EVALUATION OF THE INCLUSION OF SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY IN A TELEMEDICINE DIABETIC RETINOPATHY SCREENING PROGRAM: A Real Clinical Practice.

PURPOSE: To evaluate whether combining spectral domain optical coherence tomography with monoscopic fundus photography using a nonmydriatic camera (MFP-NMC) improves the accuracy of diabetic macular edema (DME) referrals in a teleophthalmology diabetic retinopathy screening program. METHODS: We conducted a cross-sectional study with all diabetic patients aged 18 years or older who attended screening from September 2016 to December 2017. We assessed DME according to the three MFP-NMC and the four spectral domain optical coherence tomography criteria. The sensitivity and specificity obtained for each criterion were estimated by comparing them with the ground truth of DME. RESULTS: This study included 3,918 eyes (1,925 patients; median age, 66 years; interquartile range, 58-73; females, 40.7%; once-screened, 68.1%). The prevalence of DME ranged from 1.22% to 1.83% and 1.54% to 8.77% on MFP-NMC and spectral domain optical coherence tomography, respectively. Sensitivity barely reached 50% in MFP-NMC and less for the quantitative criteria of spectral domain optical coherence tomography. When macular thickening and anatomical signs of DME were considered, sensitivity increased to 88.3% and the false DMEs and non-gradable images were reduced. CONCLUSION: Macular thickening and anatomical signs showed the highest suitability for screening, with a sensitivity of 88.3% and a specificity of 99.8%. Notably, MFP-NMC alone missed half of the true DMEs that lacked indirect signs.

Atomic force microscopy for the evaluation of corneal surface roughness after femtosecond laser flap creation and excimer ablation.

INTRODUCTION: It is well known that the femtosecond laser lamellar cut induces some degree of surface roughness. Nevertheless, as in femtosecond laser-assisted LASIK (FS-LASIK), an excimer LASIK ablation is performed, and the post-ablation stromal bed should show some degree of smoothening. We decided to compare, using atomic force microscopy (AFM), the roughness of the corneal stromal bed, after a femtosecond lasers device flap was created with or without an excimer myopic ablation. METHODS: Using 6 freshly enucleated porcine eyes, we created in every eye a flap using a femtosecond laser. Additionally, in 3 eyes, an excimer laser ablation to correct-3 diopters (D) was made. AFM imaging of the remaining corneal stroma was performed. Ten different square areas of 20 µm x 20 µm at the central area of the stroma of each corneal sample were studied. The roughness parameters used were the root-mean-square deviation from a perfectly flat surface. RESULTS: The RMS deviation was 360 ± 120 nm in femtosecond laser only, and 110 ± 20 nm in those cases where excimer is also involved (p < 0.0001). CONCLUSIONS: Our results show that the roughness of the surface treated with excimer is clearly lower than in the group with no excimer ablation; thus, the application of laser excimer after a flap created by femtosecond laser seems to soften the nano-irregularities created by this technique.

Effect of prostaglandin analogues on the biomechanical corneal properties in patients with open-angle glaucoma and ocular hypertension measured with dynamic scheimpflug analyzer.

PURPOSE: The aim of the study is to evaluate the effect of topical prostaglandin (PG) treatment on the corneal biomechanical properties in treatment-naïve patients with either primary open-angle glaucoma (POAG) or ocular hypertension (OHT) using the Corvis ST device. METHODS: This is an observational study. We analyzed the Corvis ST dynamic corneal response parameters of our database using the newest software available. Thirty-four eyes of 34 patients were included. They were all newly diagnosed and treatment-naïve. Patients were evaluated at baseline and after 6 months of treatment with prostaglandin analogues. Ultrasound pachymetry, Optical Coherence Tomography (OCT) and a 24-2 visual field test were performed in baseline visit. Goldman Applanation Tonometry (GAT-IOP) and Corvis ST dynamic corneal response parameters were registered at baseline and at the 6-month visit. RESULTS: After 6 months of treatment, the IOP decrease (Δ) values obtained with the different tonometers were ΔGAT -6.5 ± 3.7, ΔIOPnct -4.4 ± 5.7 and ΔbIOP -3.8 ± 5.4. The differences between ΔGAT vs ΔIOPnct, ΔGAT vs ΔbIOP, and ΔIOPnct vs ΔbIOP, were statistically significant (p < 0.05 for all comparisons). Statistically significant lower values of the stress-strain index (SSI) (1.77 ± 0.3 at baseline vs 1.54 ± 0.27 at the 6-month visit) were found (p = 0.0002). CONCLUSION: The SSI provided by the Corvis ST seems to decrease significantly after topical prostaglandin therapy. We believe that our results support the hypothesis that topical PG therapy does decrease the corneal stiffness and thus, that the ocular hypotensive effect of these drugs is overestimated if GAT is used for IOP measurement.

Femtosecond LASIK for the correction of low and high myopic astigmatism.

INTRODUCTION: Higher preoperative myopic astigmatism is associated with a higher probability of retreatment due to patient dissatisfaction as a result of residual cylindrical error. Nonetheless, retreatment is safe and the final clinical results are comparable to those of patients with lower preoperative astigmatism who were satisfied with the primary treatment. Our purpose is to compare the efficacy and safety of femtosecond LASIK (FS-LASIK) for the refractive correction of patients with low (< 1.5 Diopters (D) versus high (≥ 1.5 D) myopic astigmatism. METHODS: Retrospective observational study of 841 eyes of 825 eligible patients treated with FSLASIK for the correction of simple or compound myopic astigmatism. Outcome measures included residual error, best corrected and uncorrected distance visual acuity (BCVA and UCVA), efficacy and safety 3 months after the primary procedure or the retreatment. RESULTS: Of 841 eyes in total, 432 (51.37%) had < 1.5 D (Group 1) and 409 (48.63%) had ≥ 1.5 D (Group 2) preoperative myopic astigmatism. The efficacy index of primary treatment was 0.94 ± 0.18 in Group 1 and 0.89 ± 0.22 in Group 2 (P = 0.001). Of 138 eyes (16.41%) that were retreated due to dis-satisfaction related to residual refractive error, 28 belonged to Group 1 (6.5%) and 110 (26.9%) to Group 2 (P < 0.001). Following retreatment, small but statistically significant differences in the residual mean postoperative cylinder (-0.08 ± 0.24 vs -0.27 ± 0.46 D, P = 0.001) and UCVA (1.11 vs 0.96, P = 0.0001) were detected for Groups 1 and 2, respectively. However, there were no statistically significant differences in the safety and efficacy indices. CONCLUSION: Following FS-LASIK, eyes with myopic astigmatism ≥ 1.5 D have approximately four times more chances of undergoing retreatment due to dis-satisfaction caused by residual refractive error compared to eyes with myopic astigmatism < 1.5 D. However, the clinical results after retreatment are highly satisfactory and comparable in both groups.

Atomic force microscopy comparative analysis of the surface roughness of two posterior chamber phakic intraocular lens models: ICL versus IPCL.

BACKGROUND: To compare the anterior surface roughness of two commercially available posterior chamber phakic intraocular lenses (IOLs) using atomic force microscopy (AFM). METHODS: Four phakic IOLs were used for this prospective, experimental study: two Visian ICL EVO+ V5 lenses and two iPCL 2.0 lenses. All of them were brand new, were not previously implanted in humans, were monofocal and had a dioptric power of - 12 diopters (D). The anterior surface roughness was assessed using a JPK NanoWizard II® atomic force microscope in contact mode immersed in liquid. Olympus OMCL-RC800PSA commercial silicon nitride cantilever tips were used. Anterior surface roughness measurements were made in 7 areas of 10 × 10 µm at 512 × 512 point resolution. The roughness was measured using the root-mean-square (RMS) value within the given regions. RESULTS: The mean of all anterior surface roughness measurements was 6.09 ± 1.33 nm (nm) in the Visian ICL EVO+ V5 and 3.49 ± 0.41 nm in the iPCL 2.0 (p = 0.001). CONCLUSION: In the current study, we found a statistically significant smoother anterior surface in the iPCL 2.0 phakic intraocular lenses compared with the VISIAN ICL EVO+ V5 lenses when studied with atomic force microscopy.

Effect of Laser-assisted Subepithelial Keratectomy with Mitomycin C on Corneal Optical Density Measured with Confocal Microscopy.

SIGNIFICANCE: The development of confocal microscopy allows one to obtain high-resolution corneal images like its optical density. Some studies have evaluated the optical density with Scheimpflug cameras in the early post-operative period after photorefractive keratectomy, but no studies have evaluated the long-term evolution of optical density after surface ablation when mitomycin C is used. PURPOSE: This work aimed to study the changes in corneal optical density measured with confocal microscopy in eyes treated with laser-assisted subepithelial keratectomy (LASEK) and intraoperative mitomycin C (MMC) to correct myopia. METHODS: A study of 24 consecutive myopic eyes that underwent LASEK with 0.02% MMC and a control group of 24 healthy nontreated eyes was performed. Optical density was measured using the images by the confocal microscopy of the Heidelberg Retina Tomograph II with the Rostock Cornea Module. An analysis of confocal microscopy images was performed using the ImageJ software to obtain the optical density, in gray-scale units (GSU). The optical density of the stromal bed was evaluated 3 months, 15 months, and 3 years after surgery and was compared with the optical density at the equivalent depth of the stroma in controls. RESULTS: The mean values of optical density for the LASEK group were 81.7 ± 9.7, 78.6 ± 11.7, and 73.6 ± 18.7 GSU at 3 months, 15 months, and 3 years, respectively, and it was 61.8 ± 8.2 GSU for the control group. A statistically higher optical density 3 and 15 months after LASEK with MMC was found compared with controls (P < .001). No significant difference was found in optical density at 3 years post-operatively. CONCLUSIONS: Our study suggests that, after LASEK with MMC, the anterior corneal stroma has a higher optical density at 3 and 15 months post-operatively, which gradually returns to normal values 3 years after surgery.

Thinner retinal nerve fibre layer in healthy myopic eyes with thinner central corneal thickness.

PURPOSE: Thinner central corneal thickness (CCT) is a risk factor for conversion from ocular hypertension to glaucoma and for disease progression. However, little is known about the relationship between CCT and characteristics of the optic nerve and the retinal nerve fibre layer (RNFL) in non-glaucomatous eyes. Because myopic eyes may pose diagnostic challenges when assessed for glaucoma, characterising the relationship between CCT and RNFL in these eyes is clinically relevant. Our aim was to investigate the relationship between CCT and RNFL thickness in non-glaucomatous eyes with small/moderate myopia. METHODS: This was a single-centre, observational, prospective, assessor-masked study. Consecutive eligible patients (myopia ≤ - 6.0 dioptres, astigmatism ≤ 2.0 dioptres) without other ocular or neurodegenerative diseases were included. Based on their CCT, the participants were allocated to group 1 (CCT > 555 µm) or group 2 (CCT < 555 µm). Peripapillary RNFL measurements were performed by a masked observer using the Spectralis OCT platform. RESULTS: Sixty eyes were included in group 1 and 63 in group 2. The CCT in the two groups was significantly different (584.27 ± 22.8 µm vs 522.23 ± 20.03 µm, p = 0.0001). There were no other significant differences in the groups in terms of age, refraction, or intraocular pressure. The peripapillary RNFL thickness was higher (all p < 0.005) in group 1 at several sectors: superior-temporal, inferior-temporal, inferior-nasal, and average. A significant positive correlation between CCT and average RNFL thickness was found for the whole population (r = 0.31, p = 0.0001). CONCLUSION: Otherwise, healthy myopes with thinner CCT have thinner RNFL compared with participants of similar age and refraction with thicker CCT.

Optical coherence tomography analysis of filtering blebs after long-term, functioning trabeculectomy and XEN® stent implant.

PURPOSE: The purpose of this study was to use Triton® SweptSource OCT to evaluate the morphology of blebs formed when eyes are treated with XEN® implants and to compare these with the blebs in successfully functioning eyes after trabeculectomy (TB) and with eyes of healthy controls. METHODS: A cross-sectional, observational study. We analyzed 25 eyes, 15 after TB and 10 with XEN® implants, comparing them with 23 healthy eyes (controls). We evaluated the conjunctival morphology of the eyes using AS-OCT. The main parameters evaluated were bleb height, sub-epithelial fibrosis, epithelial thickness, and changes in intraocular pressure (IOP). RESULTS: We found that the filtering blebs formed in eyes in which a XEN® stent was implanted were significantly flatter (bleb height 417 ± 183 µm) than the blebs formed in TB eyes (bleb height 618 ± 256 µm, p < 0.05). Moreover, sub-epithelial fibrosis did not develop in any of the blebs produced by the XEN stent, whereas some fibrosis was evident in 40% of the blebs that formed after TB (p < 0.05). The epithelium was thicker when the XEN implant was used (65 ± 18.5 µm) than when eyes underwent TB (60 ± 17.7 µm), and it was thicker than in control eyes (51 ± 9.7 µm, p < 0.05). Moreover, the decrease in the IOP induced by the XEN® stent (- 8.5 ± 5.3 mmHg) was similar to that produced by TB (- 8.8 ± 5.2 mmHg, p > 0.05). CONCLUSIONS: Filtering blebs obtained after the introduction of a XEN® stent were morphologically distinct to those produced by TB, and they are more similar to the healthy conjunctiva.

Analysis of corneal stromal roughness after iFS 150 kHz and LenSx femtosecond LASIK flap creation in porcine eyes.

PURPOSE: To describe and compare the stromal bed roughness obtained after laser in situ keratomileusis (LASIK) flap creation using a corneal femtosecond laser platform (iFS 150) and a "dual" femtosecond (FS) laser platform (LenSx). METHODS: This ex vivo experimental study was conducted in an animal model using 12 freshly enucleated porcine eyes, six with each femtosecond laser. The standard laser treatment parameters were used for the experiment. After LASIK flap creation, the corneal stromal roughness was assessed using atomic force microscopy (AFM) in contact mode immersed in liquid. In each sample, surface measurements were obtained in 60 regions of six eyes per FS laser in 10 20 × 20-micron areas of the central corneal stroma at 512 × 512-point resolution. The surface roughness was measured and the root-mean-square (RMS) values of the roughness were obtained. RESULTS: The mean RMS ± standard deviation values were 430 ± 150 nm for the corneal femtosecond laser platform and 370 ± 100 nm for the dual FS laser platform (P < 0.011). CONCLUSIONS: In this experimental study with AFM, we found smoother stromal beds after LASIK flap creation with LenSx compared to iFS 150 kHz. Further studies are needed to understand visual implications of the differences found.

Myopic Laser-Assisted Subepithelial Keratectomy (LASEK) outcomes using three different excimer laser platforms: a retrospective observational study.

BACKGROUND: To compare the visual and refractive outcomes after myopic LASEK using three different excimer lasers and standardized surgical and mitomycin C (MMC) application protocols. METHODS: In this retrospective, observational cohort study, we examined 122 eyes treated with Allegretto, 135 eyes treated with Esiris and 137 eyes treated with Technolas excimer lasers. All eyes were treated under the same surgical protocol, and a standardized MMC dosage was used. The three groups were refraction-matched, and both visual and refractive outcomes were evaluated at 1 and 7 days and 1 and 3 months after surgery. RESULTS: At 3 months postsurgery, Allegretto provided significantly better outcomes than Esiris and Technolas in terms of postoperative uncorrected distance visual acuity (UDVA) (1.11 ± 0.2 vs 1.01 ± 0.2 vs 0.98 ± 0.2) (P = 0.0001), corrected distance visual acuity (CDVA) (1.13 ± 0.2 vs 1.10 ± 0.1 vs 1.04 ± 0.2) (P = 0.0001), residual sphere (- 0.01 ± 0.2 vs + 0.29 ± 0.7 vs + 0.27 ± 0.6) (P = 0.0001), and efficacy index (0.99 ± 0.2 vs 0.90 ± 0.2 vs 0.91 ± 0.2) (P = 0.0004). CONCLUSIONS: We found slightly better visual and refractive outcomes in the Allegretto group at 3 months post-op after LASEK with MMC to correct myopia.

Influence of LASEK on Schiøtz, Goldmann and dynamic contour Tonometry.

PURPOSE: Our purpose was to assess the effect of LASEK surgery on ocular rigidity and to compare its effect on intraocular pressure (IOP) readings with Goldmann applanation tonometry (GAT), Schiøtz indentation tonometry (ST) and dynamic contour tonometry (DCT). METHODS: Prospective, observational, single-masked cohort study. One eye per patient from 31 consecutive subjects who underwent LASEK refractive surgery to correct myopia, as well as from 108 non-operated myopic patients, were included. IOP was measured using GAT, DCT, and ST. The coefficient of ocular rigidity (Ko) was obtained from the regression line of the three readings obtained with each weight of the ST. Linear multiple regression analysis was performed with dummy variables to assess the effect of age, central corneal thickness (CCT), and previous refractive surgery on IOP values. RESULTS: Age, CCT, and LASEK surgery explained 23% of the IOP readings with GAT, 11% with DCT, and had no significant influence on ST readings. The IOP readings obtained with GAT and DCT, but not with ST, were significantly different between LASEK and control groups. Significant differences in Ko were observed between LASEK (0.014 mmHg/µL ±0.007) and control groups (0.021 mmHg/µL ±0.013) (P = 0.001). Ko values were not related with age or CCT, in either LASEK or control groups. CONCLUSIONS: ST readings seems to be less affected by LASEK surgery than the other tonometers evaluated. There is a difference in the ocular rigidity between the control and the LASEK eyes that it is not correlated with CCT, so it seems that ST can detect changes in the biomechanical behavior of the LASEK operated corneas.

Tear Film Osmolarity in Response to Long-Term Orthokeratology Treatment.

PURPOSE: To compare tear film osmolarity (TFO) measurements in non-contact lens (CL) wearers and wearers of hydrogel or overnight orthokeratology (OK) CLs, and to assess possible effects of long-term OK on TFO. METHODS: Overall, 108 subjects with moderate myopia participated in 2 experiments, and TFO was measured using the TearLab osmolarity system. In experiment 1, TFO measurements were made in 77 right eyes of 23 non-CL wearers, 26 hydrogel wearers, and 28 OK wearers. Subjects in the last 2 groups had worn their CL for at least 3 years. In experiment 2, 31 individuals (habitual soft CL wearers) were enrolled for prospective long-term follow-up of OK treatment. These subjects were fitted with Paragon-CRT (n=16) or Seefree (n=15) lenses, and TFO readings were taken at baseline and after 1 month and 1 year of lens wear and after 1 month of OK treatment interruption. RESULTS: Values of TFO were within the normal limits in all 3 subject groups, although significantly lower osmolarities (P<0.01) were observed in non-CL wearers (281.7±5.9 mOsm/L) compared with hydrogel (291±16.5 mOsm/L) or OK lens wearers (301.7±10.8 mOsm/L). In experiment 2, TFO differed significantly at baseline between the Paragon-CRT and Seefree groups (P<0.05), and a significant decrease in TFO compared with baseline (P<0.01) was observed in the Paragon-CRT group after 1 month of cessation of lens wear. CONCLUSION: Higher TFO values were observed in lens wearers (hydrogel or OK) than non-CL wearers. After interruption of OK treatment, TFO returned to similar values to those found in non-CL wearers.

Long-Term Impacts of Orthokeratology Treatment on Sub-Basal Nerve Plexus and Corneal Sensitivity Responses and Their Reversibility.

PURPOSE: To examine the effects of one year of overnight orthokeratology (OK) treatment on the sub-basal nerve plexus (SBNP) and corneal sensitivity and to assess the reversibility of these effects one month after treatment interruption. METHODS: Thirty-two subjects with low-moderate myopia underwent OK treatment for one year. Fifteen non-contact lens wearers served as controls. At the time points baseline, one year of treatment, and one month after removing the OK lenses, two tests were conducted: corneal sensitivity (Cochet-Bonnet esthesiometer) and SBNP imaging by in vivo confocal microscopy. RESULTS: In participants wearing OK lenses, significant reductions over the year were produced in SBNP nerve density (P=0.001 and P=0.006) and number of nerves (P<0.001 and P=0.001) in the central and mid-peripheral cornea, respectively. Differences over the year were also detected in central objective tortuosity (P=0.002). After lens removal, baseline values of nerve density (P=0.024 and P=0.001) and number of nerves (P=0.021 and P<0.001) for the central and mid-peripheral cornea, respectively, were not recovered. At one month post-treatment, a difference was observed from one-year values in central corneal sensitivity (P=0.045) and mid-peripheral Langerhans cell density (P=0.033), and from baseline in mid-peripheral objective tortuosity (P=0.049). Direct correlation was detected at one year between nerve density and tortuosity both in the central (P<0.01; r=0.69) and mid-peripheral cornea (P<0.01; r=0.76). CONCLUSIONS: Long-term OK treatment led to reduced SBNP nerve density and this was directly correlated with corneal tortuosity. After one month of treatment interruption, nerve density was still reduced.

Effect of Riboflavin/UVA Collagen Cross-linking on Central Cornea, Limbus and Intraocular Pressure. Experimental Study in Rabbit Eyes.

The Purpose of present study was to investigate the effect of riboflavin/ultraviolet-A-induced collagen cross-linking (CXL) on central cornea, limbus and intraocular pressure (IOP). This was an animal experimental study. The right corneas of 10 rabbits were ultraviolet-A irradiated (3 mW/cm2 for 30 minutes) after de-epithelialization and instillation of 0.1% riboflavin / 20% Dextran drops. Left corneas served as controls. Samples were examined histologically one month postoperatively. Before and after treatment, IOP measurements were recorded bilaterally. At central cornea of eyes underwent CXL keratocyte repopulation, normal arrangement of collagen fibres and a statistically significant change in fibres diameter were detected, compared to controls. At limbus area, there were not any significant histological differences after CXL. There was no statistically significant difference between pre- and postoperative IOP in all eyes.

Comparison of Two Topical Lubricants on the Corneal Surface Recovery and Patient Discomfort After Photorefractive Keratectomy.

INTRODUCTION: This study aimed to compare the effect of two preservative-free (PF) artificial tears, one containing carboxymethylcellulose (CMC) (control group) vs another containing hyaluronic acid and hydroxypropyl guar (HA + HP-guar) (study group), on the healing of the corneal epithelium and the ocular discomfort after bilateral photorefractive keratectomy (PRK) surgery. METHODS: A total of 68 patients that were scheduled to have PRK to correct myopia were randomized into two groups: 34 patients (68 eyes) in the study group and 34 patients (68 eyes) in the control group. Ocular examinations were performed on postoperative days 1, 4, 7, 30, and 90, evaluating the diameter of the de-epithelized cornea, the fluorescein staining using the Oxford scale, the tear film osmolarity and stability (tear breakup time), and the pain using visual analog scale (VAS). RESULTS: On postoperative day 4, 97% of the study eyes vs 84.4% of the control eyes were completely re-epithelized (p = 0.01). Less ocular pain was observed on postoperative day 3 in the study group (5.0 (3.0-6.0) vs 6.0 (3.5-7.0), p = 0.03). No differences were observed beyond postoperative day 7 in the healing of the corneal epithelium, non-invasive Keratograph breakup time (NIKBUT), and the self-perceived ocular discomfort between the two groups. CONCLUSION: The current study shows faster healing of the corneal epithelium and less ocular pain and discomfort in the first days after PRK with the use of topical lubricants containing HA + HP-guar compared to conventional CMC artificial tears, probably due to the different trophic effect of the aforementioned tears on the corneal epithelial cells. TRIAL REGISTRATION: EudraCT No. 2020-003488-25.

Hybrid deep learning models for the screening of Diabetic Macular Edema in optical coherence tomography volumes.

Several studies published so far used highly selective image datasets from unclear sources to train computer vision models and that may lead to overestimated results, while those studies conducted in real-life remain scarce. To avoid image selection bias, we stacked convolutional and recurrent neural networks (CNN-RNN) to analyze complete optical coherence tomography (OCT) cubes in a row and predict diabetic macular edema (DME), in a real-world diabetic retinopathy screening program. A retrospective cohort study was carried out. Throughout 4-years, 5314 OCT cubes from 4408 subjects who attended to the diabetic retinopathy (DR) screening program were included. We arranged twenty-two (22) pre-trained CNNs in parallel with a bidirectional RNN layer stacked at the bottom, allowing the model to make a prediction for the whole OCT cube. The staff of retina experts built a ground truth of DME later used to train a set of these CNN-RNN models with different configurations. For each trained CNN-RNN model, we performed threshold tuning to find the optimal cut-off point for binary classification of DME. Finally, the best models were selected according to sensitivity, specificity, and area under the receiver operating characteristics curve (AUROC) with their 95% confidence intervals (95%CI). An ensemble of the best models was also explored. 5188 cubes were non-DME and 126 were DME. Three models achieved an AUROC of 0.94. Among these, sensitivity, and specificity (95%CI) ranged from 84.1-90.5 and 89.7-93.3, respectively, at threshold 1, from 89.7-92.1 and 80-83.1 at threshold 2, and from 80.2-81 and 93.8-97, at threshold 3. The ensemble model improved these results, and lower specificity was observed among subjects with sight-threatening DR. Analysis by age, gender, or grade of DME did not vary the performance of the models. CNN-RNN models showed high diagnostic accuracy for detecting DME in a real-world setting. This engine allowed us to detect extra-foveal DMEs commonly overlooked in other studies, and showed potential for application as the first filter of non-referable patients in an outpatient center within a population-based DR screening program, otherwise ended up in specialized care.

Effectiveness and safety of XEN63 in patients with primary-open-angle glaucoma.

This paper evaluates the effectiveness and safety of XEN63 stent, either standalone or in combination with phacoemulsification, in patients with primary open-angle glaucoma (POAG). Eighty eyes from 80 patients with medically uncontrolled POAG were assigned to undergo XEN63 implant. The primary outcome was the surgical success, defined as an intraocular pressure (IOP) lowering from preoperative values ≥ 20% and an IOP absolute value between 6 and 18 mmHg, with or without antiglaucoma medications. Forty-three (53.7%) eyes underwent XEN63-standalone and 37(46.2%) eyes a XEN63 + Phacoemulsification procedure. Success rate was 68.8% (55/80) eyes in the overall study sample, 69.8% (30/43) eyes in the XEN63-standalone group; and 67.6% (25/37) eyes in the XEN63 + Phaco group (p = 0.6133). Preoperative IOP was significantly lowered from 22.1 ± 4.9 mmHg and 19.8 ± 3.7 mmHg to 14.7 ± 5.3 mmHg and 13.8 ± 3.4 mmHg in the XEN63-standalone and XEN63 + Phaco groups, respectively (p < 0.0001 each, respectively); without significant differences between them at any of the time-points measured. Preoperative number of ocular-hypotensive drugs was significantly reduced from 2.3 ± 0.8 to 0.3 ± 0.7 drugs, from 2.5 ± 0.7 to 0.3 ± 0.7 drugs; and from 2.0 ± 0.8 to 0.3 ± 0.7 drugs, in the overall, XEN63-standalone, and XEN63 + Phaco groups, respectively. Regarding safety, 3(42.5%) eyes had transient hypotony at some point during the study, although only in one (1.2%) eye was clinically significant. Four (5.0%) eyes underwent a needling, 4 (5.0%) eyes underwent surgical-bleb-revision, 1 (1.2%) eye required a device replacement and 1 (1.2%) eye a device removal due to maculopathy. XEN63, either alone or in combination with phacoemulsification, significantly lowered IOP and reduced the number of ocular hypotensive medications. The rate of ocular hypotony was relatively high, although it was clinically relevant only in one eye.

Creation of a new femtosecond laser-assisted mini-flap to enhance late regression after LASIK.

PURPOSE: To describe a method of LASIK enhancement in which a new femtosecond laser-assisted mini-flap is created over the original LASIK flap. METHODS: The 60-kHz IntraLase femtosecond laser (IntraLase Corp., Irvine, CA) was used to create a new mini-flap over an original LASIK flap for the re-treatment of late regression after LASIK. The diameter of the mini-flap was 7 mm and the attempted flap depth was 100 µm. RESULTS: The procedure was performed on 10 eyes of 7 patients. No intraoperative or postoperative complications developed in any case during the follow-up. At the 6-month follow-up visit, all eyes were within ±0.5 diopters of the targeted refraction. CONCLUSIONS: The preliminary results suggest that creation of a femtosecond laser-assisted mini-flap over a previous LASIK flap seems to be a safe and effective procedure for the enhancement of late regression after LASIK. By creating a femtosecond laser-assisted mini-flap that is smaller in diameter than the original flap, the adhesion of the primary flap edges and peripheral interface remain intact, thus decreasing the risk of dislocation of the original LASIK flap and of losing a sliver of tissue.

Comparison of keratocyte density after femtosecond laser vs mechanical microkeratome from 3 months up to 5 years after LASIK.

BACKGROUND: To compare keratocyte density after mechanical microkeratome LASIK (MK-LASIK) and femtosecond-laser assisted LASIK (FS-LASIK). METHODS: We performed a prospective study of myopic patients that underwent MK-LASIK or FS-LASIK. We measured keratocyte density 3 and 15 months, and 3-5 years after the surgery using confocal microscopy, and compared them with healthy, non-operated corneas. RESULTS: Thirty-one eyes were included in the FS-LASIK group, 30 in the MK-LASIK group and 28 in the control group. Three months postoperatively, there was an increase in the keratocyte population of the whole cornea, mainly due to the mid and posterior stromal layers, in both treatment groups. It was also increased in the stromal bed after MK-LASIK, but not after FS-LASIK. In both groups, this was followed by a normalisation and stabilisation of cell density in those deeper layers 15 months after the surgery. Keratocyte density in the flap and stromal bed was decreased 15 months after FS- and MK-LASIK compared to 3 months postoperatively and compared to controls. It seemed to remain stable thereafter. In spite of this decrease, the average cell density throughout the cornea was not decreased compared to controls at any time point. CONCLUSION: We found a reorganization of keratocytes density after LASIK, with an initial increase, followed by a decrease in the stromal flap and stromal bed 15 months postoperatively, and stable from then onwards, but still maintaining normal average densities in the total cornea. There were no differences between MK- and FS-LASIK.