Medical hypothesis discovery and innovation in ophthalmology

Patients with high hyperopia are generally confined to either spectacle wear or contact lenses as a primary means of refractive correction. For this patient population, the surgical corrective methods, such as hyperopic laser assisted in-situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) are imperfect options due to induction of higher-order aberrations, optical regression, and loss of best corrected distance visual acuity. Recently, there has been growing interest in lenticule implantation underneath a flap via lenticule intrastromal keratoplasty (LIKE) for high hyperopia correction (+3 diopters to +10 diopters). We instead propose a modified surgical technique (small-incision lenticule intrastromal keratoplasty, sLIKE), in which the lenticule is implanted inside an intrastromal pocket thereby causing less injury to the subbasal nerve plexus injury, less postoperative dry eye symptoms, less reduction in biomechanical strength, and lower chances for epithelial ingrowth. We provide an overview of these novel surgical techniques to treat high hyperopia, and compare the associated advantages and disadvantages. In addition, we will discuss the enhancement options and methods of optimization for both surgical techniques. 

This study was performed to evaluate a healthcare strategy based on teleophthalmology for diagnosis and management of primary healthcare users. A descriptive cross-sectional study was conducted to review the medical records of patients from January 2013 to December 2014 from primary care units in the city of São Paulo. The units referred patients, who had diabetes or high blood pressure, and were users of chloroquine compounds, for a fundus examination. The images were sent to a reading center for review, diagnosis, and patient referrals. From 9173 analyzed patients, 570 (6.2%) were excluded because of poor image quality. Of the remaining patients, 4933 (57.3%) had diabetes, 7242 (84,2%) systemic hypertension, and 113 (1.3%) used chloroquine. Of these, 989 (11.5%) patients needed ophthalmologic treatment. The most frequently prescribed treatments were cataract extraction in 692 (70%) of 989 and photocoagulation in 245 (24.8%) of 989 cases. Overall, cataract extraction was indicated in 692 (8%) of 8603 cases and photocoagulation in 245 (2.8%) of 8603 cases. When only patients with diabetes were considered, the indication for photocoagulation increased to 4.5%.The results showed that non-medical professionals could produce good-quality ocular images for screening of ocular diseases in most cases; only 6.2% of ocular images did not meet quality requirements. Most patients referred for fundus examination did not need a specific treatment, indicating that this system could be an inexpensive and reliable tool for use in developing countries. 

This study was performed to assess the short-term effect of sutureless scleral tunnel trabeculectomy procedure with and without topical bevacizumab. Thirty patients with Primary Open-Angle Glaucoma (POAG) were enrolled and randomly divided to two groups. Patients in the first group (15 patients) underwent sutureless trabeculectomy without topical bevacizumab and patients in the second group (15 patients) underwent sutureless trabeculectomy with 1.25 mg of topical bevacizumab. Intraocular Pressure (IOP) of both groups was measured by an expert ophthalmologist, without awareness of the patient’s study group before the operation and six months post-operatively. Out of 30 patients in this study, six females (40%) and nine males (60%) underwent the sutureless trabeculectomy procedure (group A) as well as seven females (46.7%) and eight males (53.3%) underwent sutureless trabeculectomy with topical bevacizumab (group B). The mean age of the patients was not significantly different between the two groups (P = 0.91). A statistically significant difference in time variation of IOP was found between the two groups (P < 0.001). Mean IOP was 18.4 ± 4.35 mmHg in the sutureless group without bevacizumab and 11.73 ± 2.12 mmHg in the sutureless group with bevacizumab, six months post-surgically. No statistical significant differences were found in the baseline IOP between the two groups (P = 0.28). However, IOP changed significantly in group A and B from baseline to six months post-operatively (P = 0.004 and P < 0.001 respectively). According to the current findings, the sutureless trabeculectomy procedure is an effective surgical method for reduction of IOP. Addition of a single dose of 1.25 mg topical bevacizumab was more effective in reduction of IOP compared to sutureless trabeculectomy alone. 

The correct estimation of Intraocular Pressure (IOP) is the most important factor in the management of various types of glaucoma. Primary congenital glaucoma is a type of glaucoma that can cause blindness in the absence of control of the IOP. In this retrospective observational study, 95 eyes, including 48 healthy eyes and 47 eyes with Primary Congenital Glaucomatous (PCG) were studied. Two groups were matched for age, gender, and Goldman Applanation Tonometry (GIOP). Corneal Hysteresis (CH), Corneal Resistance Factor (CRF), and Goldman intraocular pressure were measured by ORA (IOPg), and corneal compensated Intraocular Pressure (IOPcc) was measured for each patient using the Ocular Response Analyzer (ORA). Central Corneal Thickness (CCT) was measured by ultrasonic pachymetry. For each patient, one eye was selected randomly. Student’s t-test and analytical regression were used for statistical analysis. The two groups were matched for age (P = 0.34), gender (P = 0.47), and GIOP (P = 0.17). Corneal hysteresis and CRF were significantly lower in PCG than in normal eyes (P < 0.0001), yet CCT was significantly thicker in PCG than normal eyes (P < 0.0001). The regression equation on the effect of CH, CRF, and CCT on GIOP in the PCG group showed that CH and CRF (P-value = 0.001 and P-value<0.0001) also had a significant effect yet CCT did not (P-value = 0.691). A significant decrease in CH and CRF was found in the PCG group compared to the normal controls. In the PCG group, the CCT was greater than normal. These results showed the usefulness of biomechanical properties (CH, CRF) in order to interpret IOP measurements. Furthermore, GIOP measurement may not be confined to consideration of CCT alone. A low CH and CRF value could be responsible for under-estimation of GIOP in the PCG group, in comparison to the normal controls.

This study was performed to determine the surgical outcomes and the related risk factors of second operation in patients with residual horizontal deviations. In this interventional case series study, a total of 119 patients with a history of reoperation were included (39 exotropia and 80 esotropia). Cases with consecutive strabismus, muscular palsy, systemic disease, lack of ocular fixation, and those, who had vertical deviation and Dissociated Vertical Deviation (DVD)>5 Prism Diopters (pd) were excluded. Medial Rectus (MR) resection in residual Exotropia (XT) and Lateral Rectus (LR) resection in residual Esotropia (ET) were performed. Unilateral or bilateral operations were considered if the preoperative residual deviation was < 20 pd or > 20 pd, respectively. Success of the reoperation was considered if the postoperative angle of deviation was ≤ 10 pd. Unilateral and bilateral MR resection was performed in 26% and 74% of patients with XT, respectively, with greater dose response in unilateral cases (2.8 versus 2.6 mm/pd). Successful surgical outcomes were observed in 94.9% of patients with XT. Unilateral and bilateral LR resection was also performed in patients with residual ET, each in 50% of patients. Unilateral cases showed greater dose-response compared to bilateral ones (2.6 versus 2 mm/pd) and successful surgical outcomes were observed in 83.8% of patients with ET. No variable was found as a risk factor of reoperation in both groups. In conclusion, both LR and MR resection are easy and predictable surgical approaches with high success rate in patients with residual ET and XT. Generally, MR resection is more effective than LR resection. Unilateral operation is less recommended in the residual exotropic group, due to its lower success compared to the bilateral operation. Unfortunately, none of the mentioned variables were found to be the risk factor of reoperation in the sampled patients. 

This study was performed to describe lateral rectus myectomy and maximal medial rectus resection for correction of eye deviation in complete third cranial nerve palsy. A retrospective review of thirteen patients (fourteen eyes) with complete third cranial nerve palsy, who underwent lateral rectus myectomy and maximal medial rectus resection, was performed. These procedures were combined with superior oblique tendon transposition in nine patients with a large angle of exotropia (more than 60 prism diopters [∆]), or significant hypotropia (more than 5 ∆). Preoperative deviations were exotropia of 50 to 120 ∆ in thirteen cases and hypotropia of 5 to 25 ∆ in eight cases. Six months after the surgery, eleven patients were within 10 ∆ of orthotropia in primary position. Revision surgery was performed for two patients, eight and 18 months after the first operation. Eventually, five patients (38%) achieved orthotropia in the primary position, and seven patients (54%) had < 11 ∆ exotropia and < 6 ∆ vertical deviation. In conclusion, this procedure can be considered as an acceptable approach for treatment of strabismus in complete third cranial nerve palsy. This procedure is simple and can be easily performed even in very young children. 

This study was conducted to investigate the effects of Artificial Tear Preparations (ATP) with three different ingredients on contrast sensitivity in patients with dry eye syndrome. Contrast sensitivity measurements were obtained before and 5, 15, 30, 60, and 90 minutes after administering three different ATPs, containing dextran 70, hydroxypropyl methylcellulose (ATP-1), polyvinyl alcohol-povidone (ATP-2) and carbomer (ATP-3) to one eye of 20 patients with dry eye syndrome, who had been divided to three groups. Contrast sensitivity measurements were obtained at 1.5, 3, 6, 12, and 18 spatial frequencies (cpd). Compared with the baseline measurements, ATP-1 provided a significant increase of 1.5 and 3 cpd at the 15th minute, 12 cpd at the 60th minute, and 18 cpd at the 30th minute, ATP-2 significantly increased contrast sensitivity compared with the baseline at the 15th, 30th, 60th, and 90th minute measurements, recorded as 1.5, 3, 12, and 18 cpd, and ATP-3 provided significant increases of 18 cpd at 60th and 90th minute measurements compared with the baseline. In conclusion, while  ATP-2 increased the majority of contrast sensitivity measurements both at early, mid, and late terms, the ATP-1 and ATP-3 were found to be effective on mid-term and late-term contrast sensitivity measurements, respectively.