An optimal strategy for prediction of sudden cardiac death through a pioneering feature-selection approach from HRV signal.

BACKGROUND AND OBJECTIVE: Taking into consideration the critical importance of Sudden cardiac death (SCD), as it could be the first and the last heart condition to be diagnosed in a person while continuing to claim millions of lives around the world, prediction of sudden cardiac death has increasingly been regarded as a matter of substantive significance. This study does not seek to once again define features to predict and detect SCD, as there already has been adequate discussion addressing feature extraction in our previous works and other recent studies. What seems to be lacking attention is the need for an appropriate strategy to manage the extracted features to such an extent that the best classification is presented. To this end, deploying a suitable tactic to select extracted features could bring about outstanding results compared to other works in the literature. METHODS: This research has accordingly applied a novel and automated approach to Local Feature Subset Selection through the most rigorous methodologies, which have formerly been developed in previous works of this team, for extracting features from nonlinear, time-frequency and classical processes. We are therefore enabled to select features that differ from one another in each minute before the incident through the agency of optimal feature selection in each one-minute interval of the signal. RESULTS: Using the proposed algorithm, SCD can be predicted 13 min before the onset, thus, better results are achieved compared to other techniques proposed in this field. Additionally, through defining a Utility Function and employing statistical analysis the alarm threshold has been effectively determined as 84% for the prediction accuracy. Having selected the best combination of features, based on their ability to generate the highest classification accuracy, the two classes are classified by means of the Multilayer Perceptron (MLP), K- Nearest Neighbor (KNN) the Support Vector Machine (SVM), and the Mixture of Expert (ME) classifier. The Mixture of Experts classification yielded more precise class discrimination than other well-known classifiers. The performance of the proposed method was evaluated using the MIT-BIH database which led to sensitivity, specificity, and accuracy of 84.24%, 85.71%, and 82.85%, respectively for thirteen one-minute. CONCLUSIONS: The outcome of the obtained prediction would be analyzed and compared to other results. The most applicable and effective features would subsequently be presented according to the number of times they have been chosen. Finally, principal features in each time interval are discussed and the importance of each type of processing will be drawn into focus. The results indicate the significant capacity of the proposed method for predicting SCD from Electrocardoigram (ECG) signals as well as selecting the appropriate processing method at any time before the incident.

Successful treatment of allergic conjunctival granuloma by topical tacrolimus: A clinicopathologic case report.

Allergic conjunctival granuloma is a rare cause of conjunctival ocular lesions. The aim of this case report was to present a successful treatment of an allergic conjunctival granuloma with topical tacrolimus eye drops. A 20-year-old female presented with bilateral multiple yellow nodules of the bulbar conjunctival epithelium and conjunctival injection. The patient had tearing, photophobia, itching, foreign body sensation, and red eye. The patient's signs and symptoms progressed despite the use of topical steroids. The patient was treated by application of tacrolimus eye drop (0.005%) in her right eye every 6 h while the left eye was put on placebo. Her signs and symptoms were recorded at each visit. After 3 weeks' therapy with topical tacrolimus eye drop, the patient became asymptomatic in her right eye and conjunctival granulomas fully resolved. Topical tacrolimus seems to be an effective therapeutic option for the treatment of allergic conjunctival granulomas.

Ocular higher-order aberrations changes after implantable collamer lens implantation for high myopic astigmatism.

PURPOSE: To investigate the changes in higher-order aberrations (HOAs) induced by the implantation of implantable collamer lenses (ICLs) and Toric ICL (TICL) in eyes with high myopia and high myopic astigmatism. METHODS: We investigated 33 eyes of 18 consecutive patients (in a prospective, interventional case series study), with spherical equivalent errors of -6.00 to -21.09 diopters (D) and cylindrical errors of -0.5 to -4.75 D, who underwent ICL and TICL implantation. Before and after 5 days, 2 and 6 months of surgery, the uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), defocus and adverse events of the surgery were assessed. Ocular HOAs were also evaluated by Hartmann-Shack aberrometry (Technolas PV, Rochester, New York, USA) before and after 6 months of surgery. RESULTS: At 6.0 months after surgery, the UCVA and BCVA in 40% and 66.7% of eyes were 20/20, respectively. Mean defocus refraction and astigmatism was reduced to -0.66 and 0.65 D from -12.79 and 2.18 at baseline, respectively. For a 6 mm pupil, HOAs were not significantly changed, merely from 0.417 ± 0.162 µ before surgery to 0.393 ± 0.119 µ after surgery (P = 0.45). Spherical aberration (Z400) increased significantly (P = 00.0). Surgical induced astigmatism was lower than 0.25 D, and there were no changes in trefoils and coma aberration. No vision-threatening complications occurred during the observation period. CONCLUSION: This study shows that the ICL and TICL performed well in correcting high myopic astigmatism without significant changes in HOAs during a 6-month observation period, although the spherical aberration (Z400) increased significantly.

Visual Outcomes and Complications of Piggyback Intraocular Lens Implantation Compared to Aphakia for Infantile Cataract.

PURPOSE: To evaluate the long-term visual outcomes and complications of the piggyback intraocular lens (IOL) implantation compared to aphakia for infantile cataract. PATIENTS AND METHODS: In a comparative study from 1998 to 2007, piggyback IOL implantation (piggyback IOL group) was performed for 14 infants (23 eyes) with infantile cataract and 20 infants (32 eyes) who were aphakic (aphakia group) after infantile cataract surgery. Data were collected on logMAR visual acuity, and postoperative complications over a mean follow-up time of 6.2 ± 1.7 years and 5.8 ± 1.7 years. RESULTS: The mean age at surgery was 7.5 ± 0.6 months and 6.0 ± 3.3 months for the piggyback and the aphakic group respectively (P > 0.05). At the last follow-up visit, visual acuity was 0.85 ± 0.73 (median = 0.70, interquartile range = 0.3-1.32) in the piggyback IOL group and 0.89 ± 0.56 (median = 0.86, interquartile range = 0.50-1.24) in the aphakic group (P > 0.05). There was a positive relationship between age and visual outcomes in the aphakic group (r = 0.4, P = 0.04) but not in the piggyback IOL group (P = 0.48). There was no significant difference between the mean myopic shift in the piggyback IOL group (-5.28 ± 1.06 D) and the aphakic group (-5.10 ± 1.02 D) (P > 0.05). The incidence of reoperation due to complications in piggyback IOL group was higher than aphakic group (%48 vs. %16, respectively, P ≤ 0.01). However, in patients older than 6 months, this risk was not significantly different compared to the aphakic group. CONCLUSIONS: Although piggyback IOL implantation for infantile cataract is optically acceptable as a treatment option, there is no significant difference in visual outcomes compared to aphakia. The incidence in reoperation due to complications in patients aged 6 months or younger is higher than those treated with aphakia.

Customized Clinical Practice Guidelines for Management of Adult Cataract in Iran.

PURPOSE: To customize clinical practice guidelines (CPGs) for cataract management in the Iranian population. METHODS: First, four CPGs (American Academy of Ophthalmology 2006 and 2011, Royal College of Ophthalmologists 2010, and Canadian Ophthalmological Society 2008) were selected from a number of available CPGs in the literature for cataract management. All recommendations of these guidelines, together with their references, were studied. Each recommendation was summarized in 4 tables. The first table showed the recommendation itself in clinical question components format along with its level of evidence. The second table contained structured abstracts of supporting articles related to the clinical question with their levels of evidence. The third table included the customized recommendation of the internal group respecting its clinical advantage, cost, and complications. In the fourth table, the internal group their recommendations from 1 to 9 based on the customizing capability of the recommendation (applicability, acceptability, external validity). Finally, customized recommendations were sent one month prior to a consensus session to faculty members of all universities across the country asking for their comments on recommendations. RESULTS: The agreed recommendations were accepted as conclusive while those with no agreement were discussed at the consensus session. Finally, all customized recommendations were codified as 80 recommendations along with their sources and levels of evidence for the Iranian population. CONCLUSION: Customization of CPGs for management of adult cataract for the Iranian population seems to be useful for standardization of referral, diagnosis and treatment of patients.

Spontaneous wound dehiscence after penetrating keratoplasty.

Spontaneous wound separation may be developed even months after suture removal especially in the context of long-term corticosteroid therapy. A 68-year-old Caucasian woman presented to our cornea clinic with spontaneous wound dehiscence after her third penetrating keratoplasty (PKP) which was performed three years ago. An Ahmed glaucoma valve (New World Medical, Ranchos Cucamonga, CA) was inserted ten months after the third PKP, which successfully controlled intraocular pressure (IOP). At the examination, the last sutures were removed eight months ago and she was using flourometholone 0.1 % (Sina Darou, Tehran, Iran) with a dose of once a day. There was one quadrant of wound dehiscence from 8 to 11 òclock associated with anterior wound gape and severe corneal edema. Resuturing was performed for the patient. At the one month examination, the corneal edema was resolved and best corrected visual acuity was 20/200 mainly due to previous glaucomatous optic neuropathy. Caution about the prolonged use of corticosteroids is necessary. Topical immunosuppressives could be a promising choice in this field.

Toric implantable collamer lens for high myopic astigmatism in keratoconic patients after six months.

BACKGROUND: The aim was to evaluate the safety, efficacy, stability and predictability of posterior chamber collagen copolymer phakic intraocular lens (pIOL) implantation to correct myopia and myopic astigmatism associated with keratoconus. METHODS: The unaided vision and visual acuity, refraction and adverse events were measured in 22 keratoconic eyes of 14 patients after using an implantable collamer lens (ICL) (STAAR Surgical Inc.) to correct refractive error. The outcome was evaluated over six months. RESULTS: The mean pre-operative spherical equivalent (SE) and cylinder changed from -4.98 ± 2.63 DS and -2.77 ± 0.99 DC to -0.33 ± 0.51 DS and -1.23 ± 0.65 DC, respectively at the end of six months. Before the surgery the mean Snellen decimal visual acuity was 0.63 ± 0.20. The mean unaided vision and visual acuity changed to 0.76 ± 0.23 and 0.85 ± 0.21, respectively at the end of six months. The mean safety and efficacy indices were 1.40 ± 0.32 and 1.24 ± 0.34, respectively. No eye lost a line of visual acuity and 17 eyes (77.3 per cent) gained one or more lines. Fifteen eyes (68.2 per cent) were within 0.50 D and 20 (90.9 per cent) were within 1.00 D of the desired spherical equivalent refraction. There was a change in manifest refraction of 0.09 ± 0.21 (ranging from -0.25 to +0.75) from one week to six months after the surgery. CONCLUSION: The clinical outcomes of the current study demonstrate the safety, efficacy and predictability of toric implantable collamer lens in the correction of myopia and myopic astigmatism associated with keratoconus. The patients' refractions achieved early stability and remained stable during the course of the study.

Ocular higher-order aberrations and mesopic pupil size in individuals screened for refractive surgery.

AIM: To study the distribution of ocular higher-order aberrations(HOAs) and mesopic pupil size in individuals screened for refractive surgery. METHODS: Ocular HOAs and mesopic pupil size were studied in 2 458 eyes of 1 240 patients with myopia, myopic astigmatism and compound myopic astigmatism and 215 eyes of 110 patients with hyperopia, hyperopic astigmatism and compound hyperopic astigmatism using the Zywave aberrometer (Busch& Lomb). All patients had correctable refractive errors without a history of refractive surgery or underlying diseases. Root-mean-square values of HOAs, total spherical aberration, total coma and mesopic pupil size were analyzed. Ocular HOAs were measured across a ≥ 6.0 mm pupil, and pupil size measurements were performed under the mesopic condition. RESULTS: The mean values of HOAs, total spherical aberration and total coma in the myopic group were 0.369µm, ±0.233, 0.133± 0.112µm and 0.330±0.188µm, respectively. In the hyperopic group the mean values of HOAs, total spherical aberration and total coma were 0.418µm ±0.214, 0.202±0.209µm and 0.343±0.201µm, respectively. Hyperopes showed greater total HOAs (P<0.01) and total spherical aberration (P<0.01) compared to myopes. In age-matched analysis, only the amount of total spherical aberration was higher in the hyperopic group (P=0.05). Mesopic pupil size in the myopic group was larger (P≤0.05). CONCLUSION: The results suggested that significant levels of HOAs were found in both groups which are important for planning refractive surgeries on Iranians. There were significantly higher levels of total spherical aberration in hyperopes compared to myopes. Mesopic pupil size was larger in myopic group.

Ocular toxoplasmosis in Iran: 40 cases analysis.

AIM: To report ocular symptoms, funduscopic findings and demographic distribution of ocular toxoplasmosis in Iran METHODS: In this cross-sectional study, a total of 40 patients with ocular toxoplasmosis (24 female, 16 male) were enrolled. The distribution of symptoms and funduscopic findings were studied. RESULTS: The patients' age was in the range of 13-52 with the most common age of 19 years old. Twenty-four patients were female (60.0%). The most common presenting sign was visual loss. There was anterior chamber (AC) inflammation in 23 patients (57.5%). Vitritis was presented in 36 patients (90.0%). In 35 patients (87.5%), the retinal lesion was central. In patients with peripheral lesion, 3 patients (60.0%) had flashing vs 12.5% chance of flashing in all patients. Older patients had larger lesion (P=0.04). CONCLUSION: Ocular toxoplasmosis substantially varies among patients with different age, gender, status of immunity, site of lesion and other undetermined factors. One of ocular symptoms, flashing, may necessitate a more precise peripheral fundus examination.

Predictive value of visual evoked potentials, relative afferent pupillary defect, and orbital fractures in patients with traumatic optic neuropathy.

BACKGROUND: The purpose of this study was to determine the predictive value of flash visual-evoked potentials (VEP), relative afferent pupillary defect, and presence of orbital fractures in patients with traumatic optic neuropathy. METHODS: A prospective study was conducted in 15 patients with indirect traumatic optic neuropathy. All patients underwent a thorough ophthalmic examination. Initial visual acuity, final visual acuity, and relative afferent pupillary defect were determined, and visual acuity was converted into logMAR units. We performed flash VEP and an orbital computed tomography scan in all patients. RESULTS: There was a good correlation between relative afferent pupillary defect and final visual acuity (r = -0.83), and better initial visual acuity could predict better final visual acuity (r = 0.92). According to findings from flash VEP parameters, there was a relationship between final visual acuity and amplitude ratio of the wave (r = 0.59) and latency ratio of the wave (r = -0.61). Neither primary visual acuity nor final visual acuity was related to the presence of orbital fractures in the orbital CT scan. CONCLUSION: Patients with traumatic optic neuropathy often present with severe vision loss. Flash VEP, poor initial visual acuity, and higher grade of relative afferent pupillary defect could predict final visual acuity in these patients. Presence of orbital fracture was not a predictive factor for primary visual acuity or final visual acuity.

Perilimbal bevacizumab injection for interface neovascularization after deep anterior lamellar keratoplasty.

PURPOSE: To evaluate the effect of perilimbal bevacizumab injection on neovascularization at the interface of donor and recipient tissues after deep anterior lamellar keratoplasty (DALK). METHODS: This interventional case series included 4 patients with interface neovascularization after DALK (3 patients with advanced keratoconus and 1 patient with scarring because of herpetic keratitis). Bevacizumab (2.5 mg/0.1 mL) was injected subconjunctivally near the limbus adjacent to the abnormal blood vessels. Depending on regression of new vessels, injections were repeated. If neovascularization occurred in more than 1 quadrant, injections were administered at 2 sites (2.5 mg for each injection). Total corneal neovascularization, longest neovascular length, and degree of neovascular circumference were evaluated by digital slit lamp corneal photography before injection and 1 week, 1, 3, and 6 months afterward. RESULTS: The mean follow-up period was 14 ± 7.52 months from the first bevacizumab injection. Corneal neovascularization, on average,was 33.70% ± 7.8% (SD) of the total corneal surface before the injections, which decreased to 4.83% ± 3.3% (P = 0.005, t test) at the last follow-up examination. Mean degree of neovascularized circumference decreased from 165 degrees before injection to 77.5 degrees (P = 0.023) at the last follow-up examination. Mean longest neovascularized length decreased from 6.714 mm before injection to 1.497 mm (P = 0.021) at the last follow-up examination. At the end of the study, all patients had clear grafts with no sign of graft failure. Mean best-corrected visual acuity before injection was 20/100, which improved to 20/30 at the last examination. CONCLUSIONS: This small case series suggests that perilimbal bevacizumab injection is safe and effective for partial regression of new blood vessels at the interface of donor and recipient tissues after DALK and may effectively prevent graft rejection.

Traumatic wound dehiscence and lens extrusion after penetrating keratoplasty.

PURPOSE: The purpose of this study was to investigate risk factors for and results of treatments in patients with traumatic wound dehiscence and lens extrusion after penetrating keratoplasty. METHODS: In this retrospective case series, 7 eyes (4 right eyes and 3 left eyes) of 7 patients who had traumatic wound dehiscence and lens extrusion were studied at Rassoul Akram Hospital. Six patients were male and one patient was female. After emergency treatment for the trauma, the wound was checked under general anesthesia, and anterior vitrectomy was performed. The iris was repositioned as needed and the dehiscence site was sutured in all patients using 10-0 nylon thread. Follow up was similar to that after keratoplasty. All recorded data were statistically analyzed using SPSS software (version 15; SPSS Inc., Chicago, IL). RESULTS: Mean age at trauma was 21 years (range, 10-30 years), and the mean interval between keratoplasty and trauma was 15.6 months (range, 2.5-26.5 months). Mean best-corrected visual acuity of patients before blunt trauma and after final treatment was 20/80 and 20/160, respectively. In one case, visual acuity decreased to light perception after final treatment. The dehiscence site was superior to the graft in 4 patients. Hitting by a hand was the cause of most cases of blunt trauma. No cases of endophthalmitis were seen. CONCLUSION: Patients who undergo penetrating keratoplasty are susceptible to graft wound dehiscence resulting from trauma, especially during the first year after keratoplasty. This type of dehiscence is more prevalent in young people, who engage in more social activities and are more exposed to trauma that may lead to blindness. Patient education about the effects of trauma, use of protective eye shields by patients, and performance of lamellar keratoplasty instead of penetrating keratoplasty can decrease trauma and its effects in these patients.

Topical antiglaucoma medications and lacrimal drainage system obstruction.

PURPOSE: To evaluate the effect of topical antiglaucoma medications on the lacrimal drainage system. METHODS: In a prospective controlled blind observational case series, 627 eyes of 384 patients (219 males, 165 females) were screened. Data recording (demographics and history taking), allocation in case (on topical antiglaucoma medications) and control (no glaucoma) groups, and examinations (eye examination and dye disappearance test) were performed by a senior ophthalmology resident. Exclusion criteria were epiphora prior to onset of treatment with topical antiglaucoma medication (only for case group), history of long-term use of topical medications (other than antiglaucoma medications in the case group), and previous ocular and periocular disorders. Diagnostic probing and irrigation of the lacrimal drainage system were performed by an oculoplastic surgeon masked to a patient's status as case or control. RESULTS: After exclusion, there were 130 eyes from 98 patients and 280 eyes from 178 patients in the case and control groups, respectively. Case and control groups were matched. There was significantly more lacrimal drainage system obstruction in the case group (26 of 130, 20%) than in the control group (24 of 280, 8.57%) (p = 0.002). Upper lacrimal drainage system obstruction was significantly more in the case group (p = 0.018). Increasing age was associated with significantly more obstruction in the control group only (p = 0.029). Statistically significant obstruction was found in the patients taking timolol + dorzolamide (p = 0.021) and timolol + dorzolamide + pilocarpine (p = 0.017) with a duration of 2 weeks to 156 months. CONCLUSION: Patients taking a combination of topical antiglaucoma medications showed significantly increased risk of developing lacrimal drainage system obstruction. Both total and upper obstruction was significantly more frequent in patients on topical antiglaucoma medications.