Peripheral defocus of monofocal intraocular lenses.

PURPOSE: To quantify the angular dependence of monofocal intraocular lens (IOL) power. SETTING: Ophthalmic Biophysics Laboratory, Kallam Anji Reddy campus, L V Prasad Eye Institute, Hyderabad, India. DESIGN: Laboratory study. METHODS: Experiments were performed on IOLs from 2 different manufacturers (APPALENS 207, Appasamy Associates and SN60WF, Alcon Laboratories, Inc.). IOL powers ranged from 17 to 25 diopters (D). The IOLs were mounted in a fluid-filled chamber, and the on-axis and off-axis powers were measured using a laser ray tracing system over the central 3 mm zone with delivery angles ranging from -30 to +30 degrees in 5-degree increments. The position of the best focus was calculated for each IOL at each angle. The angular dependence of IOL power was compared with theoretical predictions. RESULTS: Peripheral defocus increased significantly with increasing incidence angle and power. The peripheral defocus at ±30 degrees increased from 5.8 to 8.5 D when the power increased from 17.5 to 24.5 D for APPALENS 207 and from 4.9 to 7.4 D when the power increased from 17 to 25 D for SN60WF. The mean difference between the measured and theoretical tangential power at ±30 degrees was 0.50 ± 0.16 D for the APPALENS 207 and -0.40 ± 0.10 D for the SN60WF, independent of IOL power. CONCLUSIONS: IOLs introduce a significant amount of peripheral defocus which varies significantly with IOL power and design. Given that peripheral defocus is related to lens power, replacement of the crystalline lens (approximately 24 D) with an IOL will produce a significant difference in peripheral defocus profile after surgery.

Keratoconus in India: Clinical presentation and demographic distribution based on big data analytics.

PURPOSE: This paper aims to describe the clinical presentation and demographic distribution of keratoconus (KCN) in India by analyzing the electronic medical records (EMR) of patients presenting at a multitier ophthalmology hospital network. METHODS: This cross-sectional hospital-based study included the data of 2,384,523 patients presenting between January 2012 and March 2020. Data were collected from an EMR system. Patients with a clinical diagnosis of KCN in at least one eye were included in this study. Univariate analysis was performed to identify the prevalence of KCN. A multiple logistic regression analysis was performed using R software (version 3.5.1), and the odds ratios are reported. RESULTS: Data were obtained for 14,749 (0.62%) patients with 27,703 eyes diagnosed with KCN and used for the analysis. The median age of the patients was 22 (inter-quartile range (IQR): 17-27). In total, 76.64% of adults (odds ratio = 8.77; P = <0.001) were affected the most. The majority of patients were male (61.25%), and bilateral (87.83%) affliction was the most common presentation. A significant proportion of the patients were students (63.98%). Most eyes had mild or no visual impairment (<20/70; 61.42%). Corneal signs included ectasia (41.35%), Fleischer ring (44.52%), prominent corneal nerves (45.75%), corneal scarring (13.60%), Vogts striae (18.97%), and hydrops (0.71%). Only 7.85% showed an association with allergic conjunctivitis. A contact lens clinic assessment was administered to 47.87% of patients. Overall, 10.23% of the eyes affected with KCN underwent a surgical procedure. the most common surgery was collagen cross-linking (8.05%), followed by deep anterior lamellar keratoplasty (1.13%) and penetrating keratoplasty (0.88%). CONCLUSION: KCN is usually bilateral and predominantly affects males. It commonly presents in the second and third decade of life, and only a tenth of the affected eyes require surgical treatment.

Interocular Contrast Balancing Partially Improves Stereoacuity in Keratoconus.

SIGNIFICANCE: Partial improvement in stereoacuity may be achieved by balancing the contrast input to the two eyes of patients with bilaterally asymmetric keratoconus. PURPOSE: Interocular differences in image quality, characterized by dissimilar contrast loss and phase shifts, are implicated in stereoacuity loss in keratoconus. This study determined whether contrast balancing improves stereoacuity in this disease condition and, if so, whether it is dependent on the baseline interocular contrast imbalance. METHODS: Interocular contrast imbalance and stereoacuity of 43 subjects (16 to 33 years) with bilaterally asymmetric keratoconus were tested with spectacle correction as baseline using a binocular rivalry paradigm and random-dot stereograms, respectively. Stereoacuity measurements were repeated in a subset of 33 subjects at their contrast balance point (i.e., contrast level in stronger eye allowing balanced rivalry with 100% contrast in weaker eye) and with contrast levels biased in favor of stronger or weaker eye, all conditions in randomized order. RESULTS: Contrast imbalance level was significantly correlated with the subject's stereoacuity at baseline ( r = -0.47, P = .002). The median (25th to 75th interquartile range) stereoacuity improved by 34.6% (19.0 to 65.1%) from baseline (748.8 arc sec [261.3 to 1257.3 arc sec]) to the contrast balanced condition (419.0 arc sec [86.6 to 868.9 arc sec]) ( P < .001), independent of their baseline stereoacuity or contrast imbalance levels ( r < 0.2, P > .26 for both). Contrast bias in favor of the weaker eye (881.3 arc sec [239.6 to 1707.6 arc sec]) worsened stereoacuity more than a bias toward the stronger eye (502.6 arc sec [181.9 to 1161.4 arc sec]), both relative to the contrast balanced condition ( P < .002). CONCLUSIONS: Interocular contrast balancing partially improves stereoacuity in bilaterally asymmetric keratoconus, independent of their baseline contrast imbalance level. Cyclopean viewing may be inherently biased toward the input from the stronger eye in keratoconus.

Recent developments in the intraocular lens formulae: An update.

BACKGROUND: The precision of refractive outcomes after uneventful cataract surgery largely depends on the biometry and intraocular lens (IOL) formula used for selecting the IOL. To improve the accuracy of post-op refractive outcomes, several new IOL power calculation formulae have come up. This review would aim to summarise the differences among the new formulae in their performance among normal and variable ocular biometry conditions like short and long axial lengths. METHODS: A literature review was performed by searching the PubMed and Cochrane databases from 2016 to 2021, identified 483 articles, of which 51 were included in the review. RESULTS: We identified 15 new IOL formulas (including updates on older formulas) of which, only 8 newer formulas (BUII, Hill-RBF 2.0, Kane, Pearl DGS, LSF AI, Naesar 2, EVO 2.0 and VRF) met the eligibility criteria. They were compared according to the reported median absolute error, mean absolute error and percentage of eyes within 0.5D. CONCLUSION: The Kane formula and Barrett Universal-II formula performed better than other formulas over the entire axial length (AL) spectrum. In the long eye (AL > 26.0 mm) sub-group, the Kane formula was the most accurate, while in the short eye (AL < 22.0 mm) sub-group, both Kane and EVO 2.0 formulas fared better than other formulas.

Keratoconus in pre-teen children: Demographics and clinical profile.

Purpose: To study the demographics and clinical profile of keratoconus (KC) presenting in pre-teen children in India. Methods: This was a retrospective case series conducted as a single-institutional study at a tertiary eye center in India. A total of 586 eyes from 294 KC patients (aged 12 years or less) without any active comorbid conditions of the eye were included in the study. Slit-lamp biomicroscopy was used to document the clinical signs of KC. Information on age; gender; reason for consultation; family history; history of allergy, atopy, and eye rubbing; manifest refraction; uncorrected and best-corrected distance visual acuity (UCVA and BCVA, respectively); clinical presentation; and contact lens usage were also analyzed, along with data on types of medical and surgical treatments for KC and their outcomes. Results: The mean age of this pediatric KC patient cohort was 9.3 ± 1.8 years, and there was a male (70%) preponderance. Baseline mean UCVA, BCVA, steep keratometry, and flat keratometry were 0.86 ± 0.58 logMAR, 0.44 ± 0.38 logMAR, 54.82 ± 8.4 D, and 48.21 ± 9.5 D, respectively. Progression, necessitating collagen crosslinking (CXL), was noted in 12.7% eyes. Post-CXL, visual and topographic parameters remained stable without any complications till 6 months posttreatment. However, in eyes that did not undergo CXL, significant progression over time (P < 0.001) was observed. A keratoplasty was required in 2.3% eyes. Conclusion: KC was present at an advanced stage in 25% of the pre-teens in our series, and therefore, it is an important diagnostic entity when a refractive error is diagnosed, even in very young children.

Clinical profile and demographic distribution of ophthalmia nodosa: An electronic medical record-driven big data analytics from a multitier eye care network.

Purpose: To describe the demographics and clinical profile of ophthalmia nodosa in patients presenting to a multitier ophthalmology hospital network in India. Methods: This cross-sectional, hospital-based study included 3,082,727 new patients presenting between August 2010 and December 2021. Patients with a clinical diagnosis of ophthalmia nodosa in at least one eye were included as cases. The data were collected using an electronic medical record system. Results: Overall, 434 (0.014%) patients were diagnosed with ophthalmia nodosa. Most of the patients were male (71.43%) and had unilateral (97.7%) affliction. The most common age group at presentation was during the third decade of life with 116 (26.73%) patients. The overall prevalence was higher in patients from a higher socioeconomic status (0.015%) presenting from the urban geography (0.019%) and in professionals (0.027%). The setae were identified and removed at presentation in 287 (66.13%) patients. The most common location of the setae was conjunctiva (45.72%) followed by cornea (39.64%). Most of the eyes (355; 79.95%) had mild or no visual impairment (<20/70). The most documented ocular signs were eye lid edema (35.81%), conjunctival congestion (73.87%), and corneal abrasion (29.05%). Less than one-tenth of the eyes required a surgical intervention for removal of the setae, corneal foreign body removal was performed in 10 (2.25%) eyes and conjunctival foreign body removal in four (0.90%) eyes. Conclusion: Ophthalmia nodosa more commonly affects males presenting during the third decade of life and is predominantly unilateral. The setae are most commonly lodged in the conjunctiva followed by the cornea, and the majority of the eyes have mild or no visual impairment.

Impact of teleconsultation on visual and refractive outcomes in patients undergoing laser refractive surgery during COVID-19.

Purpose: To assess the role of remote teleconsultation (TC) follow-up care following a successful and uneventful laser vision correction. Methods: The study is a retrospective, comparative analysis of patients undergoing laser vision correction at tertiary care eye hospital in Southern India. The patients were divided into two groups. The first group included patients operated on before the coronavirus disease (COVID-19) pandemic and were followed up with physical consultations during their follow-up visit (Group 1). The second group comprised patients operated on during the pandemic and had at least one remote TC during their post-operative follow-up (Group 2). Results: A total of 1088 eyes of 564 patients and 717 eyes of 372 patients were included in Group 1 and 2, respectively. The mean number of visits for the patients from Group 2 during the COVID period (2.56 +/- 0.74 days) was significantly lesser (P < 0.0001) than that of Group 1 in the pre-COVID period (3.53 +/- 1.07 days). Close to 90% of the eyes achieved an uncorrected distance visual acuity (UDVA) of 20/20 in both groups (P = 0.925). 96.50% of the eyes in Group 1 and 98.18% of the eyes in Group 2 achieved UCVA 20/25 or better (P = 0.049). Eight eyes (0.73%) in Group 1 and one eye (0.14%) in Group 2 reported a loss of 2 or more lines. However, the results were not statistically significant (P = 0.156). None of the groups had any patients who had a sight-threatening complication. Conclusion: Remote TC following refractive surgery is safe and can be effectively integrated into routine refractive practice to reduce travel to the hospital for a physical consult.

KEDOP: Keratoconus early detection of progression using tomography images.

PURPOSE: To investigate a method to identification of early progression of keratoconus using deep learning neural networks. METHODS: Retrospective evaluation of medical records of patients with progressive keratoconus and had more than one followup visits. Images extracted from the single scheimplug analyzer for analysis were captured during the patient visits. The baseline progression of keratoconus is detected by a change in flat or steep K of ≥1.0D which is labeled as keratometric progression (KP) and progression detected by image based deep learning convolutional neural network (CNN) models, is labeled as latent progression (LP). Patient data consisted of model data (385 eyes of 351patients) to train and test the learning models and prediction data (1331 eyes of 828 patients) to determine the LP based on the learning models. RESULTS: The LP prediction model was able to identify progression at a mean of 11.1 months earlier than KP (p < 0.001). LP prediction model was able to identify progression earlier than KP irrespective of age category, gender, the severity of keratoconus, presenting visual acuity, astigmatism, and spherical equivalent (P < 0.001). When compared to the first visit the corrected distance visual acuity was more stable in 71% of the eyes at LP prediction visit compared to 50% at KP visit (p < 0.001). CONCLUSION: Through this study, we propose a possible solution to address the shortcomings noted in the current approaches of detecting progression relying only on KP. Avoiding bias towards feature selection from tomography images as done in the current study aids in identifying very subtle changes on the images between visits.

Differences in Image Quality after Three Laser Keratorefractive Procedures for Myopia.

SIGNIFICANCE: Psychophysical estimates of spatial and depth vision have been shown to be better after bilateral ReLEx small-incision lenticule extraction (SMILE) refractive surgery for myopia, relative to photorefractive keratectomy (PRK) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK). The present study provides the optical basis for these findings using computational image quality analysis. PURPOSE: This study aimed to compare longitudinal changes in higher-order wavefront aberrations and image quality before and after bilateral PRK, FS-LASIK, and SMILE refractive procedures for correcting myopia. METHODS: Wavefront aberrations and image quality of both the eyes of 106 subjects (n = 40 for FS-LASIK and SMILE and n = 26 for PRK) were determined pre-operatively and at 1-week, 1-month, 3-month, and 6-month post-operative intervals using computational through-focus analysis for a 6-mm pupil diameter. Image quality was quantified in terms of its peak value and its interocular difference, residual defocus that was needed to achieve peak image quality (best focus), and the depth of focus. RESULTS: The increase in root mean squared deviations of higher-order aberrations post-operatively was lesser after SMILE (1-month visit median [25th to 75th interquartile range], 0.34 µm (0.28 to 0.39 µm]) than after PRK (0.80 µm [0.74 to 0.87 µm]) and FS-LASIK (0.74 µm [0.59 to 0.83 µm]; P ≤ .001), all relative to pre-operative values (0.20 µm [0.15 to 0.30 µm]). The peak image quality dropped and its interocular difference increased, best focus shifted myopically by 0.5 to 0.75 D, and depth of focus widened significantly after PRK and FS-LASIK surgeries, all relative to pre-operative values (P < .001). All these changes were negligible but statistically significant in a minority of instances after SMILE surgery (P ≥ .01). CONCLUSIONS: Although all three refractive surgeries correct myopia, the image quality and its similarity between eyes are better and closer to pre-operative values after SMILE, compared with FS-LASIK and PRK. These results can be explained from the underlying increase in higher-order wavefront aberrations experienced by the eye post-operatively.

Congenital central corneal dermoid: A rare entity.

BACKGROUND: To understand the pathogenesis of a central corneal dermoid (CD) in a 12-day-old child, a comparison of CD specimen was done with limbal dermoid (LD) and cadaveric corneal (CC) specimens by immuno-histochemical staining. METHODS: The child underwent penetrating keratoplasty for visual rehabilitation. The corneal tissue was sent for histo-pathological and immunochemistry evaluation. The corneal specimen obtained was compared the origin of central CD with LD and CC based on their antigenic expression profile. RESULTS: Clinically over a period of 75 months post operatively the child maintained a clear graft. Hematoxylin and Eosin staining of LD had a typical morphology including stratified keratinized epithelium, hair shaft with pilo sebaceous glands, eccrine sweat glands, lymphocytes, and blood vessels. Immuno-histochemical staining showed positive stain for Cytokeratin 3 epithelial marker in the epithelium of CC, LD, and CD. Smooth muscle maker (SMA) was identified in LD and CD but not in the CC as it is devoid of blood vessels. Limbal stem cell maker (P63) was detected only in LD. Vimentin, a mesenchymal stem cell marker stained positively in all three tissues of CC, LD, and CD. CONCLUSIONS: Corneal dermoid showed positive staining for mesodermal tissue components compared to both ectodermal and mesodermal components in limbal dermoid suggesting possibly a different origin of corneal dermoid.

Comparison of total keratometry with corneal power measured by optical low-coherence reflectometry and placido-dual Scheimpflug system.

PURPOSE: To compare the total keratometry (TK) and astigmatism measurements in eyes with cataract using automated keratometry of swept-source optical coherence tomography (ss-OCT), optical low-coherence reflectometry (OLCR), simulated keratometry (SimK), and total corneal power (TCP) of combined placido-dual Scheimpflug imaging system. SETTING: The study was conducted at LV Prasad Eye Institute, Hyderabad, India. DESIGN: Retrospective evaluation of electronic medical records of patients who were evaluated for cataract surgery. METHODS: Twenty-eight eyes of 28 patients were included in the study. All patients evaluated for cataract surgery underwent corneal power measurements using three devices: ssOCT, OLCR, and combined placido-dual Scheimpflug imaging were included in the study. Vector analysis was performed to evaluate corneal astigmatism and Bland-Altman analysis was conducted to evaluate the limits of agreement of similar parameters among devices. RESULTS: The mean TK was statistically significantly different from the keratometry obtained from optical biometers and values measured by the Scheimpflug imaging system. The magnitude of mean difference was greater between TK and TCP (0.75 ± 0.25) compared to other variables. The mean difference in astigmatism between TK, ss-OCT-K (0.09 ± 0.12, p = 0.48), OCLR-K (0.10 ± 0.48, p = 0.91), and TCP (0.09 ± 0.47, p = 0.31) was not statistically significant but was statistically significant between TK and SimK values (0.23D ± 0.49D). The axis of orientation (<20°) of astigmatism was comparable (100%, 28 eyes) between two keratometry variables measured by ss-OCT. CONCLUSION: There appears to be a greater correlation of automated keratometry, and TK values obtained from ss-OCT compared to other variables studied. The measurements from TK, Simk, and TCP cannot be used interchangeably.

Clinical features and microbiology of post-cataract surgery endophthalmitis with and without intracameral moxifloxacin prophylaxis: Endophthalmitis prophylaxis study report 3.

PURPOSE: This study aimed to analyze the clinical presentations, microbiology, and management outcomes of post-cataract surgery endophthalmitis, with and without intracameral moxifloxacin prophylaxis. METHODS: This study was designed as a retrospective, consecutive, comparative case series. Records of consecutive cataract surgery from January 1, 2015, till June 30, 2020, were analyzed. The cases that developed endophthalmitis were analyzed. The endophthalmitis cases were divided by their prophylaxis treatment into two groups: with intracameral moxifloxacin (ICM) and without (N-ICM). Inclusion criteria were (1) age ≥ 18 years, (2) cataract surgery with intraocular lens implantation, (3) endophthalmitis within 6 weeks of cataract surgery, and (4) cataract surgery in the institute by any of the three methods-phacoemulsification, manual small incision cataract surgery, and extracapsular cataract extraction. RESULTS: In the study period, 66,967 cataract surgeries were performed; 48.7% (n = 32,649) did not receive ICM. There was no difference between the N-ICM and ICM groups in the incidence of clinical (n = 21, 0.064% and n = 15, 0.043%; P = 0.23) and culture proven (n = 19, 0.033% and n = 11, 0.023%; P = 0.99) endophthalmitis, respectively. Greater number of patients in the N-ICM group had lid edema (76.2% vs. 40%; P = 0.03), corneal edema (71.4% vs. 33.3%; P = 0.03) and lower presenting vision with available correction (logMAR [logarithm of the minimum angle of resolution] 1.26 ± 1.2 vs. logMAR 0.54 ± 0.85; P = 0.02). The final best-corrected visual acuity following treatment was worse in the N-ICM group (logMAR 1.26 ± 1.2 vs. 0.54 ± 0.85; P = 0.02). CONCLUSION: Endophthalmitis after intracameral moxifloxacin may have relatively milder signs and symptoms and may respond better to treatment.

Changes in post-keratoplasty astigmatism after suture removal: refraction vs tomography vs aberrometry.

AIM: To analyse the changes in magnitude and orientation of astigmatism after suture removal (SR) in keratoplasty eyes as measured by refraction, tomography, and aberrometry. METHODS: Twenty-six eyes of 25 patients after optical keratoplasty requiring SR to reduce the astigmatism during the follow-up period were prospectively included. Eyes with poor quality topography scans or if there were no sutures in the steepest semi meridian were excluded. Corrected distance visual acuity (CDVA), manifest refraction, corneal tomography and aberrometry were performed on all patients before and after SR. RESULTS: The mean age of the patients was 40.8±14.4y. Penetrating keratoplasty was performed in 23 eyes (89%) and deep anterior lamellar keratoplasty was done in 3 eyes (11%). There was a statistically significant reduction in the magnitude of refractive, tomographic and aberrometry astigmatism after SR (P<0.001) at 2h after suture removal. The mean net reduction of the astigmatism was greater as measured by corneal tomography compared to refractive astigmatism (P<0.05). There was no statistically significant change in refractive astigmatism between 2h and 2mo after SR (P=0.55). Vector calculations demonstrated a greater amount of undercorrection in the tomography group and the rotational error was more towards counterclockwise direction. Mean monocular logMAR CDVA improved from 0.57 D to 0.49 D after SR (P=0.002). CONCLUSION: The net reduction in the magnitude of astigmatism after SR is greater in the tomography and aberrometry groups. With one episode of SR, there is no difference in the aberration profile.

Year one of COVID-19 pandemic: Effect of lockdown and unlock phases on cataract surgery at a multi-tier ophthalmology network.

Purpose: To describe the impact of lockdown and unlock phases of the COVID-19 pandemic on cataract surgery at a multitier ophthalmology network. Methods: This cross-sectional hospital-based study included 106,279 eyes operated between March 23, 2019 and March 31, 2021. The data of patients who underwent cataract surgery presenting during the lockdown and unlock phases were compared with the respective periods in the previous year before COVID-19. Results: The cataract surgeries performed decreased to 5.6% (839/14,994) of pre-COVID-19 volumes during the lockdown phase. There was a gradual recovery of the cataract surgeries performed to 86.7% of pre-COVID-19 volumes by May 2020 and exceeded by 17.9% by September 2020. There was a decrease in the number of women who underwent cataract surgery during the lockdown phase (49.11%) compared to the pre-COVID-19 (52.59%) or unlock phase (52.29%, P < 0.001). Patients operated during the lockdown phase were younger when compared to other groups (P < 0.001). The mean LogMAR presenting visual acuity at the time of surgery was worse in patients operated during the lockdown phase (1.84 ± 1.16) as compared to pre-COVID-19 (1.39 ± 1.05) and unlock phases (1.51 ± 1.08, P =<0.001). The proportion of patients with total cataracts were higher during the lockdown and unlock phases compared to the pre-COVID-19 phase (P < 0.001). Conclusion: The first year of the COVID-19 pandemic saw a drastic reduction in the surgical volume in the lockdown phase, which recovered quickly during the unlock period. Patients of younger age, male gender, poor presenting visual acuity, denser cataracts, and living close to the surgical center were able to access surgical care due to lockdown restrictions.

Complications and visual outcomes of cataract surgery in patients with pseudoexfoliation.

PURPOSE: To compare outcomes of cataract surgery performed by ophthalmic trainees and consultants in patients associated with pseudoexfoliation (PXF) METHODS: Retrospective review of medical records of all patients with PXF who had undergone cataract surgery from January 2016 to December 2018 at L V Prasad Eye Institute, Hyderabad, India, were analysed RESULTS: A total of 914 eyes were included in the study; surgeries on 501 (54.8%) eyes with PXF were performed by trainees, while 413 (45.2%) were performed by consultants. Posterior capsule rupture (PCR) with vitreous loss (VL) occurred in significantly fewer eyes operated on by consultants (n = 8, 1.9%) than those operated on by trainees (n = 23, 4.5%) (p = 0.002). Eyes that underwent small incision cataract surgery (n = 100, 21.2%) had a significantly greater number of complications than those that underwent phacoemulsification (n = 31, 7.1%) (p = 0.00001). Multivariate logistic regression analysis shows that chances of a complication are higher when operated on by a trainee (OR = 1.59, 95% CI: 1.09-2.34, p = 0.02).The mean logMAR corrected distance visual acuity of patients one month post-surgery was significantly higher for patients in the consultant group (0.15 ± 0.3) than for those in the trainee group (0.2 ± 0.4) (p = 0.003). CONCLUSION: Patients with PXF operated on by trainees for cataract had a relatively higher risk of developing PCR with VL and had poorer visual outcomes than those operated on by consultants.

Complications of laser-assisted in situ keratomileusis.

Laser-assisted in situ keratomileusis (LASIK) is one of the most commonly performed kerato-refractive surgery globally. Since its introduction in 1990, there has been a constant evolution in its technology to improve the visual outcome. The safety, efficacy, and predictability of LASIK are well known, but complications with this procedure, although rare, are not unknown. Literature review suggests that intraoperative complications include suction loss, free cap, flap tear, buttonhole flap, decentered ablation, central island, interface debris, femtosecond laser-related complications, and others. The postoperative complications include flap striae, flap dislocation, residual refractive error, diffuse lamellar keratitis, microbial keratitis, epithelial ingrowth, refractive regression, corneal ectasia, and others. This review aims to provide a comprehensive knowledge of risk factors, clinical features, and management protocol of all the reported complications of LASIK. This knowledge will help in prevention as well as early identification and timely intervention with the appropriate strategy for achieving optimal visual outcome even in the face of complications.

Effectiveness of simulation-based training for manual small incision cataract surgery among novice surgeons: a randomized controlled trial.

This study was designed to determine the effect of a novel simulation-based training curriculum for scleral tunnel construction in manual small incision cataract surgery (MSICS) compared with traditional training. In this multicenter, investigator-masked, randomized clinical trial, resident surgeons within 3 months of matriculation with minimal or no prior experience with MSICS were assigned either to simulation-based training, the Experimental Group (EG), or to conventional training, the Control Group (CG). EG residents were trained to perform scleral tunnel construction using a simulation-based curriculum (HelpMeSee Eye Surgery Simulator), while residents in the CG followed institution-specific curriculum before progressing to live surgery. Surgical videos of the first 20 attempts at tunnel construction were reviewed by masked video raters. The primary outcome was the total number of any of 9 pre-specified errors. On average, the total number of errors was 9.25 (95% CI 0-18.95) in the EG and 17.56 (95% CI 6.63-28.49) in the CG (P = 0.05); the number of major errors was 4.86 (95% CI 0.13-9.59) in the EG and 10.09 (95% CI 4.76-15.41) in the CG (P = 0.02); and the number of minor errors was 4.39 (95% CI 0-9.75) in the EG and 7.47 (95% CI 1.43-13.51) in the CG (P = 0.16). These results support that novice surgeons trained using the novel simulation-based curriculum performed fewer errors in their first 20 attempts at tunnel construction compared to those trained with a conventional curriculum.

Clinical Outcomes After Bilateral Implantation of a Trifocal Presbyopia-Correcting Intraocular Lens in an Indian Population.

PURPOSE: To evaluate the effectiveness and safety of a presbyopia-correcting trifocal intraocular lens (IOL), AcrySof® IQ PanOptix® (TFNT00), in an Indian population. PATIENTS AND METHODS: This prospective, multicenter, observational, single-arm, post-marketing study included 67 patients undergoing cataract surgery with bilateral implantation of TFNT00 across five Indian sites. Postoperative outcomes were assessed at 3 months after second eye surgery. Effectiveness outcomes included: mean binocular and monocular visual acuity (VA) at distance (4 m), intermediate (60 cm), and near (40 cm); binocular defocus curve; manifest refraction; and subjective symptom questionnaire evaluation. Safety outcomes included the rate of ocular adverse events and mesopic contrast sensitivity. RESULTS: Mean binocular and monocular distance-corrected and uncorrected VAs of 0.1 logMAR or better (approximately 20/25 Snellen) were achieved at distance, intermediate, and near. Overall, ≥70% of patients achieved binocular 0.1 logMAR vision or better across all distances. TFNT00 maintained a mean VA of 0.1 logMAR or better at the defocus range of +0.5 diopters (D) to -2.5 D (200 cm to 40 cm). The subjective symptom questionnaire-assessed frequency of halo visual disturbances was low at Month 3; halos were reported "none of the time" to "only some of the time" in 86.6% of patients. The large majority of patients (98.5%) were "satisfied" or "very satisfied" with their near, intermediate, and distance vision at Month 3, and ≥94.0% of patients reported spectacle independence for tasks at all distances. The adverse event rate was low; no patients discontinued due to an adverse event. CONCLUSION: TFNT00 provided a continuous range of vision of 20/25 or better for distance to near and performed effectively at an intermediate functional distance of 60 cm, resulting in high levels of spectacle independence and patient satisfaction. TFNT00 demonstrated a good safety profile and a low post-operative frequency of halo visual disturbances.

Early results of circularity and centration of capsulotomy prepared by three different methods.

AIM: To compare the difference of capsulotomy produced by precision pulse capsulotomy (PPC), manual (M-CCC), and femtosecond laser assisted capsulotomy (FLAC) in relation to intraocular lens (IOL) centration, circularity and its effect on visual outcomes. METHODS: Prospective, non-randomized comparative study conducted at LV Prasad Eye Institute, Hyderabad, India. Sixty eyes of 52 patients were grouped into 3 (FLAC, PPC and M-CCC) based on capsulotomy techniques used. Twenty consecutive eyes with uneventful phacoemulsification and with no comorbidities affecting the capsulotomy or visual outcome were included in each group. The main outcome measure was IOL centration in relation to capsulotomy and pupil. Secondary outcome measures were post-operative visual acuity, manifest refraction and aberration profile between groups. RESULTS: At 5wk the visual, refractive outcomes and endothelial cell density were comparable between the 3 groups. The median circularity index of FLAC was statistically significantly different to M-CCC or PPC (1-10) groups (P<0.01) but PPC (11-20) was comparable to FLAC. Decentration of IOL center in relation to capsulotomy was seen only between the PPC (1-10) group and FLAC group (P=0.02). The IOL was well centered in relation to the pupil in all the groups (P=0.46). The quality of vision parameters like the higher order aberrations, spherical aberration, coma, trefoil, modular transfer function, and Strehl ratio were comparable between the groups. CONCLUSION: Our study shows that despite differences in the morphology of capsulotomy produced by PPC, M-CCC, FLAC a well-centered IOL can be achieved. The measured capsular morphology parameters do not affect visual outcomes.