Applications of Anterior Segment Optical Coherence Tomography in Cornea and Ocular Surface Diseases

Optical coherence tomography (OCT) is a noncontact technology that produces high-resolution cross-sectional images of ocular tissues. Anterior segment OCT (AS-OCT) enables the precise visualization of anterior segment structure; thus, it can be used in various corneal and ocular surface disorders. In this review, the authors will discuss the application of AS-OCT for diagnosis and management of various corneal and ocular surface disorders. Use of AS-OCT for anterior segment surgery and postoperative management will also be discussed. In addition, application of the device for research using human data and animal models will be introduced

Advances and Clinical Applications of Anterior Segment Imaging Techniques

10.1155/2016/8529406Journal of Ophthalmology2016852940

Sex and Age Morphometric Variations in Bony Nasolacrimal Duct and Fossa for Lacrimal Gland in Mexican Population

SUMMARY: Primary acquired nasolacrimal duct obstruction is greater in women over 40 years and has been associated with morphometric variations in the osseous nasolacrimal duct, which varies according to age and sex. The objective is to determine variations regarding sex and age of the nasolacrimal duct and osseous fossa for lacrimal gland. One hundred sixteen dry orbits from Mexican population were analyzed; subdivided into four groups based on age and sex. The length, transverse and anteroposterior diameters of the bone entrance of the nasolacrimal duct, and the length and width of the fossa for lacrimal gland were determined. Statistical tests were applied to determine the significance of the differences found between groups. The nasolacrimal duct in women had shorter length than men in both age groups. The entrance had a wider transverse diameter in women than men independently of age and its anteroposterior diameter was shorter in men under 40 years than over 40 years. The fossa for lacrimal gland was larger in women under 40 years than in men of same age group and women over 40 years old. The lower third of the was wider in women under 40 years than in women over 40 years. Our study confirms significant differences between sex and age groups in some of the morphometric measurements of bony nasolacrimal duct and fossa for lacrimal gland in Mexican population. Comparative studies with and without clinical illness are needed to clarify if the bony characteristics of those structures participate in the etiopathogenesis and distribution differences observed in sex, age and ethnicity of thisillness. KEY WORDS: Nasolacrimal duct; Fossa for lacrimal gland; Morphometry; Primary acquired nasolacrimal duct obstructio

Cornea lenticule viability and structural integrity after refractive lenticule extraction (ReLEx) and cryopreservation

Molecular Vision173437-3449MVEP

Short-term outcomes after the loading phase of intravitreal bevacizumab and subthreshold macular laser in non-center involved diabetic macular edema

AIM: To compare the effectiveness of intravitreal bevacizumab and subthreshold macular photocoagulation (SMP), for the treatment of non-center involved diabetic macular edema (non-CI DME). METHODS: Prospective, randomized, controlled clinical study included patients with type 2 diabetes, non-CI DME and best-corrected visual acuity (BCVA) of 0.30 logMAR or better. Each eye was randomized into three groups: group 1, monthly intravitreal bevacizumab; group 2, single SMP; group 3, single SMP and monthly bevacizumab. Main outcome measures were BCVA, and macular thickness measured with optical coherence tomography as macular central subfield thickness (CST), macular area of greater thickness (MAGT) and total macular volume (TMV). Results were analyzed after 3mo. RESULTS: A total of 32 eyes were included. Group 3 improved in BCVA (0.19±0.16 to 0.12±0.14 logMAR; P=0.041) and in TMV (7.90±0.57 to 7.65±0.73 mm3; P=0.025). Group 1 improved in MAGT (325±26.26 to 298.20±44.85 μm; P=0.022) and TMV (7.79±0.57 to 7.50±0.56 mm3, P=0.047). Group 2 didn’t show significant improvement of any variable. CONCLUSION: The loading phase of bevacizumab as monotherapy or combined with SMP is superior to SMP as monotherapy in providing short-term visual and anatomical improvement in non-CI DME

Olfactomedin‑like 2 A and B (OLFML2A and OLFML2B) expression profile in primates (human and baboon)

Background: The olfactomedin‑like domain (OLFML) is present in at least four families of proteins, including OLFML2A and OLFML2B, which are expressed in adult rat retina cells. However, no expression of their orthologous has ever been reported in human and baboon. Objective: The aim of this study was to investigate the expression of OLFML2A and OLFML2B in ocular tissues of baboons (Papio hamadryas) and humans, as a key to elucidate OLFML function in eye physiology. Methods: OLFML2A and OLFML2B cDNA detection in ocular tissues of these species was performed by RT‑PCR. The amplicons were cloned and sequenced, phylogenetically analyzed and their proteins products were confirmed by immunofluorescence assays. Results: OLFML2A and OLFML2B transcripts were found in human cornea, lens and retina and in baboon cornea, lens, iris and retina. The baboon OLFML2A and OLFML2B ORF sequences have 96% similarity with their human’s orthologous. OLFML2A and OLFML2B evolution fits the hypothesis of purifying selection. Phylogenetic analysis shows clear orthology in OLFML2A genes, while OLFML2B orthology is not clear. Conclusions: Expression of OLFML2A and OLFML2B in human and baboon ocular tissues, including their high simi‑ larity, make the baboon a powerful model to deduce the physiological and/or metabolic function of these proteins in the eye

TFOS lifestyle: Impact of the digital environment on the ocular surface

Eye strain when performing tasks reliant on a digital environment can cause discomfort, affecting productivity and quality of life. Digital eye strain (the preferred terminology) was defined as “the development or exacerbation of recurrent ocular symptoms and/or signs related specifically to digital device screen viewing”. Digital eye strain prevalence of up to 97% has been reported, due to no previously agreed definition/diagnostic criteria and limitations of current questionnaires which fail to differentiate such symptoms from those arising from non-digital tasks. Objective signs such as blink rate or critical flicker frequency changes are not ‘diagnostic’ of digital eye strain nor validated as sensitive. The mechanisms attributed to ocular surface disease exacerbation are mainly reduced blink rate and completeness, partial/uncorrected refractive error and/or underlying binocular vision anomalies, together with the cognitive demand of the task and differences in position, size, brightness and glare compared to an equivalent non-digital task. In general, interventions are not well established; patients experiencing digital eye strain should be provided with a full refractive correction for the appropriate working distances. Improving blinking, optimizing the work environment and encouraging regular breaks may help. Based on current, best evidence, blue-light blocking interventions do not appear to be an effective management strategy. More and larger clinical trials are needed to assess artificial tear effectiveness for relieving digital eye strain, particularly comparing different constituents; a systematic review within the report identified use of secretagogues and warm compress/humidity goggles/ambient humidifiers as promising strategies, along with nutritional supplementation (such as omega-3 fatty acid supplementation and berry extracts)

Evaluación terapéutica del bevacizumab, intravítreo, en el tratamiento del edema macular diabético difuso.

Tesis (Doctor en Medicina) UANL, 2011.UANLhttp://www.uanl.mx

Corneal Melting after Collagen Cross-Linking for Keratoconus in a Thin Cornea of a Diabetic Patient Treated with Topical Nepafenac: A Case Report with a Literature Review

Purpose: To report the case of a 50-year-old woman with diabetes that presented with corneal melting and perforation 6 weeks after collagen cross-linking (CxL) for keratoconus (KC) and postoperative use of nepafenac eye drops, a nonsteroidal anti-inflammatory drug (NSAID). Methods: This is a case report of a patient with diabetes, KC and a thin cornea that had undergone left eye corneal CxL at a different hospital followed by postoperative use of nepafenac eye drops for 6 weeks. Results: The patient presented for the first time to our clinic with left corneal melting, perforation and iris prolapse 6 weeks after corneal CxL and topical nepafenac use. She was treated with a left eye tectonic penetrating keratoplasty, extracapsular cataract extraction, intraocular lens implantation and pupilloplasty. Conclusions: The corneal melting and perforation in this patient was associated with multiple risk factors: (1) nepafenac eye drop use, (2) CxL in a cornea thinner than 400 µm and (3) diabetes. The recommended corneal thickness limits should be respected. Topical NSAIDs should be used with caution if used as postoperative treatment after corneal CxL and in patients with diabetes, epithelial defect or delayed healing, because of the possible increased risk for corneal melting when multiple risk factors are observed