Relationship between age, corneal astigmatism, and ocular dimensions with reference to astigmatism in eyes undergoing routine cataract surgery

Reliability and Agreement of Keratometry Measurements Obtained With Eye Surface Profilometry and Partial Coherence Interferometry

PURPOSE

The aim of this study was to assess the repeatability of keratometry parameters obtained using the Eye Surface Profiler (ESP) system and their agreement with the IOL Master 500 device.

METHODS

Seventy-one eyes of 71 healthy participants were evaluated. Three repeated measurements were performed using the ESP system. Simulated keratometry in the flat (SimKf) and steep (SimKs) meridians, astigmatism, and axis were obtained. The same parameters were measured using the IOL Master 500 device. The J0 and J45 vector components of the astigmatism were calculated. The intrasession repeatability was analyzed using within-subject SD (Sw) and intraclass correlation coefficient (ICC). Agreement was assessed using paired statistical tests and the Bland-Altman method.

RESULTS

The Sw was 0.07 mm, 0.04 mm, 0.51 D, 0.33 D, and 0.22 D, and the ICC was 0.96, 0.98, 0.74, 0.61, and 0.55 for SimKf, SimKs, astigmatism, J0, and J45, respectively. The mean difference and limits of agreement when comparing the ESP system with the IOL Master 500 device were 0.37 mm (0.08/0.66) for SimKf ( P < 0.001), 0.18 mm (0.00/0.35) for SimKs ( P < 0.001), -0.93 D (-2.42/0.56) for astigmatism ( P < 0.001), 0.51 D (-0.22/1.24) for J0 ( P < 0.001), and 0.06 D (-0.48/0.60) for J45 ( P = 0.09).

CONCLUSIONS

The ESP system provides consistent values for simulated keratometry, showing moderate consistency for astigmatism parameters. Contact lens practitioners should be aware that the ESP system and IOL Master 500 device provide different simulated keratometry from a clinically viewpoint.

Comparison of clinical outcome after implantation of two toric intraocular lenses with different haptic type: a prospective randomized controlled trial

OBJECTIVE

To study the effect of astigmatism correction, rotational stability, and related factors of two different haptic type toric intraocular lenses.

METHODS

A prospective, randomized, controlled trial. Cataract patients with preoperative corneal astigmatism of > 1 D were randomly implanted with C-loop haptic toric IOL (AcrySof-toric IOL) (group A) or plate-haptic toric IOL (AT TORBI 709 M IOL) (group B). The residual astigmatism, intraocular lens rotation, and visual quality were determined and compared between the two groups at 3 months after surgery.

RESULTS

Seventy-nine eyes were included in this study, including 40 eyes in the group A and 39 eyes in the group B. No significant difference in preoperative visual acuity, intraocular pressure, and ophthalmic biological parameters was found between the two groups. There was no significant difference in residual astigmatism between the two groups at 3 months after surgery (P > 0.05). The rotation degree in the group A was 3.85 ± 2.92°, the rotation degree in the group B was 2.33 ± 2.31°, and a significant difference in intraocular lens rotation was identified between the two groups (P < 0.05). Upon exploring the rotation-related factors of the two different haptic type toric intraocular lenses, the rotation after implanting C-loop haptic toric IOL was positively correlated with axial length (Pearson r = 0.522, P = 0.01) and corneal white-to-white distance (Pearson correlation analysis r = 0.356, P = 0.024).

CONCLUSIONS

The two different haptic type toric intraocular lenses effectively corrected regular corneal astigmatism and provided a good rotational stability after surgery. But the stability of plate-haptic toric IOL was better than that of C-loop haptic toric IOL. The rotational stability of C-loop haptic toric IOL was often related to axial length and corneal white-to-white distance.

Astigmatism Influences Quantitative and Qualitative Analysis in Optical Coherence Tomography Angiography Imaging

Purpose

The purpose of this paper was to study the influence of astigmatism in optical coherence tomography angiography (OCTA) images in a quantitative and qualitative analysis.

Methods

This was a prospective, cross-sectional study. We included 110 eyes of 110 patients: 20 eyes without astigmatism and 90 eyes with astigmatism ≥0.5 diopters (D). We performed a macula centered OCTA as a reference image. In patients without astigmatism, registered follow-up scans were performed after induction of -1 and -2 D astigmatism. In patients with astigmatism, we performed the follow-up scan after astigmatism correction. We used a set of cylindrical lenses attached to the camera head of the SPECTRALIS (Heidelberg Engineering, Heidelberg, Germany). A quantitative and qualitative analysis of the superficial vascular complex (SVC) and deep vascular complex (DVC) was performed. The main outcome measures were vessel density (VD), image quality, and the presence of artifacts.

Results

Mean VD of the SVC was significantly higher in the reference images compared with the images after induction of -2 D. Differences with -1 D were nonsignificant. Higher degrees of astigmatisms had higher VD dropout (0.012-0.02 per diopter in SVC). Astigmatism axis showed no relevance in our cohort. Image quality assessed by two independent observers was graded as higher in images without astigmatism. Defocus and attenuation were more prevalent in images with astigmatism.

Conclusions

Astigmatism of -2 D affects quantification of VD in OCTA images, mainly affecting the SVC, as well as the subjective quality assessment. Correction of this refractive error might be necessary for an accurate quantitative assessment of OCTA images.

Translational Relevance

Correcting astigmatism of 2 D or greater appears to be necessary when analyzing OCTA images.

Toric Intraocular Lens versus Peripheral Corneal Relaxing Incisions for Astigmatism between 0.75 and 2.5 Diopters: 5-Years Outcomes

PURPOSE

To compare 5-year outcomes of toric intraocular lens (tIOL) or peripheral corneal relaxing incision (PCRI) for correction of keratometric astigmatism (KA) between 0.75 and 2.5 diopters (D).

METHODS

Setting: University Hospital. Design: Randomized clinical trial. Eighty eyes (80 participants) received either tIOL or PCRI. Patients were assessed preoperatively, 1-month, 1, and 5 years. Primary outcomes were uncorrected (UDVA) and best-corrected distance logMAR visual acuity (CDVA). Secondary outcomes were a manifest refractive sphere, refractive astigmatism (Ra), spherical equivalent (SEQ), KA & mean keratometry (KM), and Quality-of-Life Impact of Refractive Correction (QIRC) scores.

RESULTS

There was no difference between the two groups in UDVA, CDVA, refractive sphere, KM, RA, and SEQ. KA reduced after 1 month in the PCRI group and remained stable until 5 years. From 1 to 5 years, the number of eyes with distance emmetropia (within ±0.13D) changed from 59% (20/34 eyes) to 32% (6/19 eyes) for tIOLs and from 43% (15/36 eyes) to 20% (4/21 eyes) for PCRIs with 32% (6/19 eyes) and 20% (4/21 eyes) showing >0.5D change in SEQ at 5-years respectively. Compared to 1-year, Ra significantly increased at 5 years in both groups with no difference between the groups. Mean overall QIRC scores were not different between the groups (tIOL: 49.88 ± 7.47; PCRI: 52.09 ± 7.02; p = .18).

CONCLUSIONS

Although there was no difference between the overall visual and vision-related quality of life outcomes between tIOLs and PCRIs, an increase in refractive astigmatism and reduction in distance emmetropia with time was noted in both groups.

Gender- and Age-Related Differences of Ocular Biometric Parameters in Patients Undergoing Cataract Surgery in Bosnia and Herzegovina

Purpose

The aim of the study is to determine the distribution and mutual relationship of ocular biometric parameters, as well as to evaluate gender- and age-related differences in patients undergoing cataract surgery in Bosnia and Herzegovina.

Materials and Methods

It was a retrospective cross-sectional study of consecutive patients who underwent cataract surgery between January 2017 and December 2021 in a tertiary care clinic. All biometric measurements were performed using the optical biometer OA-2000 (Tomey, Nagoya, Japan).

Results

The study evaluated 1278 eyes from 1278 consecutive cataract patients. The average age of all included patients was 69.4 ± 9.98 (range 40-96). A total of 672 eyes (52.58%) were from females. The mean axial length (AL), anterior chamber depth (ACD), lens thickness (LT), and mean keratometry were 23.46 ± 1.18 mm, 3.17 ± 0.40 mm, 4.54 ± 0.48 mm, and 43.42 ± 1.55D, respectively. Corneal astigmatism of ≥1D, >2D and >3D was found in 33.4%, 7.8% and 2.5% patients, respectively. Females were found to have shorter AL (p < 0.0001), shallower ACD (p < 0.0001) and steeper corneas (p < 0.0001). In both genders, AL, ACD and with the rule astigmatism showed a decreasing trend (p = 0.0001), while keratometry, the average cylinder, and against the rule astigmatism showed an increasing trend (p = 0.0001) with increasing age. Furthermore, in both genders, there was an increasing trend in ACD (p = 0.0001), and a decreasing trend in keratometry (p = 0.0001) and LT (p = 0.0001) with increasing AL.

Conclusions

This study provides useful reference data on ocular biometry for cataract surgeons in Bosnia and Herzegovina. Female patients tend to have steeper corneas, shorter AL and shallower AC than males, and these differences are independent of age or AL.

Combined Femtosecond Laser-Assisted Keratotomy and Cataract Surgery for Enhancing Refractive Outcomes. An Indonesian Case Study

Purpose

We evaluate the reduction of corneal astigmatism and the improvement of visual outcomes of this surgical method in the Indonesian population. We also assess the accuracy and predictability of using femtosecond laser astigmatic keratotomy (FLAK) combined with cataract surgery.

Patients and Methods

In a retrospective study, a total of 275 subjects (78 with against-the-rule (ATR) astigmatism, 178 with with-the-rule (WTR) astigmatism, and 19 with oblique (OBL) astigmatism) with preexisting corneal astigmatism ranging from 0.75D to 3.00D underwent FLAK. All subjects completed a 3-month follow-up. The femtosecond laser used for creating paired AK 2.2 mm, primary incision, and paracentesis incision was the FEMTO Z8 NEO from Ziemer Ophthalmic System, Switzerland. The surgical approach was guided by the "NAPA" nomogram.

Results

The reduction in postoperative astigmatism was 56.90% for the WTR group, 49.46% for the ATR group, and 47.33% for the oblique group. A significant reduction in astigmatism was observed at the 1-week, 1-month, and 3-month follow-up intervals in both the WTR and ATR groups. The reduction in astigmatism was more favorable in cases of moderate astigmatism within the WTR group, as compared to the ATR and oblique groups. Postoperative astigmatism reduction was found to be more predictable in the right eye than in the left eye.

Conclusion

The combination of FLAK can be considered as a potential method for reducing corneal astigmatism ranging from 1.00D to <3.00D. The highest reduction was observed in the WTR group, along with a higher rate of intended correction without astigmatism meridian shift in the right eye for the WTR group. However, factors such as cyclotorsion resulting from the surgical technique, alignment of docking, incision length, and preoperative astigmatism need to be taken into account for further enhancement and predictability of astigmatism reduction with this method.

Spherical Aberration of Astigmatic Corneas in a Cataract Population

PURPOSE

To study the distribution of spherical aberration (SA) in astigmatic corneas in a cataract population and the relationship between magnitude of corneal astigmatism and fourth-order corneal SA.

METHODS

Data routinely collected using a Scheimpflug camera (Pentacam; Oculus Optikgeräte GmbH) were retrospectively analyzed. Patients with a minimum age of 60 years were included. Total corneal SA (from anterior and posterior corneal surface) was obtained for a 6-mm cor-neal area aligned with the pupil center. Exclusion criteria were insufficient measurement quality, total deviation index (Belin/Ambrósio Deviation) greater than 1.60, and corneal thickness at the thinnest point of less than 490 μm. One eye per patient was chosen randomly. Eyes were divided into low (≤ 1.00 diopters [D]), moderate (> 1.00 to ≤ 2.00 D), and high (> 2.00 D) astigmatism groups according to the Scheimpflug measurements.

RESULTS

A total of 528 eyes were included in this analysis. Low astigmatism was found in 129 patients, moderate astigmatism in 265 patients, and high astigmatism in 134 patients. Mean astigmatism was 0.68 ± 0.24, 1.45 ± 0.28, and 2.91 ± 0.95 D in the low, moderate, and high astigmatism groups, respectively. Mean corneal SA in patients with moderate and high astigmatism was higher than in the low astigmatism group. The difference reached the significance level for the comparison of low and high astigmatism groups (P = .023). The fourth-order SA increased gradually with the magnitude of astigmatism with a slope of 0.015.

CONCLUSIONS

SA was significantly larger in the cataract population with high corneal astigmatism. The increase of positive sign SA with the magnitude of astigmatism suggests that patients with moderate to high astigmatism may benefit more from intraocular lenses with negative sign SA correction. [J Refract Surg. 2023;39(8):532-538.].

Rotational stability and clinical outcomes after implantation of a new monofocal toric intraocular lens with double C-loop design

PURPOSE

To investigate rotational stability and visual outcomes of patients unilaterally or bilaterally implanted with a new monofocal toric intraocular lens (IOL).

SETTING

Ophthalmology service, clinique Beausoleil, avenue de Lodève, Montpellier.

DESIGN

Single-center retrospective study.

METHODS

This study included patients who underwent routine cataract surgery with the PODEYE toric (BVI/PhysIOL SA, Liège, Belgium) IOL using the ZEISS CALLISTO eye®. Biometry and keratometry data, refractive outcomes, rotational stability, and astigmatism correction were recorded. IOL rotation was evaluated using an image analysis technique. Postoperative assessments were performed at 1 week, 1 month, and 4 to 6 months after surgery.

RESULTS

Clinical outcomes of 102 patients (136 eyes) were analyzed. Patients had a mean age of 74 years. Of the included eyes, 25% had an axial length greater than 24.5mm. Median postoperative IOL rotation from baseline (surgery) was 2̊. With the exception of one outlier (15̊ rotation), IOL rotation was ≤ 6̊ (1 month) and ≤ 10̊ (4-6 months) in 100% of the eyes. No surgical IOL re-positioning was required. Median postoperative corrected distance visual acuity was -0.08 logMAR, and median postoperative subjective cylinder was between 0.25 and 0.50 D.

CONCLUSION

The PODEYE toric IOL showed high rotational stability, allowing for correction of corneal astigmatism during cataract surgery.

Epidemiology and Burden of Astigmatism: A Systematic Literature Review

SIGNIFICANCE

This is the first literature review to report the epidemiology, patient burden, and economic burden of astigmatism in the general adult population. The unmet needs of astigmatism patients with coexisting ocular conditions (cataract, glaucoma, dry eye, presbyopia, or macular degeneration) and risks associated with untreated astigmatism are also reviewed and reported.

PURPOSE

This study aimed to identify, report, and summarize the published literature on epidemiology, patient burden, and economic burden of astigmatism using a systematic literature review.

METHODS

MEDLINE, EMBASE, and Cochrane Library databases were searched (January 1996 to May 2021). Search results were limited to the English language. Proceedings (2018 to 2021) from ophthalmology congresses were searched along with gray literature using the Google Scholar platform.

RESULTS

The literature search yielded 6804 citations, of which 125 met the inclusion criteria (epidemiology, 68; patient burden, 60; economic burden, 6). Astigmatism prevalence in the general population varied from 8 to 62%, with higher rates in individuals 70 years or older. The prevalence of with-the-rule astigmatism was higher in individuals 40 years or younger, whereas rates of against-the-rule and oblique astigmatism increased with age. Astigmatic patients experienced decreased vision quality, increased glare (53 to 77%), haloes (28 to 80%), night-time driving difficulties (66%), falls, and spectacle dependence (45 to 85%). Astigmatic patients performed vision-related tasks slower (1 D, 9% slower; 2 D, 29% slower) and made more errors (1 D, 38% more errors; 2 D, 370% more errors) compared with fully corrected individuals. In cataract patients with astigmatism, the annual mean per-patient productivity loss costs ranged from €55 ($71) to €84 ($108), and mean informal care costs ranged from €30 ($39) to €55 ($71) with a mean of 2.3 to 4.1 hours spent on informal care.

CONCLUSIONS

Uncorrected astigmatism decreases patients' vision-related quality of life, decreases productivity among working-age adults, and poses an economic burden on patients and their families.

Pattern of astigmatism using partial coherence interferometry in patients of different age groups undergoing cataract surgery

BACKGROUND

Astigmatism is a refractive error that accounts for 70% of refractive errors in the elderly population. It is important to be aware of the distribution, extent, and type of astigmatism in patients undergoing cataract surgery to guide in reducing postoperative spectacle dependency.

AIM

To study the demography, amount, and pattern of astigmatism using partial coherence interferometry in patients of different age groups undergoing cataract surgery.

MATERIALS AND METHODS

A cross-sectional observational study. Keratometry and demography data were collected for patients planned for cataract surgery at a tertiary care center between January 2018 and December 2019. It was done with noncontact partial coherence interferometry in patients above 50 years undergoing cataract surgery.

RESULTS

Out of 385 patients, 216 (56%) were males and 169 (44%) were females. Astigmatism was more common in males than females (P = 0.00). Against-the-rule (ATR) astigmatism was found in 262 cases (68%), while with-the-rule (WTR) astigmatism was seen in 87 cases (23%). ATR was more common than WTR (P = 0.00). The number of patients with ATR seems to be increased with aging eyes and was more common between 61 and 70 years of age group (P = 0.00). The total amount of astigmatism increased with increasing age (P = 0.00029) which was found to be significant. Frthermore, there was a gradual change of WTR to ATR astigmatism with aging eyes.

CONCLUSION

Two hundred and sixty-two cases (68%) had ATR astigmatism mainly seen in the age group of 61-70 years. Majority had astigmatism up to 1.0 D that can be easily managed by simple cost-effective keratorefractive procedures like on-axis incision, opposite clear corneal incision, and limbal relaxing incisions.

Astigmatism profile in the elderly population: Tehran Geriatric Eye Study

PURPOSE

To determine the prevalence of astigmatism and its associated factors and examine astigmatism symmetry patterns in an elderly population.

STUDY DESIGN

Population based cross-sectional study.

METHODS

The present population-based cross-sectional study was conducted on an elderly population above 60 years of age in Tehran, Iran in 2019. The sampling was done using the stratified multistage random cluster sampling method. All study participants underwent a complete optometric examination and slit-lamp biomicroscopy.

RESULTS

The prevalence of astigmatism higher than -0.50, -1.00, and -2.00 D was 83% (95% CI: 81 -84), 52 % (95% CI: 50 -54), and 19% (95% CI: 17-20), respectively. These prevalence was 79%(95% CI: 77-81), 46(95% CI: 44-49) and 14(95% CI: 13-16) in subjects without a history of ocular surgery, respectively. Based on cylinder power worse than -1.00 D, 10% (95% CI: 9-12), 20% (95% CI: 18-22), and 21% (95% CI:19-23) of study participants had with the rule, against the rule, and oblique astigmatism, respectively. According to the results of the multiple regression model, male gender, older age, low education level, pure posterior subcapsular cataract, pseudophakia, and myopia were independent factors associated with astigmatism. The prevalence of anisorule astigmatism was 57 % (95% CI: 56-59), the most common anisorule astigmatism was against the rule-oblique type with a prevalence of 36% (95% CI: 34-38).

CONCLUSION

The prevalence of astigmatism was high in the elderly population of Tehran. More than half of the participants in this study had anisorule astigmatism, and against the rule-oblique combination was more prevalent than other types. A posterior subcapsular cataract, a history of cataract surgery, and myopia were the associated factors of astigmatism in this study.

Defocus curves: Focusing on factors influencing assessment

ABSTRACT

Defocus curve assessment is used to emulate defocus over a range of distances and is a valuable tool that is used to differentiate the performance of presbyopia-correcting intraocular lenses. However, defocus curves are limited by a lack of standardization, and multiple factors can impact their generation and interpretation. This review discusses key factors that influence the assessment of defocus curves, including pupil size, level of contrast, sphere versus cylinder defocus, viewing distance, monocular versus binocular assessment, use of Snellen versus logarithm of the minimum angle of resolution charts, and diopter range and step size. There are also different methods to analyze defocus curves, including the direct comparison method, range-of-focus analysis, and area under the curve analysis, which can impact result interpretation. A good understanding of these factors and standardization of the methodology are important to ensure optimal cross-study comparisons.

Comparison of the rotational stability between plate-haptic toric and C-loop haptic toric IOLs in myopic eyes

PURPOSE

To compare the rotational stability of a plate-haptic toric intraocular lens (IOL) vs a C-loop haptic toric IOL in myopic cataract eyes.

SETTING

Eye and Ear, Nose, and Throat Hospital of Fudan University, China.

DESIGN

Prospective, randomized, controlled study.

METHODS

Cataract eyes with axial length (AL) more than 24.5 mm were randomly assigned to receive implantation of a C-loop haptic toric IOL (AcrySof Toric IOL) (Group A) or a plate-haptic toric IOL (AT TORBI 709M IOL) (Group B). IOL rotation, residual astigmatism, visual acuity, and higher-order aberrations (HOAs) evaluated with OPD-Scan III aberrometer were compared at 3 months postoperatively.

RESULTS

In total, 62 eyes of 62 patients were eligible for analysis: 31 in Group A and 31 in Group B. The mean rotation of toric IOLs was greater in Group A than that in Group B (8.00 ± 3.60 degrees vs 4.42 ± 3.24 degrees, respectively, P < .001), especially when IOLs were vertically placed. IOL rotation was positively correlated with AL in Group A, whereas no such correlations were found in Group B. Residual astigmatism in Group A was greater than that in Group B (-0.76 ± 0.30 diopter [D] vs -0.51 ± 0.29 D, respectively, P = .001). Fewer eyes achieved residual astigmatism of 0.50 D or less in Group A than in Group B (38.71% vs 64.52%). Group A had worse postoperative uncorrected visual acuity and higher total HOAs and coma for a 6.0 mm pupil than Group B, whereas postoperative corrected visual acuity was not different between the 2 groups.

CONCLUSIONS

The plate-haptic toric IOL might be a better choice for myopic cataract eyes with corneal astigmatism because of reduced postoperative rotation.

Comparison of corneal astigmatism characteristics and prevalence of corneal astigmatism between Turkish individuals and Syrian refugees

PURPOSE

To compare the prevalence, magnitude and type of corneal astigmatism between Turkish individuals and Syrian refugees.

MATERIAL AND METHODS

Data of patients scheduled for cataract surgery between January 2019 and 2020 were reviewed. The patients were randomly stratified according to their ethnicity (Turkish individuals or Syrian refugees). Keratometry was performed with the keratometer of IOLMaster 500. Quantitative analysis was performed using the power vector method (J0 and J45). The association between age and astigmatism in the two groups was explored.

RESULTS

The study included 4085 eyes of 2049 patients (3962 eyes of Turkish individuals and 123 eyes of Syrian refugees). The mean magnitude of corneal astigmatism, J0, J45 and prevalence of against the rule (ATR) astigmatism and with the rule (WTR) astigmatism were 1.01 D, 0.06, 0.01 D, 37.6% and 43.7% in Turkish individuals and 1.13 D, -0.02, 0.07 D, 46.3% and 37.4% in Syrian refugees, respectively. There were no significant differences according to age, sex, right/left eyes, corneal astigmatism magnitude, keratometric values, J0 and J45 (p > 0.05) between the two groups. Below 40 years of age, the mean corneal astigmatism magnitude in Syrian refugees was significantly higher than that in Turkish individuals (p = 0.037). At all ages, ATR astigmatism prevalence was higher in Syrian refugees than in Turkish individuals. ATR astigmatic shift began at a younger age in Syrian refugees (p = 0.037). Age- and sex-adjusted analysis showed that J0 was significantly lower in Syrian refugees than in Turkish individuals (p = 0.013).

CONCLUSION

The prevalence and magnitude of ATR astigmatism were higher and onset earlier in Syrian refugees than in Turkish individuals.

Central and mid-peripheral corneal astigmatism in an elderly population: a retrospective analysis of Scheimpflug topography results

Implantation of toric intraocular lenses (IOLs) has become standard in the correction of corneal astigmatism. The IOL selection is based on keratometric measurements of the central cornea. However, mid-peripheral corneal changes may yield suboptimal correction in patients with larger pupils. This study retrospectively analyzed corneal topography data collected using a Scheimpflug device during routine clinical examinations. Of 11,953 patients, 641 met the inclusion criteria. Total corneal astigmatism was compared between five concentric zones (2–6 mm) using vector analysis. The absolute difference between astigmatism at 2 mm and 6 mm was 0.30 D (− 0.36 to 0.64), which decreased to 0.10 D (0 to 0.20) between the 5- and 6-mm zone. With-the-rule astigmatism was the most prevalent (53%), 34% had against-the-rule (ATR), and 13% had oblique. The decrease of the cylinder power with the diameter differed significantly between the three types, with ATR and oblique astigmatism being associated with the steepest change. Patients with high corneal astigmatism tend to demonstrate larger differences between the center and mid-periphery than those with low and moderate astigmatism. In conclusion, we demonstrated that central corneal astigmatism differs from that measured at the mid-periphery and that a larger difference was found in patients with ATR, oblique and high astigmatism.

Prevalence of Astigmatism in Patients Undergoing Cataract Surgery at a Tertiary Care Center in North India

AIM

To assess the demography, magnitude, and type of corneal astigmatism in patients undergoing cataract surgery in North India.

METHODS

It is a clinic-based, cross-sectional, observational study. Keratometric values and demographic data were collected for eligible patients who had undergone phacoemulsification at a tertiary eye care center between January 2010 and December 2017, using a non contact, optical low coherence reflectometry (OLCR).

RESULTS

A total of 3597 eyes were recruited for the study. There were 1810 (50.3%) females and 1787 (49.7%) males. The mean age was 59.121±15.19 (range 5-100 years). A total of 3559 eyes were qualified for astigmatism analysis. The mean corneal astigmatism among all patients was 1.17±1.15 D (range 0-12.5 D). There was no astigmatism in 99 eyes (2.78%), with-the-rule (WTR) in 1062 eyes (29.83%), against-the-rule (ATR) in 1843 eyes (51.72%) and oblique astigmatism (OA) in 555 eyes (15.59%). The tendency of a gradual change from with the rule (WTR) to against the rule (ATR) astigmatism was noted as the age advanced.

CONCLUSION

In the present study around 56.69% of eyes had corneal astigmatism of <1.0 D that can be managed by simple cost-effective keratorefractive procedures especially in developing countries. However, our 40.49% patients had >1.0 D of corneal astigmatism, which may benefit by toric intraocular lenses.

Comparison of surgical repositioning rates and outcomes for hydrophilic vs hydrophobic single-piece acrylic toric IOLs

PURPOSE

To evaluate the comparative rotational stability and the repositioning rates and outcomes of a hydrophilic and hydrophobic acrylic monofocal toric intraocular lens (IOLs).

SETTING

Single center, Aravind Eye Hospital in Madurai, India.

DESIGN

Retrospective cohort study.

METHODS

All patients had either an Auroflex hydrophilic acrylic toric IOL (n = 4603) or AcrySof hydrophobic acrylic toric IOL (n = 926) implanted between January 2015 and April 2019. Surgical repositioning was offered if the toric IOL was 15 degrees or greater misaligned or there was a 2-line or greater improvement in uncorrected distance visual acuity (UDVA) predicted with repositioning.

RESULTS

A total of 5529 single-piece toric IOLs were implanted during the study period. There was no statistically significant difference between the hydrophilic and hydrophobic acrylic toric IOL groups in need for surgical repositioning (2.5% vs 1.9%; P = .34) or actual surgical repositioning rate (1.8% vs 1.5%; P = .59). A higher rate of surgical toric IOL repositioning was associated with younger age (62.7 vs 67.2 years; P < .0001), higher presurgical astigmatism (2.32 vs 1.99 diopters [D]; P < .0001), and with-the-rule astigmatism (4.7% vs 2.1% against-the-rule astigmatism; P = .002). In 95 eyes that underwent toric IOL repositioning, there was significant preoperative to postoperative improvement in UDVA (0.48 vs 0.12 logarithm of the minimum angle of resolution; P < .001), mean residual cylinder (1.79 vs 0.7 D; P < .001), and mean toric IOL misalignment (49.7 vs 5.4 degrees; P < .001). The repositioning outcomes were statistically similar with both toric IOL models. There were no major complications or recurrent toric IOL rotation after surgical repositioning.

CONCLUSIONS

The hydrophilic acrylic toric IOL had comparable rates of postoperative misalignment and surgical repositioning with the hydrophobic acrylic toric IOL. Early postoperative surgical repositioning was both safe and effective with both toric IOLs.

Prevalence of epiretinal membrane in the phakic eyes based on spectral-domain optical coherence tomography

The prevalence of epiretinal membrane (ERM) and associated factors in the phakic eyes have not been fully elucidated yet. This cross-sectional study included 2,354 phakic eyes without retinal diseases or surgical history. Ocular parameters, such as uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent (SE), intraocular pressure (IOP), white-to-white corneal diameter (WTW), mean keratometric value (Km) of total corneal refractive power at 4-mm diameter (TCRP4), astigmatism of TCRP4, total corneal irregular astigmatism (TCIA), pupil diameter, axial length (AXL), anterior chamber depth (ACD), lens thickness (LT), and posterior vitreous detachment (PVD) were compared between ERM group and control group. Additionally, an age-matched control group was selected by individual matching and compared with the ERM group to eliminate the confounders. Multiple logistic regression analysis was performed to evaluate the factors associated with the presence of ERM. Among 2,354 eyes, 429 eyes (18.2%) had ERM based on spectral-domain optical coherence tomography. The ERM group showed higher prevalence of PVD, worse CDVA, higher astigmatism of TCRP4, higher TCIA, smaller pupil size, longer AXL, and thicker LT than control group (P < 0.001, P < 0.001, P = 0.011, P < 0.001, P = 0.023, P < 0.001, and P < 0.001, respectively). Only PVD, CDVA, SE, astigmatism of TCRP4, TCIA, and AXL maintained the significance when compared with the age-matched control group (P < 0.001, P = 0.026, P < 0.001, P = 0.001, P = 0.003, and P < 0.001, respectively). Multivariate logistic regression analysis showed that age, PVD, CDVA, and TCIA were independently associated with the presence of ERM (P < 0.001, P < 0.001, P = 0.011, and P = 0.002). The prevalence of ERM detected using SD-OCT was 18.2% in the middle aged phakic population. Eyes with TCIA, in addition to older age and PVD, were more likely to have ERM.

Effects of Induced Astigmatism on Spectral Domain-OCT Angiography Quantitative Metrics

PURPOSE

To analyze the effect of induced astigmatism on en-face spectral-domain optical coherence tomography angiography quantitative metrics.

DESIGN

Prospective crossover study.

METHODS

Normal eyes without astigmatism and with 0.75, 1.75, and 2.75 diopters (D) of with-the-rule (WTR) astigmatism were imaged using a 3 × 3-mm scan pattern SD-OCTA CIRRUS 5000 HD-OCT with AngioPlex (Carl Zeiss Meditec, Dublin, CA, USA). Quantitative parameters, including foveal avascular zone metrics, parafoveal vessel length density (VD), and perfusion density (PD) were corrected for magnification secondary to axial length and analyzed. Univariate linear regressions were performed within each eye to correlate quantitative metrics to the level of an induced astigmatic cylinder.

RESULTS

Fifteen eyes from 15 patients were imaged. Every 1-D increase in induced WTR astigmatism was associated with a statistically significant decrease in VD and PD within all Early Treatment Diabetic Retinopathy Study inner ring quadrants; however, especially more so nasally (VD: 0.63; P < .001; PD: 0.0089; P = .001). For every 1-D increase in induced astigmatism, the resulting decrease in the inner ring superior quadrant was 12% greater for VD and 16% greater for PD versus that in the inferior quadrant. The resulting decrease in the inner ring nasal quadrant was 40% greater for VD and 48% greater for PD versus that in the temporal quadrant.

CONCLUSIONS

Increasing levels of induced WTR astigmatism correlated with globally diminishing VD and PD, was more symmetrical for vertical than horizontal quadrants, and was most pronounced nasally. This may be due to a high prevalence of horizontally oriented vessels nasally and the horizontal optical defocus induced by WTR astigmatism.

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).

Correlations of Corneal Spherical Aberration with Astigmatism and Axial Length in Cataract Patients

Purpose

To clarify the distribution of corneal spherical aberrations (SAs) in cataract patients with different corneal astigmatism and axial length.

Setting

Department of Ophthalmology and Vision Science of the Eye and ENT Hospital of Fudan University, Shanghai, China.

Design

Retrospective case series.

Methods

The axial length, corneal SAs, and other corneal biometrics were collected in cataract patients with Pentacam HR and IOLMaster 500. The statistical analysis of the corneal SAs was based on the stratification of axial length and anterior corneal astigmatism.

Results

In total, 6747 eyes of 6747 patients were recruited, with 2416 eyes (58.17 ± 16.81 years old) in the astigmatism group (anterior corneal astigmatism ≥1 D) and others (61.82 ± 12.64 years old) in the control group. In patients with astigmatism <2 D, the total and anterior SAs decreased as the axial length increased (P < 0.001). The total corneal SAs of patients with astigmatism of 2-3 D stabilized at around 0.29 μm, whereas those of patients with anterior corneal astigmatism ≥3 D tended to be variable. Age and anterior corneal astigmatism had positive and negative effects, respectively, on SA in the regression model.

Conclusions

Axial length has a negative effect on the anterior and total corneal SAs, which stabled around 0.33 μm and 0.30 μm in patients with axial length of ≥26 mm, respectively. Individualized SA adjustments are essential for patients undergoing aspheric toric IOL implantation with preoperative anterior corneal astigmatism of 1-2 D or ≥3 D. Toric IOLs with a negative SA of −0.20 μm are recommended for patients with anterior corneal astigmatism of 2-3 D if no customized therapy is warranted.

Ocular Cyclorotation and Corneal Axial Misalignment in Femtosecond Laser-Assisted Cataract Surgery

Purpose: To explore ocular cyclorotation and the source of corneal axial misalignment during femtosecond laser-assisted cataract surgery (FLACS).Methods: Forty-five sequential patients (50 eyes) who had undergone FLACS (LenSx Laser System, Alcon Inc) were recruited. We took screenshots from videos of FLACS to analyze ocular cyclorotation and the real angle between primary incision and secondary incision (RAPS). In addition, crystalline lens tilt and theoretic angle between the primary and secondary incisions (TAPS) was also calculated.Results: The mean absolute value of ocular cyclorotation was 8.03 ± 4.48 degrees (0-19.1 degrees). The crystalline lens tilt was 3.30 ± 1.44 degrees (0.93-6.44 degrees). And the mean preoperative uncorrected visual acuity was 0.89 ± 0.50 LogMAR units. Pearson bivariate correlation analysis showed significant positive correlation between ocular cyclorotation with crystalline lens tilt (r = 0.37, p = .008), and ocular cyclorotation negatively correlated with axial length (r = -0.29, p = .038). In addition, the TAPS was 89.78 ± 1.45 degrees, and the RAPS was 85.68 ± 2.04 degrees. The angle error was 4.11 ± 1.28 degrees (p<0.001).Conclusions: Ocular cyclorotation commonly occurred during FLACS. In addition, increased axial length was associated with less ocular cyclorotation and increased crystalline lens tilt was related to more ocular cyclorotation. Importantly, machinery systemic errors during corneal astigmatism correction by arcuate incision in FLACS should be taken into consideration.

Residual Refractive Astigmatism following Toric Intraocular Lens Implantation without Consideration of Posterior Corneal Astigmatism during Cataract Surgery with Low Anterior Keratometric Astigmatism upto 2.5 Dioptres

Purpose: To determine the refractive astigmatism following toric intraocular lens (tIOL) implantation without consideration of posterior keratometric astigmatism with a conventional tIOL calculator for eyes with low keratometric astigmatism (0.75D to 2.5D) and to theoretically compare the outcomes with predicted refractive astigmatism using a calculator with Barrett's formula.Methods: 34 eyes (34 patients) were assessed with Scheimpflug imaging and underwent tIOL implantation employing conventional tIOL calculator. Eyes were grouped on preoperative keratometric astigmatism as against-the-rule (ATR), with-the-rule (WTR), and oblique (OB). The refractive astigmatism was assessed at 1, 3, 6 and 12 months postoperatively and was classified as ATR, WTR, and OB. Theoretical refractive astigmatism calculations were performed for the same eyes using Barrett's formula.Results: Preoperatively keratometric astigamtism was ATR, WTR, and OB in 32%, 53% and 15% of eyes. At 12 months, in ATR, WTR and OB groups, 45.5%, 16.7% and 60% had ATR refractive astigmatism; 16.7%, 0%, and 20% had WTR refractive astigmatism; 55.6%, 54.5% and 20% were emmetropic (no sphere and cylinder) respectively. There was a significant difference between the theoretical predicted postoperative refractive astigmatism using conventional tIOL calculator and Barrett's formula (P < .05). Postoperative refractive astigmatism was not significantly different from the theoretical predicted refractive astigmatism with Barrett's formula but it was significantly higher than that with a conventional tIOL calculator.Conclusions: At 12 months, with a conventional tIOL calculator, postoperative emmetropia is achieved in half, two third and one-fifth of eyes with preoperatively ATR, WTR, and OB keratometric astigamtism respectively. Around 1/4^th WTR keratometric astigamtism eyes preoperatively were overcorrected to ATR refractive astigmatism whereas ½ATR remained undercorrected at 12 months Outcomes achieved were dissimilar to predicted outcomes with a conventional tIOL calculator but similar to those with Barrett's formula.

Cataract surgery and lens implantation

PURPOSE OF REVIEW

This review aims to introduce recent updates in cataract surgery and lens implantation.

RECENT FINDINGS

Compared to phacoemulsification, femtosecond laser-assisted cataract surgery (FLACS) may offer benefit for cataract patients with other complicated ocular diseases, such as corneal disease and vitreous abnormalities. Meanwhile, several types of novel intraocular lenses (IOLs) have been introduced to the market, and each of them has particular features in improving patients' visual acuity. In addition, based on a series of studies, multifocal IOL is superior to monofocal IOL when it comes to providing a better visual correction at different distances. Furthermore, a research group has introduced a new approach for cataract surgery - all laser surgery (FLACS band with nanolaser emulsification), which can effectively reduce iatrogenic trauma to the cornea. Also, a novel technique designed for children can lessen damage from cataract surgery.

SUMMARY

Based on previous studies, we summarize the new proceedings in FLACS and the indications for applying multifocal or toric IOL. In addition, we briefly introduce a new approach to cataract surgery - all laser surgery (FLACS band with nanolaser emulsification), and a less invasive surgical procedure used in pediatric cataract patients.

Comparing spectacle and toric contact lens prescribing trends for astigmatism

BACKGROUND

The purpose of this study is to investigate and compare spectacle and contact lens (CL) prescription trends, with an emphasis on astigmatic refractive error prescribing differences for patients who purchase spectacles or CLs in South Korea.

METHODS

A retrospective study of patient records of a major optical chain in South Korea was conducted. De-identified data of age, gender, power of prescribed spectacles and/or CLs were extracted from the practice database. Inclusion criteria were being within the first 10,000 purchasers of spectacles or CLs or both.

RESULTS

The first 10,000 purchases comprised spectacles (59%) and CLs (41%) (male:female ratio 4:6). The proportion of purchasers who were female was significantly higher for CLs (88% female, 12% male) than spectacles (43% female, 57% male) (χ ² =4480.36, df=1, P<0.0001). There was a significant difference in the proportions of purchases by age group for spectacles and CLs (χ ² =3246.69, df=3, P<0.0001). Spherical power distribution of prescribed lenses was similar between the groups; however, cylinder power and axis were significantly different (P<0.0001). CL astigmatic powers were more likely to be 1.00 DC or greater, whereas the majority of spectacle lenses had astigmatic power of 0.75 DC or less. In total, 90% of toric CLs were prescribed ×180 and 9% other meridians, unlike spectacles where 50% were prescribed ×180, 14% ×90 and 40% at oblique meridians.

CONCLUSION

There is scope for providing increased toric lens correction amongst CL wearers and increasing the proportion of wearers who are male. The estimated gap for toric lens prescription amongst CL wearers who have clinically significant astigmatism ≥0.75 DC is about 59%.

Age-related changes in with-the-rule and oblique corneal astigmatism

PURPOSE

To describe the age-related changes in with-the-rule (WTR) and oblique keratometric astigmatism (KA), posterior corneal astigmatism (PCA) and total corneal astigmatism (TCA).

METHODS

We used a Pentacam HR (high-resolution) rotating Scheimpflug camera to determine the KA, PCA and TCA in the right eyes of 710 patients, aged from 20 to 88 years. The age-related changes along the vertical, horizontal and oblique meridians were analyzed with Naeser's polar value method in a cross-sectional study.

RESULTS

In the whole group, all meridional astigmatic powers and polar values were stable in the age groups from 20 to 49 years, followed by a 1.0 dioptre (D) against-the-rule (ATR) change in KA and TCA, and a 0.12 D reduction in against-the-rule PCA. A nasal rotation of the steep meridian in KA and TCA was noted in the 70-88 years old. The PCA averaged approximately 0.25 D ATR in all age groups. Females displayed the same early astigmatic stability as in the whole group, while male eyes demonstrated a linear decay from 1.5 D WTR at 20 years to 0.5 D ATR astigmatism for the oldest patients.

CONCLUSION

Corneal astigmatism is stable until the age of 50 years; thereafter both keratometric and total corneal astigmatism show a 0.25 D ATR change per 10 years. The average 0.25 D ATR PCA compensates the predominant keratometric WTR astigmatism in the younger patients and increases the TCA in the elderly with keratometric ATR astigmatism. The gender-based differences in age-related astigmatism require further studies.

Corneal astigmatism in cataract surgery patients from Bosnia and Herzegovina

PURPOSE

To determine corneal astigmatism prevalence, its correlations with age and symmetry pattern in fellow eyes of patients undergoing cataract surgery.

METHODS

This is a clinical-based retrospective cross-sectional study. Keratometry measurements of patients undergoing cataract surgery assigned to University Clinical Center Tuzla, Bosnia and Herzegovina, between January 2011 and June 2012 were recorded and analyzed retrospectively.

RESULTS

The study consisted of 4080 eyes of 2205 consecutive cataract surgery patients with a mean age of 68.24 years ± 9.25 (SD) (range 32-84 years), and 54.0% of the patients were women. Mean corneal astigmatism was 0.72 ± 0.61 D (range 0-6.5 D). The prevalence of corneal astigmatism 1.0 D or more was in 1291 eyes (31.64%), 1.5 D or more in 736 eyes (18.03%), 2.0 D or more in 396 eyes (9.71%) and 3.0 D or more in 108 eyes (2.65%). There was no significant difference in the magnitude of astigmatism between age groups (p = 0.10), male and female (p = 0.29) or right and left (p = 0.75) eyes. The prevalence and amount of astigmatism increased with age (p < 0.05). Gradual shift from with-the-rule astigmatism toward against-the-rule astigmatism was observed (p = 0.03). Patients with higher amount of astigmatism in one eye are more likely to have significant astigmatism in fellow eye (p < 0.01). Symmetry in pairs of eyes is present in eyes with astigmatism greater than 2.5 D (p < 0.01).

CONCLUSION

This study provides useful reference data for cataract surgeons and patients from Bosnia and Herzegovina.

Prevalence of uncorrected refractive errors among children aged 3-10 years in western Saudi Arabia

Objectives:

To determine the prevalence of uncorrected refractive errors (URE) among children 3-10 years and to affirm the necessity of a national school-based visual screening program for school-aged children.

Methods:

This retrospective cross-sectional study was conducted in Medina, Saudi Arabia in 2015. Children were selected through a multistage stratified random sampling from 8 kindergarten and 8 primary schools. Those included were screened to diagnose UREs using a visual acuity chart and an auto refractometer according to American guidelines. The prevalence and types of UREs were estimated.

Results:

Of the 2121 children enumerated, 1893 were examined, yielding a response rate of 89.3%. The prevalence of UREs was 34.9% (95% CI = 32.8%-37.1%), with significant differences in different age groups. The prevalence of astigmatism (25.3%) was higher compared to that of anisometropia (7.4%), hypermetropia (1.5%), and myopia (0.7%). Risk of uncorrected refractive error was positively associated with age, and this was noted in astigmatism, myopia, and anisometropia. In addition, the risk of hypermetropia was associated with boys and that of myopia was associated with girls.

Conclusions:

The prevalence of UREs, particularly astigmatism, was high among children aged 3-10 years in Medina, with significant age differences. Vision screening programs targeting kindergarten and primary schoolchildren are crucial to lessen the risk of preventable visual impairment due to UREs.

Comparative evaluation of toric intraocular lens alignment and visual quality with image-guided surgery and conventional three-step manual marking

Purpose

To compare toric intraocular lens (IOL) alignment assisted by image-guided surgery or manual marking methods and its impact on visual quality.

Patients and methods

This prospective comparative study enrolled 80 eyes with cataract and astigmatism ≥1.5 D to undergo phacoemulsification with toric IOL alignment by manual marking method using bubble marker (group I, n=40) or Callisto eye and Z align (group II, n=40). Postoperatively, accuracy of alignment and visual quality was assessed with a ray tracing aberrometer. Primary outcome measure was deviation from the target axis of implantation. Secondary outcome measures were visual quality and acuity. Follow-up was performed on postoperative days (PODs) 1 and 30.

Results

Deviation from the target axis of implantation was significantly less in group II on PODs 1 and 30 (group I: 5.5°±3.3°, group II: 3.6°±2.6°; p=0.005). Postoperative refractive cylinder was −0.89±0.35 D in group I and −0.64±0.36 D in group II (p=0.003). Visual acuity was comparable between both the groups. Visual quality measured in terms of Strehl ratio (p<0.05) and modulation transfer function (MTF) (p<0.05) was significantly better in the image-guided surgery group. Significant negative correlation was observed between deviation from target axis and visual quality parameters (Strehl ratio and MTF) (p<0.05).

Conclusion

Image-guided surgery allows precise alignment of toric IOL without need for reference marking. It is associated with superior visual quality which correlates with the precision of IOL alignment.

Qualitative and quantitative evaluation of acute angle-closure mechanisms

BACKGROUND

To evaluate ocular biometric parameters in different subtypes of acute angle closure and compared to fellow eyes of AAC and PACS eyes.

METHODS

This is a retrospective chart review study. A total of 167 eyes (96 patients) consisting of 71 AAC eyes, 71 fellow eyes of AAC, and 25 PACS eyes were recruited. All patients underwent ocular examination and biometry. The mechanism of AAC was confirmed by ultrasound biomicroscopy. We then subdivided AAC eyes into four subgroups: crowded-angle (CR), lens subluxation (LS) pupillary block (PB), and plateau iris syndrome (PL). Outcome variables included anterior chamber depth (ACD), lens thickness (LT), vitreal length (VL), axial length (AL), lens position and relative lens position (LP and RLP, respectively), and lens axial length factor (LAF).

RESULTS

Among the three groups, ACD was shallower in AAC eyes than fellow eyes of AAC and PACS eyes (p < 0.01 for both) and AAC eyes demonstrated a lesser LP and RLP. The LT, VL, AL, and LAF were not significantly different among the three groups. Among the four subgroups, LS displayed the most shallow ACD (p = 0.01). The lens position in PL was greater than in CR and LS (p < 0.05 and <0.01, respectively).

CONCLUSIONS

AAC eyes had a more anterior lens position than fellow eyes and PACS eyes, though lens thickness did not differ among the groups. As such, an anterior lens position may offer more sensitive prognostication regarding future development of AAC compared to lens thickness.

Toric Intraocular Lenses Versus Peripheral Corneal Relaxing Incisions for Astigmatism Between 0.75 and 2.5 Diopters During Cataract Surgery

PURPOSE

To compare the outcomes after toric intraocular lens (tIOL) or peripheral corneal relaxing incisions (PCRI) for keratometric astigmatism (K_A) between 0.75 and 2.5 diopters (D) during cataract surgery.

DESIGN

Prospective randomized clinical trial.

METHODS

Eighty eyes (80 participants) received either tIOL or PCRI and were assessed preoperatively, 1, 3, 6, and 12 months postoperatively.

PRIMARY OUTCOME MEASURE

Uncorrected (UCDVA) and best-corrected distance logMAR visual acuity (BCDVA) at 12 months.

SECONDARY OUTCOME MEASURES

Uncorrected near visual acuity (UCNVA), manifest refraction, K_A and mean keratometry (K_M), corneal aberrometry, tIOL rotation, and quality-of-life questionnaire.

RESULTS

Comparing tIOLs vs PCRIs, there was no significant difference in the UCDVA, BCDVA, and UCNVA. At 12 months, 61% vs 53% had UDCVA of 20/25 or better, 100% vs 76% gained ≥1 lines, and 59% vs 43% were within ±0.13 D spherical equivalent. In the PCRI group, anterior K_A decreased at 1 month and remained stable thereafter; there was a nonsignificant trend toward a flatter posterior K_A and steeper posterior K_M and the total corneal Z₂^-2 was low at 1 and 12 months. Over 12 months, there were changes in posterior corneal tilt, coma, and hexafoil in the PCRI group. The mean rotation of the tIOLs at 12 months was 1.8 ± 1.4 degrees. tIOL patients were happier and were glad to use the nonprescription sunglasses.

CONCLUSION

There was no difference in visual acuity, although more tIOL patients gained ≥1 line and were within ±0.13 D. After PCRIs, the anterior K_A decreased in the early postoperative period and remained stable thereafter and posterior corneal aberrations changed constantly over 12 months.

Prevalence of corneal astigmatism before cataract surgery in Western Indian Population

Background

The prevalence and nature of corneal astigmatism among cataract surgery candidates has not been well-documented in Indian population. The purpose of the study is to analyse prevalence and presentation patterns of corneal astigmatism (CA) in cataract surgery candidates.

Methods

Keratometric values were measured in patients before cataract extraction. Descriptive statistics of CA were analysed including the assessment with age ranges.

Results

Mean CA of 223 eyes of 223 patients [mean age 61 ± 10 years (range, 29-90 years)] was 0.88 ± 0.61 (95% CI, 0.80-0.96) with 27.8%, 51.1% and 21.1% having with the rule (WTR), against the rule (ATR) and oblique astigmatism (OBL) respectively. Between 40 and 50 years, ATR exceeds WTR and reaches 100% by 80 years. A trend of less negative CA was seen up to 60 years and then increases up to 90 years. CA was below 0.25 dioptre (D) in 17.5% of eyes, between 0.25 and 1.25 D in 63.7% and ≥1.50 D in 18.8% of eyes.

Conclusions

Considering CA < 1.25 D in majority of cataract surgery candidates, it is preferable to perform inexpensive keratorefractive procedures rather expensive toric IOLs, especially in developing world.