Elise Taniguchi

The evolution of corneal and refractive surgery with the femtosecond laser

The use of femtosecond lasers has created an evolution in modern corneal and refractive surgery. With accuracy, safety, and repeatability, eye surgeons can utilize the femtosecond laser in almost all anterior refractive procedures; laser in situ keratomileusis (LASIK), small incision lenticule extraction (SMILE), penetrating keratoplasty (PKP), insertion of intracorneal ring segments, anterior and posterior lamellar keratoplasty (Deep anterior lamellar keratoplasty (DALK) and Descemets stripping endothelial keratoplasty (DSEK)), insertion of corneal inlays and cataract surgery. As the technology matures, it will push surgical limits and open new avenues for ophthalmic intervention in areas not yet explored. As we witness the transition from femto-LASIK to femto-cataract surgery it becomes obvious that this innovation is here to stay. This article presents some of the most relevant advances of femtosecond lasers to modern corneal and refractive surgery.

Clinicians’ perspectives on the use of drug-eluting contact lenses for the treatment of glaucoma

Glaucoma is the leading cause of irreversible blindness worldwide. The perspective of clinicians who treat the disease is important and may ultimately dictate the adoption of new treatment modalities, such as drug-eluting contact lenses. Recent advances have enabled contact lenses to serve as a sustained-release drug-delivery platform capable of treating glaucoma. This review covers the medical treatment of glaucoma, suboptimal adherence rates to treatment, and factors that may influence the clinical applicability of drug-eluting contact lenses. Ophthalmologists who treat glaucoma were surveyed to determine their perspective on treatment adherence, bandage contact lens use and the use of a drug-eluting contact lens to treat glaucoma. Given the challenge of treating glaucoma and the clinical need for improved drug delivery, drug-eluting contact lenses appear to be a promising treatment option.

Comparison of swept-source and enhanced depth imaging spectral-domain optical coherence tomography in quantitative characterisation of the optic nerve head

Aims To compare swept-source optical coherence tomography (SS-OCT) and enhanced depth imaging spectral-domain OCT (EDI-OCT) in quantitative assessment of optic nerve head (ONH) parameters. Methods In a cross-sectional study, patients with primary open angle glaucoma (POAG) and age-matched control subjects underwent SS-OCT and EDI-OCT B-scans of the ONH in a single visit. Two masked readers independently measured the horizontal and vertical lamina cribrosa depth (LCDH and LCDV, respectively), as well as thinnest Bruchs membrane opening minimum rim width (BMO-MRW) from SS-OCT and EDI-OCT scans. We assessed agreement between SS-OCT and EDI-OCT measurements by linear regression models, Bland-Altman analysis and concordance correlation coefficients (CCC). Intrareader and inter-reader reproducibility was assessed using intraclass correlation coefficients (ICC). Results One eye from each of 40 patients with POAG and 20 controls were included. All three ONH measurements were higher on SS-OCT than on EDI-OCT, with significant differences in LCDH (mean difference=31.7 µm, p<0.01) and thinnest BMO-MRW (mean difference=20.5 µm, p<0.01). Linear regression models described the agreement between SS-OCT and EDI-OCT measurements with R2>0.8 for LCDH among both patients with POAG and controls and for thinnest BMO-MRW among patients with POAG. The CCC was >0.8 overall for each parameter. Intrareader and inter-reader ICCs were ≥0.989 and ≥0.964, respectively, for all parameters. Conclusions LCDH, LCDV and thinnest BMO-MRW measurements are not interchangeable between SS-OCT and EDI-OCT, but show good intrareader and inter-reader reproducibility and interdevice agreement for quantitative characterisation of the ONH, particularly among patients with glaucoma.

Periprosthetic Tissue Loss in Patients With Idiopathic Vitreous Inflammation After the Boston Keratoprosthesis.

Purpose: Idiopathic vitritis is a poorly understood complication after Boston keratoprosthesis surgery with unclear etiology. We sought to determine whether an association exists between periprosthetic corneal tissue loss and the development of idiopathic vitritis in keratoprosthesis recipients. Methods: Thirteen Boston type I keratoprosthesis recipient eyes with a history of idiopathic vitritis and 34 type I keratoprosthesis recipient eyes with no history of idiopathic vitritis underwent anterior segment optical coherence tomography (AS-OCT) at a median time postoperatively of 2.4 years versus 1.9 years (range, 0.5–14.2 vs. 0.1–13.6 years), respectively. Areas of corneal graft tissue loss (“gaps”) around the keratoprosthesis stem were identified and analyzed by 2 masked observers. The difference in the presence, number, and size of gaps was compared between cases and controls. Results: A periprosthetic gap was identified more commonly in idiopathic vitritis cases than in controls on AS-OCT (11/13, 86% vs. 11/34, 33.3%, P < 0.001). The number of gaps between cases and controls was also significantly different (2.6 ± 1.6 vs. 0.5 ± 0.8, P < 0.001), but not the estimated gap area (0.056 ± 0.049 mm2 vs. 0.039 ± 0.025 mm2, P = 0.22). Conclusions: A significantly higher proportion of keratoprosthesis recipient eyes with idiopathic vitritis had corneal tissue loss around the keratoprosthesis stem than did controls. Tissue loss could serve as an entry point for debris or bacterial components, triggering idiopathic vitritis. Our study underscores the utility of AS-OCT imaging in the postoperative management of keratoprosthesis patients.

Optic Nerve Head Characteristics in Chronic Angle Closure Glaucoma Detected by Swept-Source OCT

ABSTRACT Purpose: To compare structural features in prelaminar and laminar tissues of the optic nerve head (ONH) in chronic angle closure glaucoma (CACG), primary open angle glaucoma (POAG), and control subjects. Materials and Methods: ONH imaging was performed using swept-source optical coherence tomography (SS-OCT) for measurements of minimum rim width at Bruch’s membrane opening (BMO-MRW), horizontal, and vertical lamina cribrosa depth (LCD). Prelaminar defects, categorized as hole and wedge, and lamina cribrosa (LC) defects were identified. Enhanced depth imaging spectral domain OCT (EDI-OCT) customized to perform high-resolution volume scans was used in conjunction to further characterize prelaminar holes. One eye per subject was analyzed. Results: Eighty subjects (20 CACG, 40 POAG, and 20 controls) were included in the study. CACG and POAG groups had similar mean deviation on Humphrey visual field testing (−6.9 ± 5.1 vs. −6.3 ± 6.0 dB, p > 0.05) and IOP on the day of imaging (14.0 ± 3.1 vs. 13.8 ± 2.7 mmHg, p > 0.05). Thinnest and global BMO-MRW in CACG (120.3 ± 44.8, 225.5 ± 53.9 μm) and POAG (109.7 ± 56.3, 213.8 ± 59.7 μm) groups were lower than controls (200.1 ± 40.8, 308.3 ± 70.8 μm; p < 0.001 for both). Prelaminar holes were most frequent in CACG (65.0%) than POAG (25.0%, p=0.008) or control groups (20.0%, p=0.01). After adjusting for demographic and ophthalmic covariates, CACG was associated with increased odds of having prelaminar holes compared to POAG (odds ratio, 9.79; 95% CI, 2.12–45.19; p=0.003). Hole volume was similar between CACG and POAG (p > 0.05), but the CACG group had more holes per scan than POAG (maximum 2.5 ± 1.9 vs. 1.2 ± 0.4, p=0.02). Prelaminar wedge defects were less common in the CACG than the POAG group (5.0% vs. 37.5%, p=0.02). The CACG group did not differ from controls in laminar characteristics, such as LCD and LC defects. Conclusions: SS-OCT evaluation of the ONH revealed more frequent prelaminar holes in CACG compared to POAG and control patients.

Thin minimal rim width at Bruch’s membrane opening is associated with glaucomatous paracentral visual field loss

Purpose To compare optic nerve head (ONH) measurements in glaucomatous eyes with paracentral visual field (VF) loss to eyes with peripheral VF loss and controls. Methods Open-angle glaucoma (OAG) patients with early paracentral VF loss or isolated peripheral VF loss as well as control subjects underwent ONH imaging with swept-source optical coherence tomography (OCT) and retinal nerve fiber layer (RNFL) imaging with spectral-domain OCT. Minimum rim width at Bruch’s membrane opening (BMO-MRW), lamina cribrosa depth (LCD), and RNFL thickness were compared among the glaucoma and control groups with one-way analysis of variance, Kruskal–Wallis test, and multiple regression analysis. Results Twenty-nine eyes from 29 OAG patients (15 early paracentral and 14 isolated peripheral VF loss) and 20 eyes of 20 control subjects were included. The early paracentral and isolated peripheral VF loss groups had similar VF mean deviation (MD) (−5.3±2.7 dB and −3.7±3.0 dB, p=0.15, respectively). Global BMO-MRW was lower in OAG eyes than in controls (193.8±40.0 vs 322.7±62.2 μm, p<0.001), but similar between eyes with early paracentral VF loss and those with isolated peripheral VF loss (187.6±43.4 vs 200.6±36.3 μm; p>0.99). In contrast, the minimal BMO-MRW was lower in eyes with early paracentral loss (69.0±33.6 μm) than in eyes with isolated peripheral loss (107.7±40.2 μm; p=0.03) or control eyes (200.1±40.8 μm; p<0.001). Average and thinnest RNFL thickness did not differ between OAG groups (p=0.61 and 0.19, respectively). Horizontal and vertical LCD did not differ among the OAG groups and controls (p=0.80 and 0.82, respectively). Multivariable linear regression analysis among OAG cases confirmed the association between lower minimal BMO-MRW and early paracentral VF loss (β=−38.3 μm; 95% confidence interval, −69.8 to −6.8 μm; p=0.02) after adjusting for age, gender, MD, and disc size. Conclusion Thin minimal BMO-MRW may represent a new structural biomarker associated with early glaucomatous paracentral VF loss.