Exploring the effect of hypertension on retinal microvasculature using deep learning on East Asian population.

Hypertension is the leading risk factor of cardiovascular disease and has profound effects on both the structure and function of the microvasculature. Abnormalities of the retinal vasculature may reflect the degree of microvascular damage due to hypertension, and these changes can be detected with fundus photographs. This study aimed to use deep learning technique that can detect subclinical features appearing below the threshold of a human observer to explore the effect of hypertension on morphological features of retinal microvasculature. We collected 2012 retinal photographs which included 1007 from patients with a diagnosis of hypertension and 1005 from normotensive control. By method of vessel segmentation, we removed interference information other than retinal vasculature and contained only morphological information about blood vessels. Using these segmented images, we trained a small convolutional neural networks (CNN) classification model and used a deep learning technique called Gradient-weighted Class Activation Mapping (Grad-CAM) to generate heat maps for the class "hypertension". Our model achieved an accuracy of 60.94%, a specificity of 51.54%, a precision of 59.27%, and a recall of 70.48%. The AUC was 0.6506. In the heat maps for the class "hypertension", red patchy areas were mainly distributed on or around arterial/venous bifurcations. This indicated that the model has identified these regions as being the most important for predicting hypertension. Our study suggested that the effect of hypertension on retinal microvascular morphology mainly occurred at branching of vessels. The change of the branching pattern of retinal vessels was probably the most significant in response to elevated blood pressure.

Unilateral ectasia after small-incision lenticule extraction.

A 23-year-old man developed unilateral corneal ectasia after bilateral small-incision lenticule extraction (SMILE). The preoperative corneal topography was normal, with a minimum corneal thickness of 582 µm and 586 µm in the right eye and left eye, respectively. The refractive correction was -3.00 diopters (D) sphere in the right eye and -3.50 D sphere in the left eye. At the 12-month postoperative visit, corneal topography showed early signs of ectasia in the right eye; the ectasia had deteriorated by the 15-month examination. Corneal crosslinking was performed to arrest further progression. At the last examination, the uncorrected distance visual acuity in the right eye was 0.1 logarithm of the minimum angle of resolution (logMAR) and the corrected distance visual acuity, -0.1 logMAR.

Pupil influence on the quality of vision in rotationally asymmetric multifocal IOLs with surface-embedded near segment.

PURPOSE: To evaluate the influences of preoperative pupil parameters on the visual outcomes of the SBL-3, a rotationally asymmetric multifocal intraocular lens (IOL) with a surface-embedded near segment. SETTING: Cathedral Eye Clinic, Belfast, Northern Ireland, United Kingdom. DESIGN: Retrospective comparative case series. METHODS: Postoperatively, patients divided into 4 groups according to their pupil size as follows: Group A: 2.50 to 2.99 mm, Group B: 3.00 to 3.50 mm, Group C: 3.51 to 4.00 mm, and Group D: 4.01 to 4.50 mm. The uncorrected distance (UDVA), intermediate (UIVA), and near (UNVA) visual acuities, IOL centration and tilt, and quality of vision (QoV) questionnaires were compared between the 4 groups for 18 months postoperatively. RESULTS: The study comprised 90 patients (180 eyes). The mean preoperative pupil (photopic and mesopic) diameter was 4.3 mm ± 0.3 (SD) and 5.6 ± 1.4 mm, respectively, which decreased to 3.8 ± 0.7 mm and 4.9 ± 1.2 mm, respectively, at 18 months. Eighteen months postoperatively, both photopic and mesopic pupil groups had a statistically significant reduction in size from preoperative levels. No significant differences in UDVA, UIVA, and UNVA were found between the groups (P > .001). Significant differences in the QoV questionnaire day scores and night scores were found between the 4 groups (P < .001). CONCLUSIONS: The rotationally asymmetric multifocal IOL provided excellent optical performance during 18-months follow-up. The preoperative photopic pupil is an important parameter for consideration of this type of IOL because smaller pupils have a significant negative subjective impact on QoV.

Rotationally asymmetric multifocal intraocular lenses: preoperative considerations and postoperative outcomes.

PURPOSE OF REVIEW: The manuscript presents a review of recently published studies reporting objective and subjective outcomes and preoperative considerations of asymmetrical multifocal intraocular lenses (IOLs). RECENT FINDINGS: Current publications suggest that asymmetrical multifocal IOLs provide good, distance, intermediate and near vision for cataract and clear lens extraction patients. The contrast sensitivity achieved is similar to monofocal IOLs. Photopic phenomenon such as glare and halos has been reduced through the use of these IOLs leading to better patient satisfaction. Centration plays a critical role and the lack of a gold standard assessment tool has led to a minority of patients experiencing lower quality of vision and side-effects such as glare and hazy vision. The frequency of dissatisfied patients can be minimized by appropriate patient selection. This is achieved by assessing pupil parameters which guides the surgeon to align the IOL accordingly. SUMMARY: Asymmetric multifocal IOLs provide the surgeon with an IOL that achieves excellent visual and refractive outcomes enabling patients to see clearly at a range of distances. Subjectively patients report low levels of photopic phenomena and high levels of spectacle independence resulting in high overall patient satisfaction.

Optimized Visual Outcome After Asymmetrical Multifocal IOL Rotation.

PURPOSE: To report improved visual outcome after rotation of an asymmetrical multifocal intraocular lens (IOL). METHODS: Case report. RESULTS: A 58-year-old patient underwent bilateral phacoemulsification with asymmetrical multifocal IOL implantation. Postoperative uncorrected distance visual acuity (UDVA) was 0.0 logMAR (20/20 Snellen) and uncorrected near visual acuity was 0.0 logMAR (20/20 Snellen) in both eyes. Quality of vision questionnaire scores for day and night were 5 and 7, respectively. The center of the multifocal IOL in the dominant eye was initially found to be 0.2 mm superotemporally displaced, increasing the percentage area of 'near-add' compared to 'distance-add' within the physiological pupil. Rotation of this IOL 120° clockwise greatly improved the IOL centration within the pupil center and resulted in an immediate improvement in UDVA to -0.1 logMAR (20/16 Snellen) and quality of vision questionnaire scores to 8 and 9, respectively. CONCLUSIONS: Assessment of the centration of an asymmetrical multifocal IOL is important, particularly if there are dysphotoptic or other visual complaints. [J Refract Surg. 2016;32(7):494-496.].