Interocular Symmetry of Choroidal Thickness and Volume in Healthy Eyes on Optical Coherence Tomography.

BACKGROUND: We aimed to determine the physiological symmetry, with spectral-domain optical coherence tomography, of choroidal measurements in a healthy population in all the areas defined in the Early Treatment Diabetic Retinopathy Study (ETDRS). METHODS: One hundred and fifty-four eyes of 77 healthy young adults between the ages of 19 and 32 years were enrolled. Differences in choroidal thickness (CT) and volume (CV) between the left and right eyes were calculated. Normal ranges of absolute interocular differences were established as the 95th percentile. RESULTS: The mean ± SD subfoveal CT (SFCT) and total CV values in the right and left eyes were 342.03 ± 77.38 versus 361.64 ± 76.45 µm (correlation coefficient ρ = 0.820; p < 0.001) and 0.27 ± 0.06 versus 0.28 ± 0.06 mm3 (ρ = 0.830; p < 0.001), respectively. Differences in 5 of the 9 areas of the ETDRS map were statistically significant (p < 0.05), but with a strong interocular correlation (ρ > 0.8; p < 0.001). The 95th percentile of interocular tolerance limits for CT in the 1-, 3-, and 6-mm areas were 97, 70, and 57 µm, respectively; the 95th percentile for the volume values were 0.06, 0.51, and 1.73 mm3. CONCLUSIONS: CT and CV are highly correlated between eyes, statistically significant differences between them can be found, and absolute interocular differences may reach 97 µm in SFCT, and 1.73 mm3 in total CV.

CHOROIDAL THICKNESS AND VOLUME IN A HEALTHY PEDIATRIC POPULATION AND ITS RELATIONSHIP WITH AGE, AXIAL LENGTH, AMETROPIA, AND SEX.

PURPOSE: To evaluate choroidal thickness (CT) and volume in healthy pediatric individuals using enhanced depth imaging spectral domain optical coherence tomography (SD-OCT), as well as its association with age, sex, axial length (AL), and refractive error. METHODS: Ninety-three eyes from 93 healthy pediatric individuals were examined. An Early Treatment Diabetic Retinopathy Study grid was applied to analyze CT and volume map in each of its nine sectors. RESULTS: The mean subfoveal CT and volume were 314.22 ± 55.48 µm and 0.25 ± 0.04 mm, respectively. The nasal CT and volume of both the inner and the outer rings were significantly lower than the temporal area of the same ring and lower than the subfoveal choroidal thickness. A significant negative correlation between the subfoveal CT and AL (r = -0.250, P = 0.015) and a significant positive correlation between the subfoveal CT and refractive error (r = 0.238, P = 0.006) were found. The estimation of the variation in the subfoveal CT in relationship to the AL was -13.55 µm per millimeter. The variation in the subfoveal CT with refractive error was 7.52 µm per diopter. The estimation of the variation in the total choroidal volume related to the AL and ametropia was, respectively, -0.2354 mm per millimeter and 0.1412 mm per diopter. CONCLUSION: Healthy pediatric subjects exhibit choroidal differences in refractive error and AL. In the study population, CT and volume show an increase with age after adjusting for AL.

Descemet's Membrane Detachment during Phacocanaloplasty: Case Series and In-Depth Literature Review.

This article presents three cases of Descemet's membrane detachment (DMD) occurring during 'ab externo' phacocanaloplasty procedures in three patients with uncontrolled primary open-angle glaucoma (OAG) and discusses the management of this condition by reviewing the available literature. Following a successful 360° cannulation of Schlemm's canal (SC), the microcatheter was withdrawn while an ophthalmic viscosurgical device (OVD) was injected into the canal. During passage through the inferonasal quadrant, a spontaneous separation of the posterior layer of the cornea was observed. Each case was managed differently after diagnosis, with the third case being drained intraoperatively based on experience gained from the previous cases. On the first postoperative day, slit-lamp biomicroscopy (BMC) revealed multiple DMDs in case one and a hyphema in the lower third of a deep anterior chamber. In the other two cases, a single DMD was observed. The second case developed hemorrhagic Descemet membrane detachment (HDMD), while the other two were non-hemorrhagic. In all three cases, anterior segment optical coherence tomography (AS-OCT) revealed the presence of retrocorneal hyperreflective membranes indicative of DMDs. These membranes were located in the periphery of the cornea and did not impact the visual axis. After evaluation, a small incision was made in the inferotemporal DMD of the first case. However, for the two remaining cases, a strategy of watchful waiting was deemed appropriate due to the location and size of the DMDs, as they did not affect the best-corrected visual acuity (BCVA). Over time, the patients demonstrated progressive improvement with a gradual reduction in the size of the DMDs.

Modification of Corneal Biomechanics and Intraocular Pressure Following Non-Penetrating Deep Sclerectomy.

Changes in the cornea can influence outcomes in patients with primary open-angle glaucoma (POAG). We aimed to evaluate the relevance of changes in corneal biomechanics and intraocular pressure (IOP) in patients undergoing non-penetrating deep sclerectomy (NPDS) with the Esnoper V2000 implant® (AJL Ophthalmic S.A., Gasteiz, Spain). We included 42 eyes of 42 patients with POAG scheduled for NPDS with the Esnoper V2000 implant. Biomechanical properties were measured by Ocular Response Analyzer® G3 (ORA; Reichert Inc., Depew, NY, USA). Corneal hysteresis (CH), corneal resistance factor (CRF), corneal compensated IOP (IOPcc), and Goldmann-correlated IOP (IOPg) were measured the day before surgery and on day 1, 7, and 30 and 2 and 3 months after surgery. CH initially increased, fell below the presurgical value at 30 days after the surgery, and increased again at 2 and 3 months. CRF, IOPcc, and IOPg decreased on the first day after surgery, then followed a trend of increasing but stayed below pre-surgery levels. All values reached statistical significance. While observed changes in corneal biomechanics after NPDS and Esnoper V2000 implant were significant, more studies are needed if we are to understand their influence on corneal biomechanics and their clinical relevance in POAG.