Medical hypothesis discovery and innovation in ophthalmology

Retrospective and prospective studies looking at the role of cerebrospinal fluid pressure (CSFP)/intracranial pressure (ICP) have stimulated new theories and hypotheses regarding the underlying causal events for glaucoma. Most recently, studies supporting a low CSFP/ICP as a risk factor for glaucoma have been published. This review summarizes the current understanding of CSFP/ICP and its potential role in the pathogenicity of the disease.

Background: Diabetic retinopathy is the major cause of blindness among working-age population across the world. Despite the urgent need for research strategic planning in this field, no systematic research has been previously performed analyzing the published research on diabetic retinopathy. The study aimed to analyze the scientific productions on DR for drawing a general roadmap for future research strategic planning in this field. Methods: A bibliometric method was used to obtain a view of the scientific production about diabetic retinopathy by data extracted from the Institute for Scientific Information (ISI). Specific parameters were retrieved from the ISI. Articles about diabetic retinopathy published from 1993-2013 were analyzed to obtain a view of the topic’s structure, history, and document relationships. Also, the trends in the most influential publications and authors were analyzed. Results: Most highly cited articles addressed epidemiologic and translational research topics in this field.  During the past three years, there has been a trend towards biomarker discovery and also more molecular translational research. Areas such as gene therapy and microRNAs are also among the recent hot topics. Conclusions: Through analyzing the characteristics of papers and the trends in scientific production we performed the first scientometric report on diabetic retinopathy. Most influential articles have been addressing epidemiology and translational research subjects in this field, which reflects that globally, the earlier diagnosis and treatment of this devastating disease still has the highest global  priority.

Anterior megalophthalmos is characterized by megalocornea associated with a very broad anterior chamber and ciliary ring elongation. It is also known as X-linked megalocornea. It is accompanied by the early development of cataracts, zonular anomalies, and rarely vitreoretinal disorders. Cataract surgery involves the risk of subluxation of the cataract because zonular weakness. In addition, in most cases, standard IOL decentration is a danger due to the enlargement of the sulcus and capsular bag. Cataract surgery is challenging because of these unique circumstances. Several approaches have been performed to date. Implantation of a retropupillary iris-claw aphakic intraocular lens might be a good option, since it is easier than suturing the IOL and could have better and more stable anatomic and visual outcomes compared with the other techniques.

This study compared tear function tests and cytologic changes on the conjunctival surface in asymptomatic patients wearing contact lens of different materials. Included in this study were 40 eyes wearing daily wear 4 week replacement hydrogel (H) lenses, 32 eyes wearing silicone hydrogel (SiH) lenses, 18 eyes wearing rigid gas-permeable (RGP) lenses, and 21 healthy eyes (no lenses) as the control group. Epithelial morphology of the conjunctival surface was evaluated, based on Nelson classification with conjunctival impression cytology (CIC), after the tear break-up time (TBUT) and Schirmer test were performed. The mean values of the Schirmer and TBUT tests were significantly higher in the control group than in the other lens groups (p < 0.001). Grade 0 was the most frequent CIC in the control group (66.7%) and least frequent in the SiH lens group (40.6%); grade I was least frequent in the control and RGP groups (33.3%) and most frequent in the SiH lens group (40.6%). Moreover, grade 2 was most frequent in the SiH lens group (18.8%). There was no statistically significant difference in goblet cell densities between the groups (p = 0.462). In addition to the different Schirmer and TBUT test results between contact lens wearers and healthy non-wearers, some cytologic changes may occur on the ocular surface with direct mechanical effects of contact lenses. This simple and noninvasive technique may be used to evaluate the ocular surface with regard to intolerance to contact lenses.

To evaluate the clinical results of endoscopic endonasal surgical dacryocystorhinostomy (EES-DCR) as team work by an ophthalmologist and an ear-nose-throat (ENT) surgeon and the appropriate selection of the patients this study performed.All candidates for DCR underwent computed tomography (CT) scan of the paranasal sinuses (PNS). Patients who did not want a scar on the medial canthus skin or who did not have intranasal problems received EES-DCR, which was performed as team work by an ophthalmologist and an ENT surgeon. Surgical success was the resolution of epiphora (i.e., functional success) and free passage of the fluid on irrigation (i.e., anatomical success) by six months after surgery.One hundred twenty-eight patients underwent EES-DCR. Six months following the operation, six patients underwent surgical failure (three cases of anatomical failure and three cases of functional failure); the success rate was therefore 95.3%. The most common intranasal problems that led to EES-DCR were sinusitis, septal deviation, close proximity of the agger nasi to the lacrimal bone, and concha bullosa; moreover, 15.5% of patients selected EES-DCR for cosmetic reasons. Cooperation between ophthalmologists and ENT surgeons in the preoperative assessment of patients with epiphora before EES-DCR increases its success rate, and it may replace external DCR in some patients.

Glaucoma is the second leading cause of irreversible blindness and a neurodegenerative disease with a complex pathogenesis. Increasing evidence suggests that oxidative stress and mitochondrial dysfunction have crucial roles in most neurodegenerative diseases such as glaucoma. The conventional clinical treatment for glaucoma is lowering the intraocular pressure (IOP). Some patients have normal IOP, whereas other patients appear to obtain adequate control of IOP after filtration surgery or medication. However, these patients still experience progressive visual field loss. Vision loss in glaucoma is attributed to retinal ganglion cell (RGC) apoptosis. Much recent research demonstrates that the link between oxidative stress and mitochondrial dysfunction is a major cause of RGCs apoptosis. How oxidative stress can lead to RGCs apoptosis in glaucoma is unclear but may involve the neurotoxic effects of oxidative stress-induced mitochondrial dysfunction and/or damage from reactive oxygen species (ROS). Investigations are needed concerning the mitochondria as effective targets for potential therapeutic interventions to maintain mitochondrial function and reduce oxidative stress, and thereby delay or stop RGC loss and prolong visual function. The mitochondria-targeted antioxidant Szeto-Schiller (SS) peptide is a candidate molecule. Szeto-Schiller-31 (H-D-Arg-Dmt-Lys-Phe-NH2) is an attractive mitochondria-targeted–antioxidant that can protect the mitochondria and RGCs against oxidative damage. Therefore, we suggest SS-31 as a novel neuroprotective ophthalmic drug for protecting RGCs in glaucoma.