Discrimination between keratoconus, forme fruste keratoconus, and normal eyes using a novel OCT-based tomographer.

PURPOSE: To combine objective machine-derived corneal parameters obtained with new swept-source optical coherence tomography (SS-OCT) tomographer (Anterion) to differentiate between normal (N), keratoconus (KC) and forme fruste KC (FFKC). SETTING: Laser Center, Hôpital Fondation Adolphe de Rothschild, Paris, France. DESIGN: Retrospective study. METHODS: 281 eyes of 281 patients were included and divided into 3 groups: N (n = 156), FFKC (n = 43), and KC (n = 82). Eyes were included in each group based on objective evaluation using Nidek Corneal Navigator, and subjective evaluation by authors. The SS-OCT system provided anterior and posterior corneal surface and pachymetry derived variables. The training set was composed of 143 eyes (95 N, 43 FFKC). Discriminant analysis was used to determine the group of an observation based on a set of variables. The obtained formula was tested in the validation set composed of 61 N and 82 KC. RESULTS: Among curvature parameters, the FFKC had significantly higher irregularity index at 3 mm and 5 mm, higher inferior-superior index, higher SteepK-OppositeK index and inferiorly decentered posterior steepest keratometry. Among thickness parameters: central pachymetry, thinnest pachymetry, percentage of thickness increase from center to periphery, and inferior decentration of the thinnest point were statistically different between groups. Combination of multiple variables into a discriminant function (F1) included 5 parameters and reached an area under the receiver operating characteristic curve (AUROC) of 0.95 (sensitivity = 75%, specificity = 98.5%) for detection of FFKC. F1 differentiates N from KC with AUROC = 0.99 (sensitivity = 99%, specificity = 99%). CONCLUSIONS: Combining anterior and posterior curvatures variables along with pachymetric data obtained from SS-OCT allowed automated detection of early KC and KC with very good accuracy (87% and 99.5% respectively).

Intraocular Pressure Changes After Intravitreal Fluocinolone Acetonide Implant: Results from Four European Countries.

INTRODUCTION: The 0.19 mg fluocinolone acetonide (FAc) intravitreal implant delivers a continuous intravitreal corticosteroid dose for the treatment of refractory diabetic macular oedema (DMO). The aim of this study was to assess the impact of an FAc intravitreal implant on intraocular pressure (IOP). METHODS: We retrospectively collected anonymised data on the patients' characteristics, DMO treatment, and IOP and IOP-lowering treatments before and after the FAc intravitreal implant between September 2013 and March 2020 in several European centres. RESULTS: A total of 221 eyes from 179 patients were included. The mean follow-up duration was 13.4 (± 12.5, range 2.4-33.5) months. Overall, 194 eyes (88.2%) had received an intravitreal dexamethasone injection before the FAc intravitreal implant. For 25 eyes (11.3%) there was a history of glaucoma, and 52 eyes (23.5%) had previous IOP-lowering treatment. Mean IOP before injection was 14.7 (3.4) mmHg and increased to 16.9 (3.7) mmHg 12 months after injection (P < 0.0001). During follow-up, 55 eyes (24.9%) required the addition or initiation of topical IOP-lowering medication, only one patient (0.5%) had laser trabeculoplasty and one patient (0.5%) a minimally invasive glaucoma surgery, and no patient required incisional IOP-lowering surgery. CONCLUSION: The FAc intravitreal implant led to substantial IOP elevation. This elevation was monitored most of the time with addition or initiation of topical IOP-lowering medication.

Outcomes of Gel Stent Implantation for Glaucoma in Patients With Previous Corneal Graft Surgery: A Case Series.

PURPOSE: To report a series of 5 cases with successful placement of a minimally invasive glaucoma surgery (MIGS) device for glaucoma refractory to medical management in patients with previous corneal grafts. METHODS: This is a retrospective analysis of all cases with a Xen45 Gel Stent (Allergan plc, Dublin, Ireland) for ocular hypertension and glaucoma refractory to medical treatment after corneal graft surgery between 2016 and 2019 at the Rothschild Foundation, Paris. We did the imaging studies and studied the intraocular pressure (IOP) and the endothelial cell count preimplantation and postimplantation with a MIGS device. RESULTS: Five cases were included in this study, demonstrating a well-tolerated, highly effective, and sustained method for controlling the IOP, which was refractory to previous treatment. An average IOP reduction of 70.5% was noted with a needling rate of 20%, and no adverse events were noted except 1 IOP spike day 7 post-op with no long-term effects. CONCLUSIONS: Glaucoma after graft surgery is a well-known and devastating complication, and as numbers of graft surgery performed increases, so will the incidence of glaucoma. MIGS devices such as the Xen45 Gel Stent (Allergan plc) should become a part of our accepted armory to treat raised IOP refractory to medical treatment without delay.

Comparison of Laser Platform Estimation and Objective Measurement of Maximum Ablation Depth Using Scheimpflug Pachymetry in Myopic Femtosecond Laser In Situ Keratomileusis.

PURPOSE: To compare the preoperative estimation of maximum ablation depth provided by the laser platform with objective measurement using Scheimpflug pachymetry in myopic femtosecond laser-assisted in situ keratomileusis (FS-LASIK). METHODS: This is a prospective study carried out at the Rothschild Foundation, Paris, France. In 89 consecutive myopic eyes (45 patients) treated with FS-LASIK, the maximum ablation depth was calculated by measuring the difference between preoperative and 3-month postoperative measurements in central corneal thickness using Scheimpflug pachymetry (Pentacam HR; Oculus Optikgeräte, Wetzlar, Germany). These values were compared with the preoperative estimation of the maximum ablation depth provided by the laser platform, without nomogram adjustment. RESULTS: We found a strong linear correlation between laser platform estimation of maximum ablation depth and Scheimpflug pachymetry (P < 0.00001). The mean ablation depth measured using Scheimpflug pachymetry was greater than that predicted by the laser platform, with a mean overall difference of 2.15 µm (P < 0.05). Subgroup analysis revealed a difference in ablation depth measurements of 7.1 µm in the high myopia subgroup, which was the only subgroup where the difference remained statistically significant. CONCLUSIONS: In myopic FS-LASIK, laser platform estimation of maximum ablation depth correlates well with measurement of maximum ablation depth using Scheimpflug pachymetry and therefore can be used safely.

Recurrent Exposure of XEN Gel Stent Implant and Conjunctival Erosion.

PURPOSE: The purpose of this study was to report a case of recurrent conjunctival erosion and XEN Gel Stent exposure after implantation in a primary open-angle glaucoma patient. Minimally invasive glaucoma surgery (MIGS) is a new approach in glaucoma surgery, and there is a lack of published data with regard to the management of postoperative ocular surface complications. METHODS: This is a case report of a patient with a persistent corneal erosion after XEN Gel Stent implantation. A standalone MIGS surgery was planned for both eyes in this case of refractory glaucoma. Despite a first surgical revision, the patient was suffering from a chronic leaking bleb, an exposed XEN Gel Stent, and severe hypotonia in the left eye. RESULTS: A free conjunctival autografting technique covered with a complementary amniotic membrane graft was performed under local anesthesia. One month following bleb revision, the intraocular pressure was 13 mm Hg on medical treatment, and slit-lamp examination showed a well-formed moderate bleb with no leakage. CONCLUSIONS: This is the first described case of the use of a free conjunctival autograft to treat a persistently leaking bleb after XEN Gel Stent implantation. This case highlights the potential complication of conjunctival erosion due to XEN Gel Stent implantation. It emphasizes the management of complicated filtration blebs after MIGS surgery.

Changes to Corneal Aberrations and Vision After Monovision in Patients With Hyperopia After Using a Customized Aspheric Ablation Profile to Increase Corneal Asphericity (Q-factor).

PURPOSE: To evaluate the visual outcomes and fourth-order Zernike spherical aberrations induced with a customized change in corneal asphericity (ΔQ) correction of presbyopia combined with monovision for hyperopic patients. METHODS: Consecutive hyperopic patients who underwent presbyopic LASIK between September 2013 and July 2014 were included. For the non-dominant eyes, the aspheric ablation profile associated with a myopic refraction was planned using the Custom-Q nomogram (Alcon Laboratories, Inc., Fort Worth, TX). Uncorrected distance visual acuity (UDVA), uncorrected near visual acuity (UNVA), spherical equivalent refraction, ΔQ, and change in corneal spherical aberration coefficient (ΔC40) were analyzed. Postoperative data were collected at 1, 3, and 6 months. RESULTS: Sixty-five patients were included. The mean age was 56.5 ± 5.7 years (range: 47 to 70 years). At the 6-month follow-up, the spherical equivalent refraction for non-dominant and dominant eyes was -1.07 ± 0.74 and 0.32 ± 0.55 diopters (D), respectively. The mean binocular UDVA was 0.01 ± 0.04 logMAR (range: -0.12 to 0.30 logMAR); 91% of patients achieved 20/20 or better binocular UDVA and 83% of patients had Jaeger 3 (Parinaud 4) or better binocular UNVA. The ΔQ for non-dominant and dominant eyes was -0.61 ± 0.15 and -0.33 ± 0.25, respectively, for a 6-mm pupil diameter and was significantly higher for non-dominant eyes (P < .0001). The achieved ΔC40 was -0.49 ± 0.23 µm for non-dominant eyes (for a theoretical ideal value of -0.40 µm) and -0.30 ± 0.18 µm for dominant eyes. For non-dominant eyes, the attempted ΔQ (-0.60) was close to the achieved value (-0.61 ± 0.15). CONCLUSIONS: For hyperopic patients, combining the customized corneal aspheric ablation profile with monovision is safe, effective, and reproducible, inducing intended changes in corneal spherical aberrations. [J Refract Surg. 2016;32(11):734-741.].

Repeatability of Keratometry Measurements Obtained With Three Topographers in Keratoconic and Normal Corneas.

PURPOSE: To assess the repeatability of the corneal topography functions of Orbscan II (Bausch & Lomb, Rochester, NY), OPD-Scan III (Nidek, Gamagori, Japan), and iTrace (Tracey Technologies, Houston, TX) in keratoconic eyes and in a control group of normal patients. METHODS: In this prospective cohort study, patients were recruited between November 2011 and May 2012. Measurements were performed with a combined Placido-scanning slit system (Orbscan II) and two combined Placido-aberrometer systems (OPD-Scan III and iTrace). Repeatability limit and intraclass correlation coefficients (ICCs) of keratometric readings were calculated. RESULTS: Fifty-nine keratoconic eyes of 34 patients and 54 normal eyes of 27 patients were included. Three groups were evaluated: all stage I-IV keratoconic eyes (59 eyes), a subgroup consisting of stage I-II keratoconic eyes (41 eyes), and normal eyes (54 eyes). For almost all parameters studied, the repeatability limit was higher in the two groups of keratoconic eyes compared to normal eyes with all three topographers, indicating lower repeatability. For the maximum keratometry measurement, repeatability limit was 1.73, 1.49, and 1.41 diopters (D) in the stage I-IV keratoconic eyes group, 1.11, 1.02, and 0.98 D in the stage I-II keratoconic eyes group, and 0.61, 0.37, and 1.02 D in the normal eyes group with Orbscan II, OPD-Scan III, and iTrace, respectively. CONCLUSIONS: Topographies performed in keratoconic eyes are less repeatable than those performed in normal eyes. Threshold values of keratometric changes used to ascertain keratoconus progression should be carefully considered. Caution should be taken when interpreting the topographies of such patients. The higher variability should be taken into account before performing any treatment.

Opaque Bubble Layer Risk Factors in Femtosecond Laser-assisted LASIK.

PURPOSE: To determine the characteristics and risk factors for occurrence of opaque bubble layer (OBL) during femtosecond laser-assisted flap creation for LASIK. METHODS: One hundred ninety-eight eyes of 102 consecutive patients who underwent LASIK flap creation performed with the Alcon WaveLight FS200 laser (Alcon Laboratories, Inc., Fort Worth, TX) were retrospectively analyzed in a cohort study. Preoperative manifest refraction, corneal keratometry, central corneal thickness, white-to-white corneal diameter, corneal hysteresis, corneal resistance factor, and programmed flaps parameters were collected. Digital images automatically recorded after flap creation were analyzed to measure OBL areas. Correlation tests were performed between preoperative corneal parameters and OBL areas. RESULTS: The incidence rate of OBL was 48% (103 eyes). The mean OBL area as a percentage of the corneal flap area in the OBL group was 4.25% ± 7.16% (range: 0% to 32.9%). The central corneal thickness, corneal resistance factor, and corneal hysteresis were significantly positively correlated with the OBL area (r = 0.242, P = .001; r = 0.254, P = .028; and r = 0.351, P < .0001, respectively). Corneal hysteresis and OBL area were positively correlated, independently of the central corneal thickness and other confounder factors with standardized coefficient (r = 0.353 ± 0.227, P = .002). CONCLUSIONS: This study confirms the already known OBL risk factors with a larger cohort and suggests for the first time that an elevated corneal hysteresis is an independent predictive risk for OBL occurrence.

Intraoperative OCT-Assisted DMEK: 14 Consecutive Cases.

PURPOSE: To describe the utility of a new intraoperative optical coherence tomographer (OCT) to evaluate endothelio-Descemet graft orientation during Descemet membrane endothelial keratoplasty (DMEK) procedures. METHODS: Prospective, observational, and single-center pilot case series including 14 eyes of 14 patients consecutively scheduled for DMEK surgery. After injecting the graft into the anterior chamber, the graft orientation was assessed with the help of anterior segment OCT. The surgical time and unfolding time were measured. The postoperative measurements included best-corrected visual acuity, central pachymetry, and specular microscopy at 1 month. RESULTS: Using the OCT images, it was possible to evaluate the graft orientation in all cases. The mean unfolding time was 6.1 ± 3.0 minutes, the mean best-corrected visual acuity was 0.3 ± 0.3 logarithm of the minimum angle of resolution, the mean decrease in central pachymetry was 213 ± 177 µm, and the mean central endothelial cell count was 1906 ± 319 cells per square millimeter. CONCLUSIONS: Live intraoperative OCT is useful to visualize and assess graft orientation in DMEK surgery. It enables faster graft positioning with less graft manipulation in the presence of severe corneal edema.

Objective assessment of crystalline lens opacity level by measuring ocular light scattering with a double-pass system.

PURPOSE: To assess the crystalline lens opacity level by measuring ocular light scattering with a double-pass system. DESIGN: Prospective, single-center, cross-sectional study. METHODS: Two hundred fifty-three eyes of 135 patients referred for cataract evaluation were enrolled. Patients with corneal or retinal anomalies potentially impairing ocular transparency were excluded. Lens opacification was assessed by the Lens opacities classification system III. Optical Quality Analysis System (Visiometrics SL) measurements provided ocular Modulation Transfer Function cutoff frequency and Objective Scatter Index. Best-corrected visual acuity and Quality of Vision questionnaire scores (Rasch-scaled) were recorded. We analyzed correlations between visual acuity, type and severity of cataract, Optical Quality Analysis System measurements, and discomfort level in each group. RESULTS: In patients with best-corrected visual acuity better than 20/32, we found correlations between Objective Scatter Index, Modulation Transfer Function, and visual acuity (r = 0.4, P < .0001). The Objective Scatter Index, Modulation Transfer Function, and visual acuity were correlated with each type of cataract. In patients with good visual acuity and moderate functional symptoms, the Objective Scatter Index values also were correlated to the severity of posterior subcapsular cataract (r = 0.4, P = .0006). CONCLUSIONS: Patients with incipient cataract may report visual discomfort, despite minor lens opacity on slit-lamp examination, minor loss of best-corrected visual acuity, or both. The measurement of ocular scattering with the Optical Quality Analysis System device may be a useful tool in the preoperative evaluation of patients with early cataract.

Corneal thickness, curvature, and elevation readings in normal corneas: combined Placido-Scheimpflug system versus combined Placido-scanning-slit system.

PURPOSE: To evaluate agreement in central corneal thickness (CCT), keratometry, and anterior and posterior elevation map measurements in normal corneas between a combined Placido-Scheimpflug system and a combined Placido-scanning-slit elevation topography system. SETTING: Department of Cataract & Refractive Surgery, Rothschild Foundation, Paris, France. DESIGN: Evaluation of diagnostic test or technology. METHODS: Measurements were performed with a combined Placido-Scheimpflug system (TMS-5) and a combined Placido-scanning-slit system (Orbscan II). Ultrasound (US) pachymetry was used as the reference for CCT measurements. Bland-Altman plots were used to evaluate agreement between instruments. RESULTS: The mean CCT measurements by US pachymetry, the Placido-Scheimpflug system, and the Placido-scanning-slit system were 556.74 µm ± 42.45 (SD), 543.23 ± 36.73 µm, and 564.45 ± 41.26 µm, respectively. Although the CCT readings were statistically significantly thinner with the Placido-Scheimpflug system than with the other systems, there was high correlation between instruments. Peripheral corneal thickness readings were also thinner with the Placido-Scheimpflug system than with the Placido-scanning-slit system. Keratometry and anterior and posterior best-fit sphere (BFS) measurements were comparable between the 2 optical devices. Anterior and posterior maximum central elevations measured by the 2 instruments were not comparable or strongly correlated. Repeatability after 3 successive measurements was excellent for all parameters except maximum central elevation. CONCLUSIONS: Although highly correlated, with corneal thickness readings were not interchangeable between the 2 optical devices. No statistically significant differences in keratometry or BFS measurements were observed between the 2 devices. There were important discrepancies in the maximum central elevation between the 2 topographers. FINANCIAL DISCLOSURE: Drs. Gatinel and Saad are consultants to Technolas Perfect Vision. No other author has a financial or proprietary interest in any material or method mentioned.

Assessment of corneal biomechanical properties in normal tension glaucoma and comparison with open-angle glaucoma, ocular hypertension, and normal eyes.

PURPOSE: To assess the biomechanical properties of corneas in patients with normal tension glaucoma (NTG) and to compare them with those of patients with primary open-angle glaucoma (POAG), ocular hypertension (OHT), and normal controls (N). METHODS: Corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann intraocular pressure (IOPg), and corneal compensated IOP (IOPcc) were obtained using an ocular response analyzer for 28 eyes in 14 patients with NTG, 75 eyes in 38 patients with chronic POAG, 53 eyes of 27 patients with OHT, and 44 eyes of 22 N controls. IOP using Goldmann applanation tonometry (IOPGA) and ultrasonic central corneal thickness (CCT) were also measured for each eye. Analysis of variance test was used for statistical analysis. RESULTS: CH was significantly lower in the NTG group (9.88±2.02 mm Hg) compared with the N group (11.05±1.53 mm Hg; P<0.01). CRF was significantly lower in the NTG group (9.5±1.89 mm Hg) compared with the POAG group (11.15±2.35 mm Hg; P<0.01) and to the N group (11.00±1.75 mm Hg; P<0.01). CCT was not considered significantly different between the 4 groups. However, IOPcc was found to be significantly lower in NTG group compared with the POAG group and OHT group (P<0.001). CONCLUSION: NTG was associated with significantly lower CRF than chronic POAG and N patients. CH and CRF could be a useful tool in early diagnosis of NTG.

Bilateral loss in the quality of vision associated with anterior corneal protrusion after hyperopic LASIK followed by intrastromal femtolaser-assisted incisions.

A patient was treated bilaterally for hyperopia (twice in the right eye and 3 times in the left eye) using laser in situ keratomileusis (LASIK) and achieved stable vision. Preoperatively, there was no known risk factor for ectasia. Three years after the last LASIK enhancement treatment, intrastromal femtolaser-assisted incisions (Intracor procedure using the Technolas femtosecond laser) were made bilaterally. After the procedure, a severe loss in the corrected distance visual acuity and in the quality of vision occurred, associated with a topography pattern suggestive of isolated anterior central protrusion. This case suggests that intrastromal femtosecond incisions in eyes that have had hyperopic LASIK should be done with caution, as there is no certainty about how the treated corneas will respond.