In the last two decades, electrical stimulation (ES) has been tested in patients with various eye diseases and shows great treatment potential in retinitis pigmentosa and optic neuropathy. However, the clinical application of ES in ophthalmology is currently limited. On the one hand, optimization and standardization of ES protocols is still an unmet need. On the other hand, poor understanding of the underlying mechanisms has hindered clinical exploitation.
Main Text
Numerous experimental studies have been conducted to identify the treatment potential of ES in eye diseases and to explore the related cellular and molecular mechanisms. In this review, we summarized the in vitro and in vivo evidence related to cellular and tissue response to ES in eye diseases. We highlighted several pathways that may be utilized by ES to impose its effects on the diseased retina.
Conclusions
Therapeutic effect of ES in retinal degenerative diseases might through preventing neuronal apoptosis, promoting neuronal regeneration, increasing neurotrophic factors production in Müller cells, inhibiting microglial activation, enhancing retinal blood flow, and modulating brain plasticity. Future studies are suggested to analyse changes in specific retinal cells for optimizing the treatment parameters and choosing the best fit ES delivery method in target diseases.
To develop a paraxial eye model based on a previously collected cohort of adults with well-controlled type 1 diabetes mellitus (DM1) and a limited range of refractive errors.
Methods
The study used the previously published biometric data of 72 participants (Age: 41.5 ± 12.4 years) with DM1. Measurements included objective refraction, anterior and posterior corneal radii of curvatures, and internal distances. Moreover, phakometry was used to determine the lens radii of curvature and lens equivalent indices, from which the lens powers were calculated. A multivariate linear regression was performed for each biometric parameter with respect to current age (Age), the time since the onset of diabetes (Tdb), and current levels of glycated hemoglobin (HbA1c). The vitreous chamber depth was determined from other distances, and lens equivalent index was chosen to balance the models. These were compared with an existing model for non-diabetic eyes.
Results
Some dependent parameters were not affected by the independent variables (spherical equivalent, anterior corneal radius of curvature, central corneal thickness), some were affected by time since onset (the lens radii of curvatures, anterior chamber depth) and others were affected by both age and time since onset (posterior corneal radius of curvature, lens thickness, axial length). None of the dependent parameters were affected by current levels of HbA1c.
Conclusions
The proposed model accurately describes the age-related changes in the eyes of people with DM1. In this description the age of diabetes onset plays an important role, especially if the diabetes onset occurred during childhood.
Dengue fever (DF) epidemics in Singapore in 2005–2006 and 2007 were caused predominantly by dengue virus serotypes 1 (DENV-1) and 2 (DENV-2) respectively. We investigated the prevalence of ophthalmic manifestations during these consecutive epidemics.
Methods
Seropositive DF patients admitted to the hospital during two separate dengue epidemics were enrolled from June 2005 to December 2007. Demographic, ophthalmic, and laboratory data were collected. The primary outcome measures were differences in ophthalmic and laboratory features across the two epidemics. Factors associated with increased risk of developing various DF-related ophthalmic manifestations were the secondary outcome measures.
Results
Of the 115 patients enrolled, 109 (94.7%; 33 in 2005–2006 and 76 in 2007) completed the eye screening protocol. Majority of patients were Chinese (65, 59.6%) and males (81, 74.3%). The mean age was 40.8 years (range, 18–87). Colour vision impairment (12 vs 14 [36.4% vs 18.7%]; P = 0.04), cotton wool spots (10 vs 3 [30.3% vs 3.9%]; P < 0.001), bleeding diathesis (7 vs 3 [21.2% vs 3.9%]; P = 0.004) and abnormal liver function (mean alanine amino-transferase [150.2 U/L vs 68.28 U/L; P = 0.001], mean aspartate amino-transferase [196.86 U/L vs 99.53 U/L; P = 0.002], total protein [68.43 g/L vs 72.27 g/L; P = 0.016], serum albumin [36.86 g/L vs 40.5 g/L; P = 0.001]) were noted more often in DF epidemics predominantly caused by DENV-1 compared to DENV-2.
Conclusions
A higher prevalence of colour vision impairment, cotton wool spots, bleeding diathesis, and abnormal liver function was found in DF epidemics predominantly caused by DENV-1 compared to DENV-2.
To evaluate the impact of video and verbal counselling on patients' undergoing phacoemulsification under topical anaesthesia.
Methods
This is a prospective randomized controlled trial conducted at Aravind Eye Care System, Pondicherry, India. All patients had a 15 min one-on-one verbal counselling covering surgical technique, implant options, anaesthesia and payment options one day prior to surgery. On the day of surgery, patients were randomized into two groups; in the first group, patients were provided with video counselling and in the second group, patients were given verbal counselling prior to undergoing phacoemulsification under topical anaesthesia. Measurements of blood pressure, heart rate, respiration rate, and the Likert-scale anxiety rating were collected at preoperative, perioperative, and postoperative time points.
Results
A group of 186 patients (aged 45–70 years) were provided video counselling via portable iPad before first-time phacoemulsification, and a second group of 186 patients underwent surgery with verbal counselling. Systolic and diastolic blood pressure measurements were lower in both the video and verbally counselled groups during the intraoperative time point. Furthermore, during the intraoperative period, 123 (66.1%) video counselled patients felt relaxed compared to 119 (64%) patients who were provided verbal counselling (P = 0.6636). Patient cooperation during surgery was excellent in 76(40.9%) video counselled patients and 67(36%) verbally counselled patients (P = 0.3374). 25.8% and 21% (P = 0.2703) of patients experienced no pain during surgery in the video and verbal counselled groups respectively.
Conclusions
Although measures such as pulse rate, respiratory rate and feelings of relaxation did not show significant differences among the two groups of video and verbal counselling, patients marked cooperation during surgery and furthermore, the level of anxiety is most reassuring.
To evaluate the safety and effectiveness of photobiomodulation (PBM) in the treatment of diabetic macular edema (DME).
Methods
It was a single-center, self-controlled prospective study. The clinical records of 12 diabetic retinopathy patients (5 males and 7 females, 20 eyes in total) who were treated with PBM for DME at the Second Affiliated Hospital, Zhejiang University School of Medicine, were analyzed. The mean age was 56 (26–68) years. All the participants received PBM treatment during darkness at night in no less than 5 days per week and no less than 8 h per day. In the baseline check and follow-up checks (1, 2, 6, 10, and 12 months after the start of treatment), the best-corrected visual acuity, the thickness of the retina in the macula, and the changes of the fundus lesions were observed. Wilcoxon signed rank test was used to compare the results before and after treatment. P < 0.05 was considered statistically significant.
Results
No fundus complication was observed during follow-up checks. In baseline and 12-month follow-up checks, the best-corrected visual acuity was 71.75 ± 12.47 and 79.50 ± 10.85, maximal retinal thickness in macular area was 390.95 ± 77.12 μm and 354.13 ± 55.03 μm, average retinal thickness in macular area was 334.25 ± 36.45 μm and 314.31 ± 33.28 μm, foveal thickness was 287.00 ± 46.79 μm and 265.63 ± 67.14 μm. The best-corrected visual acuity, average retinal thickness in macular area in consecutive follow-up results except that in the 1st month showed significant difference compared with baseline results. There were significant difference between every follow-up result and baseline result of maximal retinal thickness in macular area (P < 0.05). All follow-up results of foveal thickness were not significantly different (P > 0.05) from the baseline result, except that in the 6th month (P = 0.049). Obvious improvement could be observed in retinal fundus fluorescein angiography images.
Conclusions
PBM is a safe and effective treatment of DME, which deserves further investigation.
To determine the possible use of near-infrared(NIR) light-emitting-diode (LED) radiation for imaging intraocular tumours by transpalpebral transillumination.
Methods
This study was a pilot, open-label, prospective and non-interventional. Thirty patients (30 eyes; age 30–72 years) with uveal melanomas located in the iris, ciliary body, or choroid were under our observation. A biomicroscopy, ophthalmoscopy, transpalpebral NIR transillumination, and ultrasound examination were performed in all cases.
Results
In all cases, NIR transillumination with transpalpebral approach enables visualization of the ciliary body and accurately estimates the projection of the pars plicata and ora serrata onto the sclera. In all patients, transpalpebral NIR transillumination made it possible to image the shadow of intraocular melanoma, estimate its dimensions and location concerning the ciliary body structures.
Conclusions
We recommend the non-invasive transpalpebral NIR transillumination technique, together with traditional ultrasound imaging, to improve the accuracy of assessing the size and location of intraocular tumours.