Value of optical coherence tomography for anterior segment surgery

Crystalline lens nuclear age prediction as a new biomarker of nucleus degeneration

BACKGROUND

The crystalline lens is a transparent structure of the eye to focus light on the retina. It becomes muddy, hard and dense with increasing age, which makes the crystalline lens gradually lose its function. We aim to develop a nuclear age predictor to reflect the degeneration of the crystalline lens nucleus.

METHODS

First we trained and internally validated the nuclear age predictor with a deep-learning algorithm, using 12 904 anterior segment optical coherence tomography (AS-OCT) images from four diverse Asian and American cohorts: Zhongshan Ophthalmic Center with Machine0 (ZOM0), Tomey Corporation (TOMEY), University of California San Francisco and the Chinese University of Hong Kong. External testing was done on three independent datasets: Tokyo University (TU), ZOM1 and Shenzhen People's Hospital (SPH). We also demonstrate the possibility of detecting nuclear cataracts (NCs) from the nuclear age gap.

FINDINGS

In the internal validation dataset, the nuclear age could be predicted with a mean absolute error (MAE) of 2.570 years (95% CI 1.886 to 2.863). Across the three external testing datasets, the algorithm achieved MAEs of 4.261 years (95% CI 3.391 to 5.094) in TU, 3.920 years (95% CI 3.332 to 4.637) in ZOM1-NonCata and 4.380 years (95% CI 3.730 to 5.061) in SPH-NonCata. The MAEs for NC eyes were 8.490 years (95% CI 7.219 to 9.766) in ZOM1-NC and 9.998 years (95% CI 5.673 to 14.642) in SPH-NC. The nuclear age gap outperformed both ophthalmologists in detecting NCs, with areas under the receiver operating characteristic curves of 0.853 years (95% CI 0.787 to 0.917) in ZOM1 and 0.909 years (95% CI 0.828 to 0.978) in SPH.

INTERPRETATION

The nuclear age predictor shows good performance, validating the feasibility of using AS-OCT images as an effective screening tool for nucleus degeneration. Our work also demonstrates the potential use of the nuclear age gap to detect NCs.

Update on Femtosecond Laser-Assisted Cataract Surgery: A Review

The advent of femtosecond lasers has resulted in a new standard in cataract surgery, intended to overmatch the paradigm of conventional phacoemulsification. Femtosecond laser-assisted cataract surgery (FLACS) enables a higher level of reproducibility, precision, accuracy, and customization when performing several steps of cataract (or lens) surgery. Capsulotomy, corneal incisions, lens fragmentation, and arcuate incisions are the main procedures performed using FLACS. As the demand for better refractive outcomes and spectacle independence increases, the features of FLACS are highly relevant, especially when considering the implantation of premium intraocular lenses, such as toric, enhanced depth-of-focus, or multifocal lenses. The present article reviews the state of the art of femtosecond laser-assisted cataract (lens) surgery, contemplating the advantages and limitations of the two types of femtosecond laser pulses available (high and low energy) by evaluating their reported outcomes and complications.

Peters Anomaly: Novel Non-Invasive Alternatives to Penetrating Keratoplasty

BACKGROUND

Peters' anomaly (PA) is the most commonly encountered congenital corneal opacity (CCO) and displays a wide phenotypical range. The relatively recent adoption of high-quality anterior segment imaging in the form of high-frequency ultrasound biomicroscopy and anterior segment optical coherence tomography has aided in the accurate diagnosis of CCOs, facilitated distinction of PA from "pseudo-Peters' anomaly," and aided in prognostication and surgical risk stratification in PA. While the definitive management of PA, especially the more severe forms, is penetrating keratoplasty (PK), long-term success rates have overall been disappointing. This spurred the development of more non-invasive procedures, such as optical iridectomy and the more recently described selective endothelial removal, which represent viable alternatives to PK, at least in the less severe phenotypes of PA.

METHODS

Literature searches for the components of this review were performed using PubMed, in September 2021. The following keywords and their iterations were employed for the searches: "Peters' anomaly," "anterior segment dysgenesis," "kerato-irido-lenticular dysgenesis," "congenital corneal opacities." These were entered into the PubMed search engine, revealing 2852 related articles. The inclusion criteria included publications in the English language, specific to Peters' anomaly. Fifty-five studies that were published as systematic reviews or as nonrandomized comparative studies (cohort or case series) on the topic of Peters' anomaly were finally selected for this review.

RESULTS

This review provides a summary of Peters' anomaly in the context of advances in diagnosis, classification, and genotype-phenotype correlation of congenital corneal opacities, with a focus on penetrating keratoplasty, its outcomes, and non-invasive surgical options. While conservative therapies such as spontaneous clearing, mydriatic eye drops, and optical iridectomy may have variable success in milder variants of PA, penetrating keratoplasty in these eyes is fraught with several challenges and typically results in poor long-term functional outcomes. The management strategy depends on several variables such as phenotypical severity of PA, laterality, age at presentation, and capacity to adhere to the follow-up schedule. Notwithstanding the choice of treatment, it is essential that early and aggressive amblyopia therapy, a thorough systemic examination, and appropriate referral are undertaken for all patients of PA.

CONCLUSION

Peters' anomaly has seen recent advances in diagnosis, but treatment options remain limited. Focus directed towards less-invasive alternatives to keratoplasty may yield better functional outcomes.

Correction of refractive distortion in whole-eye optical coherence tomography imaging of the mouse eye

Optical coherence tomography (OCT) is an imaging modality that acquires high-resolution cross-sectional images of living tissues and it has become the standard in ophthalmological diagnoses. However, most quantitative morphological measurements are based on the raw OCT images which are distorted by several mechanisms such as the refraction of probe light in the sample and the scan geometries and thus the analysis of the raw OCT images inevitably induced calculation errors. In this paper, based on Fermat's principle and the concept of inverse light tracing, image distortions due to refraction occurred at tissue boundaries in the whole-eye OCT imaging of mouse by telecentric scanning were corrected. Specially, the mathematical correction models were deducted for each interface, and the high-precision whole-eye image was recovered segment by segment. We conducted phantom and in vivo experiments on mouse and human eyes to verify the distortion correction algorithm, and several parameters of the radius of curvature, thickness of tissues and error, were calculated to quantitatively evaluate the images. Experimental results demonstrated that the method can provide accurate and reliable measurements of whole-eye parameters and thus be a valuable tool for the research and clinical diagnosis.

Anterior segment optical coherence tomography characteristics and management of a unique spectrum of foreign bodies in the cornea and anterior chamber

Purpose

To report anterior-segment optical coherence tomography (ASOCT) characteristics of different types of corneal and anterior chamber (AC) foreign bodies (FBs) and their usefulness in diagnosis and management.

Methods

This is a retrospective descriptive clinical study involving 11 eyes of 11 patients who presented at the outpatient department of a tertiary ophthalmic care center from January 2017 to January 2022. All patients had a diagnosed or suspected corneal FB. All participants underwent a comprehensive ophthalmological examination, followed by slit-lamp photography and ASOCT. FB removal was done where required by an external, internal, or combined approach.

Results

The mean age of patients was 28.2 (7-53) years. Ten were male, and one was female. Seven patients had a definitive positive history of injury; in one, there was a history suggestive of trauma, one had the post-operative complication of scleral buckling surgery, and two patients had a history of insect fall in the eyes. Three patients had acute, four had sub-acute, and four had chronic presentations. Descemet's membrane (DM) breach was suspected in three cases of deep FB, which was later confirmed on ASOCT. In two cases, DM was presumed to be intact clinically, but ASOCT showed an AC penetration. The FB was removed in seven patients, one via slit-lamp, one via an external approach, two via an internal approach, and three via a combined approach.

Conclusion

ASOCT facilitates non-invasive rapid imaging of ocular tissue at various depths, provides an accurate assessment of FB characteristics, and thereby serves as an additional tool in our armamentarium for diagnosis and management of deep corneal and AC FBs.

Anterior scleral thickness dimensions by swept-source optical coherence tomography

Clinical relevance: Given the association of scleral characteristics with many ophthalmological diseases, there is an important need to measure the anterior scleral thickness (AST).Background: This study examined the AST by swept-source optical coherence tomography (SS-OCT) in a large healthy population, assessing also the reproducibility of AST measurements and the correlation with different parameters.Methods: Cross-sectional study in 605 eyes of 605 subjects. AST measurements were made in the temporal and nasal quadrants at 1 (AST1) and 3 mm (AST3) from the scleral spur using SS-OCT. These dimensions were then assessed for associations in a multivariate model with the factors age, sex, refractive error, conjunctival-Tenon capsule thickness (CTT), anterior chamber angle (ACA), intraocular pressure (IOP), iris thickness (IT), limbus-sulcus distance (LSD), and ciliary muscle thickness (CMT). The reproducibility of the AST measurements was determined in 30 of the participants.Results: The mean age was 42.6 ± 17.3 years (range 5 to 86 years). The following means were recorded: AST1 was 522.3 ± 65.7 µm (355 to 761) and 558.4 ± 71.5 µm (357 to 889); AST2 was 513.3 ± 67.3 µm (343 to 732) and 574.4 ± 71.6 µm (389 to 789), and AST3 548.8 ± 71.9 µm (356 to 762) and 590.1 ± 76.6 µm (414 to 873) in the temporal and nasal quadrants respectively, being thicker the nasal quadrant (all p < 0.001). A positive correlation was detected between AST and age, sex, temporal ACA and LSD (all p ≤ 0.043), being negative the correlation with CMT (p ≤ 0.044). No correlation was observed between AST measurements and refractive error, CTT and IT (p ≥ 0.064). The reproducibility of AST measurements was excellent (intraclass correlation coefficient ≥0.951).Conclusions: SS-OCT allows for in vivo AST measurements. Our data contained a wide range of measurements, showing an association between AST and age, sex, ACA, LSD and CMT.

Tear Film Cytokine Profile of Patients With the Boston Keratoprosthesis Type 1: Comparing Patients With and Without Glaucoma

Purpose

Inflammatory cytokines are involved in glaucoma pathogenesis. The purpose is to compare cytokine levels in the tear film of Boston keratoprosthesis (KPro) patients with and without glaucoma, relative to controls, and correlate levels with clinical parameters.

Methods

This cross-sectional study enrolled 58 eyes (58 patients): 41 KPro eyes with glaucoma, 7 KPro eyes without glaucoma, and 10 healthy controls. Twenty-seven cytokines were measured by multiplex bead immunoassay. Intraocular pressure (IOP), cup-to-disk ratio (CDR), retinal nerve fiber layer, visual acuity, topical medications, and angle closure were assessed in all KPro eyes. Cytokine levels between groups were analyzed by nonparametric tests, and correlations with clinical parameters by Spearman's test.

Results

Levels of TNF-ɑ, IL-1β, FGF-basic, and IFN-ɣ were significantly higher in KPro with glaucoma compared to KPro without (P = 0.020; 0.008; 0.043; 0.018, respectively). KPro groups had similar characteristics and topical antibiotic/steroid regimen. Levels of IL-1Ra, IL-15, VEGF, and RANTES were significantly higher in KPro with glaucoma compared to controls (P < 0.001; = 0.034; < 0.001; = 0.001, respectively). IL-1β and IFN-ɣ levels were positively correlated with CDR (r = 0.309, P = 0.039 and r = 0.452, P = 0.006, respectively) and IOP (r = 0.292, P = 0.047 and r = 0.368, P = 0.023, respectively). TNF-α and FGF-basic levels were positively correlated with CDR (r = 0.348, P = 0.022 and r = 0.344, P = 0.021, respectively).

Conclusions

TNF-α, IL-1β, FGF-basic, IFN-ɣ are elevated in tears of KPro patients with glaucoma and correlate with CDR and IOP. These results show, for the first time in humans, concordance with documented elevations of TNF-α and IL-1β in the murine KPro model. Ocular surface inflammation may reflect inflammatory processes of KPro glaucoma.

An Efficient Lens Structures Segmentation Method on AS-OCT Images

Lens structures segmentation on anterior segment optical coherence tomography (AS-OCT) images is a fundamental task for cataract grading analysis. In this paper, in order to reduce the computational cost while keeping the segmentation accuracy, we propose an efficient segmentation method for lens structures segmentation. At first, we adopt an efficient semantic segmentation network in the work, and used it to extract the lens area image instead of the conventional object detection method, and then used it once again to segment the lens structures. Finally, we introduce the curve fitting processing (CFP) on the segmentation results. Experiment results show that our method has good performance on accuracy and processing speed, and could be applied to CASIA II device for practical applications.

Developments in Contact Lens Imaging: New Applications of Optical Coherence Tomography

Optical coherence tomography (OCT) is a high-speed and non-contact optical imaging technology widely used for noninvasive cross-sectional imaging of biological objects. Two main OCT technologies have been developed: time domain and Fourier domain technologies. The latter can be further divided into spectral domain OCT, which uses a broadband light source and a spectrometer as a detector, and swept source OCT, which employs a quickly-rotating laser source. Advances in OCT technology have made it one of the most helpful devices in ophthalmic practice. Fourier OCT has revolutionized imaging of the posterior segment of the eye, as well as of anterior structures and has enhanced the ability to diagnose and manage patients. It provides high-resolution information about the tear film, contact lens (CL), a qualitative and quantitative assessment of the anterior eye that is important in contact lens fitting, and allows possible eye surface changes while wearing contact lenses to be monitored. Potential swept source OCT technology applications include industrial processes of lens design and quality control. In this paper, we describe clinical applications and outline a variety of multifunctional uses of OCT in the field of refractive error correction with contact lenses.

Anterior segment optical coherence tomography and its clinical applications

Anterior segment optical coherence tomography (AS-OCT) has become one of the cornerstones of non-contact imaging modalities for assessing such structures as the cornea, anterior chamber angle, aqueous outflow pathway, sclera, and ocular surface structures. As such, it has a broad range of clinical applications, which have been independently reported in the literature. This paper aims to present a review of extant literature on the utility of AS-OCT and its efficacy in clinical applications, and to evaluate the quality of available evidence. The following databases were searched from inception to 24 June 2018: Medline via Ovid, Cochrane Central Register of Controlled Trials, PubMed, World Health Organization International Clinical Trials Registry Platform, EMBASE, and CINAHL. Bibliographies of identified papers were hand searched. Inclusion criteria: articles describing or assessing the use of OCT for visualising the AS. The authors excluded studies without an identified primary outcome variable. One author independently selected studies, extracted data, and assessed for risk of bias using PRISMA guidelines. This review included 82 studies, of which there were 11 cohort studies, 37 case series, 10 case studies, 21 comparative observational studies, and three non-systematic review articles. Primary outcome variables included anterior chamber angle, angle opening distance, angle recess area, trabecular iris angle, trabecula-iris space area, corneal thickness, tear meniscus height, tear meniscus area, tear meniscus volume, and the morphology of AS structures, including the ocular surface, blebs, flaps, and graft sites. This review attempts to encompass the breadth and depth of evidence for AS-OCT in the arena of diagnostics, therapeutics, and prognostics. At the same time, it brings to light the dearth of high-level evidence on this topic, suggesting the important role of randomised controlled trials and meta-analyses for the future validation of this technology.

Anterior segment optical coherence tomography for evaluation of cornea and ocular surface

Current corneal assessment technologies make the process of corneal evaluation extremely fast and simple. Several devices and technologies allow to explore and manage patients better. Optical coherence tomography (OCT) technology has evolved over the years, and hence a detailed evaluation of anterior segment (AS) structures such as cornea, conjunctiva, tear meniscus, anterior chamber, iris, and crystalline lens has been possible in a noncontact and safe procedure. The purpose of this special issue is to present and update in the evaluation of cornea and ocular surface, and this paper reviews a description of the AS-OCT, presenting the technology and common clinical uses of OCT in the management of diseases involving cornea and ocular surface to provide an updated information of the clinical recommendations of this technique in eye care practice.

Correlation of the anterior ocular segment biometry with HbA1c level in type 2 diabetes mellitus patients

Objectives

To compare the anterior ocular segment biometry among Type 2 diabetes mellitus (DM) with no diabetic retinopathy (DR) and non-proliferative diabetic retinopathy (NPDR), and to evaluate the correlation of anterior ocular segment biometry with HbA1c level.

Methods

A cross-sectional study was conducted in Hospital Universiti Sains Malaysia, Kelantan from November 2013 till May 2016 among Type 2 DM patients (DM with no DR and DM with NPDR). The patients were evaluated for anterior ocular segment biometry [central corneal thickness (CCT), anterior chamber width (ACW), angle opening distance (AOD) and anterior chamber angle (ACA)] by using Anterior Segment Optical Coherence Tomography (AS-OCT). Three ml venous blood was taken for the measurement of HbA1c.

Results

A total of 150 patients were included in this study (DM with no DR: 50 patients, DM with NPDR: 50 patients, non DM: 50 patients as a control group). The mean CCT and ACW showed significant difference among the three groups (p < 0.001 and p = 0.015 respectively). Based on post hoc result, there were significant mean difference of CCT between non DM and DM with NPDR (mean difference 36.14 μm, p < 0.001) and also between non DM and DM with no DR (mean difference 31.48 μm, p = 0.003). The ACW was significantly narrower in DM with NPDR (11.39 mm SD 0.62) compared to DM with no DR (11.76 mm SD 0.53) (p = 0.012). There were no significant correlation between HbA1c and all the anterior ocular segment biometry.

Conclusion

Diabetic patients have significantly thicker CCT regardless of retinopathy status whereas ACW was significantly narrower in DM with NPDR group compared to DM with no DR. There was no significant correlations between HbA1c and all anterior ocular segment biometry in diabetic patients regardless of DR status.

Descemet membrane detachment during cataract surgery: etiology and management

PURPOSE OF REVIEW

The review updates the mechanisms, clinical presentations, diagnoses, and managements of Descemet membrane detachment during cataract surgery.

RECENT FINDINGS

The advent of new imaging techniques such as anterior segment optical coherence tomography and better comprehension of the clinical and pathological aspects of detachment have improved the diagnosis and treatment of this complication to the extent that the first algorithms and protocols have been proposed.

SUMMARY

Though infrequent, Descemet membrane detachment is a complication of intraocular surgery, including cataract surgery and phacoemulsification. Since the first systematic description and classification in the literature by Samuels in 1928 and its characterization as a potential sight-threatening condition by Scheie in 1964, plenty of retrospective and anecdotal evidence contribute to uncertainty and debate. The main controversy still lies in the choice between conservative treatment in hopes of spontaneaous reattachment and surgical treatment in a timely manner to maximize visual recovery.

Utility of anterior segment swept-source optical coherence tomography for imaging eyes with antecedent ocular trauma

PURPOSE

To evaluate the utility of swept source optical coherence tomography (SS-OCT) for the analysis of anterior segment structures in cases with previous traumatic eye injuries.

OBSERVATIONS

We report three eyes of three patients with anterior segment traumatic eye injury and highlight the role of SS-OCT in their evaluation and management. This technology enabled us to visualize the structural details of anterior segment of the eye and augment the clinical examination in our patients. Given that it is non-invasive and that there is no contact involved, it may be an ideal imaging modality for traumatic eye injuries for viewing the details before and after any clinical intervention especially in the sub-acute setting.

CONCLUSIONS

The anterior segment SS-OCT is a useful device allowing non-invasive, non-contact, real-time, cross-sectional anterior segment images of eyes with previous ocular trauma.

Applications of Anterior Segment Optical Coherence Tomography in Cornea and Ocular Surface Diseases

Optical coherence tomography (OCT) is a noncontact technology that produces high-resolution cross-sectional images of ocular tissues. Anterior segment OCT (AS-OCT) enables the precise visualization of anterior segment structure; thus, it can be used in various corneal and ocular surface disorders. In this review, the authors will discuss the application of AS-OCT for diagnosis and management of various corneal and ocular surface disorders. Use of AS-OCT for anterior segment surgery and postoperative management will also be discussed. In addition, application of the device for research using human data and animal models will be introduced.

Change of Optical Intensity during Healing Process of Corneal Wound on Anterior Segment Optical Coherence Tomography

The purpose of this study is to investigate the process of corneal wound healing after penetrating injury with the change in optical intensity on anterior segment optical coherence tomography (AS-OCT) and to investigate factors associated with severity of corneal scar. Forty-seven eyes from 47 patients with repaired corneal laceration were included. AS-OCT was performed on 1day, 1week, 1, 3 and 6 months after primary repair. Internal aberrations of wound edges were observed on AS-OCT images. Parameters including height of steps, width of gaps, maximal corneal thickness, area and optical intensity of corneal wound/scar were measured. The relationship between the parameters at day 1 and the optical intensity at 6 months were analyzed. The results showed that optical intensity of corneal wound/scar increased from 124.1 ± 18.8 on day 1 postoperatively to 129.3 ± 18.7, 134.2 ± 23.4, 139.7 ± 26.5, 148.2 ± 26.4 at 1 week, 1 month, 3 months and 6 months postoperatively. Height of steps at 1 day after surgery was the only factor identified as correlated with optical intensity of corneal scar at 6 months (beta = 0.34, p = 0.024). The increase of optical intensity represents the process of fibrosis of corneal wound healing. Higher step after suturing is associated with more severity of corneal scar at last.

An angle-supported foldable phakic intraocular lens for correction of myopia: A five-year follow-up

OBJECTIVE

To evaluate the efficacy and safety of an angle-supported foldable phakic intraocular lens (pIOL) for the correction of moderate to high myopia after 5 years follow-up.

METHODS

Prospective and retrospective, observational, longitudinal, non-randomised consecutive series of cases conducted on a total of 100 eyes of 67 patients with moderate to high myopia implanted with an Acrysof Cachet pIOL (Alcon Laboratories Inc.) with the aim of minimising the refractive error. The ages ranged between 18 to 60years. Uncorrected distance visual acuity (UDVA), manifest refraction, corrected distance visual acuity (CDVA), endothelial cells density, pIOL position, intraocular pressure, and complications were recorded preoperatively and during the 5 year follow-up.

RESULTS

Five years after implantation, the mean manifest spherical equivalent refraction reduced significantly from -11.62±3.35 dioptres (D) to -0.33±0.85D. UDVA was 20/20 or better in 5 of 25 cases (20%), and 20/40 or better in 22 cases (88%). CDVA was 20/20 or better in 17 cases (68%), and 20/32 or better in 23 cases (92%) of eyes. The residual refractive error was within ±0.50D of emmetropia in 12 cases (48%), and within ±1.00D in 19 cases (76%). Mean endothelial cell loss at 5 years was 11.8% central, and 13.7% peripheral. Mean endothelium-pIOL distance was 2.11±0.18mm, and mean pIOL-crystalline distance was 0.88±0.20mm.

CONCLUSIONS

This angle supported pIOL provided a favourable refractive correction and predictability, as well as acceptable safety in patients with moderate to high myopia. Although endothelial cell density decreased over 5years, the results are within the range reported in previous studies with other pIOLs.

Comparing Gonioscopy With Visante and Cirrus Optical Coherence Tomography for Anterior Chamber Angle Assessment in Glaucoma Patients

PURPOSE

The aim of this study was to compare gonioscopy with Visante and Cirrus optical coherence tomography (OCT) for identifying angle structures and the presence of angle closure in patients with glaucoma. A secondary objective was to assess interrater agreement for gonioscopy grading among 3 independent examiners.

METHODS

Gonioscopy grading using Spaeth Classification and determination of angle-closure risk was performed on 1 randomly selected eye for 50 phakic patients. Images of the same eye using both Visante and Cirrus OCT were obtained in both light and dark conditions. Agreement of angle closure among 3 devices and interrater agreement for gonioscopy were determined using Cohen's κ (K) or Kendall's coefficient of concordance (W).

RESULTS

Of the 50 patients, 60% were female, 64% were white, and the mean age was 62 years. Angle closure was detected in 18%, 16%, and 48% of quadrants with Visante, Cirrus, and gonioscopy, respectively. The scleral spur was identified in 56% and 50% of quadrants with Visante and Cirrus OCT, respectively. Visante and Cirrus OCT showed moderate agreement in detecting angle closure (K=0.42 light, K=0.53 dark) but slight-to-fair agreement with gonioscopy (Visante K=0.25, Cirrus K=0.15). Gonioscopy demonstrated substantial agreement in angle closure (K=0.65 to 0.68) and angle-closure risk assessment (W=0.83) among 3 examiners.

CONCLUSIONS

Visante and Cirrus OCT imaging may have limited ability to identify angle closure because of difficulty identifying angle structures. Gonioscopy by well-trained clinicians had remarkably consistent agreement for identifying angle-closure risk.

Metrics of the normal anterior sclera: imaging with optical coherence tomography

BACKGROUND

To investigate anterior scleral thickness in a cohort of healthy subjects using enhanced depth imaging anterior segment optical coherence tomography.

METHODS

Observational case series. The mean scleral thickness in the inferonasal, inferotemporal, superotemporal, and superonasal quadrant was measured 2 mm from the scleral spur on optical coherence tomography in healthy volunteers.

RESULTS

Fifty-three eyes of 53 Caucasian patients (25 male and 28 female) with an average age of 48.6 years (range: 18 to 92 years) were analysed. The mean scleral thickness was 571 μm (SD 84 μm) in the inferonasal quadrant, 511 μm (SD 80 μm) in the inferotemporal quadrant, 475 (SD 81 μm) in the superotemporal, and 463 (SD 64 μm) in the superonasal quadrant. The mean scleral thickness was significantly different between quadrants (p < 0.0001, repeated measures one-way ANOVA). The association between average scleral thickness and age was statistically significant (p < 0.0001, Pearson r = 0.704).

CONCLUSIONS

Enhanced depth imaging optical coherence tomography revealed the detailed anatomy of the anterior sclera and enabled non-invasive measurements of scleral thickness in a non-contact approach. The anterior scleral thickness varies significantly between quadrants, resembling the spiral of Tillaux. An association of increasing scleral thickness with age was found.

Optical coherence tomography in the diagnosis of scleritis and episcleritis

PURPOSE

To describe the optical coherence tomography (OCT) findings in eyes with active anterior scleritis and compare the findings to those with episcleritis and normal controls.

DESIGN

Prospective evaluation of a diagnostic test.

METHODS

We included a total of 30 eyes of 30 patients with unilateral anterior scleral or episcleral inflammation. The contralateral 30 eyes with no active ocular disease served as controls. OCT was performed over the anterior sclera in the inflamed area on all cases. The OCT images were analyzed to determine the thickness of the sclera and the presence or absence of scleral hyporeflective areas representing intrascleral edema.

RESULTS

There were 17 male and 13 female patients. The mean age was 43 years with an age range of 21-77 years. Eighteen patients had anterior scleritis and 12 patients had episcleritis. The mean transconjunctival scleral thickness was 747 μm (SD ± 68.97) with a range of 616-877 μm in normal eyes, 882 μm (SD ± 87.35) with a range of 773-1089 μm in patients with scleritis, and 825 μm (SD ± 85.57) with a range of 718-949 μm in patients with episcleritis.

CONCLUSIONS

Patients with active anterior scleritis showed increased thickness of the sclera and presence of intrascleral hyporeflective areas of edema by OCT compared to patients with episcleritis and normal eyes. OCT adds both qualitative and quantitative information to diagnosis and monitoring of patients with scleritis.

Estimation of intraocular lens power calculation after myopic corneal refractive surgery: using corneal height in anterior segment optical coherence tomography

PURPOSE

To investigate the feasibility of estimating effective lens position (ELP) and calculating intraocular lens power using corneal height (CH), as measured using anterior segment optical coherence tomography (AS-OCT), in patients who have undergone corneal refractive surgery.

METHODS

This study included 23 patients (30 eyes) who have undergone myopic corneal refractive surgery and subsequent successful cataract surgery. The CH was measured with AS-OCT, and the measured ELP (ELPm) was calculated. Intraocular lens power, which could achieve actual emmetropia (Preal), was determined with medical records. Estimated ELP (ELPest) was back-calculated using Preal, axial length, and keratometric value through the SRK/T formula. After searching the best-fit regression formula between ELPm and ELPest, converted ELP and intraocular lens power (ELPconv, Pconv) were obtained and then compared to ELPest and Preal, respectively. The proportion of eyes within a defined error was investigated.

RESULTS

Mean CH, ELPest, and ELPm were 3.71 ± 0.23, 7.74 ± 1.09, 5.78 ± 0.26 mm, respectively. The ELPm and ELPest were linearly correlated (ELPest = 1.841 × ELPm - 2.018, p = 0.023, R = 0.410) and ELPconv and Pconv agreed well with ELPest and Preal, respectively. Eyes within ±0.5, ±1.0, ±1.5, and ±2.0 diopters of the calculated Pconv, were 23.3%, 66.6%, 83.3%, and 100.0%, respectively.

CONCLUSIONS

Intraocular lens power calculation using CH measured with AS-OCT shows comparable accuracy to several conventional methods in eyes following corneal refractive surgery.

In vivo evaluation of the cornea and conjunctiva of the normal laboratory beagle using time- and Fourier-domain optical coherence tomography and ultrasound pachymetry

OBJECTIVE

To obtain normative data for the canine cornea and conjunctiva using high-resolution time- and Fourier-domain optical coherence tomography (TD-OCT and FD-OCT) and ultrasound pachymetry (USP).

ANIMALS

One hundred sixty-eight eyes of 133 healthy young intact laboratory beagles.

PROCEDURES

The cornea and conjunctiva of 16 eyes of 8 healthy young intact female beagles were imaged using FD-OCT. Corneal thickness was measured with FD-OCT and USP, while corneal epithelial thickness and conjunctival epithelial thickness were measured with FD-OCT. The central corneal thickness (CCT) was determined in 152 eyes of 125 healthy young adult intact female (35) and male (90) beagles using TD-OCT. Mixed effects linear regression was used for statistical analysis.

RESULTS

The CCT was (mean ± standard deviation) 497.54 ± 29.76, 555.49 ± 17.19, and 594.81 ± 33.02 μm as measured by FD-OCT, USP, and TD-OCT, respectively. The central, superior paraxial, superior perilimbal corneal epithelial thickness and superior bulbar conjunctival epithelial thickness were 52.38 ± 7.27, 56.96 ± 6.47, 69.06 ± 8.84 and 42.98 ± 6.17 μm, respectively. When comparing techniques used for measuring CCT (USP vs. FD-OCT and FD-OCT vs. TD-OCT), USP and TD-OCT generated significantly greater values in comparison with FD-OCT (both P < 0.001). For all dogs, CCT increased with increasing age and body weight (both P < 0.001) and was higher in intact males vs. females using TD-OCT (P = 0.034).

CONCLUSION

High-resolution FD-OCT and TD-OCT provide detailed noninvasive evaluation of in vivo canine anterior segment structures. Normative values of the canine cornea and conjunctiva are reported.

Limitations in imaging common conjunctival and corneal pathologies with fourier-domain optical coherence tomography

Purpose:

To describe the limitations of Fourier-domain optical coherence tomography (OCT) in imaging common conjunctival and corneal pathology.

Materials and Methods:

Retrospective, single-center case series of 40 patients with conjunctival and cornea pathology.

Results:

Fourier-domain OCT imaged laser in situ keratomileusis (LASIK) flaps in detail, including its relation to other corneal structures and abnormalities. Similarly, in infectious or degenerative corneal disorders, Fourier-domain OCT successfully showed the extent of infiltration or material deposition, which appeared as hyper-reflective areas. In cases with pterygium, the underlying cornea could not be imaged. All cases of common conjunctival pathologies, such as nevus or pinguecula, were successfully imaged in detail. Nevi, scleritis, pterygium, pinguecula, and subconjunctival hemorrhage were hyper-reflective lesions, while cysts and lymphangiectasia were hyporeflective. The details of the underlying sclera were not uniformly imaged in conjunctival pathologies. Fourier-domain OCT imaged the trabeculectomy bleb in detail, whereas the details of structures of the anterior chamber angle were not routinely visualized in all cases.

Conclusions:

Light scatter through vascularized, densely inflamed, or thick lesions limits the imaging capabilities of Fourier-domain anterior segment OCT.

Full anterior segment biometry with extended imaging range spectral domain optical coherence tomography at 1340 nm

We demonstrate an extended-imaging-range anterior-segment optical coherence tomography (eAS-OCT) system for the biometric assessment of full AS in human eye. This newly developed eAS-OCT operating at 1340-nm wavelength band is simultaneously capable of an imaging speed of 120 kHz A-line scan rate, an axial resolution of 7.2 μm, and an extended imaging range of up to 16 mm in air. Imaging results from three healthy subjects and one subject with a narrow-angle demonstrate the instrument's utility. With this system, it can provide anatomical dimensions of AS, including central corneal thickness, anterior chamber width, anterior chamber depth, crystalline lens vault, crystalline lens thickness, angle opening distance (AOD500/AOD750), and the area described by the trabecular-iris space (TISA500/TISA750) at 500/750  μm. We also use eAS-OCT to image and quantify dynamic functional changes of the AS in response to a light stimulus that induces physiological pupillary changes as well as accommodative efforts that induce lens changes. The results show that the described eAS-OCT is able to provide full anatomical biometry for AS and is useful for the studies where the dynamic response of AS compartment to certain stimulus is required.

Current trends in the monitoring and treatment of diabetic retinopathy in young adults

The diagnosis and treatment of diabetic retinopathy (DR) in young adults have significantly improved in recent years. Research methods have widened significantly, for example, by introducing spectral optical tomography of the eye. Invasive diagnostics, for example, fluorescein angiography, are done less frequently. The early introduction of an insulin pump to improve the administration of insulin is likely to delay the development of diabetic retinopathy, which is particularly important for young patients with type 1 diabetes mellitus (T1DM). The first years of diabetes occurring during childhood and youth are the most appropriate to introduce proper therapeutic intervention before any irreversible changes in the eyes appear. The treatment of DR includes increased metabolic control, laserotherapy, pharmacological treatment (antiangiogenic and anti-inflammatory treatment, enzymatic vitreolysis, and intravitreal injections), and surgery. This paper summarizes the up-to-date developments in the diagnostics and treatment of DR. In the literature search, authors used online databases, PubMed, and clinitrials.gov and browsed through individual ophthalmology journals, books, and leading pharmaceutical company websites.

Reduced fluorescein angiography and fundus photography use in the management of neovascular macular degeneration and macular edema during the past decade

PURPOSE

We assessed recent trends in the use of diagnostic testing for neovascular age-related macular degeneration (NVAMD) and macular edema (ME).

METHODS

Claims data from a managed-care network were analyzed on patients with NVAMD (n = 22,954) or ME (n = 31,810) to assess the use of fluorescein angiography (FA), fundus photography (FP), and optical coherence tomography (OCT) from 2001 to 2009. Repeated-measures logistic regression was performed to compare patients' odds of undergoing these procedures in 2001, 2005, and 2009. In addition, the proportions of patients with an incident NVAMD or ME diagnosis in 2003 or 2008 who underwent FA, FP, and OCT were compared.

RESULTS

From 2001 to 2009, among patients with NVAMD, the odds of undergoing OCT increased 23-fold, whereas the odds of receiving FA and FP decreased by 68% and 79%, respectively. Similar trends were observed for ME. From 2003 to 2008, the proportion of patients undergoing OCT within 1 year of initial diagnosis increased by 315% for NVAMD and by 143% for ME; the proportion undergoing OCT without FA within 1 year increased by 463% for NVAMD and by 216% for ME.

CONCLUSIONS

Use of OCT increased dramatically during the past decade, whereas use of FA and FP declined considerably, suggesting that OCT may be replacing more traditional diagnostic testing in patients with NVAMD or ME. Future studies should evaluate whether this increased reliance on OCT instead of FA and FP affects patient outcomes.

Anterior segment imaging in combat ocular trauma

Purpose. To evaluate the use of ocular imaging to enhance management and diagnosis of war-related anterior segment ocular injuries. Methods. This study was a prospective observational case series from an ongoing IRB-approved combat ocular trauma tracking study. Subjects with anterior segment ocular injury were imaged, when possible, using anterior segment optical coherence tomography (AS-OCT), confocal microscopy (CM), and slit lamp biomicroscopy. Results. Images captured from participants with combat ocular trauma on different systems provided comprehensive and alternate views of anterior segment injury to investigators. Conclusion. In combat-related trauma of the anterior segment, adjunct image acquisition enhances slit lamp examination and enables real time In vivo observation of the cornea facilitating injury characterization, progression, and management.

Baerveldt drainage tube motility in the anterior chamber

PURPOSE

To investigate the stability in position of the Baerveldt glaucoma drainage tube over time and to study movement of the drainage tube in the anterior chamber (AC) under varying light conditions.

METHODS

This prospective study included 70 eyes with implantation of a Baerveldt glaucoma drainage tube in the anterior chamber. Anterior segment optical coherence tomography (AS-OCT) images were made preoperatively to quantify AC depth. AS-OCT images were made twice under photopic and twice under scotopic conditions, in the angle parallel to the Baerveldt tube to quantify drainage tube position, at 3, 6, 12, and 24 months postoperatively. Tube-corneal (T-C) and tube-iris (T-I) distances were measured. Additionally, the central AC depth and the peripheral angle opening (AOD 500) were determined. Two subgroups were distinguished according to tube position: free in the AC (group 1, n = 48) and transiridal (group 2, n = 22).

RESULTS

After 24 months of follow-up, the drainage tube was found to move statistically significantly closer (0.12 mm) to the corneal endothelium in group 1 (p<0.01). There was no statistically significant difference in T-C distance over time in group 2. The T-C distance did not differ under photopic versus scotopic circumstances (p = 0.32). In both groups, the T-I distance was larger under scotopic conditions, a result of pupil dilation.

CONCLUSIONS

The Baerveldt glaucoma drainage tube remained in a stable position when a transiridal implantation was performed, whereas the tube moved closer to the endothelium when placed free into the AC. Transiridal implantation of the Baerveldt tube seems a safe alternative for tube implantation with respect to tube motility.

Anterior segment imaging and the intraocular pressure lowering effect of cataract surgery for open and narrow angle glaucoma

Anterior segment imaging modalities including anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) are increasingly widespread, and can quantify several parameters of the anterior segment, such as anterior chamber depth and angle anatomy. These parameters are important to assess, particularly in patients with forms of narrow angle glaucoma. In many cases of open and narrow angle glaucoma, cataract extraction has been shown to result in favorable modification of these parameters, and a lasting decrease in intraocular pressure. Anterior segment imaging has the ability to enable the development of predictive models regarding the potential intraocular pressure lowering effect of cataract extraction in a given individual.

The use of anterior segment imaging after trabeculectomy

Evaluation of patients after trabeculectomy can be aided by the use of anterior segment imaging. Two commonly used forms of imaging are ultrasound biomicroscopy (UBM) and optical coherence tomography (OCT). Both modalities can be used to assess bleb morphology and how it affects treatment outcome, measure anterior chamber biometry, identify the presence of supraciliochoroidal fluid, cyclodialysis clefts and malignant glaucoma, and evaluate treatment modalities after trabeculectomy such as in laser suture lysis and needling. OCT, with its finer resolution, is able to view the bleb wall anatomy in detail and because of its non-contact nature can examine the eye sooner after trabeculectomy. UBM, on the other hand, is superior for the visualization of deeper structures such as the ciliary body and posterior chamber essential to identify malignant glaucoma.

Anterior segment biometry using ultrasound biomicroscopy and the Artemis-2 very high frequency ultrasound scanner

Purpose

To compare the precision of anterior chamber angle (ACA) and anterior chamber depth (ACD) measurements taken with ultrasound biomicroscopy (UBM) and the Artemis-2 Very High Frequency Ultrasound Scanner (VHFUS) in normal subjects.

Design

Prospective study.

Methods

We randomly selected one eye from each of 59 normal subjects in this study. Two subjects dropped out of the study; the associated data were excluded from analysis. ACA and ACD measurements were obtained using the VHFUS and the UBM. The results were compared statistically using repeated-measures analysis of variance for the intraobserver repeatability, unpaired t-test, and limits of agreement.

Results

The average ACA values for the UBM and the VHFUS (±standard deviation) were 41.83° ± 5.03° and 33.36° ± 6.03°, respectively. The average ACD values were 2.96 ± 0.34 mm and 2.87 ± 0.31 mm. The intraobserver repeatability analysis of variance P-values for ACA and ACD measurements using UBM were 0.10 and 0.68, respectively; for the Artemis-2 VHFUS, the respective values were 0.68 and 0.09. The difference in ACA measurements was statistically significant (t = 8.41; P < 0.0001), while the difference in ACD values was not (t = 1.51; P < 0.13). The mean ACA difference was 8.50° ± 2.50°, and the limits of agreement were +13.30° to −3.60°. The mean ACD difference was 0.09 ± 0.27 mm, and the limits of agreement ranged from 0.61 mm to −0.43 mm. The mean difference percentage of ACD was 3.1% for both instruments.

Conclusion

In case of the ACD, both instruments can be used interchangeably; however, with the ACA instruments, they cannot be used interchangeably.

Repeatability and reproducibility of corneal thickness using SOCT Copernicus HR

PURPOSE

The aim of this study is to determine the reliability of corneal thickness measurements derived from SOCT Copernicus HR (Fourier domain OCT).

METHODS

Thirty healthy eyes of 30 subjects were evaluated. One eye of each patient was chosen randomly. Images were obtained of the central (up to 2.0 mm from the corneal apex) and paracentral (2.0 to 4.0 mm) cornea. We assessed corneal thickness (central and paracentral) and epithelium thickness. The intra-observer repeatability data were analysed using the intra-class correlation coefficient (ICC) for a range of 95 per cent within-subject standard deviation (S(W)) and the within-subject coefficient of variation (C(W)). The level of agreement by Bland-Altman analysis was also represented for the study of the reproducibility between observers and agreement between methods of measurement (automatic versus manual).

RESULTS

The mean value of the central corneal thickness (CCT) was 542.4 ± 30.1 μm (SD). There was a high intra-observer agreement, finding the best result in the central sector with an intra-class correlation coefficient of 0.99, 95 per cent CI (0.989 to 0.997) and the worst, in the minimum corneal thickness, with an intra-class correlation coefficient of 0.672, 95 per cent CI (0.417 to 0.829). Reproducibility between observers was very high. The best result was found in the central sector thickness obtained both manually and automatically with an intra-class correlation coefficient of 0.990 in both cases and the worst result in the maximum corneal thickness with an intra-class correlation coefficient of 0.827. The agreement between measurement methods was also very high with intra-class correlation coefficient greater than 0.91. On the other hand the repeatability and reproducibility for epithelial measurements was poor.

CONCLUSION

Pachymetric mapping with SOCT Copernicus HR was found to be highly repeatable and reproducible. We found that the device lacks an appropriate ergonomic design as proper focusing of the laser beam onto the cornea for anterior segment scanning required that patients were positioned slightly farther away from the machine head-rest than in the setup for retinal imaging.

Extended imaging depth to 12 mm for 1050-nm spectral domain optical coherence tomography for imaging the whole anterior segment of the human eye at 120-kHz A-scan rate

ABSTRACT. We demonstrate a 1050-nm spectral domain optical coherence tomography (OCT) system with a 12 mm imaging depth in air, a 120 kHz A-scan rate and a 10 μm axial resolution for anterior-segment imaging of human eye, in which a new prototype InGaAs linescan camera with 2048 active-pixel photodiodes is employed to record OCT spectral interferograms in parallel. Combined with the full-range complex technique, we show that the system delivers comparable imaging performance to that of a swept-source OCT with similar system specifications.

Retinal, anterior segment and full eye imaging using ultrahigh speed swept source OCT with vertical-cavity surface emitting lasers

We demonstrate swept source OCT utilizing vertical-cavity surface emitting laser (VCSEL) technology for in vivo high speed retinal, anterior segment and full eye imaging. The MEMS tunable VCSEL enables long coherence length, adjustable spectral sweep range and adjustable high sweeping rate (50-580 kHz axial scan rate). These features enable integration of multiple ophthalmic applications into one instrument. The operating modes of the device include: ultrahigh speed, high resolution retinal imaging (up to 580 kHz); high speed, long depth range anterior segment imaging (100 kHz) and ultralong range full eye imaging (50 kHz). High speed imaging enables wide-field retinal scanning, while increased light penetration at 1060 nm enables visualization of choroidal vasculature. Comprehensive volumetric data sets of the anterior segment from the cornea to posterior crystalline lens surface are also shown. The adjustable VCSEL sweep range and rate make it possible to achieve an extremely long imaging depth range of ~50 mm, and to demonstrate the first in vivo 3D OCT imaging spanning the entire eye for non-contact measurement of intraocular distances including axial eye length. Swept source OCT with VCSEL technology may be attractive for next generation integrated ophthalmic OCT instruments.

Role of optical coherence tomography on corneal surface laser ablation

This paper focuses on reviewing the roles of optical coherence tomography (OCT) on corneal surface laser ablation procedures. OCT is an optical imaging modality that uses low-coherence interferometry to provide noninvasive cross-sectional imaging of tissue microstructure in vivo. There are two types of OCTs, each with transverse and axial spatial resolutions of a few micrometers: the time-domain and the fourier-domain OCTs. Both have been increasingly used by refractive surgeons and have specific advantages. Which of the current imaging instruments is a better choice depends on the specific application. In laser in situ keratomileusis (LASIK) and in excimer laser phototherapeutic keratectomy (PTK), OCT can be used to assess corneal characteristics and guide treatment decisions. OCT accurately measures central corneal thickness, evaluates the regularity of LASIK flaps, and quantifies flap and residual stromal bed thickness. When evaluating the ablation depth accuracy by subtracting preoperative from postoperative measurements, OCT pachymetry correlates well with laser ablation settings. In addition, OCT can be used to provide precise information on the morphology and depth of corneal pathologic abnormalities, such as corneal degenerations, dystrophies, and opacities, correlating with histopathologic findings.

Anterior segment optical coherence tomography in congenital corneal opacities

PURPOSE

To evaluate the clinical usefulness of anterior segment (AS) optical coherence tomography (OCT) in diagnosis and follow-up of children with congenital corneal opacities.

DESIGN

Noncomparative case series.

PARTICIPANTS

Seven consecutive patients with bilateral congenital corneal opacity between 2 days and 2.5 years of age.

METHODS

In addition to basic outpatient examination, eyes were imaged using AS OCT. Anterior segment structures and corneal thicknesses were evaluated from the images. Three children also underwent evaluation under anesthesia, including measurement of corneal thickness with ultrasound pachymetry.

MAIN OUTCOME MEASURES

Evaluation of the type and severity of the congenital corneal opacity based on the findings in AS OCT.

RESULTS

Thirteen of the 14 eyes could be imaged using AS OCT. The youngest patient studied was only 2 days old. Three distinct phenotypes were found based on the AS OCT findings. Three patients with iridocorneal adhesions were deduced to have type 1 Peters' anomaly, and 2 patients with lenticulocorneal adhesions were deduced to have type 2 Peters' anomaly. The 2 youngest patients had complete corneal opacity with features of corneal staphyloma and marked changes in the AS structures during the first months of life.

CONCLUSIONS

Anterior segment OCT was a valuable method in the diagnosis and follow-up of patients with congenital corneal opacities. As a fast and noncontact technique, it was applicable even for neonates. It allowed early characterization of the type and the extent of the AS disorder.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Optical coherence tomography for the evaluation of retinal and optic nerve morphology in animal subjects: practical considerations

Optical coherence tomography (OCT) is a noninvasive, noncontact imaging technique capable of producing high-resolution images of the retina and optic nerve. These images provide information that is useful for following the progression and/or resolution of posterior segment disease. Rapid advances in OCT technology allow the acquisition of increasingly detailed images, approaching the original goal of providing in vivo histopathology. Increases in scan acquisition speeds and axial resolution enhance the clinical diagnostic value of this modality. Adapting instrumentation designed for use in human patients for use in animals can be challenging. Each species has a unique set of adjustments that need to be made but it is possible to obtain reproducible, high-quality OCT images in a variety of animals, including rodents, dogs, cats, pigs, and monkeys. Deriving quantitative measurements from OCT instruments is hindered by software algorithm errors in detecting the edges of the distinct retinal layers. These segmentation errors occur in scans of human eyes as well in other species and arise with similar frequency with each of the different OCT instruments. Manual segmentation methods to derive optic nerve head and other structural indices have been developed for several species.

Preliminary in vivo positional analysis of a posterior chamber phakic intraocular lens by optical coherence tomography and its correlation with clinical outcomes

Purpose

To analyze by spectral-domain optical coherence tomography the anatomical relationship of a specific type of posterior chamber phakic intraocular lens (pIOL) implanted in cases of high to moderate myopia with the adjacent intraocular structures and to correlate it with clinical outcomes.

Methods

Prospective observational case series including 18 eyes with high to moderate myopia (spherical equivalent between −5.88 and −15.75 D) of 9 patients (age range, 29–49 years) undergoing bilateral Phakic Refractive Lens (PRL, Zeiss) implantation. Postoperative visual acuity, refraction, contrast sensitivity (CS), and ocular higher order aberrations (HOA) were evaluated. Furthermore, the in vivo position of the PRL was analyzed by means of spectral domain optical coherence tomography (3D OCT-1000, Topcon). Central (CENV), temporal (TEMV) and nasal vault (NASV) were measured. Correlation of these anatomical parameters with clinical data was also investigated. Mean follow-up was 47 ± 25 months.

Results

A statistically significant visual and refractive improvement (p < 0.01) was found postoperatively. Mean postoperative CENV, NASV, and TEMV were 157.88 ± 69.93 μm, 168.29 ± 65.02 μm, and 188.59 ± 55.99 μm, respectively. Significant difference was found between NASV and TEMV (p = 0.01). No significant correlations were found between ocular aberrometric and anatomical parameters (p ≥ 0.12). CENV, NASV and TEMV correlated significantly with 6-cycles per degree (cpd) photopic CS as well as with 18-cpd low mesopic CS (r ≥ 0.57, p ≤ 0.04). Furthermore, NASV also correlated significantly with preoperative anterior chamber depth (r = −0.65, p = 0.01).

Conclusions

This posterior chamber pIOL shows a trend to nasal position, with potential impact on refractive and visual outcomes, particularly in eyes with deep anterior chambers.