This review will highlight recent insights into measuring retinal structure in Alzheimer’s disease (AD). A growing body of evidence indicates that disturbances in retinal blood flow and structure are related to cognitive function, which can severely impair vision. Optical coherence tomography (OCT) is an optical imaging technology that may allow researchers and physicians to gain deeper insights into retinal morphology and clarify the impact of AD on retinal health and function. Direct and noninvasive measurement of retinal morphology using OCT has provided useful diagnostic and therapeutic indications in several central nervous system (CNS) diseases, including AD, multiple sclerosis, and Parkinson disease. Despite several limitations, morphology assessment in the retinal layers is a significant advancement in the understanding of ocular diseases. Nevertheless, additional studies are required to validate the use of OCT in AD and its complications in the eye.

Since the introduction of phacoemulsification, cataract surgery has evolved remarkably. The use of premium intraocular lenses (IOLs) (aspheric, toric, multifocal), refractive lens exchange and patients after refractive surgery procedures require extremely precise clinical measurements and IOL calculation formulas to achieve desired postoperative refraction. For many years, ultrasound biometry has been the standard for measurement of ocular parameters. The introduction of optical biometry (fast and non-invasive) has replaced ultrasound methods and is now considered as the clinical standard for ocular biometry. Recently, several modern optical instruments have been commercially launched and there are new methods available, including the empirical, analytical, numerical or combined methods to determine IOL power. The aim of this review is to present current techniques of ocular biometry and IOL power calculation formulas, which will contribute to achieve highly accurate refractive outcomes.

PurposeTo measure the maximum, objectively measured, accommodative amplitude, produced by pharmacologic stimulation.MethodsThirty-seven healthy subjects were enrolled, with a mean age of 20.2±1.1 years, corrected visual acuity of 20/20, and mean spherical equivalent refraction (SER) =-0.83±1.60 diopters. For each subject, the right pupil was dilated with phenylephrine 10%. After 30 minutes, the pupil was measured, the left eye was patched, and the right eye was autorefracted. Pilocarpine 4% was then instilled in the right eye, followed by phenylephrine. At 45 minutes after the pilocarpine, autorefraction and pupil size were again measured.ResultsMean pupil size pre- and postpilocarpine was 8.0±0.8 mm and 4.4±1.9 mm, respectively. Pre- and postpilocarpine, the mean SER was -0.83±1.60 and -10.55±4.26 diopters, respectively. The mean pilocarpine-induced accommodative amplitude was 9.73±3.64 diopters. Five subjects had accommodative amplitudes ≥14.00 diopters. Accommodative amplitude was not significantly related to baseline SER (p-value =0.24), pre- or postpilocarpine pupil size (p-values =0.13 and 0.74), or change in pupil size (p-value =0.37). Iris color did not statistically significantly affect accommodative amplitude (p-value =0.83).ConclusionFollowing topically applied pilocarpine, the induced objectively measured accommodation in the young eye is greater than or equal to the reported subjectively measured voluntary maximum accommodative amplitude.

A small increase in lens thickness was associated with a large change in accommodative amplitude and no significant change in lens position as predicted by the Schachar theory.

Rationale:To analyze cardiovascular risk factors and comorbidity of acute unilateral visual loss due to combined central retinal vein occlusion (CRVO) and cilioretinal artery occlusion (CLRAO).Patient concerns:Among patients with retinal vein or artery occlusion hospitalized at the Department of Ophthalmology between January 2011 and August 2017, subjects with combined CRVO/CLRAO were selected. All of them underwent ophthalmologic and cardiologic examination, including fluorescein angiography, optical coherence tomography, 12-lead electrocardiogram, transthoracic and transesophageal echocardiography, carotid Doppler sonography, cerebral magnetic resonance imaging, and a panel of laboratory tests.Diagnoses:Four subjects with coexisting CRVO and CLRAO were found among 146 patients with retinal vein or artery occlusion. There were no other types of concomitance of CRVO and retinal artery occlusion.Interventions:All patients were treated with low molecular heparin in a full dose for 2 weeks, then with 1 mg/kg once daily for the next 2 weeks, followed by acetylsalicylic acid 75 mg/kg/d. Other medication included long-term statins, angiotensin-converting-enzyme inhibitor in 3 patients and beta-blocker in one patient.Outcomes:All patients with CRVO/CLRAO presented multiple cardiovascular risk factors, including hypertension, obesity, hyperlipidemia, chronic nicotine addiction, and a positive family history of coronary artery disease or stroke. In all of them, echocardiography revealed left ventricular hypertrophy and atherosclerotic lesions in the descending aorta; in addition, 3 patients had insignificant atherosclerotic plaques in the carotid artery. Also, in 3 subjects, focal ischemic cerebral changes were diagnosed.Lessons:Patients with combined CRVO and CLRAO present numerous cardiovascular risk factors and abnormalities on imaging examinations, which should be routinely evaluated and treated.