Luís Abegão Pinto

Choroidal Thickness in Nonarteritic Anterior Ischaemic Optic Neuropathy: A Study with Optical Coherence Tomography

Abstract Nonarteritic anterior ischemic optic neuropathy (NA-AION) is the most common nonglaucomatous optic neuropathy in adults over 50 years of age. It is usually related to cardiovascular risk factors. The primary objective of this study was to evaluate choroidal thickness in patients with chronic NA-AION, and the secondary objective was to evaluate macular thickness in these patients. This cross-sectional study compared two groups: group 1 included 20 eyes of 20 patients with chronic NA-AION, and group 2 included 31 eyes of 31 healthy controls. In both groups, the choroidal thickness was measured using the enhanced depth imaging program of Heidelberg Spectralis® optical coherence tomography (Heidelberg Engineering, Heidelberg, Germany). The macular thickness was also measured using the automatic software of the same device. The mean follow-up time after NA-AION in group 1 was 57.17u2009±u200926.92 months. The mean choroidal thickness of the posterior pole was 244.38u2009±u200961.03u2009µm in group 1 and 214.18u2009±u200965.97u2009µm in group 2 (pu2009=u20090.004). The mean macular thickness was higher in group 2. Macular thickness is reduced in eyes that had an episode of NA-AION, whereas choroidal thickness is generally higher in these eyes when compared with normal eyes. The increase in choroidal thickness may be due to a local dysfunction in vascular autoregulatory mechanisms, which may predispose to ischemic phenomena.

Hypoxia challenge test and retinal circulation changes - a study using ocular coherence tomography angiography

Previous studies report that the response of retinal vessels to a decrease in oxygen (hypoxia) is vasodilation, thus increasing blood flow. We aimed to characterize the changes in retinal microvasculature induced by a mild hypoxia stress test in a healthy population, using ocular coherence tomography angiography (OCT‐A) technology.

Circadian Arterial Blood Pressure Variation and Glaucoma Progression: More Questions Than Answers?

To the Editor: We are delegates of the European Glaucoma Panel comprising young European glaucoma specialists, having recently discussed the article “Circadian Variation in Arterial Blood Pressure and Glaucomatous Optic Neuropathy—A Systematic Review and Meta-Analysis” by Bowe et al.1

Automated gonioscopy photography for iridocorneal angle grading

Purpose: The aim of this study is to assess the agreement between manual and automated gonioscopy for iridocorneal angle opening. Methods: The research is a cross-sectional observational study. Manual and automated gonioscopy were performed to consecutive patients in a glaucoma clinic. Iridocorneal angle opening grading was performed according to Shaffer’s classification. Automated gonioscopy was performed with NGS-1 automated gonioscope (NIDEK Co., Gamagori, Japan). The automated gonio-photos were graded by two independent observers. Agreement between automated and manual gonioscopy and also among raters was ascertained by Fleiss’ kappa statistic and comparison of area under curve. Results: In total, 88 eyes of 47 subjects were analysed. Mean age was 63u2009±u200910u2009years. Twenty eyes (22.7%) were excluded from grading due to poor quality images. Angle closure was detected in 23.4% with dynamic gonioscopy in comparison with 4.3% using automated image grading. The agreement for angle closure diagnosis between dynamic and automated gonioscopy was low (κu2009=u20090.09u2009±u20090.10; pu2009=u20090.18). The area under curve for detecting eyes with angle closure showed poor accuracy between automated and manual methods (area under curve: 0.53u2009±u20090.05, 95% confidence interval: 0.44–0.62). There was modest inter-rater agreement for angle opening assessment of automated images with Fleiss’ kappa of 0.17 (95% confidence interval: 0.035–0.238). Conclusion: Manual and automated gonioscopy showed only slight agreement for the assessment of iridocorneal angle opening status. Further improvements of the NGS-1 automated gonioscopy and technique are desired for widespread use in a real-life setting.

Nanotechnology-Ocular Devices for Glaucoma Treatment: A Literature Review

ABSTRACT Nanotechnology enabled the development of materials and devices with great utility in different fields of medicine. By using engineered-based nano-devices and structures, human biological systems may be controlled and repaired at a molecular scale, ultimately leading to a biological benefit. In particular, in the field of glaucoma treatment, nanotechnology may, for example, enhance drug residence time on the ocular surface and ocular bioavailability, as well as improve surgical success by both optimizing postoperative scarring and providing a wider safety window. Further studies are still needed to entirely explain the pharmacodynamics of nanotechnology-based therapeutic approaches and prove their biological consequences in human eyes. This review aims to summarize the literature concerning the advances in nanotechnology, specifically regarding ocular devices applied to the treatment of glaucoma.

Steroid-induced protracted severe ocular hypertension in a 14-year-old girl

Steroid-induced ocular hypertension (SIOH) is a challenging entity in paediatric age, with many being refractory to medical therapy. Literature is scarce about surgical options in these cases. A 14-year-old girl with bilateral uveitis and macular oedema had received an intravitreal and subconjunctival triamcinolone injection in the right (OD) and left (OS) eye, respectively. While the steroid was effective in resolving the oedema, intraocular pressure (IOP) increased to about 40u2009mm Hg OD and 34u2009mm Hg OS, despite being under maximal IOP-lowering therapy. An initial conservative approach was preferred due to the young patient age and given that most cases of SIOH are transient. However, progressive structural changes were documented, and bilateral sequential minimally invasive glaucoma surgery (MIGS: XEN gel stent) was taken. With a follow-up of 6 months, the patient is drug-free with IOP around 14u2009mm Hg. This report discusses the role and efficacy of MIGS in a paediatric case of SIOH.

Pupillary changes after laser peripheral iridotomy

and rods in the fovea HFL displays a significant part of the thickness of the retinal layers in the macular region. In standard ophthalmoscopy, the HFL cannot be distinguished from other layers within the macula. In some cases, the radially oriented HFL is indirectly visualized by intraretinal lipid exudates showing a macular star formation (e.g. in neuroretinitis, nonarteritic anterior ischaemic optic neuropathy) (Galvez-Ruiz 2015). Routinely by SD-OCT, the outer nuclear layer cannot be distinguished from HFL in the macula region due to the low contrast between these tissues. Modification of the OCT scan technique can solve this problem by altering the angle of the OCT entry beam on HFL, which consequently alters its reflectivity relative to the outer nuclear layer as shown by Lujan et al. (2011). Intraretinal, mainly HFL involving haemorrhages, is rare.To thebestknowledge of the authors, only one other case could be identified with a similar but smaller formation of haemorrhage in a patient with high myopia (Lane et al. 2004). The presented case showed the haemorrhage organized in a larger peculiar petalloid pattern with feathery distal edges, suggesting immediately localization within the radially oriented Henle fibre layer. Spectral domain optical coherence tomography (SD-OCT) revealed areas of high central backscattering and shadowing of the underlying retinal layers, consistent with a hyperreflective haemorrhage in the outer nuclear layer also demonstrated in the enface SD-OCT. (Figure 1A) Structural intraretinal changes due to the bleeding resulted in a distinct decrease of VA despite immediate intravitreal antiVEGF treatment. This unusual case with the supplement of a detailed SD-OCT analysis demonstrates vividly the anatomy of Henle fibre layer in the macular region.

Corneal properties and glaucoma: a review of the literature and meta-analysis

PURPOSEnStudies have suggested that corneal biomechanical properties influence intraocular pressure (IOP) measurements, namely central corneal thickness (CCT) and corneal hysteresis (CH). The present study aimed to investigate the associations of CH and CCT with glaucoma development.nnnMETHODSnWe performed a review of the literature and meta-analysis of observational studies (2006-2016) that included both adult glaucoma patients and controls and reported CCT and CH as outcomes. Nineteen studies were conside red eligible, and the mean difference (MD) between groups (patient and control) for both variables was used for statistical analyses.nnnRESULTSnA total of 1,213 glaucoma and 1,055 healthy eyes were studied. Quan titative analysis suggested that CH was significantly lower in the glaucoma group than in the control group (MD=-1.54 mmHg, 95% CI [-1.68, -1.41], P<0.0001). Additionally, CCT was significantly lower in the glaucoma group than in the control group (MD=-8.49 µm, 95% CI [-11.36, -5.62], P<0.001).nnnCONCLUSIONnCorneal properties appear to differ between glaucoma patients and healthy controls. Our results emphasize the importance of corneal biomechanical properties in IOP interpretation and should support further studies on the influence of CH and CCT in glaucoma screening and diagnosis.