patients operated on for a macular rupture with a diameter from 400 microns to 1000 microns was performed. The exclusion criteria were: the axial length of the eye is less than 22.0 mm and more than 26.0 mm, recurrence of previously operated macular ruptures, the presence of concomitant ocular pathology that can affect the final postoperative result (macular degeneration, glaucoma, diabetic and postocclusive retinopathy), the presence of previously performed surgical interventions on the retina. The study involved 64 eyes, of which 34,37 % (22 eyes) with a native lens; 14,06 % (9 eyes) with artifacia before vitrectomy; 6,25 % (4 eyes) vitrectomy with cataract phacoemulsification and IOL implantation and 45,31 % (29 eyes) cataract phacoemulsification with IOL implantation was performed within 4–9 months after primary vitrectomy. These patients were the study group. The comparison parameters are best corrected visual acuity, K1, K2, Ave. K1, Ave. K2, Axis, Ave. K2-K1, axial length of the eye, Ave. axial length of the eye, as well as calculated models of IOL and implantable after vitreoretinal surgery. Results. The change in the optical strength of the IOL occurred in 44,82 %. The change in the IOL model is 37,93 %. The change in the optical strength and model of the IOL is 20,68 %. The change in the optical strength of the previous IOL model is 24,1%. The change in the strong axis of more than 20 ° with the previous IOL parameters is 13,79 %. Only in 27,58 % there were no changes in the calculation of IOL. Conclusion. An individual approach to the calculation and selection of intraocular lenses in patients with vitreoretinal pathology allows implantation of all types of IOLs with maximum patient satisfaction with the functional result. Keywords: biometric indicators, IOL, vitrectomy, cataract, phacoemulsification, keratometry

Surrogate optimisation strategies for intraocular lens formula constant optimisation.

To investigate surrogate optimisation (SO) as a modern, purely data-driven, nonlinear adaptive iterative strategy for lens formula constant optimisation in intraocular lens power calculation. A SO algorithm was implemented for optimising the root mean squared formula prediction error (rmsPE, defined as predicted refraction minus achieved refraction) for the SRKT, Hoffer Q, Holladay, Haigis and Castrop formulae in a dataset of N = 888 cataractous eyes with implantation of the Hoya Vivinex hydrophobic acrylic aspheric lens. A Gaussian Process estimator was used as the model, and the SO was initialised with equidistant datapoints within box constraints, and the number of iterations restricted to either 200 (SRKT, Hoffer Q, Holladay) or 700 (Haigis, Castrop). The performance of the algorithm was compared to the classical gradient-based Levenberg-Marquardt algorithm. The SO algorithm showed stable convergence after fewer than 50/150 iterations (SRKT, HofferQ, Holladay, Haigis, Castrop). The rmsPE was reduced systematically to 0.4407/0.4288/0.4265/0.3711/0.3449 dioptres. The final constants were A = 119.2709, pACD = 5.7359, SF = 1.9688, -a0 = 0.5914/a1 = 0.3570/a2 = 0.1970, C = 0.3171/H = 0.2053/R = 0.0947 for the SRKT, Hoffer Q, Holladay, Haigis and Castrop formula and matched the respective constants optimised in previous studies. The SO proves to be a powerful adaptive nonlinear iteration algorithm for formula constant optimisation, even in formulae with one or more constants. It acts independently of a gradient and is in general able to search within a (box) constrained parameter space for the best solution, even where there are multiple local minima of the target function.

Effects of intraocular scatter on near peripheral vision.

Both cataracts and age-related macular degeneration (AMD) may occur with aging and are often developed simultaneously. We performed a study to better characterize the impact of induced scatter on the quality of vision in the near periphery, a region where individuals with AMD typically maintain their functional vision. We used an optical instrument as a cataract simulator based on projecting at the eye's pupil plane phase masks with controlled spatial properties generated with a spatial light modulator. The phase wavefronts were designed to accurately replicate the angular distribution of light intensity in the retina found in cataractous eyes with different severities. The induced amount of scatter ranged from values of straylight (S) from 10 to 85 degree2/sr, which corresponds from normal aging eye to advanced cataract stages. Mesopic visual acuity (VA) and contrast sensitivity (CS) at 3 cycles per degree were measured at the fovea and two retinal eccentricities (5 and 10 degrees in nasal visual field). We observed a consistent linear decline in VA (expressed in LogMAR) as the amount of induced scatter (quantified by the straylight parameter S) increased, both at the fovea and in the periphery. The effect of induced scattering on mesopic VA and CS at the fovea and the near periphery was evaluated. We found a relatively lower impact of scatter in the near periphery. This may explain the modest improvement in vision often found after cataract surgery in patients with AMD.

Ultrasonography and Postmortem Magnetic Resonance Imaging of Bilateral Ocular Disease in a Heifer

Bovine ocular diseases are typically characterized by the concurrent appearances of both macroscopic and intraocular abnormalities. This study examines the diagnostic efficacy of a combination of ultrasonography and magnetic resonance imaging (MRI) for the bilateral ocular disease observed in a 9-month-old Japanese Black heifer. This case presented with bilateral strabismus and a white-colored lens structure in the right eye. A combination of ultrasonography and MRI revealed formations of corn-like and V-shaped membranous structures within the vitreous cavities of the left and right eyeballs, respectively. In the right eye, a cataract was suspected on both ultrasonogram and MRI. This case involved bilateral retinal detachments and strabismus similar to the signs of an autosomal recessive hereditary ocular disease; however, the cataract in the right eye differed from that hereditary disease. Finally, in genetic analysis, a known mutation of the WFDC1 gene was not detected. Ultrasonography is superior to MRI in demonstrating intraocular pathological changes. On the other hand, MRI is helpful for evaluating invasiveness of the ocular lesions to the peripheral structures. Thus, the combined use of these imaging modalities is recommended for diagnosing various bovine ocular diseases.

Cell Penetrability of a γ-Crystallin Peptide Fragment from the Discarded Cataractous Eye Emulsion.

The efficiency of the intracellular transport of medication and target specificity is frequently hampered by biological obstacles. The potential for therapeutic use of peptide fragments from naturally occurring proteins is promising, as peptides exhibit high selectivity due to several possibilities of interaction with their target. Certain peptide sequences, often referred to as cell-penetrating peptides (CPPs), are those that can penetrate cell membranes. Our goal is to find these sequences in the discarded postcataractery surgery emulsion known as the cataractous eye protein isolate (CEPI). One peptide fragment from this discarded protein has been identified to be a potential CPP based on the similarities with other well-known CPPs. Cell membrane penetrability and cytotoxicity of the peptide have been investigated. Fibroblast cells were incubated with the fluorescently labeled peptide and were observed under fluorescence as well as under confocal microscopy. It was found that the peptide possesses a cell-penetrating ability.

Analysis of Paudyal’s “The Parrot in the Cage” and Sama’s “Don’t Cut down the Trees, Brother Woodcutter” from Ecological Perspectives

This paper analyzes the ecological reading of Paudyal’s “The Parrot in the Cage” and Sama’s “Don’t Cut down the Trees, Brother Woodcutter.” There are several factors of modernization responsible for the destruction of natural phenomena. The deterioration of flora and fauna has not been controlled though several government monitoring agencies have been actively working. There are limited research works on Nepali writers’ works regarding environmental issues. This study explores these two authors’ works to show how the deforestation and destruction of the wild lives take place. The findings of the study show that people are cutting down trees; hunters are hunting birds and animals; and the government is cutting down trees for constructing roads, airports, and city planning. Because of these causes, the ozone layer has been depleted; global warming has increased and people are suffering from skin cataracts; eye cataracts, and respiratory problems. The over-superiority complex of man has helped destroy the flora and fauna. Whatever change takes place in nature is irreversible. The study adopts the deep ecology theory that was propounded by Norwegian philosopher Arne Naess. This essay explains the causes and effects of deforestation. The study also analyses the related consequences of deforestation. This is explanatory research rather than exploratory. The main purpose of this paper is to minimize ecological degradation and environmental problems. The study also attempts to find necessary solutions like afforestation, reforestation, and alternative energy.