Keratometric Readings Research Articles

The Effect of Eyelid Laxity on Corneal Mapping and Corneal Topography.

To evaluate the effect of eyelid laxity on the structure of the cornea. This was a retrospective study performed in one institution. Patients with and without upper and lower eyelid laxity, which were determined using the snap-back test (SBT) and the upper eyelid distraction test (LDT), were evaluated for corneal structural changes with Scheimpflug imaging corneal tomography for the keratometric readings, and cor-neal spectral domain optical coherence tomography for the epithelial thickness (ET) measurements. The ET values were obtained using the statistics report for the superior quadrant (SET), the inferior quadrant (IET) within the 2- to 7-mm region, and central thickness (CET) within the 2-mm region. The minimum corneal thickness values within the central 5-mm region (MinCT) were also included in the study. Keratometric readings (in diopters), horizontal white-to-white (HWTW) measurements, pachymetry, and ET measurements were assessed along with the presence or absence of eyelid laxity. A total of 170 eyes from 85 patients were evaluated (50.6% with eyelid laxity, and 49.4% without eyelid laxity). There was no significant difference between the mean keratometric readings, HWTW, and the mean IET and CET values (P > .05); however, the difference was significant for the MinCT and SET (P < .05). A statistically significant negative correlation was found between the SET values and age, LDT, and SBT measurements (P < .05). A strong association was found between decreased SET and MinCT values and eyelid laxity. The possible reason for these decreases may be inflammation, which plays a role in the pathophysiology of eyelid laxity. [J Refract Surg. 2024;40(11):e783-e791.].

Five-year changes in retinal nerve fibre layer thickness in the adult population: a population-based cohort study.

Distinguishing between the pathological thinning of the retinal nerve fibre layer (RNFL) and age-related reduction requires a comprehensive understanding of the longitudinal changes in RNFL thickness within a healthy population. To determine five-year changes in RNFL thickness and associated factors in people aged 45-69 years. This report pertains to the second and third phases of the Shahroud Eye Cohort Study. Participants were recruited by a multi-stage cluster sampling in Shahroud, Iran. Data on demographic details, visual acuity, non-cycloplegic refraction, and slit-lamp biomicroscopy were collected. High-definition optical coherence tomography was employed for retinal imaging. A total of 1,524 eyes from 908 participants were examined. The average RNFL thickness was 92.2 ± 8.5 (95% CI: 91.6 to 92.8) and 93.1 ± 8.7 μm (95% CI: 92.5 to 93.7) in the first and second phases with a five-year mean change of 0.95 ± 4.15 μm (95% CI: 0.70 to 1.20). The RNFL thickness mean changes in the superior, inferior, nasal, and temporal quadrants were 2.51 ± 7.86 (95% CI: 2.01 to 3.02), 2.93 ± 7.39 (95% CI: 2.56 to 3.29), -0.53 ± 6.15 (95% CI: -0.84 to -0.21), and -1.01 ± 4.67 μm (95% CI: -1.27 to -0.75), respectively. The five-year changes in average RNFL thickness were inversely correlated with axial length (β = -0.69, p < 0.001), mean keratometry (β = -0.37, p = 0.017), and baseline RNFL thickness (β = -0.617, p < 0.001). In hyperopic individuals, the increase in average RNFL thickness (β = 0.65, p = 0.012) was significantly greater than in those with emmetropia. Macular volume (β = 1.65, p < 0.001) showed a direct association with five-year changes in average RNFL thickness. Over 5 years, RNFL thickness changes were clinically insignificant in the normal population. The mean RNFL thickness seems to remain stable unless there is ocular disease. However, increased axial length and steeper keratometric readings were linked to RNFL thinning. Those with thicker RNFL measurements were at higher risk of thinning over time.

Change in Axial Length and Astigmatism after Scleral Buckling in Patients of Rhegmatogenous Retinal Detachment

Purpose: To determine changes in axial length and corneal astigmatism caused by scleral buckling in patients of uncomplicated retinal detachment undergoing scleral buckling procedure. Study Design: Quasi-experimental design. Place and Duration of Study: Peshawar Medical College and Allied hospitals, Pakistan from December, 2020 to May, 2021. Methods: This study included60 patients of uncomplicated rhegmatogenous retinal detachment, recruited through consecutive sampling technique and managed with primary scleral buckling. After a detailed history and complete examination including A-scan and Keratometric readings, patients underwent scleral buckling procedure. Changes in axial length and corneal curvatureswere measured at 6 months follow up. Quantitative analysis was done using paired T test. Results: Mean age of the sample was 41.95±13.67 years. The sample consisted of 42 males and 18 females. Encircling Band was used in 46 patients, segmental circumferential tire was used in 58 patients in one or more quadrants depending on the extent of the retinal detachment. Two patients underwent additional surgeries. The pre-operative mean axial length (AL) was 23.44±1.51 mm and post-operative AL at 6 months was 24.25±1.61mm (p &lt; 0.05). The pre-operative and post-operative astigmatism were 1.08±0.43 and 1.75 ± 0.33 diopter respectively (p &lt; 0.05). Conclusion: Scleral buckling led to a significant increase in axial length and astigmatism over a 6-month period. These changes suggest that scleral buckling can alter the optical properties of the eye, potentially affecting visual acuity and requiring careful consideration of these factors in post-operative management.

Comparison of Mean Surgically Induced Astigmatism in Manual Small Incision Cataract Surgery Using Frown Vs Chevron Incision

Purpose: To compare the mean surgically induced Astigmatism(SIA) in Manual Small Incision Cataract Surgery (MSICS) using frown (inverted U) versus inverted V (chevron) incision. Study Design: Quasi experimental study. Place and Duration of Study: Hayatabad Medical Complex from 27th July 2018 to 27th January 2019. Methods: This study included 148 patients who were distributed into the Frown group (F) and Chevron group (C) by convenient sampling. Each group had 74 patients through block operative randomization. To eliminate bias, all the surgeries were performed by one surgeon having more than 5 years’ experience of MSICS. Pre-operative and Post operative keratometric readings were taken. SIA calculator was utilized, and data was analyzed through SPSS 26. Means and standard deviation for continuous variables like age and surgically induced astigmatism were calculated. Results: In Group F, mean surgically induced astigmatism was 1.14±0.65D and in Group C it was 0.87±0.55D. The independent T test revealed that the mean SIA was significantly lower in the Chevron group compared to the Frown group.The post operative visual acuities showed that the proportion of patients with postoperative 6/6 vision in the Chevron group was more as compared to group F. Conclusion: Chevron (inverted V) incision induces less postoperative mean surgically induced astigmatism than Frown (inverted U) incision in Manual Small Incision Cataract Surgery. These findings may have implications for cataract surgery techniques and may help in reducing postoperative astigmatism.

Comparison of axial length, keratometry and refraction between DNEye Scanner 2+ and Myopia Master

Purpose. The aim of this study was to compare axial length outcomes between DNEye Scanner 2+ and Myopia Master. For this purpose the two available software modules Rodenstock Consulting and CNXT were used for axial length calculation. Axial length results of both software modules were compared with each other as well as with the results of the Myopia Master, which were used as a reference. In addition, keratometry readings and objective refraction between both devices were compared and the repeatability was evaluated. Material and Methods. In this prospective study 62 patients were enrolled and measured three times each with DNEye Scanner 2+ and Myopia Master. Axial length, keratometric readings and objective refraction were determined as well as a subjective refraction. One eye per individual was randomly selected and considered in this study. Results. The mean differences of axial length comparing Consulting and Myopia Master is 0.52 ± 0.53 mm, comparing CNXT and Myopia Master it is 0.07 ± 0.50 mm and comparing Consulting and CNXT it is 0.44 ± 0.23 mm. For the mean corneal refractive power the mean differences between DNEye Scanner and Myopia Master yielded 0.01 ± 0.24 and −0.10 ± 0.22 D for the spherical equivalent of the objective refraction. Conclusion. Due to the considerable scatter in axial length between DNEye Scanner 2+ and Myopia Master as a reference, results of Consulting and CNXT cannot be proposed for use in myopia management. Differences in keratometry readings and objective refraction are statistically significant but clinically irrelevant. Keywords Axial length, keratometry, DNEye Scanner, Rodenstock Consulting, CNXT, Myopia Master

Comparison of Optical Biometry and Scheimpflug Device Keratometric Readings Accuracy in Predicting Intraocular Lens Power in Cataract Surgery

Abstract Background: A correct preoperative intraocular lens (IOL) power measurement in cataract surgery depends on accurate assessment of axial length (AL), anterior segment parameters, and using the suitable formula for the calculation of the power. Objectives: To determine the accuracy of IOL power calculations using keratometric measurements of the IOL Master compared to the Pentacam and to determine whether the results obtained can be used interchangeably in clinical practice in calculating IOL power in routine cataract surgery. Patients and Methods: In this prospective study, the biometric data including AL, keratometric readings, and anterior chamber depth (ACD) were obtained by both the IOL Master 500 and Pentacam Scheimpflug devices added to these measures the white-to-white (WTW) distance by IOL Master and central corneal thickness by Pentacam and calculation of the IOL power using SRK/T formula for the enrolled patients who undergone uneventful cataract surgery with IOL implantation. Postoperatively, spherical equivalent refraction was measured and the mean arithmetic error and the mean absolute error (MAE) for both keratometric readings were calculated to compare the accuracy between them in calculating the IOL power. Results: The study evaluated 57 eyes of 57 patient, the mean K value for the IOL Master was 43.92 (D) ± 1.5 (standard deviation [SD]) and the mean K value for the Pentacam was 43.77 (D) ± 1.7 (SD) (P = 0.62), ACD values between the two groups, was 3.19 ± 0.44 mm measure by IOL Master compared to 3.22 ± 0.48 mm in Pentacam (P = 0.769), with a very strong positive correlation between the two values (r = 0.995, P &lt; 0.001). MAE for the IOL Master was 0.230 (D) ± 0.187 (SD), while for the Pentacam was 0.255 (D) ± 0.204 (SD), with no statistically significant differences between two devices’ values (P = 0.54). Conclusions: Pentacam Scheimpflug measured keratometric and ACD data had good correlation with IOL Master data with good interchangeability between two devices readings in measuring the IOL power in routine cases of cataract surgeries.

Prevalence and associations of keratokonus among children, adults and elderly in the population‐based ural eye studies

Aims/Purpose: To estimate prevalence and associations of keratoconus in populations in Russia with an age from childhood to seniority.Methods: The study population consisted of the cohorts of three population‐based studies performed in urban and rural areas within the same geographical region in Bashkortostan/Russia: The Ural Children Eye Study (UCES; age: 6–18 years; n = 4890), Ural Eye and Medical Study (UEMS; age: 40+ years; n = 5314) and Ural Very Old Study (UVOS; age: 85+ years; n = 651). Based upon Scheimflug imaging, keratoconus was defined by a keratometric reading of ≥48 D in any eye.Results: The mean maximal and minimal corneal refractive power increased from the UCES (43.58 ± 1.50 dioptres (D) and 42.70 ± 1.42D, respectively) to the UEMS (44.26 ± 1.70 D and 43.61 ± 1.76D, resp.) and to the UVOS (45.1 ± 1.72D and 43.98 ± 1.68D, resp.). Correspondingly, keratoconus prevalence increased from the UCES (42/4890; 0.086%; 95% CI: 0.060, 0.112) to the UEMS (112/5314; 2.11%; 95% CI: 1.72, 2.49) and to the UVOS (42/651; 6.45%; 95% CI: 4.56, 8.34). In the UCES, higher keratoconus prevalence was associated (multivariable analysis) with higher birth order (OR: 2.34; 95% CI: 1.32, 4.15; p = 0.004), lower birthweight (OR: 0.99; 95% CI: 0.99, 0.99; p &lt; 0.001), and shorter axial length (OR: 0.15;9 5% CI: 0.08, 0.30; p &lt; 0.001). In the UEMS, keratoconus prevalence correlated with shorter axial length (OR: 0.15; 95% CI: 0.10, 0.23; p &lt; 0.001), larger corneal volume (OR: 1.17; 95% CI: 1.09, 1.25; p = 0.001), thicker lens (OR: 2.27; 95% CI:1.06, 5.28; p = 0.04), cortical cataract degree (OR: 1.02; 95% CI:1.01, 1.04; p = 0.01), and higher stage of age‐related macular degeneration (OR: 1.65; 95% CI: 1.09, 2.51; p = 0.02). In the UVOS, keratoconus prevalence correlated with lower educational level (OR: 0.84; 95% CI:0.71, 0.99; p = 0 0.04) and lower dynamometric hand grip force (OR: 0.92; 95% CI: 0.88, 0.97; p = 0.003).Conclusions: In this study on multiethnic groups from Russia, keratokonus prevalence increased from the paediatric group (0.09%) to the adult group (2.11%) and seniority group (6.45%), correlated mostly with biometric ocular parameters, and was in all age groups statistically independent of most systemic parameters.

Agreements' profile of Scheimpflug-based optical biometer with gold standard partial coherence interferometry.

To determine the agreement of ocular biometric indices including axial length, keratometric readings, anterior chamber depth, and horizontal corneal diameter between the Pentacam AXL and IOL Master 500. The study was a large cross-sectional population-based study (Tehran Geriatric Eye Study) conducted from Jan 2019 to Jan 2020. A total of 160 clusters were randomly selected proportional to size (each cluster contained 20 individuals) from 22 strata of Tehran city. All people aged 60y and above were invited to participate in the study. For all participants, preliminary ocular examinations were performed including the measurement of uncorrected and best-corrected visual acuity, objective and subjective refraction, anterior and posterior segment examinations. All participants underwent an ocular biometry using the Pentacam AXL and IOL Master 500. The 95% limits of agreement (LoA) between the two devices were -0.13 to 0.19, -0.15 to 0.17, and -0.13 to 0.19 in normal, pseudophakic, and cataractous eyes, respectively. With increasing the axial length, the difference between the two devices significantly increased in all three groups of normal, pseudophakic, and cataractous eyes (P<0.001). The 95% LoAs between the two devices regarding the mean keratometry shows that the best LoAs were seen in cataractous (-0.33 to 0.81) and followed by normal eyes (-0.36 to 0.86) and the pseudophakic eyes (-0.48 to 0.90) had the widest LoA. The 95% LoAs for horizontal corneal diameter measurements were -0.08 to 0.86, -0.03 to 0.83, and -0.07 to 0.87 in normal, pseudophakic, and cataractous eyes, respectively. The 95% LoAs of anterior chamber depth measurements between the two devices was -0.39 to 0.19 and -0.37 to 0.13 in normal eyes and cataractous, respectively. The Pentacam AXL has excellent agreement with the gold standard, IOL Master 500 in measuring axial length. In eyes with cataracts, the difference between the two devices is more scattered. With the increasing of axial length, the difference between the two devices increased, which should be considered when using Pentacam AXL.

Prevalence and Associations of Keratoconus Among Children, Adults, and Elderly in the Population-Based Ural Eye Studies.

To estimate prevalence and associations of keratoconus in populations in Russia with an age from childhood to seniority. The study population consisted of the cohorts of 3 population-based studies performed in urban and rural areas within the same geographical region in Bashkortostan/Russia: the Ural Children Eye Study (UCES; age = 6-18 y; n = 4890), the Ural Eye and Medical Study (UEMS; age = >40 y; n = 5314), and the Ural Very Old Study (UVOS; age = >85 y; n = 651). Based on Scheimflug imaging, keratoconus was defined by a keratometric reading of ≥48 diopters (D) in any eye. The mean maximal and minimal corneal refractive power increased from the UCES (43.58 ± 1.50 D and 42.70 ± 1.42 D, respectively) to the UEMS (44.26 ± 1.70 D and 43.61 ± 1.76 D, respectively) and to the UVOS (45.1 ± 1.72 D and 43.98 ± 1.68 D, respectively). Correspondingly, keratoconus prevalence increased from the UCES (42/4890; 0.086%; 95% CI = 0.060, 0.112) to the UEMS (112/5314; 2.11%; 95% CI = 1.72, 2.49) and to the UVOS (42/651; 6.45%; 95% CI = 4.56, 8.34). In the UCES, higher keratoconus prevalence was associated (multivariable analysis) with higher birth order [odds ratio (OR) = 2.34; 95% CI = 1.32, 4.15; P = 0.004], lower birth weight (OR = 0.99; 95% CI = 0.99, 0.99; P < 0.001), and shorter axial length (OR = 0.15; 95% CI = 0.08, 0.30; P < 0.001). In the UEMS, keratoconus prevalence correlated with shorter axial length (OR = 0.15; 95% CI = 0.10, 0.23; P < 0.001), larger corneal volume (OR = 1.17; 95% CI = 1.09, 1.25; P = 0.001), thicker lens (OR = 2.27; 95% CI = 1.06, 5.28; P = 0.04), cortical cataract degree (OR = 1.02; 95% CI = 1.01, 1.04; P = 0.01), and higher stage of age-related macular degeneration (OR = 1.65; 95% CI = 1.09, 2.51; P = 0.02). In the UVOS, keratoconus prevalence correlated with lower educational level (OR = 0.84; 95% CI = 0.71, 0.99; P = 0.04) and lower dynamometric handgrip force (OR = 0.92; 95% CI = 0.88, 0.97; P = 0.003). In this study on multiethnic groups from Russia, keratoconus prevalence increased from the pediatric group (0.09%) to the adult group (2.11%) and seniority group (6.45%), correlated mostly with biometric ocular parameters and was in all age groups statistically independent of most systemic parameters.

Modified technique for corneal laceration repair using amniotic membrane

Background Water-tight closure of lacerated corneal wounds may require a lot of sutures and result in significant corneal scarring and irregular astigmatism. Aim The aim of this study was to describe the technique of amniotic membrane (AM) onlay strip for corneal lacerations repair and to evaluate its outcome. Patients and methods This is a retrospective case series that included eight eyes with traumatic corneal lacerations. A strip of AM was applied to the corneal surface to cover the wound which was then sutured with 10/0 Nylon sutures involving the membrane. The sutures were well-spaced, and the suturing was avoided in the visual axis. Average keratometric (K) reading, keratometric astigmatism (KA), manifest refractive astigmatism (RA) in diopters (D), and spectacle or soft contact lens best corrected visual acuity (BCVA) were assessed 2 months after suture removal. Results Transient postoperative hypotony was encountered in five cases (62.5%). The average K was 44.61±2.81 D, KA 2.20±0.71 D, and RA 1.78±0.73 D (range=1–3 D). The postoperative LogMAR BCVA was 0.39±0.18 (range=0.22–0.70). Conclusions The application of AM inlay strip during repair of corneal lacerations was associated with good visual outcome possibly due to the reduction of wound and suture related corneal astigmatism.

First European results of a new refractive lenticular extraction procedure-SmartSight by SCHWIND eye-tech-solutions.

To evaluate vision 3 months after SmartSight lenticule extraction treatments. Case series. This case series of patients were treated at Specialty Eye Hospital Svjetlost in Zagreb, Croatia. Sixty eyes of 31 patients consecutively treated with SmartSight lenticule extraction were assessed. The mean age of the patients was 33 ± 6 years (range 23-45 years) at the time of treatment with a mean spherical equivalent refraction of -5.10 ± 1.35 D and mean astigmatism of 0.46 ± 0.36 D. Monocular corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA) were assessed pre- and post-operatively. Ocular and corneal wavefront aberrations have been postoperatively compared to the preoperative baseline values. Changes in ocular wavefront refraction, as well as changes in keratometric readings are reported. At 3 months post-operatively, mean UDVA was 20/20 ± 2. Spherical equivalent showed a low myopic residual refraction of -0.37 ± 0.58 D with refractive astigmatism of 0.46 ± 0.26 D postoperatively. There was a slight improvement of 0.1 Snellen lines at 3-months follow-up. Compared to the preoperative status, ocular aberrations (at 6 mm diameter) did not change at 3 months follow-up; whereas corneal aberrations increased (+0.22 ± 0.21 µm for coma; +0.17 ± 0.19 µm for spherical aberration; and +0.32 ± 0.26 µm for HOA-RMS). The same correction was determined using changes in ocular wavefront refraction, as well as changes in keratometric readings. Lenticule extraction after SmartSight is safe and efficacious in the first 3 months postoperatively. The post-operative outcomes indicate improvements in vision.

Clinical Results of Accelerated Iontophoresis-Assisted Epithelium-on Corneal Cross-linking for Progressive Keratoconus in Children.

To evaluate the clinical characteristics of pediatric patients with progression of keratoconus after accelerated iontophoresis-assisted epithelium-on corneal cross-linking (I-ON CXL) and to assess the efficacy and safety of re-treatment using accelerated epithelium-off CXL (epi-OFF CXL). Sixteen eyes of 16 patients (mean age: 14.6 ± 2.5 years) with keratoconus underwent I-ON CXL. The main outcome measures were uncorrected distance visual acuity, corrected distance visual acuity, maximum keratometry index (Kmax), minimum corneal thickness, elevation front and elevation back measured at the thinnest point, total higher order aberrations root main square (HOA RMS), coma RMS, and spherical aberration. An increment of Kmax greater than 1.00 diopter (D) and a decrease of greater than 20 µm in pachymetry were considered to determine the progression of keratoconus. Patients with progression of keratoconus after I-ON CXL were re-treated using an epi-OFF CXL protocol. Two years after I-ON CXL, 12 patients showed progression of keratoconus, whereas 4 patients were stable. There was significant worsening of Kmax (P = .04) and steepest keratometric reading (P = .01). Furthermore, a significant correlation was documented between progression of keratoconus and age (P = .02). These patients were re-treated using an epi-OFF protocol and after 2 years all patients were stable, and a statistically significant reduction of the mean Kmax (P = .007), HOA RMS (P = .05), and coma RMS (P = 05) was observed. I-ON CXL was ineffective in the treatment of pediatric keratoconus in younger children, whereas it had an efficacy of 2 years in older children. Re-treatment using epi-OFF CXL proved effective to halt progression of keratoconus after I-ON CXL failure. [J Pediatr Ophthalmol Strabismus. 2024;61(1):44-50.].

Role of swept-source anterior segment optical coherence tomography in imaging pediatric cataract

Purpose: To determine the morphology of pediatric cataracts and assess the status of the anterior and posterior capsules preoperatively on swept-source anterior segment optical coherence tomography (ASOCT) and compare the findings to those of intraoperative examination. Secondly, we aimed to obtain biometric measurements on ASOCT and compare them to those obtained on A-scan/optical methods. Methods: This was a prospective and observational study carried out at a tertiary care referral institute. ASOCT scans for anterior segment were obtained preoperatively for all patients, aged <8 years, scheduled for paediatric cataract surgery. The morphology of the lens and capsule and biometry were performed on ASOCT and the same were assessed intraoperatively. The main outcome measures were comparison of ASOCT findings to intraoperative findings. Results: The study included 33 eyes of 29 patients (range 3 months–8 years). The morphological characterization of cataract on ASOCT was accurate in 31/33 (94%) cases. ASOCT accurately identified fibrosis and rupture of the anterior and posterior capsules in 32/33 (97%) cases each. In 30% of eyes, ASOCT gave additional information preoperatively compared to the slit lamp. Intraclass correlation coefficient (ICC) calculation revealed a good agreement between the keratometry values obtained on ASOCT and those obtained preoperatively with a handheld/optical keratometer (ICC = 0.86, P = 0.001). Conclusion: ASOCT is a valuable tool that could provide complete preoperative information of the lens and capsule in pediatric cataract cases. In children as young as 3 months of age, intraoperative risks and surprises could be diminished. The keratometric readings are highly dependent on patient cooperation but show good agreement with the handheld/optical keratometer readings.

Assessment of the effect of Posterior Sub-capsular cataract on the refractive status of the eye at the outpatient department of Hayatabad Medical Complex, Peshawar

Introduction: Cataract-induced refractive change is the refraction change caused by a cataract. It can reach multiple diopters (D). It modifies expected refraction errors during cataract surgery by modifying axial length measurement.&#x0D; Objective: To find the effect of the Posterior subcapsular Cataracts on the refractive status of the eye.&#x0D; Methodology: A cross-sectional study was progressed in Eye OPD in Hayatabad Medical Complex, Peshawar. 102 patients having Posterior Subcapsular Cataracts were part of this study. The anterior segment was examined with a slit lamp for evaluation of the posterior subcapsular cataract. The refractive status of an eye having a posterior subcapsular cataract was determined using Retinoscopy and subjective refraction techniques. The axial length of the eye was measured using A-Scan. Keratometric reading was measured using Keratometer.&#x0D; Results: A total of 102 patients were included in this study. Of these, 27 were males and 75 were females. The mean age was 60.5 years with 5.8SD. Results from the study showed refractive error due to Posterior Subcapsular Cataracts were mainly myopic astigmatism and spherical myopia with 0.16SD. Patients with PSCs had myopic astigmatism with a mean value of (1.7diopters, 15.7%) with 0.93SD and spherical myopia with a mean value of (0.1D, 2.9%) with 0.67SD. &#x0D; Conclusion: The most common refractive error found in PSCs was Astigmatism followed by Myopia. These results may help to clarify the types of refractive errors in patients with PSCs and the prediction of visual outcomes with spectacles.

Comparison of anterior segment parameters in myopia with and without primary open-angle glaucoma.

To compare anterior segment parameters between myopes with and without primary open-angle glaucoma using Pentacam scheimpflug tomography. This was a single-center retrospective cross-sectional study. Records of patients examined with a Pentacam scheimpflug tomographer (Wavelight-Allegro Oculyzer, GmbH, Erlangen, Germany) were reviewed. Variables studied were recorded from the topographic map and included anterior chamber angle, anterior chamber volume, anterior chamber depth, keratometric readings, and corneal thickness. A general linear model for age-and spherical equivalent refraction-adjusted intergroup comparisons of the anterior segment parameters was conducted. The study included myopes previously diagnosed with primary open-angle glaucoma (POAG) [Mild defect, n = 81; Moderate-severe defect, n = 50] and non-glaucomatous myopes (n = 247). The results revealed a smaller anterior chamber angle, shallower anterior chamber depth, and flatter cornea curvature in the mildly glaucomatous group compared to the non-glaucomatous group (p < 0.05). Smaller anterior chamber angle, shallower anterior chamber depth, and thinner cornea thickness were also observed in the moderate-severely glaucomatous group compared to the non-glaucomatous group (p < 0.05). Glaucomatous damage in myopic patients with POAG was associated with comparatively small anterior chamber angle, shallow anterior chamber depth, flat cornea curvature, and thin cornea.

Deep anterior lamellar keratoplasty in keratoconus

Aims: To analyse the outcome of DALK in patients with keratoconus in terms of best corrected and uncorrected visual acuity, average K and topographic astigmatism. Settings and design: Prospective interventional case series study Material and methods: 28 eyes of 28 patients diagnosed with keratoconus were evaluated from August 2009 – July 2011 in a tertiary eye care hospital. All patients underwent DALK and outcomes were assessed on 4 parameters: Average Keratometric reading, topographic astigmatism, UCVA and BCVA alongwith epidemiological analysis. Statistical analysis used: ANOVA testing and Dunnett multiple comparison test. Results: We had evaluated 28 eyes of 28patients (10 males and 18 females) in the age group of 15 to 35 years. Cases were classified as moderate (4) and severe (24) category. There was a statistical significant decrease Average K and Topographic Astigmatism in post op period which was evaluated at 1, 3 and 6 months. (p value &lt;0.05). From the sample size, allof the patients showed improvement in visual acuity by more than one Snellens. No significant post operative complications occurred. Conclusion: DALK is a safe and effective treatment for severe keratoconus, corneal scarring and contact lens intolerance.

Stay-at-home myopia among school children during the COVID-19 pandemic

Background: Uncorrected myopia represents a major cause of visual disability in children, especially in low-income and middle-income countries. However, there is still debate about the effect of e-learning and “stay-at-home” guidelines on the refractive status of school children, especially in the absence of long-term follow-up data. This study aimed to assess the impact of stay-at-home enforcement during the COVID-19 pandemic on myopia development or progression in students in the Suez Canal Area, Egypt.&#x0D; Methods: This longitudinal observational study included 1650 students. All students aged 8–15 years with visual complaints, who had attended routine annual vision checks since 2018, were enrolled and assessed annually for myopia development and progression until 2021. Cycloplegic and noncycloplegic refraction, axial length (AL), corneal curvature, and uncorrected and best-corrected distance visual acuity were measured. The participants were administered a questionnaire that focused mainly on collecting information on their visual habits.&#x0D; Results: Our study included 3,300 eyes of 1,650 school students with myopia during the 4-year study period from 2018 to 2021. The mean cycloplegic spherical equivalents (CSE) were - 1.02, - 1.52, - 2.00, and - 3.50 diopters (D) in 2018, 2019, 2020, and 2021, respectively. This myopic shift in CSE over time was significant (P &lt; 0.001). The average keratometric reading (Avg K) increased significantly during the follow-up period (P &lt; 0.001). The Avg K measurements were 42.32, 42.62, 43.02, and 44.19 D in 2018, 2019, 2020, and 2021, respectively. The changes in Avg K were significant (P &lt; 0.001). The mean AL measurements were 22.53, 22.59, 22.69, and 22.71 mm in 2018, 2019, 2020, and 2021, respectively. Although statistically significant (P &lt; 0.001), changes in AL were clinically insignificant throughout the study period. The mean durations spent on electronic devices at home were 2.12, 2.46, 3.10, and 6.00 hours in 2018, 2019, 2020, and 2021, respectively. The changes over time were significant (P &lt; 0.001).&#x0D; Conclusions: During the COVID-19 pandemic, studying at home accelerated the degree of refraction toward myopia in school children in Egypt. Further studies are needed to assess the academic performance of students with progressive myopia.

Mean Change in Pterygium Induced Astigmatism in Patients Undergoing Pterygium Excision with Conjunctival Autograft

Purpose: To determine the mean change in pterygium induced astigmatism in patient undergoing pterygium excision with conjunctival auto graft. Study Design: Quasi Experimental Study. Place and Duration of Study: Department of ophthalmology Dow University of Health Sciences/CHK from March 2018 to November 2018. Methods: Thirty patients with pterygium were selected through non-probability consecutive sampling. All patients meeting inclusion criteria were enrolled after taking written consent. History of duration of symptoms and co-morbidity was taken. All surgeries were performed by consultant with more than 5 years’ experience with conjunctival auto graft under topical anesthesia. Patient was followed up after one week, 15 days and then monthly for four months with the final outcome at the end of fourth month. Difference between preoperative and postoperative astigmatism was taken as mean change. Data was analyzed on SPSS version 21. Mean and Standard deviation were calculated for all quantitative variables like age, astigmatism (keratometric reading) and duration of symptoms. Frequency and percentage was calculated for gender and grade of pterygium. P &lt; 0.05 was considered significant. Results: Mean age of the patients was 50.07 ± 12.48 years. There were 19 (63.33%) males and 11 (36.67%) females. Preoperative mean astigmatism was 3.70 ± 1.36 and postoperative mean astigmatism was 1.91 ± 0.97. Post-operative mean astigmatism was significantly low as compare to preoperative astigmatism (p = 0.0005). Conclusion: This study concludes that successful pterygium excision surgery reduces the pterygium induced refractive astigmatism and improves the visual outcome either by reducing the astigmatism or by removal of the pterygium from the visual axis as in Grade IV pterygium.

Influence of Specialty Contact Lens Wear on Posterior Corneal Tomography in Keratoconus Subjects.

To evaluate the effect of specialty contact lens (CL) wear on posterior corneal tomography in keratoconus subjects. Patients with keratoconus who were wearing specialty CL were included in this retrospective cohort study. Tomographic parameters were evaluated with Scheimpflug imaging (Pentacam HR) before lens fitting and immediately after removal of CLs worn habitually for a period of several months. Subjects were divided into groups, according to type of lens (corneal, scleral, and hybrid) and keratoconus severity based on Belin/Ambrosio D (BAD-D) score, for further analysis. Thirty-four eyes of 34 subjects diagnosed with keratoconus were included. Mean duration of habitual CL wear was 7.0±0.3 months. For the entire cohort, a small increase in flat keratometric reading at the anterior corneal surface (K1F; P =0.032) and at the posterior surface (K1B; P =0.041) was found. In the corneal CL group (10 eyes; 29.4%), flattening of the anterior corneal curvature was detected (K max ; P =0.015). An increase in K1B value was seen in the scleral CL group (15 eyes; 44.1%) ( P =0.03). Combined topometric indices showed a small but significant difference in the entire cohort ( P <0.05) and in the subgroups of corneal CL wear and of moderate keratoconus (BAD-D score≥7). Various types of specialty CLs exert a differential influence on corneal parameters. A small steepening of keratometry at the posterior surface (K1B) was observed in the scleral lens group. Although corneal lens wear flattens the anterior cornea (K max ), it does not significantly alter the posterior corneal surface.

Sensory and Motor Visual Functions in Parkinson’s Disease with Respect to Freezing of Gait Symptoms

Purpose: Investigating intraobserver and interobservers repeatability, reproducibility and limits of agreement of anterior corneal indices using three different topographers. Methods: Forty five participants were recruited, involved two examiners and two sessions. They were assessed in random order with EyeSys Vista, Medmont E-300 and manual keratometer. The corneal indices were horizontal keratometer, vertical keratometer, eccentricity and inferior superior index. Repeatability and reproducibility of corneal power measurements were assessed based on the intersession, intrasession, Intraclass Correlation Coefficient (ICC), Spearman’s correlations and agreement was evaluated by Bland Altman test (95% Limits Of Agreement, LoA). Result: All devices showed high repeatability (p &lt; 0.01) and reproducibility (ICC&gt;0.75) of the corneal indices. Multivariate analysis of variance showed nonsignificant findings between visits and examiners (p &gt; 0.05), while there was a significant difference between the devices among keratometric readings (p &lt; 0.0001). The differences between the EyeSys, Medmont and manual keratometer were significant (p &lt; 0.01). Moderate relationship was found between the keratometric readings with the three devices (r = 0.60, p &lt; 0.0001). The 95% LoA for EyeSys and Medmont of the keratometric readings were larger than those for the Medmont and manual keratometer (±0.3 mm). The eccentricity and inferior superior index measurements were not significantly different between the EyeSys and Medmont (p &gt; 0.01). Conclusion: All devices exhibited excellent repeatability and reproducibility. The EyeSys is portable, repeatable, and reliable and have stable interobservers variability. Although EyeSys would not be used interchangeably with the other two devices due to lower agreement, corrected linear calculation was suggested to manage the differences between the EyeSys and the two devices.