Late Onset Interface Calcium Deposition After Laser In Situ Keratomileusis.

The aim of this study was to report a case of unilateral granular corneal dystrophy type 2 (GCD2) with exacerbation after bilateral laser in situ keratomileusis (LASIK). Clinical evaluation, Scheimpflug imaging, anterior segment optical coherence tomography (AS-OCT), cytology, and genetic testing were used to confirm the diagnosis of unilateral GCD2 with exacerbation after bilateral LASIK. Detailed literature review for possible unilateral GCD2 presentations was performed. A 54-year-old White woman presented with blurred vision in her left eye and a history of bilateral LASIK performed 8 years before. Examination revealed dense opacities in the left cornea only, which were confirmed to be confined to the LASIK interface and adjacent corneal stromal tissue, as determined by AS-OCT. The patient underwent flap lift, interface debris removal, and stromal bed phototherapeutic keratectomy. Cytological analysis showed eosinophilic corneal stromal deposits that stained with trichrome stain and were congophilic on Congo red stain. Genetic testing was positive for heterozygous GCD2 transforming growth factor β-induced gene ( TGFBI ), c.371G>A, p.R124H mutation. There were no opacities identifiable in the right eye on serial slit-lamp examination, Scheimpflug imaging, or OCT imaging at 4 or 8 years after bilateral LASIK. Literature review failed to identify any previous reports of unilateral GCD2. This is the first known reported case of unilateral granular corneal dystrophy type 2. LASIK is contraindicated in eyes with corneal stromal dystrophies related to mutations in TGFBI as both flap creation and laser ablation can exacerbate visually significant opacity formation. Scheimpflug and AS-OCT imaging are useful to identify opacities in GCD2.

Purpose To present a case of late-onset interface fluid syndrome (IFS) and a literature review on this rare clinical entity. Introduction IFS is an uncommon complication of laser in situ keratomileusis (LASIK). Although generally appearing in the early postoperative period, IFS has been reported even years after LASIK. Methods A case report of IFS manifesting 19 years after uneventful LASIK, which prompted a literature search for similar, late-onset cases in MEDLINE PubMed. This article reports on a case of IFS appearing 19 years after LASIK surgery, including extensive patient history and analytical presentation of clinical findings, ancillary testing, and short-term follow-up. Furthermore, a literature search for similar cases was performed on MEDLINE, focusing on the etiology and management of late-onset IFS. Results Through thorough ancillary testing, the interface fluid was attributed to elevated intraocular pressure (IOP) arising from primary open-angle glaucoma. Antiglaucoma drops resulted in complete fluid regression. A narrative review was conducted based on the 29 case reports that were recovered from the literature search. Conclusion IFS represents an uncommon complication that could appear years after LASIK. Careful clinical examination and anterior segment optical coherence tomography promote early diagnosis. Similar cases may manifest due to elevated IOP of variable etiology or as a result of endothelial dysfunction. Depending on the etiology, IOP control or keratoplasty may resolve the condition.

Pupil response to tropicamide following LASIK

PurposeTo develop generative adversarial networks (GANs) that synthesize realistic anterior segment optical coherence tomography (AS-OCT) images and evaluate deep learning (DL) models that are trained on real and synthetic datasets for detecting angle closure.MethodsThe GAN architecture was adopted and trained on the dataset with AS-OCT images collected from the Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong, synthesizing open- and closed-angle AS-OCT images. A visual Turing test with two glaucoma specialists was performed to assess the image quality of real and synthetic images. DL models, trained on either real or synthetic datasets, were developed. Using the clinicians’ grading of the AS-OCT images as the reference standard, we compared the diagnostic performance of open-angle vs. closed-angle detection of DL models and the AS-OCT parameter, defined as a trabecular-iris space area 750 µm anterior to the scleral spur (TISA750), in a small independent validation dataset.ResultsThe GAN training included 28,643 AS-OCT anterior chamber angle (ACA) images. The real and synthetic datasets for DL model training have an equal distribution of open- and closed-angle images (all with 10,000 images each). The independent validation dataset included 238 open-angle and 243 closed-angle AS-OCT ACA images. The image quality of real versus synthetic AS-OCT images was similar, as assessed by the two glaucoma specialists, except for the scleral spur visibility. For the independent validation dataset, both DL models achieved higher areas under the curve compared with TISA750. Two DL models had areas under the curve of 0.97 (95% confidence interval, 0.96–0.99) and 0.94 (95% confidence interval, 0.92–0.96).ConclusionsThe GAN synthetic AS-OCT images appeared to be of good quality, according to the glaucoma specialists. The DL models, trained on all-synthetic AS-OCT images, can achieve high diagnostic performance.Translational RelevanceThe GANs can generate realistic AS-OCT images, which can also be used to train DL models.

To evaluate the efficacy of a self-supervised learning Vision Transformer (ViT) for classification of the nucleus, cortex, and posterior capsule cataract severity utilizing anterior segment optical coherence tomography (AS-OCT) images. Artificial intelligence (AI) model training. Overall, 1,693 eyes were imaged using AS-OCT, with 1,023 classified according to the Lens Opacities Classification System III for supervised training at the Department of Ophthalmology, University of Tsukuba Hospital, Japan. Five AI models were compared: ResNet18, ViT with/without ImageNet pre-training, and Self-Supervised ViT (SS-ViT) constructed using AS-OCT images from 670 eyes. These models were evaluated across five classification tasks: nuclear cataract 2-class (N1 vs. N2≥), 3-class (N1, N2-N3, N4≥), and 6-class classifications; and 2-class classifications for both cortical (C1 vs. C2≥) and posterior subcapsular cataracts (P1 vs. P2≥). Performance was measured using Area Under the Precision-Recall Curve (AUPRC). In the nuclear cataract 2-class classification, ResNet18, ViT, and SS-ViT, which were pre-trained on ImageNet, demonstrated the highest AUPRC of 0.999. For the nuclear cataract 3-class classification, SS-ViT exhibited the highest AUPRC of 0.939. In the 6-class classification of nuclear cataract, SS-ViT attained the highest value with an AUPRC of 0.788. In the 2-class classification of cortical cataract, SS-ViT demonstrated the highest performance with an AUPRC of 0.774, while in the 2-class classification of posterior subcapsular cataract, SS-ViT exhibited the most favorable performance with an AUPRC of 0.506. Our findings demonstrate the effectiveness of a self-supervised ViT model for severity classification of nuclear, cortical, and posterior subcapsular cataracts on AS-OCT.

Purpose: To evaluate the changes of anterior corneal aberrations before and after laser in situ keratomileusis (LASIK) and to assess the correlation between contrast sensitivity and anterior corneal aberrations. Methods: Right eyes of 51 patients including 6 males and 45 females undergoing conventional LASIK from September 2000 to July 2003 were enrolled. The calculation of anterior corneal aberrations before and after LASIK was obtained by analyzing the corneal topography from TMS-1 by using VOL-CT Version 6.23 software. Contrast sensitivity was measured after LASIK with an MCT 8000 under daytime and nighttime settings and with glare conditions. The differences of the Zernike coefficients and root mean square (RMS) of anterior corneal aberrations before and after LASIK were analyzed. The changes of contrast sensitivity at 1.5, 3, 6, 12, and 18 cpd were added separately for daytime and nighttime contrast sensitivity with and without glare after LASIK and were correlated with the changes of anterior corneal aberrations. Results: Vertical coma, RMS of coma-like RMS of spherical-like, RMS of trefoil-like and RMS of higher-order anterior corneal aberrations increased significantly after LASIK surgery. There were no significant correlations between the changes of anterior corneal aberrations and the changes of contrast sensitivity at daytime and nighttime, with and without glare. Contrast sensitivity at daytime and nighttime decreased at each spatial frequency after LASIK. Conclusions: LASIK surgery induces changes of the anterior corneal aberrations. However, changes in anterior corneal aberrations did not correlate with the changes of contrast sensitivity at daytime and nighttime, with and without glare.

Objective To investigate the safety and effectiveness of using laser in situ keratomileusis (LASIK) for the treatment of refractive deterioration after radial keratotomy (RK) surgery.Methods Fifteen patients (28 eyes) in this retrospective study underwent repeat LASIK surgery after they had undergone RK surgery about ten years earlier.The vision of these patients had worsened so they wanted to acquire good vision through repeat LASIK surgery.The Nidek EC-5000 laser treatment system was used for the surgery.Patients were followed up for more than 6 years to monitor the changes in pre- and postoperative visual acuity, complications, corneal prosthetic condition, etc.Results During the 6-year follow-up period, uncorrected visual acuity was better than or equal to preoperative best corrected visual acuity (BCVA) in 26 eyes (93％),but near visual acuity was worse in 25 eyes (89％).Two eyes had low astigmatism (-0.50～-0.75 D) so these patients did not achieve preoperative BCVA.The corneal flap edge healed slowly in 10 eyes and the corneal flap edge had opaque-like lines in 2 eyes.Dry eye was a complication for about 98％ of the patients so eye drops had to be used for a long term.Conclusion LASIK surgery for the treatment of patients with deteriorated vision or low astigmatism after RK surgery is a safe and effective refractive surgery.Patients were satisfied with the treatment but must be informed that they need to be followed up for a long time. Key words: Keratomileusis,laser in situ; Keratotomy,radial; Treatment outcome

BackgroundPresence of corneal cystine crystals is the main ocular manifestation of cystinosis, although controversial findings concerning the corneal layer with the highest density have been reported. The aim of this study was the analysis of the characteristics of crystal arrangement in different corneal layers and the assessment of corneal morphological changes with age.MethodsA cross sectional study was carried out in three children and three adults who had nephropathic cystinosis and corneal cystine depositions. All patients underwent a comprehensive ophthalmological examination including best corrected distance visual acuity, slit-lamp examination, in vivo confocal microscopy and anterior segment optical coherence tomography. An evaluation of the depth of crystal deposits and crystal density in different corneal layers was also performed. Due to the low number of subjects no statistical comparison was performed.ResultsAnterior segment optical coherence tomography images revealed deposition of hyperreflective crystals from limbus to limbus in each patient. Crystals appeared as randomly oriented hyperreflective, elongated structures on in vivo confocal microscopy images in all corneal layers except the endothelium. In children the deposits occurred predominantly in the anterior stroma, while in adults, the crystals were mostly localized in the posterior corneal stroma with the depth of crystal deposition showing an increasing tendency with age (mean depth of crystal density was 353.17 ± 49.23 μm in children and it was 555.75 ± 25.27 μm in adults). Mean crystal density of the epithelium was 1.47 ± 1.17 (median: 1.5; interquartile range: 0.3–2.4). Mean crystal density of the anterior and posterior stroma of children and adults was 3.37 ± 0.34 (median: 3.4; interquartile range: 3.25–3.55) vs. 1.23 ± 0.23 (median: 1.2; interquartile range: 1.05–1.35) and 0.76 ± 0.49 (median: 0.7; interquartile range: 0.4–1.15) vs. 3.63 ± 0.29 (median: 3.7; interquartile range: 3.45–3.8), respectively. Endothelium had intact structure in all cases. Some hexagonal crystals were observed in two subjects.ConclusionsIn vivo confocal microscopy and anterior segment optical coherence tomography confirmed an age-related pattern of crystal deposition. In children, crystals tend to locate anteriorly, while in adults, deposits are found posteriorly in corneal stroma.

We developed a deep learning-based classifier that can discriminate primary angle closure suspects (PACS), primary angle closure (PAC)/primary angle closure glaucoma (PACG), and also control eyes with open angle with acceptable accuracy. To develop a deep learning-based classifier for differentiating subtypes of primary angle closure disease, including PACS and PAC/PACG, and also normal control eyes. Anterior segment optical coherence tomography images were used for analysis with 5 different networks including MnasNet, MobileNet, ResNet18, ResNet50, and EfficientNet. The data set was split with randomization performed at the patient level into a training plus validation set (85%), and a test data set (15%). Then 4-fold cross-validation was used to train the model. In each mentioned architecture, the networks were trained with original and cropped images. Also, the analyses were carried out for single images and images grouped on the patient level (case-based). Then majority voting was applied to the determination of the final prediction. A total of 1616 images of normal eyes (87 eyes), 1055 images of PACS (66 eyes), and 1076 images of PAC/PACG (66 eyes) eyes were included in the analysis. The mean ± SD age was 51.76 ± 15.15 years and 48.3% were males. MobileNet had the best performance in the model, in which both original and cropped images were used. The accuracy of MobileNet for detecting normal, PACS, and PAC/PACG eyes was 0.99 ± 0.00, 0.77 ± 0.02, and 0.77 ± 0.03, respectively. By running MobileNet in a case-based classification approach, the accuracy improved and reached 0.95 ± 0.03, 0.83 ± 0.06, and 0.81 ± 0.05, respectively. For detecting the open angle, PACS, and PAC/PACG, the MobileNet classifier achieved an area under the curve of 1, 0.906, and 0.872, respectively, on the test data set. The MobileNet-based classifier can detect normal, PACS, and PAC/PACG eyes with acceptable accuracy based on anterior segment optical coherence tomography images.

To compare, in the same individuals, the safety and efficacy of laser in situ keratomileusis (LASIK) in eyes with and without previous retinal detachment surgery. In a prospective clinical trial, seven myopic patients who had previously undergone scleral buckling surgery in one eye underwent conventional LASIK surgery in both eyes. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refraction, Orbscan topography and pachymetry were recorded before and 1, 3, 6 and 12 months after surgery. The eyes were divided into two groups: group 1 consisted of eyes that had undergone previous surgery for retinal detachment, and group 2 consisted of the fellow eyes of the same patients, which had not undergone any previous ocular surgery. Student's t-test for match-paired data was used to evaluate the significance of differences. LASIK was performed successfully in all patients. The UCVA improved in all eyes in both groups. The mean change in the spherical equivalent between 1 and 12 months after LASIK surgery was 1.7 +/- 1.1 and 0.6 +/- 0.5 diopter in groups 1 and 2, respectively (p = 0.019). LASIK may be considered for treatment of myopia in eyes that have had previous surgery for retinal detachment. However, the risk of regression may be higher in such eyes than in eyes with no previous scleral buckling surgery.

To determine the safety and efficacy of performing photorefractive keratectomy (PRK) in corneas previously treated with laser in situ keratomileusis (LASIK) surgery. Fifteen eyes of 14 patients who had initially received LASIK for the treatment of myopia and compound myopic astigmatism were evaluated. Variables included existence of and/or type of flap complication associated with the original LASIK procedure, refractions before and after (3 and 6 months) PRK, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and the development of complications after PRK such as haze, scarring, double vision, or ghosting. All 15 eyes were available for analysis at 6 months. Eleven eyes had experienced flap complications during the initial LASIK procedure and 4 eyes had experienced complications in the LASIK postoperative period. Characteristics prior to performing PRK included 11 myopic and 4 hyperopic eyes. By 6 months after PRK treatment, 87% of eyes had UCVA > or = 20/40, 53% had > or = 20/25, and 40% had > or = 20/20. All eyes had BSCVA of > or = 20/30, with 73% being > or = 20/20. No eye had lost 2 lines of BSCVA and only 1 eye lost 1 line of BSCVA. Sixty percent of eyes were within 1.0 diopters (D) of emmetropia, and 40% were within 0.5 D of emmetropia. A trend towards undercorrection and surgical induction of astigmatism as confirmed by vector analysis was noted. No eye developed significant haze or scarring. Photorefractive keratectomy may be a safe procedure to perform in corneas previously treated with LASIK surgery. Results show good reduction of refractive error and improvement of UCVA and BSCVA. A significant undercorrection of astigmatism was attributed to surgically induced astigmatism. Further studies are necessary to determine the long-term safety and stability of outcomes.

To evaluate the effects of laser in situ keratomileusis (LASIK) on the patients' visual field. 92 eyes of 46 patients with mild, moderate, and high degrees of myopia were undergone LASIK. Perimetry was performed before and 1 day, 1 month, 3 months, 6 months after LASIK surgery by Humphrey II-750 visual field analysis. The central 30 - 2 fast threshold program was used to examine the change in central 30 degree. Mean defect (MD) and pattern standard deviation (PSD) were record. All operations were performed by an experienced surgeon. Statistical analyses were performed by SPSS using the randomized complete block design ANOVA (two factors analysis of variance). Differences among variables were evaluated by q-test (Student-Newman-Kueuls method). 93.5% patients obtained estimated best correct visual acuity or better at six months after LASIK. No complications were found in the subjects. No difference was found in fundus examinations before and after surgery. Intraocular pressure was normal at all preoperative and postoperative examinations. MD was significant differences among preoperative and postoperative values (P < 0.05, for all comparisons) and was correlated with visual acuity post-LASIK significantly (P < 0.05). While PSD did not show significant differences before and after LASIK (P > 0.05) and was not correlated with visual acuity post-LASIK. The indexes of visual field were not correlated with the degree of myopia and the other surgical parameters (P > 0.05). In current research, no significant visual field change was demonstrated pre-LASIK and post-LASIK after 6 months follow-up. The study suggests that LASIK does not affect the retinal physiological functions.

Role of instrument cleaning and maintenance in the development of diffuse lamellar keratitis

To evaluate the intra- and inter-grader concordance of anterior segment optical coherence tomography (ASOCT) grading for detection of endothelial plaque in microbial keratitis, and to compare endothelial plaque detection via ASOCT grading versus in-person slit lamp examination. Diagnostic concordance study of 150 consecutive patients with microbiologically confirmed bacterial or fungal keratitis at a high-volume tertiary eye hospital in India. Two masked ophthalmologist graders independently evaluated ASOCT images for presence of two morphologically distinct endothelial plaque subtypes noted during image review (round and flat plaques). We assessed intra-grader and inter-grader concordance for each endothelial plaque morphology and for presence of either morphology. Diagnostic agreement between ASOCT and in-person slit lamp examination was evaluated using percent agreement, Cohen's kappa, sensitivity, and specificity. Univariable and multivariable logistic regression was used to assess odds of disagreement between ASOCT and slit lamp examination for endothelial plaque detection. ASOCT detection showed near perfect inter-grader agreement for round endothelial plaques (kappa 0.88, 94.7% agreement), flat endothelial plaques (kappa 0.84, 92.0% agreement), and either plaque (kappa 0.88, 94.0% agreement). Intra-grader agreement was substantial to near perfect for both graders across all plaque types (kappa 0.70-0.86). Ophthalmologist slit lamp examination identified endothelial plaque in 6.0% eyes, while ASOCT detected round plaques in 32.7%, flat plaques in 43.3%, and either plaque in 55.3% of eyes. Using ASOCT as reference, slit lamp examination demonstrated sensitivity of 16.3% for round plaques, 6.2% for flat plaques, and 9.6% for either plaque, with specificity exceeding 94% for all. Poor visual acuity (logMAR ≥1.0) was associated with increased disagreement for round plaques (adjusted OR 5.04), flat plaques (adjusted OR 3.63), and either plaque (adjusted OR 3.98). Bacterial infection was associated with increased disagreement for any endothelial plaque (adjusted OR 4.56). Slit lamp examination substantially under-detects endothelial plaque compared to ASOCT, while ASOCT enables reproducible detection with excellent intra- and inter-grader agreement. These findings support incorporation of ASOCT imaging into microbial keratitis evaluation protocols. Differences in round and flat endothelial plaque morphologies warrant further investigation.

To compare attempted versus achieved corneal stromal thickness reduction in a consecutive case series of patients undergoing laser in situ keratomileusis (LASIK) in one eye and small incision lenticule extraction (SMILE) in the other eye. This prospective, randomized, contralateral eye study included 22 consecutive patients (44 eyes), one eye randomized to have myopic LASIK and the contralateral eye to have SMILE. Anterior segment optical coherence tomography was performed preoperatively and at 3 months postoperatively. For each of the treatment groups, the achieved maximum stromal thickness reduction was compared to the planned/attempted thickness. The deviation of planned versus achieved stromal thickness reduction was then compared between the two groups. At 3 months postoperatively, LASIK had a lower difference between planned versus attempted stromal thickness reduction compared to SMILE (13.72 ± 14.45 vs 24.00 ± 19.45 µm, P = .03). Graphical analysis revealed this deviation to be exaggerated in higher myopic errors, when a higher maximum stromal reduction was planned. The mean stromal reduction thickness was 83.40 ± 29.52 µm achieved versus 97.13 ± 25.69 µm mean planned ablation depth in the LASIK group (P < .001) compared to 76.45 ± 29.69 µm achieved versus 100.45 ± 26.56 µm planned ablation depth in the SMILE group (P < .001). LASIK had a significantly lower difference between planned versus achieved stromal thickness reduction when compared to SMILE (P = .03). This difference was more apparent in higher myopic corrections. [J Refract Surg. 2021;37(7):454-459.].