Applications of artificial intelligence-assisted retinal imaging in systemic diseases: A literature review.

The retina is a vulnerable structure that is frequently affected by different systemic conditions. The main mechanisms of systemic retinal damage are either primary insult of neurons of the retina, alterations of the local vasculature, or both. This vulnerability makes the retina an important window that reflects the severity of the preexisting systemic disorders. Therefore, current imaging techniques aim to identify early retinal changes relevant to systemic anomalies to establish anticipated diagnosis and start adequate management. Artificial intelligence (AI) has become among the highly trending technologies in the field of medicine. Its spread continues to extend to different specialties including ophthalmology. Many studies have shown the potential of this technique in assisting the screening of retinal anomalies in the context of systemic disorders. In this review, we performed extensive literature search to identify the most important studies that support the effectiveness of AI/deep learning use for diagnosing systemic disorders through retinal imaging. The utility of these technologies in the field of retina-based diagnosis of systemic conditions is highlighted.

Outer retinal tubulation in diabetic macular edema following anti-VEGF treatment.

BACKGROUND: To address the presence and features of outer retinal tubulation (ORT) found in diabetic macular edema (DME) treated with anti-vascular endothelial growth factor (anti-VEGF) and to differentiate between ORT and cystoid DME, which have different plans of management. METHODS: This was a retrospective review of a total of 514 patients investigated with spectral domain optical coherence tomography (OCT) in patients with diabetic macular edema treated with anti-VEGF. ORT was seen in 12 eyes of 11 patients. The morphologic characteristics of ORT and its progress over time were examined using OCT data. The retinal images were obtained by horizontal and vertical scans to analyze the possible presence of ORT and to explore their morphologic features and location in the retinal layers. RESULTS: ORT was seen in DME treated with anti-VEGF. ORT was shown as round or ovoid hyporeflective spaces with hyperreflective borders on the B-scans, measuring 30 to 120 µm high and 30 to 1775 µm wide. The tubules generally remained stable over time. In a retinal practice specializing in advanced diabetic retinopathy clinic, this ORT was seen in 12 eyes of 11 patients during a 12-month period. ORT presented either after receiving 0.05 mL open-label intravitreal injections of 0.5 mg ranibizumab or 1.25 mg bevacizumab. CONCLUSION: ORT is found in DME treated with anti-VEGF that may show damage to the outer retina secondary to the severity and chronicity of the DME. ORT may be a result of underlying chronic and severe diabetic macular edema that may occur later possibly secondary to retinal layers rearrangement after several anti-VEGF injections. It is important to differentiate between ORT and cystoids DME. The presence of the ORT entity alone without the presence of DME does not require further anti-VEGF re-injections.

Tremendous result of bevacizumab in malignant hypertensive retinopathy.

Signs of hypertensive retinopathy are common and are correlated with elevated blood pressure. Patients who have swelling of both optic discs and very high blood pressure (i.e., malignant retinopathy) need urgent antihypertensive treatment. A patient was reported with malignant hypertensive retinopathy who recovered promptly following single intravitreal bevacizumab injection. Intravitreal bevacizumab (1.25 mg/0.05 mL) was injected in two eyes of a patient having malignant hypertensive retinopathy with optic disc edema, macular edema, and retinal exudates. A complete ophthalmic examination, including the best-corrected visual acuity (BCVA), central macular thickness on optical coherence tomography (OCT), and fluorescein angiography (FAG), was performed before and after the treatments. Two eyes in a patient received a single intravitreal injection of bevacizumab had improvement of macular edema on OCT at 1 month and decreased fluorescein leakage on FAG 3 months after the treatment, which led to improvements in the BCVA both eyes. The results suggest that intravitreal bevacizumab injections might be a useful and safe adjunctive treatment of malignant hypertensive retinopathy, in addition to proper medical management of malignant hypertension.

Nanocarriers of nanotechnology in retinal diseases.

We are approaching a new era of retinal pharmacotherapy where new drugs are rapidly being worked out for the treatment of posterior-segment disease. Recent development in ocular drug delivery systems research has provided new insights into drug development, and the use of nanoparticles for drug delivery is thus a promising excellent approach for advanced therapy of ocular diseases. The primary goal is to develop a variety of drug delivery systems to complement and further enhance the efficacy of the available new medications. The ideal sustained release technology will provide a high level of safety with continuous release over an extended period of time while maintaining almost total drug bioactivity. The use of nanocarriers, such as cyclodextrin nanoparticle suspension, liposomes, nanospheres and, nanoemulsions for gene therapy of retinal diseases has been highlighted in this review.

Vascular endothelial growth factor trap-eye and trap technology: Aflibercept from bench to bedside.

Anti-vascular endothelial growth factor (VEGF) currently used to treat eye diseases have included monoclonal antibodies, antibody fragments, and an aptamer. A different method of achieving VEGF blockade in retinal diseases includes the concept of a cytokine trap. Cytokine traps technology are being evaluated for the treatment of various diseases that are driven by excessive cytokine levels. Traps consist of two extracellular cytokine receptor domains fused together to form a human immunoglobulin G (IgG). Aflibercept/VEGF trap-eye (VTE) is a soluble fusion protein, which combines ligand-binding elements taken from the extracellular components of VEGF receptors 1 and 2 fused to the Fc portion of IgG. This protein contains all human amino acid sequences, which minimizes the potential for immunogenicity in human patients. This review presents the latest data on VTE in regard to the pharmacokinetics, dosage and safety, preclinical and clinical experiences. Method of the literature search: A systematic search of the literature was conducted on PubMed, Scopus, and Google Scholar with no limitation on language or year of publication databases. It was oriented to articles published for VTE in preclinical and clinical studies and was focused on the pharmacokinetics, dosage and safety of VTE.

Chromovitrectomy: update.

The basic concept for the application of vital dyes during vitreoretinal surgery is to assist in highlighting preretinal membranes and tissues which are very thin and semitransparent and thus difficult to detect. The vital dyes may be classified according to different criteria, where the most commonly applied includes chemical classification. In ophthalmic surgery, vital dyes are widely used in cataract and vitreoretinal surgery. The vital dyes, indocyanine green, infracyanine green, and brilliant blue stain the internal limiting membrane, and trypan blue and triamcinolone acetonide help to visualize epiretinal membranes and vitreous, respectively. This review exhibits the current literature regarding the properties of vital dyes, techniques of application, indications, and toxicities during vitreoretinal surgery and, also suggests that the field of chromovitrectomy represents an expanding area of research.

Successful treatment of melanocytoma associated choroidal neovascular membrane with intravitreal bevacizumab.

Melanocytoma of the optic disc is a benign melanocytic tumour that rarely causes visual impairment. We report a rare case of choroidal neovascularization (CNV) in association with optic disc melanocytoma and its response to intravitreal injection of the anti-vascular endothelial growth factor (VEGF), bevacizumab. The choroidal neovascular membrane regressed following a single intravitreal bevacizumab injection with formation of a scar. CNV associated with optic disc melanocytoma is rare. Intravitreal anti-VEGF treatment may be an effective treatment for CNV associated with optic disc melanocytoma.

Retinal detachment after laser in situ keratomileusis.

PURPOSE: To report characteristics and outcome of rhegmatogenous retinal detachment (RRD) after laser in situ keratomileusis (LASIK) for myopia. MATERIALS AND METHODS: A retrospective chart review of patients who presented with RRD after myopic LASIK over a 10-year period. RESULTS: Fourteen eyes were identified with RRD. Of these, two of 6112 LASIK procedures were from our center. The mean age of patients with RRD was 35.43 years. The mean interval of RRD after LASIK was 37.71 months (range, 4 months to 10 years). The macula was involved in eight eyes and spared in six eyes. Retinal breaks included a macular hole in two eyes, and giant tear in two eyes. Multiple breaks (>2 breaks) occurred in 6 cases. Pars plana vitrectomy (PPV) was performed in 3 (21.4%) eyes, a scleral buckle (SB) was performed in 4 (28.5%) eyes and 7 (50%) eyes underwent combined PPV and SB. Mean follow-up was 15.18 months (range, 1 month to 7 years). The retina was successfully attached in all cases. The final visual acuity was 20/40 or better in 7 (50%) eyes, 20/40 to 20/60 in 4 (28.5%) eyes, and 20/200 or less in 3 (21.4%) eyes. Poor visual outcome was secondary to proliferative vitreoretinopathy, epiretinal membrane, macular scar and amblyopia. CONCLUSION: The prevalence of RRD after LASIK was low at our institute. Anatomical and visual outcomes were acceptable in eyes that were managed promptly. Although there is no cause-effect relationship between LASIK and RRD, a dilated fundus examination is highly recommended before and after LASIK for myopia.

Visual outcome and complications of pars plana vitrectomy for dislocated intraocular lenses.

OBJECTIVE: To report factors predicting the visual outcome and complications in eyes that underwent pars plana vitrectomy (PPV) to manage dislocated intraocular lenses (IOLs). PATIENTS AND METHODS: A retrospective chart review was performed. Clinical data recorded from the patient charts include, demographic, preoperative, intraoperative, and postoperative, with emphasis on visual acuity, interval between IOL dislocation and pars plana vitrectomy, surgical method and complications. Patients with follow-up of less than three months were excluded. RESULTS: Ninety-four patients were identified, 63 males and 31 females. Age ranged from 2 to 85 years (mean 52.6). The range of follow-up was 3 to 108 months (mean ± SD 19.4 ± 17.4 months). The final visual acuity was 20/50 or better in 52 (55.3%) eyes. Our analysis indicated that visual rehabilitation with IOL was significantly associated with better visual acuity as compared with eyes that were left aphakic (P = 0.0092). There was a trend toward a better visual outcome when PPV was performed within two weeks from the diagnosis of the dislocated IOL which was associated with good visual outcome (20/200 or better) in 85.7% of eyes compared with 78.8% of eyes. Management of IOL by interofixation was associated in (90.0%) of eyes with good vision (20/200 or better) compared to 76.1% eyes that had exchange of IOL through the limbus. Postoperative complications include cystoid macular edema in 9 (9.6%), glaucoma in 9 (9.6%), bullous keratopathy in 8 (8.5%), retinal detachments in 6 (6.4%) eyes, and relapsing uveitis in 2 (2%). CONCLUSION: In this series, the final visual outcomes were improved and the rate of postoperative complications were low. Eyes that were pseudophakic had significantly good visual outcome compared with eyes that were left aphakic. To the best of our knowledge, this may be the largest study on dislocated IOL removal by PPV with good visual results compared to other studies.