2021

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Ma KK, Luo ZK. Novel Method to Determine Target Refraction in Cataract Surgery for Patients Dependent on Therapeutic Scleral Lenses. Eye Contact Lens 2021;47(6):352-355.Abstract
OBJECTIVES: To evaluate a novel approach to determine the refractive target for patients undergoing cataract surgery who are dependent on therapeutic scleral lenses, to avoid the need for postoperative scleral lens replacement. METHODS: Retrospective single-surgeon case series. The target refraction for intraocular lens selection was determined by considering the effective scleral lens system power. This was calculated by adding the known scleral lens spherical power to the difference between the scleral lens base curve and the average keratometry value. RESULTS: Six eyes from three patients with moderate myopia or emmetropia with ocular graft versus host disease dependent on therapeutic scleral lenses underwent cataract surgery with intraocular lens selection based on this method. All six eyes had corrected visual acuities of 20/30 or better while wearing their previous scleral lenses at the postoperative week 1 visit. All six eyes resumed full-time scleral lens use 1 week after phacoemulsification and did not require scleral lens replacement. CONCLUSIONS: Using this method, patients requiring therapeutic scleral lenses can quickly experience optimal vision, comfort, and ocular surface protection 1 week after cataract surgery. These patients can continue to use their existing scleral lenses and avoid the costs and burdens associated with lens replacement.
Ma KK, Yuan A, Sharifi S, Pineda R. A Biomechanical Study of Flanged Intrascleral Haptic Fixation of Three-Piece Intraocular Lenses. Am J Ophthalmol 2021;227:45-52.Abstract
PURPOSE: Flanged intrascleral haptic fixation (FISHF) is a useful method for securing intraocular lenses (IOLs) in eyes without capsular support. Biomechanical studies were conducted to support the use of this technique. DESIGN: Laboratory investigation. METHODS: Haptics of 3-piece IOLs were passed through cadaveric human sclera using 30- and 27-gauge needles. Flanges were created by melting 1.0 mm from the haptic ends using cautery. The forces required to remove the flanged haptic from the sclera and disinsert the haptic from the optic were measured using a mechanical tester and a custom-fabricated mount. RESULTS: The mean FISHF dislocation force using 30-gauge needles was greatest with the CT Lucia 602 (2.04 ± 0.24 newtons [N]) compared to the LI61AO (0.93 ± 0.41 N; P = .001), ZA9003 (0.70 ± 0.34 N; P = <.001), and MA60AC (0.27 ± 0.19 N; P <.001). Using 27-gauge needles with the CT Lucia resulted in a lower dislocation force (0.56 ± 0.36 N; P <.001). The FISHF dislocation force was correlated with the flange-to-needle diameter ratio (r = 0.975). The FISHF dislocation forces of the CT Lucia and LI61AO using 30-gauge needles were not significantly different from their haptic-optic disinsertion forces (P = .79 and .27, respectively). There were no differences in flange diameters between 1.0 mm and 2.0 mm haptic melt lengths across the IOLs (P = .15-.85). CONCLUSIONS: These data strongly support the biomechanical stability of FISHF with the polyvinylidene fluoride haptics of the CT Lucia using small diameter instruments for the creation of an intrascleral tunnel. 1.0 mm of haptic may be the optimal melt length.
Ma J, Chen M, Ai J, Young MJ, Ge J. Enhanced migration of engrafted retinal progenitor cells into the host retina via disruption of glial barriers. Mol Vis 2021;27:300-308.Abstract
Purpose: Migration and integration remain critical challenges for stem cell replacement therapy. Glial barriers play an important role in preventing cell migration and integration. The purpose of this study was to investigate the effect and mechanisms of chondroitinase ABC on the migration of murine retinal progenitor cells (mRPCs) transplanted into the subretinal space of B6 mice. Methods: mRPCs were harvested from the neural retinas of P1 enhanced green fluorescent protein (GFP) B6 mice. Two μl containing 2 × 105 expanded RPCs alone or combined with chondroitinase ABC in suspension were injected into the subretinal space of the recipient B6 mice. Immunohistochemistry was performed on the recipient B6 retinas to evaluate the glial barrier formation and migration of the mRPCs. Western blotting was also used to check the expression of the glial barriers. Results: Glial fibrillary acidic protein (GFAP) and vimentin could be seen around the transplanted mRPCs in the B6 mice. Formation of glial barriers prevented the migration of donor cells into the retinal layers. Chondroitinase ABC promoted the migration and survival rates of the engrafted retinal progenitor cells in the retinal layers of recipient B6 mice. Injection induced upregulation of GFAP, chondroitin, and CD44 expression. Chondroitinase ABC disrupted the glial barriers. The CD44 around the mRPCs was much lower in the chondroitinase group. However, the CD44 in the retinal layers was considerably higher in the chondroitinase group. With the employment of chondroitinase ABC, more cells migrated into the outer nuclear layer or inner nuclear layer. The chondroitin and CD44 expression decreased 3 weeks after transplantation in the chondroitinase ABC group. Conclusions: Chondroitinase ABC degraded glial barriers and enhanced the migration of transplanted mouse retinal progenitor cells. Chondroitinase ABC may also have induced activation of the CD44 signaling pathway to exert the effect.
Ma KK, Ong Tone S, Chodosh J, Saeed HN. Ochrobactrum anthropi Keratitis in a Boston Type 1 Keratoprosthesis Recipient. Cornea 2021;40(5):662-663.Abstract
PURPOSE: To report a case of Ochrobactrum anthropi keratitis in an eye with a Boston type 1 keratoprosthesis. METHODS: This is a case report and review of the literature. RESULTS: A 78-year-old man with a history of implantation of a Boston type 1 keratoprosthesis in the left eye presented for a routine follow-up with no acute complaints. In the left eye, visual acuity was 20/60 and slit-lamp examination revealed a 1.5-mm inferotemporal corneal infiltrate adjacent to the optic stem. Corneal cultures grew abundant O. anthropi. After 7 weeks of topical antimicrobial therapy and placement of a temporary tarsorrhaphy, the keratitis resolved. CONCLUSIONS: Ochrobactrum anthropi is an organism associated with indwelling medical devices and can be pathogenic in eyes with implanted keratoprostheses.
Ma KK, Kinde B, Doan T, Jacobs DS, Ong Tone S. Dual Molecular Diagnosis of Microsporidia (Encephalitozoon hellem) Keratoconjunctivitis in an Immunocompetent Adult. Cornea 2021;40(2):242-244.Abstract
PURPOSE: To report a case of microsporidia (Encephalitozoon hellem) keratoconjunctivitis acquired through avian transmission in an immunocompetent adult, diagnosed by metagenomic deep sequencing (MDS), and confirmed by polymerase chain reaction. METHODS: A case report. RESULTS: An 18-year-old woman was referred with unilateral keratoconjunctivitis unresponsive to topical and systemic therapy after exposure to birdcage debris. Slit-lamp examination of the left eye revealed a follicular papillary reaction of the palpebral conjunctiva and multiple corneal punctate epithelial opacities that stained minimally with fluorescein. In vivo confocal microscopy revealed bright double-walled structures and smaller bright round structures in the superficial epithelial debris and epithelium. Molecular diagnosis with MDS of E. hellem was confirmed by polymerase chain reaction. Clinical resolution and normalization of in vivo confocal microscopy was observed after a 6-week course of topical azithromycin. The patient elected a 3-week course of topical voriconazole 1% for definitive antimicrosporidial treatment, with no evidence of persistent infection 1 month later. CONCLUSIONS: Microsporidial (E. hellem) keratoconjunctivitis can occur through avian transmission in immunocompetent hosts. Topical azithromycin may be effective against this pathogen. MDS has utility in the diagnosis of atypical keratoconjunctivitis.
Ma KK, Robson CD, Gaier ED, Gise R. Reversal of Visual Loss From Skull Base Osteomyelitis in a Pediatric Patient. J Neuroophthalmol 2021;Publish Ahead of Print
Maallo AMS, Moulton EA, Sieberg CB, Giddon DB, Borsook D, Holmes SA. A lateralized model of the pain-depression dyad. Neurosci Biobehav Rev 2021;127:876-883.Abstract
Chronic pain and depression are two frequently co-occurring and debilitating conditions. Even though the former is treated as a physical affliction, and the latter as a mental illness, both disorders closely share neural substrates. Here, we review the association of pain with depression, especially when symptoms are lateralized on either side of the body. We also explore the overlapping regions in the forebrain implicated in these conditions. Finally, we synthesize these findings into a model, which addresses gaps in our understanding of comorbid pain and depression. Our lateralized pain-depression dyad model suggests that individuals diagnosed with depression should be closely monitored for pain symptoms in the left hemibody. Conversely, for patients in pain, with the exception of acute pain with a known source, referrals in today's pain centers for psychological evaluation should be part of standard practice, within the framework of an interdisciplinary approach to pain treatment.
Makuloluwa AK, Hamill KJ, Rauz S, Bosworth L, Haneef A, Romano V, Williams RL, Dartt DA, Kaye SB. The conjunctival extracellular matrix, related disorders and development of substrates for conjunctival restoration. Ocul Surf 2021;Abstract
The conjunctiva can be damaged by numerous diseases with scarring, loss of tissue and dysfunction. Depending on extent of damage, restoration of function may require a conjunctival graft. A wide variety of biological and synthetic substrates have been tested in the search for optimal conditions for ex vivo culture of conjunctival epithelial cells as a route toward tissue grafts. Each substrate has specific advantages but also disadvantages related to their unique physical and biological characteristics, and identification and development of an improved substrate remains a priority. To achieve the goal of mimicking and restoring a biological material, requires information from the material. Specifically, extracellular matrix (ECM) derived from conjunctival tissue. Knowledge of the composition and structure of native ECM and identifying contributions of individual components to its function would enable using or mimicking those components to develop improved biological substrates. ECM is comprised of two components: basement membrane secreted predominantly by epithelial cells containing laminins and type IV collagens, which directly support epithelial and goblet cell adhesion differentiation and growth and, interstitial matrix secreted by fibroblasts in lamina propria, which provides mechanical and structural support. This review presents current knowledge on anatomy, composition of conjunctival ECM and related conjunctival disorders. Requirements of potential substrates for conjunctival tissue engineering and transplantation are discussed. Biological and synthetic substrates and their components are described in an accompanying review.
Makuloluwa AK, Hamill KJ, Rauz S, Bosworth L, Haneef A, Romano V, Williams RL, Dartt DA, Kaye SB. Biological tissues and components, and synthetic substrates for conjunctival cell transplantation. Ocul Surf 2021;Abstract
The conjunctiva is the largest component of the ocular surface. It can be damaged by various pathological processes leading to scarring, loss of tissue and dysfunction. Depending on the amount of damage, restoration of function may require a conjunctival graft. Numerous studies have investigated biological and synthetic substrates in the search for optimal conditions for the ex vivo culture of conjunctival epithelial cells that can be used as tissue grafts for transplantation. These substrates have advantages and disadvantages that are specific to the characteristics of each material; the development of an improved material remains a priority. This review is the second of a two-part review in The Ocular Surface. In the first review, the structure and function of the conjunctiva was evaluated with a focus on the extracellular matrix and the basement membrane, and biological and mechanical characteristics of the ideal substrate with recommendations for further studies. In this review the types of biological and synthetic substrates used for conjunctival transplantation are discussed including substrates based on the extracellular matrix. .
Maleki A, Anesi SD, Look-Why S, Manhapra A, Foster SC. Pediatric uveitis: A comprehensive review. Surv Ophthalmol 2021;Abstract
Pediatric uveitis accounts for 5-10% of all uveitis. Uveitis in children differs from adult uveitis in that it is commonly asymptomatic and can become chronic and cause chronic damage to ocular structures. The diagnosis might be delayed for multiple reasons, including the preverbal age and difficulties in examining young children. Pediatric uveitis may be infectious or non-infectious in etiology. The etiology of non-infectious uveitis is presumed to be autoimmune or autoinflammatory. The most common causes of uveitis in this age group are idiopathic and juvenile idiopathic arthritis-associated uveitis. The stepladder approach for the treatment of pediatric uveitis is based on expert opinion and algorithms proposed by multidisciplinary panels. Uveitis morbidities in pediatric patients include cataract, glaucoma, and amblyopia. Pediatric patients with uveitis should be frequently examined until remission is achieved. Once in remission, the interval between follow-up visits can be extended; however, it is recommended that even after remission the child should be seen every 8-12 weeks depending on the history of uveitis and the medications used. Close follow up is also necessary as uveitis can flare up during immunomodulatory therapy. It is crucial to measure the impact of uveitis, it's treatment, and it's complications on the child and the child's family. Visual acuity can be considered as an acceptable criterion for assessing visual function. Additionally, the number of cells in the anterior chamber can be a measure of disease activity. We review different aspects of pediatric uveitis. We discuss the mechanisms of noninfectious uveitis, including autoimmune and autoinflammatory etiologies, and the risks of developing uveitis in children with systemic rheumatologic diseases. We address the risk factors for developing morbidities, the Standardization of Uveitis Nomenclature (SUN) criteria for timing and anatomical classifications and describe a stepladder approach in the treatment of pediatric uveitis based on expert opinion and algorithms proposed by multi-disciplinary panels. We describe the most common entities for each type of anatomical classification and complications of uveitis for the pediatric population. Additionally, we address monitoring of children with uveitis and evaluation of Quality of Life.
Maleki A, Anesi SD, Look-Why S, Asgari S, Manhapra A, Foster SC. Clinical course and poor prognostic factors of Vogt-Koyanagi-Harada disease in a tertiary uveitis clinic. Can J Ophthalmol 2021;
Maleki A, Garcia CM, Asgari S, Manhapra A, Foster CS. Response to the Second TNF-α Inhibitor (Adalimumab or Infliximab) after Failing the First One in Refractory Idiopathic Inflammatory Retinal Vascular Leakage. Ocul Immunol Inflamm 2021;:1-10.Abstract
: To determine the response to the second TNF-α inhibitor (adalimumab and infliximab) after failing the first agent in idiopathic inflammatory retinal vascular leakage.: This was a retrospective observational case series. Patients with the diagnosis of idiopathic inflammatory retinal vascular leakage who had received both infliximab and adalimumab were included in the study.: Twelve and 15 patients received adalimumab (Group one) and infliximab (Group two) as the first treatment, respectively. The remission rates between Group one (58.3%) and Group two (66.7%) were not statistically significant. ( = .4) As the second agent, adalimumab was more effective in younger patients (27.5 ± 20.6) compared to older patients (48.75 ± 10.2). ( = .03). Moreover, patients with lower vision responded marginally better to infliximab as the second treatment ( = .06).: Either TNF-α inhibitor, adalimumab and infliximab, can be employed in the treatment of the patients with idiopathic inflammatory retinal vascular leakage who fail one of these agents.
Maleki A, Look-Why S, Asgari S, Manhapra A, Gomez S, Foster SC. Acquired Vitelliform-Like Lesion in Uveitis: A case-series. Ocul Immunol Inflamm 2021;:1-10.Abstract
PURPOSE: To study acquired vitelliform-like lesions (AVLL) and their diagnostic and prognostic values in uveitis. PATIENTS AND METHODS: This was a retrospective case series. The clinical course, diagnostic value, and prognostic significance of AVLL were compared between uveitic patients with AVLL and uveitic patients without AVLL. RESULTS: Twelve patients (21 eyes) with both uveitis and AVLL (study group) and thirteen patients (24 eyes) without AVLL (control group) were included in the study. Macular leakage (p = .005), the presence of vasculitis (p = .01), the presence of active choroiditis (p = .01), and the presence of CME on OCT (p = .008) were significantly higher in the AVLL group compared to the control group. Best-corrected visual acuity was significantly lower at presentation (p < .001) and the last follow-up visit (p = .014) in the AVLL group. CONCLUSION: The presence of acquired vitelliform-like lesion can have both a diagnostic (uveitis as a differential diagnosis) and prognostic value in patients with different types of uveitis.
Maleki N, Szabo E, Becerra L, Moulton E, Scrivani SJ, Burstein R, Borsook D. Ictal and interictal brain activation in episodic migraine: Neural basis for extent of allodynia. PLoS One 2021;16(1):e0244320.Abstract
In some patients, migraine attacks are associated with symptoms of allodynia which can be localized (cephalic) or generalized (extracephalic). Using functional neuroimaging and cutaneous thermal stimulation, we aimed to investigate the differences in brain activation of patients with episodic migraine (n = 19) based on their allodynic status defined by changes between ictal and interictal pain tolerance threshold for each subject at the time of imaging. In this prospective imaging study, differences were found in brain activity between the ictal and interictal visits in the brainstem/pons, thalamus, insula, cerebellum and cingulate cortex. Significant differences were also observed in the pattern of activation along the trigeminal pathway to noxious heat stimuli in no allodynia vs. generalized allodynia in the thalamus and the trigeminal nucleus but there were no activation differences in the trigeminal ganglion. The functional magnetic resonance imaging (fMRI) findings provide direct evidence for the view that in migraine patients who are allodynic during the ictal phase of their attacks, the spinal trigeminal nucleus and posterior thalamus become hyper-responsive (sensitized)-to the extent that they mediate cephalic and extracephalic allodynia, respectively. In addition, descending analgesic systems seem as "switched off" in generalized allodynia.
Marmamula S, Barrenkala NR, Khanna RC, Challa R, Bhakki M, Kumbham TR, Modepalli SB, Yellapragada R, Friedman DS. Near vision impairment among the elderly in residential care-the Hyderabad Ocular Morbidity in Elderly Study (HOMES). Eye (Lond) 2021;35(8):2310-2315.Abstract
BACKGROUND/OBJECTIVE: To report on the prevalence and risk factors for near vision impairment (NVI) among the elderly in residential care in Telangana State in India. METHODS: Individuals aged ≥60 years were recruited from 41 'home for the aged' centres in Hyderabad, India. All participants had complete eye examinations including presenting and best-corrected visual acuity assessment for distance and near. NVI was defined as binocular presenting near vision worse than N8 (6/15) among those who had a normal presenting distance visual acuity of 6/18 in the better eye. RESULTS: Of the 826 participants, the mean age was 74.4 years (standard deviation-8.4 years), 525 (63.6%) were women, 715 (86.6%) had at least school education. The prevalence of NVI was 51.2% (95% CI: 47.7-54.7) based on presenting vision. On applying multiple logistic regression analysis, the odds of NVI were higher in 80 years and older age (OR: 2.17; 95% CI: 3.44-13.6). Those with school education (OR: 0.58: 95% CI: 0.36-0.94) and higher education (OR: 0.38; 95% CI: 0.21-0.69) had lower odds for NVI. Similarly, those with self-reported diabetes (OR: 0.69; 95% CI: 0.49-0.97), those using spectacles (OR: 0.09; 95% CI: 0.05-0.16), and those who had undergone cataract surgery (OR: 0.51; 95% CI: 0.36-0.74) had lower odds for NVI. CONCLUSIONS: NVI was common among the elderly in residential care in homes for the aged in Hyderabad, India. As most of this NVI is correctable, a routine screening programme and dispensing of spectacles can be undertaken to address this vision loss.
Marmamula S, Barrenakala NR, Challa R, Kumbham TR, Modepalli SB, Yellapragada R, Bhakki M, Reddy JC, Friedman DS, Khanna RC. Visual outcomes after cataract surgery among the elderly residents in the 'homes for the aged' in South India: the Hyderabad Ocular Morbidity in Elderly Study. Br J Ophthalmol 2021;105(8):1087-1093.Abstract
BACKGROUND/AIM: To report visual outcomes and factors associated with good visual outcomes after cataract surgery among the elderly residents in 'homes for the aged' in Hyderabad, India. METHODS: Individuals aged ≥60 years were recruited from 41 'homes for the aged'. All participants had a detailed eye examinations including visual acuity (VA) assessment , refraction, slit-lamp examination and fundus imaging by trained professionals. A detailed history of cataract surgery was recorded. Multivariate logistic regression was used to determine the factors associated with good visual outcomes after cataract surgery which was defined as presenting VA of 6/18 or better in the operated eye. Visual impairment (VI) is defined as presenting VA worse than 6/18 in the operated eye. RESULTS: 1215 eyes of 703 individuals had cataract surgery. The mean age of these participants was 77.5 years (SD: 8.2 years; range: 60-108 years), 66.8% were women, 29.9% reported diabetes and 61% reported hypertension. 406/1215 (33.4%; 95% CI 30.8 to 36.1) eyes had VI after cataract surgery. Posterior capsular opacification (31.8%; n=129) was the leading cause of VI followed by uncorrected refractive error (24.1%; n=98). The prevalence of good outcomes was 66.6% (95% CI 63.8 to 69.2). On applying multivariable analysis, younger age, self-reported hypertension, independent mobility, surgery in a non-government (as opposed to private) hospital and undergoing paid surgery were associated with good outcomes. CONCLUSIONS: One-third of the eyes of elderly individuals living in homes for the aged that had previously undergone cataract surgery had VI. Regular eye examinations with the provision of laser capsulotomy and appropriate refractive correction can substantially improve their vision.
Marmamula S, Barrenakala NR, Challa R, Kumbham TR, Modepalli SB, Yellapragada R, Bhakki M, Khanna RC, Friedman DS. Prevalence and risk factors for visual impairment among elderly residents in 'homes for the aged' in India: the Hyderabad Ocular Morbidity in Elderly Study (HOMES). Br J Ophthalmol 2021;105(1):32-36.Abstract
BACKGROUND/AIM: To investigate the prevalence, causes and risk factors of visual impairment (VI) among the elderly in 'home for the aged' in Hyderabad, India. METHODS: Individuals aged ≥60 years were recruited from 41 'homes for the aged'. All participants had complete eye examinations including presenting visual acuity, refraction, slit-lamp examination, intraocular pressure measurement and fundus imaging by trained clinicians. VI was defined as presenting visual acuity worse than 6/18 in the better eye. Multivariate logistic regression was used to determine the risk factors associated with VI. RESULTS: 1512 elderly residents from 41 homes for the aged were enumerated, of whom 1182 (78.1%) were examined. The mean age of examined participants was 75.0 years (SD 8.8 years; range: 60-108 years); 35.4% of those examined were men. The prevalence of VI was 30.1% (95% CI 27.5 to 32.8). The leading cause of VI was cataract (46.3%, n=165), followed by uncorrected refractive error (27.0%, n=96), posterior capsular opacification (14.9%, n=53) and posterior segment disease (6.5%, n=23). Overall, 88.2% of the VI was either treatable or correctable. In multiple logistic regression, those aged 80 years and older (OR: 1.7, p<0.01), living in 'free' homes (OR: 1.5, p<0.01) and who were immobile/bedridden (OR: 3.02, p<0.01) had significantly higher odds of VI. Gender was not associated with VI. CONCLUSIONS: VI was common and largely avoidable in residents of 'homes for the aged' in Hyderabad, India. Screening for vision loss in 'homes for aged' and the provision of appropriate services should become routine practice to achieve the goal of healthy ageing in India.
Martinez-Carrasco R, Argüeso P, Fini EM. Membrane-associated mucins of the human ocular surface in health and disease. Ocul Surf 2021;21:313-330.Abstract
Mucins are a family of high molecular weight, heavily-glycosylated proteins produced by wet epithelial tissues, including the ocular surface epithelia. Densely-packed O-linked glycan chains added post-translationally confer the biophysical properties of hydration, lubrication, anti-adhesion and repulsion. Membrane-associated mucins (MAMs) are the distinguishing components of the mucosal glycocalyx. At the ocular surface, MAMs maintain wetness, lubricate the blink, stabilize the tear film, and create a physical barrier to the outside world. In addition, it is increasingly appreciated that MAMs function as cell surface receptors that transduce information from the outside to the inside of the cell. Recently, our team published a comprehensive review/perspectives article for molecular scientists on ocular surface MAMs, including previously unpublished data and analyses on two new genes MUC21 and MUC22, as well as new MAM functions and biological roles, comparing human and mouse (PMID: 31493487). The current article is a refocus for the audience of The Ocular Surface. First, we update the gene and protein information in a more concise form, and include a new section on glycosylation. Next, we discuss biological roles, with some new sections and further updating from our previous review. Finally, we provide a new chapter on MAM involvement in ocular surface disease. We end this with discussion of an emerging mechanism responsible for damage to the epithelia and their mucosal glycocalyces: the unfolded protein response (UPR). The UPR offers a novel target for therapeutic intervention.
Maturi RK, Glassman AR, Josic K, Antoszyk AN, Blodi BA, Jampol LM, Marcus DM, Martin DF, Melia M, Salehi-Had H, Stockdale CR, Punjabi OS, Sun JK, Sun JK. Effect of Intravitreous Anti-Vascular Endothelial Growth Factor vs Sham Treatment for Prevention of Vision-Threatening Complications of Diabetic Retinopathy: The Protocol W Randomized Clinical Trial. JAMA Ophthalmol 2021;139(7):701-712.Abstract
Importance: The role of anti-vascular endothelial growth factor injections for the management of nonproliferative diabetic retinopathy (NPDR) without center-involved diabetic macular edema (CI-DME) has not been clearly established. Objective: To determine the efficacy of intravitreous aflibercept injections compared with sham treatment in preventing potentially vision-threatening complications in eyes with moderate to severe NPDR. Design, Setting, and Participants: Data for this study were collected between January 15, 2016, and May 28, 2020, from the ongoing DRCR Retina Network Protocol W randomized clinical trial, conducted at 64 US and Canadian sites among 328 adults (399 eyes) with moderate to severe NPDR (Early Treatment Diabetic Retinopathy Study severity level, 43-53), without CI-DME. Analyses followed the intent-to-treat principle. Interventions: Eyes were randomly assigned to 2.0 mg of aflibercept injections (n = 200) or sham (n = 199) given at baseline; 1, 2, and 4 months; and every 4 months through 2 years. Between 2 and 4 years, treatment was deferred if the eye had mild NPDR or better. Aflibercept was administered in both groups if CI-DME with vision loss (≥10 letters at 1 visit or 5-9 letters at 2 consecutive visits) or high-risk proliferative diabetic retinopathy (PDR) developed. Main Outcomes and Measures: Development of CI-DME with vision loss or PDR through May 2020, when the last 2-year visit was completed. Results: Among the 328 participants (57.6% men [230 of 399 eyes]; mean [SD] age, 56 [11] years), the 2-year cumulative probability of developing CI-DME with vision loss or PDR was 16.3% with aflibercept vs 43.5% with sham. The overall hazard ratio for either outcome was 0.32 (97.5% CI, 0.21-0.50; P < .001), favoring aflibercept. The 2-year cumulative probability of developing PDR was 13.5% in the aflibercept group vs 33.2% in the sham group, and the 2-year cumulative probability of developing CI-DME with vision loss was 4.1% in the aflibercept group vs 14.8% in the sham group. The mean (SD) change in visual acuity from baseline to 2 years was -0.9 (5.8) letters with aflibercept and -2.0 (6.1) letters with sham (adjusted mean difference, 0.5 letters [97.5% CI, -1.0 to 1.9 letters]; P = .47). Conclusions and Relevance: In this randomized clinical trial, among eyes with moderate to severe NPDR, the proportion of eyes that developed PDR or vision-reducing CI-DME was lower with periodic aflibercept compared with sham treatment. However, through 2 years, preventive treatment did not confer visual acuity benefit compared with observation plus treatment with aflibercept only after development of PDR or vision-reducing CI-DME. The 4-year results will be important to assess longer-term visual acuity outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT02634333.
Mazzarino RC. Targeting Future Pandemics, a Case for De Novo Purine Synthesis and Basic Research. Front Immunol 2021;12:694300.Abstract
We are currently experiencing a deadly novel viral pandemic with no efficacious, readily available anti-viral therapies to SARS-CoV-2. Viruses will hijack host cellular machinery, including metabolic processes. Here, I provide theory and evidence for targeting the host de novo purine synthetic pathway for broad spectrum anti-viral drug development as well as the pursuit of basic science to mitigate the risks of future novel viral outbreaks.

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