Mean Corneal Astigmatism Research Articles

Pre-existing Corneal Astigmatism in patients undergoing Cataract Surgery in Western Nepal; A hospital-based Unicentered, Comprehensive, Prospective Observational Study

Introduction: Cataract surgery is one of the most commonly performed surgical procedures worldwide. The final postoperative visual acuity is dependent on the pre-existing corneal astigmatism, accurate biometry and surgically induced astigmatism. Because of the increase in the patient’s demand for better postoperative visual acuity, it becomes important to evaluate the distribution of pre-existing corneal astigmatism in different populations. The objective of the study was to analyze the magnitude and pattern of pre-existing corneal astigmatism in cataract surgery patients in Western Nepal.Methods: A hospital-based cross-sectional descriptive study was carried out in the Department of Ophthalmology, Manipal Teaching Hospital, Pokhara. Three hundred and two patients undergoing routine cataract surgery between February 2016 and January 2018 were recruited in the study. Keratometric data from these patients were collected and were analyzed using the statistical software SPSS version 21.Results: The mean age of the subjects was 70.25 ± 10.97 years (range 35 to 94 years). There was a preponderance of females (62%) over males (38%). The mean corneal astigmatism was 0.78 ± 0.59 D (range 0.00 to 5.00 D). The pre-existing corneal cylinder ≥ 1.00 D was seen in 40.06% of patients. The corneal astigmatism was mainly against the rule (65.56%). The amount of corneal astigmatism and corneal steepness increased with age.Conclusion: Corneal astigmatism of 1.00 D or more was seen in 40.06% of the patients undergoing cataract surgery which should be corrected to meet the patient’s expectation for good, unaided visual acuity after cataract surgery.

Corneal and Ocular Residual Astigmatism in School-Age Children.

Purpose:To determine the distribution of residual and corneal astigmatism (CA) in children aged 6–18 years and their relationship with age, sex, spherical equivalent, and biometric parameters.Methods:In this cross-sectional study, multi-stage stratified cluster sampling was done to select students from Dezful, a city in Southwestern Iran. Examinations included the measurement of visual acuity with and without optical correction, refraction with and without cycloplegia, and biometry using the Biograph (Lenstar, Germany). The main outcomes in this report were corneal and residual astigmatism. The CA was measured by Biograph (difference between k1 and k2), and residual astigmatism was calculated using Alpine method. The power vector method was applied to analyze the data of astigmatism.Results:Of 864 students that were selected, 683 (79.1%) participated in the study. The mean residual and CA were -0.84 diopter (D) and -0.85 D, respectively. According to the results of J0 and J45 vectors, residual astigmatism was -0.33 D and 0.04 D, and CA was 0.38 D and 0.01 D, respectively. With-the-rule (WTR), against-the-rule (ATR), and oblique astigmatism were seen in 3.4%, 66.8%, and 4.5% of the children with residual astigmatism and 67.94%, 1.3%, and 1.5% of the children with CA. Residual astigmatism decreased with an increase in spherical refractive error, whereas CA increased with an increase in spherical refractive error.Conclusion:The results of the present study showed a high prevalence and amount of residual astigmatism with ATR pattern among the 6–18-year-old population and the compensatory effect of this type of astigmatism on CA that mostly followed a WTR pattern.

Prevalence and Age-Related Changes of Corneal Astigmatism in Patients Undergoing Cataract Surgery in Northern China.

Purpose To examine the magnitude, orientation, and age-related changes of corneal astigmatism of the eyes before cataract surgery. Setting. Hebei Eye Hospital, Hebei, China. Design A clinical-based retrospective study. Results The study consisted of 5662 eyes of 5662 consecutive cataract surgery patients with a mean age of 68.26 ± 10.39 (mean ± standard deviation (SD)) years (range 40 to 97 years), and 59.86% of the patients were women. Mean corneal astigmatism was 0.98 ± 0.76 diopter (D) (range 0.00–9.61 D). Corneal astigmatism of 0.50–0.99 D was the most common range of values (30.08%), followed by 1.00–1.49 D (22.15%), ≤0.50 D (21.21%), and 1.50–1.99 D (10.28%). There was a strong U-shaped relation between corneal astigmatism and age (p for nonlinearity <.01). With the increase of age, the astigmatism axis gradually changes from with-the-rule (WTR) to against-the-rule (ATR). Moreover, in young patients with age below 65 years, WTR astigmatism was negatively correlated with age, while ATR was positively correlated with age (r = −0.11, p=.001; r = 0.10, p=.010, respectively). However, in the old patients with age above and equal to 65 years, all types of astigmatism were positively correlated with age. Conclusion This study may provide valuable and practical information to surgeons when selecting the appropriate surgical method and toric intraocular lens (IOLs).

Impact of Eye Drops Instillation of Antihypertensive Drugs on the Refractive Power of the Cornea

Purpose: to assess effect of eye drops instillation on the refractive power of the cornea and potential intraocular lens (IOL) power calculation errors appearing related within.Patients and methods. There were 478 patients divided in 3 groups: 1st — patients without glaucoma and topical treatment (n = 325); 2nd — individuals with primary open angle glaucoma (POAG) on treatment (n = 122); 3rd — patients with POAG and previous trabeculectomy (TE) without using eye drops (n = 31). For each patient keratometry was performed by IOL-Master 500. Mean preoperative keratometry and corneal astigmatism were compared within IOL calculation error received by Barrett Universal II formula 1 month after phacoemulsification (PE).Results. Mean keratometry was significantly (p &lt; 0.001) less (0.6 D) at the 1st group (44.00 ± 1.96 D) versus 2nd group (44.6 ± 1.76 D). Cancellation of topical eye drops due to TE leads to insignificant decline of corneal curvature (from 44.6 ± 1.76 D to 44.1 ± 1.59 D). There was no any difference in corneal astigmatism level between study groups (0.92 ± 2.23 D, 0.8 ± 0.59 D and 0.86 ± 0.50 D for groups respectively) as like as no distinction in IOL calculation error in these groups (–0.08 ± 0.57 D, –0.06 ± 0.6 D and 0.003 ± 0.61 D). However, men have more flatter cornea (43.6 ± 1.98 D) than women (44.4 ± 1.80 D) (p &lt; 0.001). Mean keratometry at the age group 60–74 years was less (43.7 ± 2.3 D) than at 75–90 years (44.4 ± 1.54) (p = 0.002).Conclusion. Patients with coexistent cataract and glaucoma on treatment require special attention in IOL calculation. To avoid keratometric errors it is recommended to prescribe lubricants and change hypotensive eye drops to preservative-free analogs to form a stable tear film.

Relation of Corneal Astigmatism with Various Corneal Image Quality Parameters in a Large Cohort of Naïve Corneas.

PurposeTo investigate the relationship between corneal astigmatism and corneal image quality parameters (i.e., root mean square [RMS] of some major corneal higher order aberrations [HOAs] “namely RMS of coma aberrations, RMS of trefoil aberrations, and RMS of spherical aberration [RMS-SA]” and Strehl ratio [SR] of point spread function [PSF]) by using the Sirius topographer (CSO Italia, Florence, Italy).Patients and MethodsThis cross-sectional study used the Sirius topographer to evaluate the naïve corneas of right eyes (n = 1,356). The study included three groups which were based on the mean anterior corneal astigmatism value (group 1, <1 D; group 2, 1–2 D; and group 3, >2 D).ResultsThe corneal astigmatism showed statistically significant (yet narrow clinical) differences among the groups regarding all the examined parameters (P<0.001), except for the RMS-SA (which was statistically insignificant among the three groups). Correlation coefficients were weak between the corneal astigmatism and HOAs (correlation coefficient “r” not reaching 0.2 with any of the evaluated HOAs).ConclusionSignificant differences existed among the astigmatic groups regarding corneal HOAs, but the mean values were very close. The deduced relations between corneal astigmatism and corneal image quality parameters had limited clinical relevance. Thus, the corneal astigmatism should be evaluated separately from corneal image quality parameters, either when deciding between refractive correction modalities (customized versus optimized ablation techniques) or when evaluating corneal image quality of a naïve cornea.

Clinical outcomes of Ankoris toric intraocular lens implantation using a computer-assisted marker system.

To report the clinical outcomes of patients who underwent cataract surgery with implantation of Ankoris monofocal toric intraocular lens (IOL) (PhysIOL SA, Liège, Belgium) using the Zeiss Callisto Eye (Carl Zeiss AG, Dublin, CA). We conducted a retrospective case series of patients who underwent routine cataract extraction and implantation of Ankoris toric IOL using the Zeiss Callisto eye between January 2018 and December 2018 by four senior surgeons. Patients' medical records were reviewed, and clinical outcomes including postoperative refraction, visual acuity outcomes, IOL position and deviation from planned axis were collected. Fifty-six eyes of 56 patients were included, 48% were female, and the mean age was 70 ± 8years. Patients with pseudoexfoliation syndrome, glaucoma or keratoconus were excluded from the study. Pre-operative mean corneal astigmatism was 2.38 ± 0.78 diopters (D), and mean implanted IOL cylindrical power was 3.06 ± 1.07 D. IOL rotation 30days postoperatively was within 5° in 82% of eyes and between 6° and 10° in 10.8% of eyes. Mean postoperative refractive astigmatism 30days postoperatively was 0.22 ± 0.36D; in 84% of eyes the postoperative refractive astigmatism was ≤ 0.50D. IOL rotation significantly increased between day 1 to day 7 postoperatively (1.91 ± 3.15° to 3.18 ± 3.3°, P = 0.001). However, no significant rotation had occurred between day 7 and day 30 postoperatively (P = 0.093). Cataract surgery with implantation of Ankoris monofocal toric IOL using the Zeiss Callisto Eye marking system is predictable and effective in reducing refractive astigmatism.

Analysis of Age, Gender, and Refractive Error-Related Changes of the Anterior Corneal Surface Parameters Using Oculus Keratograph Topography.

Purpose:To assess refractive error, gender, and age-related differences in corneal topography of a normal population with Oculus Keratograph 4.Methods:This cross-sectional study included a total of 500 normal eyes of 500 individuals with ages ranging from 10 to 70 years. All participants underwent detailed ocular examinations, including visual acuity measurement, slit-lamp examination, and refractive error evaluation. Slit-lamp examination was performed for all individuals to rule out apparent corneal diseases. Corneal topography parameters were assessed using Oculus Keratograph. The data were analyzed based on gender, refractive error, and age groups using independent sample t-test and one-way analysis of variance.Results:Of a total of 500 participants (age: 29.51 ± 11.53 years) recruited for the present study, 66.4% were female, and 33.6% were male. The mean spherical equivalent of refraction was − 0.98 ± 1.65 diopters. Significant differences were noted in steep keratometry (P = 0.035) and corneal astigmatism (P = 0.014) between genders. Assessment of the data based on refractive error revealed significant differences in an index of vertical asymmetry (P < 0.001), index of height asymmetry (P = 0.003), and index of height decentration (P = 0.011). Considering age groups, significant differences were observed in flat keratometry readings (P < 0.001), mean corneal astigmatism (P = 0.02), minimum radius of curvature (P = 0.037), and apex power (P < 0.001).Conclusions:There was a prominent variation in some topographic parameters based on gender, age, and refractive error. The information on corneal parameters obtained with Oculus Keratograph from normal eyes provides a reference for comparison with diseased corneas.

Characterising keratometry in different dog breeds using an automatic handheld keratometer.

BackgroundKeratometry is clinically important and is routinely performed as part of human ophthalmic examination. In veterinary ophthalmology, little is known about keratometry in dogs, and its practical application has been limited. The present study aimed to describe keratometry in some dog breeds popular in Japan using a handheld keratometer.MethodsClient-owned dogs of various signalment were enrolled prospectively in the keratometry examination. Interbreed variations in mean corneal curvatures (R1R2avg) and corneal astigmatism (Δ(R1−R2)) were evaluated statistically with respect to their bodyweight based on the data which fulfilled the predetermined inclusion criteria. P<0.05 was considered statistically significant.ResultsOn examination of 237 dogs from 16 different breeds, R1R2avg (mean±sd) ranged from 7.54±0.30 mm in Pomeranians to 9.28±0.19 mm in golden retrievers. Δ(R1−R2) (mean±sd) ranged from 0.22±0.11 mm in miniature schnauzers to 0.57±0.30 mm in French bulldogs.ConclusionThe present study successfully described keratometry in 16 dog breeds. The study revealed considerable interbreed variations in both R1R2avg and Δ(R1−R2), which did not necessarily correlate with bodyweight. These results are useful both clinically in fitting contact lenses in the management of corneal diseases and non-clinically in optometric studies in dogs.

Comparison of long-term results after manual and femtosecond assisted corneal trephination in deep anterior lamellar keratoplasty for keratoconus.

To compare long-term postoperative outcomes of manual and femtosecond assisted corneal trephination in deep anterior lamellar keratoplasty (FS-DALK) for keratoconus. In the retrospective study, 17 consecutive eyes that underwent vertical side cut incision FS-DALK and 22 eyes that underwent trephine incision DALK were collected over a 2-year period. Main measurements included postoperative uncorrected-visual acuity (UCVA), corrected distance visual acuity (CDVA), refractive sphere and cylinder, manifest refraction spherical equivalent (MRSE), flat and steep corneal keratometry (K1 and K2), endothelial cell density (ECD), and time of epithelium healing and suture removal. Groups were comparable for diagnosis and preoperative visual acuity. Follow-up averaged 23mo (range, 12-36mo). At 12mo, the mean UCVA was better in the manual-DALK group (P=0.039), and the refractive sphere was lower in the FS-DALK group (P=0.040). MRSE between groups differed at 1, 6, and 12mo postoperatively (P=0.047, 0.025, 0.042, respectively). Mean CDVA, cylinder, K1, K2, corneal astigmatism, ECD, and time of epithelium healing were similar between groups. Stability of MRSE, ECD, and K1 returned sooner after FS-DALK. Initial loosened suture removal time was earlier in the manual-DALK group (P=0.042) while complete suture removal time was similar (P=0.122). Manual and femtosecond assisted corneal trephination in DALK are options for advanced keratoconus. FS-DALK do not result in improved visual acuity but it is more stable during the follow-up period. FS-DALK in the present form show limited benefit, so surgical design and parameters still need to be optimized and explored.

Evaluating Refractive and Visual Outcomes After Bilateral Implantation of an Apodized Diffractive Multifocal Toric Intraocular Lens with a Moderate Add in the Dominant Eye and a Higher Add in the Fellow Eye.

PurposeTo review refractive, visual acuity, defocus curve and subjective visual quality results after bilateral implantation of an apodized diffractive toric intraocular lens (IOL) with a moderate add in the dominant eye and a higher add in the non-dominant eye.SettingOne site in Gainesville, GA, USA.DesignSingle arm, non-randomized prospective study.MethodsThis was a single-arm prospective study of visual acuity and subjective visual quality after implantation of a toric low-add apodized diffractive multifocal IOL in the dominant eye and a higher add IOL of the same type in the non-dominant eye three months after surgery. Binocular visual acuity at 4 m, 60 cm and 40 cm was tested. Other tests included refraction, defocus curve measurement and evaluation of the quality of vision. Toric IOL orientation was also measured.ResultsA total of 29 subjects were enrolled. There were no statistically significant differences in the mean keratometry, corneal astigmatism or IOL sphere power implanted in the dominant and non-dominant eyes. Vision was preferred without any correction in more than half of the eyes tested (32/58, 55%). The residual refractive astigmatism was ≤ 0.50 D in 100% of eyes. Seventy-five percent of subjects (22/29) had 0.10 logMAR (20/25 Snellen) binocular uncorrected visual acuity at all tested distances. Glare and haloes were the most common visual disturbances, but most subjects (22/29, 76%) reported that they were not bothered by any visual disturbances. In 97% of eyes (56/58), the measured difference in orientation between 1 month and 3 months was less than 5 degrees, with no change more than 14 degrees.ConclusionThis blended bifocal IOL modality appears to be well-tolerated by subjects with a good range of vision and minimal bother from visual disturbances.

Pattern of corneal astigmatism induced by primary pterygium in patients with cataract in a secondary hospital in Southern China: a cross-sectional study

ObjectivesTo review the pattern of primary pterygium-induced corneal astigmatism in patients with cataract in a southern Chinese population.DesignClinic-based cross-sectional retrospective study.SettingA secondary hospital at southern China.ParticipantsA group of 1689 eyes...

One-piece mushroom keratoplasty outcomes

To clinically evaluate the results of one-piece mushroom-shaped keratoplasty. A total of 10 patients (10 eyes) were enrolled, all having corneal perforations and deep stromal opacities with involvement of Descemet's membrane. For transplantation, hypothermic preserved donor corneas with mean endothelial cell density of 2896±327 cells per 1 mm2 were used. Surgical technique. Recipient tissues as well as the graft were cut with the Moria trephine. For that, the 8.5-mm blade was replaced by a 6.5-mm one and vice versa, respectively, with attention paid not to violate the vacuum while making the cuts. Transparent cornea engraftment was achieved in all patients. Best corrected visual acuity averaged 0.55±0.22. Spherical component of refraction varied from -4.25 to +2.75 diopters. Mean corneal astigmatism was 3.35±1.73 diopters. At 6 months after surgery, the mean endothelial cell density was 2355±336 cells/mm2, at 1 year - 2141±304 cells/mm2. One-piece mushroom keratoplasty is an effective surgical treatment of corneal perforations and deep stromal opacities with involvement of Descemet's membrane that ensures a high rate of transparent corneal engraftment. The use of the Moria vacuum trephine in combination with blades of different diameters and secure fixation of the vacuum part of the trephine eliminate the risk of the 'mushroom stem' decentration relative to its 'head'.

Clinical outcomes after femtosecond laser-assisted implantation of an intrastromal corneal ring segment with a 340-degree arc length in postkeratoplasty patients: 12-month follow-up.

To assess the clinical outcomes after implantation of a new 340-degree arc length intrastromal corneal ring segment (ICRS) aided by the femtosecond laser in postkeratoplasty patients after a 12-month follow-up. Private practice, Brasilia, Brazil. Prospective case series. Eyes with previous keratoplasty had ICRS implantation assisted by femtosecond laser. The primary outcome measure was the change in the uncorrected distance visual acuity (UDVA) 12 months postoperatively. The secondary outcome measures were the corrected distance visual acuity (CDVA), refraction, and corneal tomography 1, 3, 6, and 12 months postoperatively. The astigmatism results were analyzed using vector analysis through the double-angle polar plot. Of the 18 patients, 7 (38.9%) were men, and 11 (61.1%) were women. The mean UDVA was 20/250 (1.15 logarithm of the minimum angle of resolution [logMAR]) before implantation and 20/70 (0.54 logMAR) at the last follow-up (P < .001). The mean CDVA improved from 20/35 (0.26 logMAR) to 20/25 (0.10 logMAR) (P < .001). The mean spherical equivalent and astigmatism components were significantly reduced after ICRS implantation. The mean corneal astigmatism decreased from 5.55 ± 2.29 D preoperatively to 3.92 ± 1.82 D postoperatively (P < .001). The CDVA remained the same or improved in 19 of 20 eyes and decreased by 1 line in 1 patient. There were no surgical complications. A new ICRS with a 340-degree arc length was effective in treating postkeratoplasty eyes, improving visual acuity and reducing corneal astigmatism.

Penetrating Keratoplasty for Keratoconus in Vietnamese Patients.

BACKGROUND:Keratoconus is an ectatic corneal disorder that can impair the visual acuity. Up to now, penetrating keratoplasty (PK) remains the most common surgical procedure to treat severe keratoconus. In Vietnam, most keratoconus patients come to visit doctor at severe stage and were treated by PK, so we conduct this study.AIM:To evaluate the results of PK for keratoconus in Vietnamese patients.METHODS:This was a retrospective study of 31 eyes with keratoconus who underwent PK in VNIO from January 2005 to December 2014.RESULTS:The average visual acuity was 0.86 ± 0.37 logMAR (20/145). In the group of patients without amblyopia, best spectacle-corrected visual acuity of 20/60 or better was recorded in 75.9% of eyes and 93.1% of eyes achieved a best corrected visual acuity with hard contact lenses of 20/40 or better. Mean postoperative corneal power was 43.8 ± 4.5D. Mean corneal astigmatism was 5.9 ± 2.7D. 94.6% of grafts remained clear. Posterior subcapsular cataract developed in 22.6% of eyes. Graft rejection was recognized in 12.9% of eyes.CONCLUSION:PK is an effective procedure with high rate of graft survival for keratoconus patients. However, patients should be aware of the necessary of optical correction to gain the best VA after surgery.

Factors predicting change in corneal astigmatism following suture removal in post-penetrating keratoplasty patients.

PurposeTo identify factors predicting corneal astigmatic change following suture removal in post-penetrating keratoplasty patients.Patients and methodsThis cross-sectional study included the data of 33 events of corneal suture removal from 27 post-penetrating keratoplasty patients. Sutures were removed from the steep axis of transplanted cornea with 16 interrupted corneal sutures. Corneal astigmatism was measured before and after suture removal using ORBSCAN II. Patients’ demographic data and corneal biomechanics parameters obtaining from the Corvis ST were recorded. The changes in corneal astigmatism were calculated using vector analysis. The correlation between changes in corneal astigmatism and the potential factors was evaluated using Spearman’s correlation coefficient and linear regression model.ResultsThe mean corneal astigmatism before and after suture removal was 7.1±3.7 diopters (D) and 5.5±3.2D, respectively. The mean astigmatic change was 7.0±6.3D (range, 0.3–30.8D) by vector analysis at 9.7±5.5 weeks after suture removal. Change in corneal astigmatism was significantly correlated with pre-suture removal astigmatism (Rs=0.47, P=0.01). There was no correlation between the donor-recipient trephine diameter difference, the duration from corneal transplantation to suture removal, the number of removed sutures with the change in corneal astigmatism, and corneal biomechanics parameters (P>0.05). Linear regression is given by the following equation: astigmatic change (D)=1.05x pre-suture removal astigmatism (D) - 0.43.ConclusionThe astigmatic change after corneal suture removal in post-keratoplasty patients was significantly correlated with pre-suture removal astigmatism. These findings will permit a validated approach for reducing corneal astigmatism in post-keratoplasty patients.

Biometry characteristics in congenital cataract patients before surgery in a tertiary eye care centre in Nepal

PurposeTo evaluate the anterior segment biometry characteristics in congenital cataract patients before undergoing surgery in a tertiary eye care centre. MethodsWe retrospectively reviewed the charts of congenital cataract patients aged less than 15 years who had undergone the congenital cataract surgery from Jan-Dec, 2015. 451 eyes of 351 patients were reviewed. The eyes were examined using an autorefract-keratometer, applanation A-scan and parameters like keratometry, axial length, corneal astigmatism were noted. ResultsThe mean age at the surgery was 92.4 ± 4.13 months (range 6 months to 15 years). The ratio of boys to girls was 2.34:1. The mean axial length was 21.94 ± 1.94 mm. Girls had shorter axial length than boys (21.53 mm vs 22.11 mm, p = 0.01). The axial length in the cataractous eyes in bilateral cases was significantly smaller than that in the unilateral cases (21.46 mm vs 22.55 mm, p < 0.0001).The mean keratometry was 44.12 ± 2.6 D. Girls had larger mean keratometry value than boys (44.71 vs 43.88, p = 0.0032). Keratometry values were higher in cataractous eyes in bilateral cases than in the unilateral cases (44.61 D vs 43.51 D, p < 0.0001). The mean corneal astigmatism was 1.49 ± 1.13 D. The prevalence of the corneal astigmatism of 2.0 D or more was 25.5%. The with-the-rule astigmatism was the most frequent type (62.53%). Girls had higher mean astigmatism than boys (p = 0.0122). The mean corneal astigmatism was higher in the cataractous eyes in bilateral cases than in the unilateral cases (p = 0.0094). ConclusionsThe axial length, mean keratometry and corneal astigmatism in congenital cataract patients varied with age, gender, and laterality. The data on biometry characteristics of Nepalese pediatric patients provided in the present study are of clinical significance and hence greatly enhance the guidelines for treatment decisions, IOL power calculations and management of congenital cataract patients.

Glued intraocular lens implantation: A three-year retrospective analysis at two hospitals in Brussels, Belgium

To analyze the outcomes and refraction of cases receiving fibrin glue-assisted posterior chamber intraocular lens implantation (Glued IOL) from December 2014 to December 2017 at Saint-Pierre Hospital and Saint-Anne Hospital in Brussels. Multicenter retrospective descriptive observational study of consecutive cases that underwent glued intraocular lens implantation from December 2014 to December 2017 at Saint-Pierre Hospital and Saint-Anne Hospital in Brussels. The purpose is to analyze the results preoperatively and 3months postoperatively, the postoperative intraocular pressure, the reasons that led us to use this surgical technique, the immediate and late complications and finally the astigmatism and refraction before and after the surgery. A total of 33 eyes were evaluated. Among the indications, 42.42% were intraoperative posterior capsular rupture, 33.3% were dislocated IOL and 12% were (sub) luxated cataract. The mean preoperative and postoperative intraocular pressure was 17.1mmHg and 16.3mmHg, respectively. There were no intraoperative complications, but there were 5 postoperative complications, one macular cystoid edema, one hyphema, one retinal detachment and 2 haptic extrusions. The mean corneal astigmatism pre- and postoperatively was 1.43 and 1.49 diopters, respectively. The postoperative spherical equivalent refractions were between -0.75 and +0.75 D.

Evaluation of biometry and corneal astigmatism in cataract surgery patients in Northern United Arab Emirates.

To analyze biometric parameters and patterns of corneal astigmatism in cataract surgery patients using optical low-coherence interferometry in Northern United Arab Emirates (UAE). Axial length (AL), anterior chamber depth (ACD), horizontal corneal diameter (white to white, WTW) and flat and steep keratometry (K1 and K2, respectively) were optically measured using optical low-coherence interferometry (Aladdin). Ocular datasets acquired between 2015 and 2018 were collected and analyzed. This study evaluated 238 eyes of 123 cataract patients with a mean age of 67.1 ± 9.4years. Mean AL, ACD, WTW, K1, and K2 were 23.22 ± 0.99mm, 3.05 ± 0.36mm, 11.19 ± 0.46mm, 43.72 ± 1.80 diopter (D), and 45.04 ± 1.71D, respectively. Mean corneal astigmatism was 1.32 ± 0.97D. Corneal astigmatism of 1.5D or greater was found in 32.4%. With the rule, against the rule, and oblique astigmatism were found in 29.8%, 57.1%, and 13.0% of eyes, respectively. Results of this study provide normative data for cataract surgery as an informative reference in Northern UAE, the Middle East. This study showed higher corneal astigmatism in Northern UAE than those in other countries.

Axial ocular dimensions and corneal astigmatism: The Kuala Pilah Cluster Cataract Study

Introduction: The Kuala Pilah Cluster Project involves Kuala Pilah Hospital as the lead hospital and the Jempol Hospital and Tampin Hospital as the district hospitals, serving as a single entity to provide ophthalmology services to the local population.&#x0D; Purpose: To evaluate the distribution of ocular biometric parameters and corneal astigmatism in patients presenting for cataract surgery within the Kuala Pilah Cluster Hospital System.&#x0D; Study design and methods: A cross-sectional study conducted on 273 consecutive patients presented for cataract surgery between January and June 2017. Ocular biometry measurements, including axial length (AXL), lens thickness (LT), and anterior chamber depth (ACD) of each right eye were measured using immersion A-scan ultrasound. Keratometric (K) readings were obtained via auto keratometer.&#x0D; Results: The mean values for AXL, ACD, and LT were 23.40 ± 0.90 mm, 3.17 ± 0.49 mm, and 4.45 ± 0.96 mm, respectively. The average K-reading was 44.40 ± 1.59 D, with a mean corneal astigmatism of 0.82 ± 0.62 D. In this population, the females have significantly shorter AXL and ACD, but steeper K compared to the males (P &lt; 0.001). The local Malays have higher AXL and ACD values compared to the Chinese and Indians. A total of 35.5% patients exhibited a corneal astigmatism greater than 1 D. The magnitude of preoperative astigmatism positively correlated with age (P &lt; 0.001).&#x0D; Conclusions: Ocular dimensions vary with gender and race in cataract patients from the Kuala Pilah cluster population. The probability of a patient requiring astigmatic correction increases with age. The average profile of ocular biometric data and corneal astigmatism may help local ophthalmologists to predict intraocular lens selections prior to cataract outreach projects.

Influence of preoperative astigmatism on corneal biomechanics and accurate intraocular pressure measurement after micro-incision phacoemulsification.

To define the corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg) and corneal compensated intraocular pressure (IOPcc) prior to and following coaxial micro-incision phacoemulsification in patients with corneal astigmatism. Of 97 patients with cataracts were enrolled in the study. Group 1 included patients with corneal astigmatism (K1-K2) values of K1-K2<+1.0 D, and group 2 with values of K1-K2 ≥+1.0 D and ≤+2.25 D. Coaxial micro-incision phacoemulsification of a corneal incision of 2.0 mm with intraocular lens (IOL) implantation was performed. CH, CRF, IOPg, IOPcc, waveform score (WS) were measured preoperatively and one week, one month postoperatively using an Ocular Response Analyzer. Axial length (AXL) was calculated by Tomey Optical Biometer OA 2000. Group 1 consisted of 51 patients with mean corneal astigmatism value of +0.49±0.25 D. Group 2 included 46 patients with astigmatism of +1.43±0.43 D. In group 1, CRF (t=2.68, P<0.05), CH (t=2.64, P<0.05) and WS (t=3.51, P<0.05) were significantly lower one week postoperatively, when compared to the preoperative values. CRF significantly decreased (t=3.61, P<0.05) when measured one month following the surgery. In group 2 CH (t=5.92, P<0.05), and WS (t=3.96, P<0.05) were significantly lowered one week after cataract surgery. Moreover, we observed a significant decrease in IOPg (t=2.24, P<0.05), CRF (t=5.05, P<0.05) and CH (t=2.31, P<0.05) one month after phacoemulsification. There was no statistically significant (t=-0.83, P=0.41) difference in AXL between study groups. CRF, CH and IOPg are reduced in patients with preoperative corneal astigmatism equal or higher than +1.0 D and lower than +2.25 D. Hence, bias of IOPg measurement in these patients may cause underestimation of the real IOP both before and after cataract surgery. The measurement of IOPcc allows the precise assessment of IOP pre- and postoperatively, independently on corneal astigmatism, CH and CRF values.