Comparison of two new integrated SS-OCT tomography and biometry devices.

PURPOSE: To evaluate the agreement in biometry measurements and intraocular lens (IOL) power calculations between 2 integrated swept-source optical coherence tomography (SS-OCT) tomography/biometry devices: the Eyestar 900 and the Anterion. SETTING: Tel Aviv Medical Center, Tel Aviv, Israel. DESIGN: Retrospective comparative study. METHODS: 113 eyes of 66 consecutive patients who were evaluated prior to cataract surgery using both devices on the same visit were included. Measurements of axial length, anterior and posterior keratometry, anterior chamber depth, corneal diameter (CD), central corneal thickness, and lens thickness were recorded from both devices and analyzed for agreement and correlation. IOL power calculations using Barrett Universal II formula were compared between the devices in addition to prediction error (PE) and the mean absolute error (MAE). RESULTS: The mean age was 71.6 ± 9.8 years. Clinically, the mean differences in measured variables were small. Measurement correlation and agreement between the devices were excellent for all variables, except for CD (Spearman r = 0.763, P < .001, and Bland-Altman 95% limits of agreement -0.21 to +0.65 mm). Good agreement was found between the devices in IOL power calculations, PE, and MAE, and the agreement was better when using the Eyestar 900 reflective keratometry measurements than the Eyestar 900 SS-OCT keratometry measurements (IOL power agreement within ±0.5 diopter (D) in 90.5% [n = 95] and 81.0% [n = 85], respectively [ P = .076], and within ±0.25 D in 64.8% [n = 68] and 44.8% [n = 47], respectively [ P = .005]). CONCLUSIONS: The 2 integrated SS-OCT tomography/biometry devices had good agreement in biometry measurements and IOL power calculations. Agreement was better when the Eyestar 900 reflective anterior keratometry measurements were used rather than the Eyestar 900 SS-OCT anterior keratometry measurements. Measurements of CD had reduced agreement and were not interchangeable.

Evaluation of a Telemedicine Model for Following Keratoconus Patients in the Era of COVID-19 Pandemic.

Purpose: To evaluate the diagnostic accuracy and reliability of a telemedicine approach for detecting keratoconus patients' progression in the era of coronavirus disease 2019 (COVID-19) pandemic. Materials and Methods: A retrospective study, comparing the office and telemedicine evaluations in determining whether keratoconus patients were at risk of progression and indicated for further treatment of corneal crosslinking, was conducted. The clinic examination included best spectacle corrected visual acuity measurement and manifest refraction, full ophthalmic examination, and corneal topography, which provided with the gold-standard diagnosis. The remote assessment included two decisions of keratoconus progression or stability: the first evaluation after revealing patient demographics and topography images, and the second with the manifest refraction and clinical findings as documented in the outpatient clinic visit. Results: Two-hundred and four eyes of 102 keratoconus patients were included. There was an agreement of assessment between the in-person and the remote diagnostic decisions in 192 (94%) of the eyes. Among the remaining 12 eyes, a false-positive diagnosis was made in 8 (3.9%) eyes, whereas a false-negative diagnosis was made in 4 (1.9%) eyes. The remote assessment showed a sensitivity and specificity of 69% and 96%, respectively. In no case was remote diagnostic decision 2 different from remote decision 1. Conclusions: The telemedicine model yielded high specificity, but low sensitivity values, therefore, not suitable as an alternative for keratoconus patient follow-up (Clinical trial number TLV-0363-20).

Antibacterial and physical properties of a novel sonochemical-assisted Zn-CuO contact lens nanocoating.

PURPOSE: This work examined the antibacterial and physical effects of a novel Zn-CuO nanocoating applied on a silicone hydrogel contact lens. METHODS: Zn-CuO coating of PureVision balafilcon-A soft contact lenses (Bausch&Lomb, Rochester, NY) was performed by sonochemical deposition using a high-intensity ultrasonic horn. Non-coated PureVision lenses served as a control in all experiments. Adhesion assays for P. aerueginosa and S. epidermidis to the coated lenses were performed to identify the minimal coating concentration which still possessed antibacterial activity. Lens water content, oxygen transfer light transfer, leaching, and electron microscopy studies were performed using this concentration. RESULTS: Coated lenses showed 3-5 log reductions in adhesion of both species. The lowest tested coating concentration of 0.02 wt% led to a log reduction of 3.25 ± 1.25 of P. aeruginosa CFU/lens (P = 0.007) and a log reduction of 4.37 ± 0.75 of S. epidermidis (p = 0.0007). Using this coating concentration, water content (36%, 33.6%), oxygen transfer (87.22 ± 10.96, 92.18 ± 2.38, × 10-11(cm2/s)(mlO2)/(ml × mmHg)), p = 0.12), and light transfer properties did not differ significantly between the coated and the control contact lenses. In the range of 380-780 nm wavelength, the coated lenses transmitted 96.47 ± 1.52% while the control lenses transmitted 97.36 ± 1.35%. The corresponding values for the range of 300-380 nm wavelength were 79.343 ± 8.754 and 80.169 ± 1.35. Leaching studies for 0.5 mM coated lenses have demonstrated the excellent stability of the coating with the release of only 0.005% of the coating after 1 week of exposure to the test solution. CONCLUSION: Sonochemical-assisted nanocoating of contact lenses showed significant and consistent antibacterial activity while preserving the basic properties of a silicone hydrogel contact lens.

Outcomes of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) performed in eyes with failure of primary Descemet membrane endothelial keratoplasty (DMEK).

AIM: To evaluate the outcomes of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) performed in eyes after failure of primary Descemet membrane endothelial keratoplasty (DMEK). METHODS: This was a retrospective, non-comparative interventional case series done in a tertiary care hospital. The study group included 21 eyes of patients which underwent UT-DSAEK following the failure of primary DMEK. Outcome measures included best spectacle-corrected visual acuity (BSCVA) and endothelial cell density (ECD) both recorded 6 and 12 months postoperatively as well as central graft thickness (CGT) measured 6 months after UT-DSAEK. RESULTS: When considering only eyes without comorbidities (17 of 21), 12 months after UT-DSAEK, BSCVA was ≥20/25 in 12/13 (92%) eyes and ≥20/20 in 4/13 (30%) eyes. Mean ECD loss rate was 38.9% at 12 months postoperatively (range 8%-57%). Six months postoperatively, CGT averaged at 81±34 µm (range 34-131 µm). No intraoperative complications were recorded. Postoperatively, one patient (no. 8) had graft wrinkles that were fixed 2 days following UT-DSAEK. Four patients have developed intraocular lens (IOL) opacification, and two of them underwent IOL exchange. No other postoperative complications were recorded. CONCLUSIONS: UT-DSAEK is instrumental in the management of primary DMEK graft failure, allowing visual rehabilitation which is comparable with that of repeat DMEK.

Microkeratome-Assisted Anterior Lamellar Keratoplasty for the Correction of High-Degree Postkeratoplasty Astigmatism.

PURPOSE: To describe the surgical technique and report the outcomes of patients treated with microkeratome-assisted anterior lamellar keratoplasty (MALK) for the correction of high-degree postkeratoplasty astigmatism. METHODS: Four eyes of 2 patients with extremely high (>10 D) and irregular [surface asymmetry index >1.0 D] post-penetrating keratoplasty astigmatism occurring after complete suture removal underwent MALK and were followed for at least 3 years after the procedure. In all cases, 250-µm lamellar keratectomy was performed, followed by 2 full-thickness incisions through the penetrating keratoplasty scar and the placement of an appropriately sized donor graft, which was secured with a double-running 10-0 nylon suture. All sutures were removed in all eyes within 1 year from surgery. Corrected distance visual acuity, refraction, corneal topography, and endothelial cell density were noted at each examination. RESULTS: At the last follow-up examination (3 years or longer after MALK), corrected distance visual acuity had improved to 20/20, refractive astigmatism had decreased to an average of 2.1 D (in all cases within 4.5 D), and the average surface asymmetry index had reduced from 2.27 to 0.56. CONCLUSIONS: MALK is an effective and safe technique for the correction of high-degree postkeratoplasty astigmatism.

Deep Anterior Lamellar Keratoplasty After Descemet Stripping Automated Endothelial Keratoplasty.

PURPOSE: To report the indications and long-term outcomes of deep anterior lamellar keratoplasty (DALK) performed after Descemet stripping automated endothelial keratoplasty (DSAEK) in cases of visually significant stromal opacities. DESIGN: Retrospective, interventional, consecutive case series. METHODS: Setting: Private hospital. STUDY POPULATION: Thirteen eyes that underwent DALK after DSAEK at our institution. Indications for DALK after DSAEK included both stromal opacities persisting after DSAEK and stromal opacities occurring secondarily in post-DSAEK corneas. DALK was always performed in a standardized fashion including exchange of a disc of full-thickness recipient cornea (up to the DSAEK stromal surface),7.0 mm in diameter, with a donor lamella obtained by microkeratome-assisted dissection, punched to 7.0 mm and sutured into place with a double running 10-0 nylon suture. MAIN OUTCOME MEASURES: Best spectacle-corrected visual acuity (BSCVA), manifest refraction, and endothelial cell density (ECD). RESULTS: Mean follow-up was 26 ± 18 months (range = 6-60 months). Indications for DSAEK were full-thickness graft failure (n = 8), DSAEK graft failure (n = 3), and pseudophakic bullous keratopathy (n = 2). Indications for subsequent DALK were persisting stromal opacity (n = 9) and stromal opacities newly occurred after DSAEK as a result of HSV keratitis (n = 2) or interface infection (n = 2). After complete suture removal, mean BSCVA was 20/28 (0.14 ± 0.8 logMAR) in eyes without ocular comorbidities affecting visual acuity (n = 7), while refractive astigmatism was within 4 diopter (D) in all but 1 eye (average = 3.2 ± 1.4 D). No intraoperative complications were recorded. CONCLUSIONS: Performing DALK on DSAEK eliminates the need for open-sky surgery, achieving visual results comparable to those of penetrating keratoplasty, while sparing a healthy endothelial graft.

Measurement of the difference in intraocular pressure between the sitting and lying body positions in healthy subjects: direct comparison of the Icare Pro with the Goldmann applanation tonometer, Pneumatonometer and Tonopen XL.

BACKGROUND: Change in intraocular pressure is known to occur with body posture. Previously, markedly different estimations of this change were reported. The Icare Pro (Icare; Tiolat Oy, Helsinki, Finland) is designed to measure intraocular pressure with the subject supine. We compared the measurement of postural change in intraocular pressure obtained with this and 3 other tonometers: Goldmann applanation tonometer (CSO, Firenze, Italy), Pneumatonometer (Model 30, Reichert, Depew, NY, USA) and the Tonopen XL (Reichert). DESIGN: Prospective comparative study. PARTICIPANTS: Twenty-one healthy subjects. METHODS: Intraocular pressure was measured in random order with four tonometers, first sitting then after 10 min of lying. MAIN OUTCOME MEASURES: Average postural intraocular pressure change (mmHg) and the 95% limits of agreement for measuring postural intraocular pressure change between tonometers. RESULTS: Average postural intraocular pressure change (lying minus sitting, mmHg) was measured highest with the Goldmann applanation tonometer (4.1 ± 2.6) and Pneumatonometer (3.9 ± 2.1), significantly lower with the Tonopen (0.9 ± 1.7) and was negative with the Icare (-0.9 ± 3.3). The 95% limits of agreement for measuring postural intraocular pressure change between Goldmann applanation tonometer and Icare, Pneumatonometer and Tonopen were -3.2-13.3, -6.4-6.9 and -2.8-9.4 mmHg, respectively. CONCLUSIONS: Postural change in intraocular pressure was measured similarly, on average, with Goldmann applanation tonometer and Pneumatonometer, and much lower with Tonopen and Icare Pro. There was poor interdevice agreement in measuring this parameter. We observed high intersubject variability, suggesting the clinical importance of this measurement in the diagnosis and management of glaucoma.

Retinal blood flow velocity in metabolic syndrome.

BACKGROUND: Metabolic syndrome (MetS) is characterized by obesity, insulin resistance, dyslipidemia, and hypertension. The Retinal Function Imager (RFI) is a new technique for measuring retinal blood-flow velocity. This study aims to compare retinal blood flow velocity between MetS and healthy subjects. METHODS: Twenty eyes of 20 MetS males and 21 eyes of 21 aged-matched healthy males underwent RFI and carotid-femoral pulse wave velocity (PWV) measurement as well as assessment of MetS parameters. The results in MetS and healthy subjects were compared. RESULTS: The average venular velocity in the MetS patients was significantly higher than in the healthy subjects (2.7 ± 0.0 mm/sec versus 2.5 ± 0.0 mm/sec respectively, P=0.013), following adjustment for age, heart rate and systolic blood pressure. Carotid-femoral PWV was higher in the MetS population than the healthy controls (10.3 ± 1.2 mm/sec versus 9.3 ± 1.5 mm/sec respectively, P=0.005). The diastolic blood pressure and MAP were correlated strongly with the arterial blood flow velocities in healthy subjects (r=0.503, P=0.020 and r=0.474, P=0.030 respectively) but not in MetS subjects. CONCLUSIONS: The RFI was able to distinguish between the retinal blood flow of normal and MetS subjects. Higher venular blood flow velocity and the poor correlation between velocity and blood pressure of MetS subjects suggest that MetS causes microvascular damage.

Results of cataract surgery with Z-flex hydrophilic acrylic toric IOL.

PURPOSE: To report the outcome of cataract surgery with implantation of the Z-flex 690TA hydrophilic acrylic toric intraocular lens (IOL).
 METHODS: We enrolled consecutive patients who had 1.75 D or more of preexisting corneal astigmatism. Patients had cataract extraction surgery with implantation of a Z-flex 690TA toric IOL (Medicontur, Hungary). Refractive outcomes, keratometry, correction ratio (CR), and error of magnitude (EM) were evaluated. RESULTS: Nineteen eyes of 13 patients were evaluated. Mean follow-up time was 4.3 ± 2.3 months. Mean preoperative keratometric astigmatism was 3.05 ± 0.74 D. Mean postoperative deviation from the anticipated spherical equivalent was +0.23 ± 0.39 D, with 100% of eyes achieving a spherical equivalent within ± 1.00 D of the target refraction. Mean deviation from the anticipated refractive cylinder was 0.46 ± 0.47 D. Mean IOL misalignment was 5.67 ± 6.45 degrees. Mean CR was 1.02 ± 0.22, and the mean EM was -0.09 ± 0.55 D. CONCLUSION: The Z-flex 690TA hydrophilic acrylic toric IOL implantation was safe, effective, and predictable in correcting corneal astigmatism during cataract surgery.