Improved predictive diagnosis of diabetic macular edema based on hybrid models: An observational study.

Diabetic Macular Edema (DME) is the most common sight-threatening complication of type 2 diabetes. Optical Coherence Tomography (OCT) is the most useful imaging technique to diagnose, follow up, and evaluate treatments for DME. However, OCT exam and devices are expensive and unavailable in all clinics in low- and middle-income countries. Our primary goal was therefore to develop an alternative method to OCT for DME diagnosis by introducing spectral information derived from spontaneous electroretinogram (ERG) signals as a single input or combined with fundus that is much more widespread. Baseline ERGs were recorded in 233 patients and transformed into scalograms and spectrograms via Wavelet and Fourier transforms, respectively. Using transfer learning, distinct Convolutional Neural Networks (CNN) were trained as classifiers for DME using OCT, scalogram, spectrogram, and eye fundus images. Input data were randomly split into training and test sets with a proportion of 80 %-20 %, respectively. The top performers for each input type were selected, OpticNet-71 for OCT, DenseNet-201 for eye fundus, and non-evoked ERG-derived scalograms, to generate a combined model by assigning different weights for each of the selected models. Model validation was performed using a dataset alien to the training phase of the models. None of the models powered by mock ERG-derived input performed well. In contrast, hybrid models showed better results, in particular, the model powered by eye fundus combined with mock ERG-derived information with a 91 % AUC and 86 % F1-score, and the model powered by OCT and mock ERG-derived scalogram images with a 93 % AUC and 89 % F1-score. These data show that the spontaneous ERG-derived input adds predictive value to the fundus- and OCT-based models to diagnose DME, except for the sensitivity of the OCT model which remains the same. The inclusion of mock ERG signals, which have recently been shown to take only 5 min to record in daylight conditions, therefore represents a potential improvement over existing OCT-based models, as well as a reliable and cost-effective alternative when combined with the fundus, especially in underserved areas, to predict DME.

[Sub-tenon steroid treatment in choroidal neovascularization caused by serpiginous choroiditis. A case report]. / Esteroides subtenonianos en neovascularización coroidea secundaria a coroiditis serpinginosa. Presentación de un caso.

CASE REPORT: We present a report of a patient suffering from serpiginous choroiditis complicated by choroidal neovascularization (CNV). Sub-tenon steroid treatment, added to the usual immunosuppressive therapy, resolved the CNV, improving visual acuity in one eye. DISCUSSION: Choroidal neovascularization is a sight-threatening complication of posterior uveitis. Our case suggests that sub-tenon steroid treatment, added to systemic immunosuppressive therapy, may accelerate the CNV resolution in posterior uveitis.

[Macular hole surgery without postoperatory <> down positioning. Pilot study]. / Cirugía de agujero macular sin posición <> postoperatoria. Estudio piloto.

PURPOSE: To evaluate the visual and anatomical outcomes of macular hole surgery using phacoemulsification, vitrectomy and intraocular gas tamponade without the use of postoperative face down positioning. METHODS: Phacoemulsification with an intraocular lens implant, followed by vitrectomy with internal limiting membrane peeling and perfluoropropane (C3F8), was performed in patients with stage 3 or 4 macular holes. After surgery, patients had to avoid the supine position for 15 days. Patients with a gas level <50% during the first week had a fluid-gas exchange. Visual acuity and closure of the macular hole were evaluated after 1 year of follow-up. RESULTS: 20 eyes of 20 patients, aged 60 to 75 years (median age 68 years), were included in this study. The best initial visual acuity ranged from 0.05 to 0.13 (ETDRS), with the median being 0.06. The final visual acuity was 0.05 to 0.30 with a median of 0.10. A statistically significant improvement (p=0.001, Wilcoxon) was found. The anatomic postoperative results revealed 90% (n=18) of the macular holes were closed while 10% (n=2) were not. CONCLUSIONS: Macular hole surgery has, in general, good results and patients can achieve improvement in their visual acuity without the need for uncomfortable and unbearable post operative posture positions.

Intravitreal memantine retinal toxicity in rabbits.

OBJECTIVE: To histologically evaluate whether the intravitreal application of memantine produces retinal toxicity in rabbits. METHODS: A cross-sectional design, experimental, descriptive study was performed on 16 eyes of 16 New Zealand rabbits of 3 kg, divided in 4 groups of 4 rabbits. A dose of 70 ng/ml of intravitreal memantine was administered in Group A, a dose of 150 ng/ml in Group B, a dose of 400 ng/ml in Group C, and Group D received 1 ml of balanced salt solution. The injected eye of half of each group was enucleated 15 days after the injection, and the rest within 30 days after injection. Following enucleation, each eye was placed in 10% formaldehyde. Histopathological analysis was performed on all enucleated eyes. The animals were treated according to the guidelines of the Association for Research on Vision and Ophthalmology (ARVO). RESULTS: Groups A, B and D did not show any histopathological changes after their enucleation at 15 and 30 days. Group C showed changes in the photoreceptor layer after enucleation at 15 and 30 days. CONCLUSIONS: In our study, it was observed that memantine concentrations at 70 ng/ml and 150 ng/ml are safe when administered intravitreally; however, doses of 400 ng/ml produced retinal structural changes. This research should continue to assess its clinical usefulness.

Radial optic neurotomy for ischaemic central vein occlusion.

BACKGROUND/AIMS: Ischaemic central retinal vein occlusion (CRVO) accounts for 20-50% of all CRVO. No treatment has been proved to be effective. The efficacy of radial optic neurotomy (RON) was evaluated in eyes with ischaemic CRVO. METHODS: 10 patients with ischaemic CRVO underwent RON. After pars plana vitrectomy, a microvitreoretinal blade was used to incise the scleral ring, cribriform plate, and adjacent sclera at the nasal edge of the optic disc. Best corrected visual acuity (BCVA), intraocular pressure (IOP), fluorescein angiography (FA), multifocal electroretinography (mfERG), and optical coherence tomography (OCT) were measured preoperatively and at 1, 3, and 6 months postoperatively. RESULTS: No visual improvement was noted in the eyes that underwent RON. FA and mfERG showed no increase in retinal perfusion or retinal function postoperatively. Mean macular central thickness changed from 841 (SD 170) mum preoperatively to 162 (SD 34) microm at the sixth postoperative month. One patient had retinal central artery perforation intraoperatively. One patient developed neovascular glaucoma. CONCLUSION: RON in ischaemic CRVO did not improve visual function (by mfERG) or visual acuity although macular thickness did improve. This technique may be associated with potential risks. Randomised studies are needed to corroborate these results.

[Retained intraocular foreign body. an unusual presentation]. / Presentación inusual de un cuerpo extraño intraocular.

CLINICAL CASE: A 25-year-old man presented with a unilateral retinal detachment, and an ipsilateral preretinal mass; ultrasonographic findings included a high-reflective peripheral mass and a retinal fold. A presumptive diagnosis of a peripheral toxocara granuloma was entertained. We performed a 360 degree circumferential scleral buckle and a conventional vitrectomy via the pars plana. Histologic examination of the mass defined a central non-metallic foreign body surrounded by fibrous tissue. DISCUSSION: An intraocular non-metallic foreign body, surrounded by a fibrous capsule and feeding and draining blood vessels, can mimic the characteristics of a peripheral toxocara granuloma, and the differential diagnosis has to be kept in mind.

Vitrectomy for ocular trauma: a question of timing?

PURPOSE: A long-standing controversy exists regarding the proper timing for vitrectomy in a traumatized eye. The present study was conducted to assess the influence of timing on the final visual acuity. MATERIALS AND METHODS: A retrospective review was made of 45 consecutive patients who underwent a pars plana vitrectomy procedure for repair of ocular trauma. The patients were divided into two groups according to the timing of the surgery post-trauma: those operated before or after 14 days. Type of trauma and pre- and postoperative visual acuities were compared. RESULTS: A contusion type of trauma was more frequent in the late surgery group. Sharp, penetrating injuries were more common in the early vitrectomy group. No significant difference was found though visual acuity was worse in the patients with a contusion component to their injury. Timing of surgery seems to have very little effect on the final outcome. CONCLUSIONS: Final visual acuity is determined by the type and extent of trauma rather than the timing of surgery.

Vitreous management in massive suprachoroidal hemorrhage.

PURPOSE: To establish whether total vitrectomy with posterior hyaloid removal and choroidal hemorrhage drainage posterior sclerotomies improved the outcome of eyes with massive postoperative suprachoroidal hemorrhage (kissing choroidals). METHODS: We reviewed the medical records of five patients with massive suprachoroidal hemorrhage (MSCH) who had received the same medical and surgical management. RESULTS: Three eyes had MSCH secondary to surgery of the anterior segment and two after ocular trauma. All had hemorrhagic choroidal detachment with retinal apposition, producing vitreous changes and adherence of the "kissing" retina. Surgery was delayed one to three weeks to allow liquefaction of the blood clot. All eyes had complete ocular evaluation including ultrasound, and were treated with steroids before surgical treatment. The procedure consisted of anterior chamber fluid infusion, posterior drainage sclerotomies, and primary total pars plana vitrectomy with posterior hyaloid removal. Mean follow-up was 9.4 months. Visual acuity after surgery improved in all eyes from light perception to 20/60. One patient without light perception improved to 20/200. CONCLUSIONS: Total vitrectomy may be indicated in selected cases with MSCH. The successful outcome of these patients comes from the combination of vitrectomy and external drainage.

Complete achromatopsia associated with skeletal anomalies: a new autosomal recessive syndrome.

Complete achromatopsia associated with skeletal anomalies: a new autosomal recessive syndrome: Achromatopsia or rod monochromatism is the complete absence of color discrimination, with an estimated frequency of 1 in 100,000. To date the McKusick Catalogue includes more than 10 entities related to Achromatopsia. This paper describes four Mexican sibs with a stationary rod monochromatism, associated with long fingers and toes, hypothenar and thenar hypoplasia and pes planus, suggesting a new genetic entity probably inherited in an autosomal recessive mode.

The use of dextran after keratoplasty for visualizing the vitreous cavity.

BACKGROUND AND OBJECTIVE: Corneal edema during penetrating keratoplasty (PK) precludes the visualization of the fundus required to perform vitreoretinal surgery. In this study, the clearing of the cornea and fundus visualization with dextran 40 following PK was evaluated. PATIENTS AND METHODS: Topical dextran 40 was used in 12 eyes that underwent uncomplicated PK (phase 1) and in 5 eyes that underwent combined PK with vitreoretinal surgery (phase 2). RESULTS: Clearing of the cornea and visualization of the fundus were observed in all eyes after dextran had been instilled for a mean of 4 and 5 minutes in eyes for phase 1 and 2, respectively. Vitreoretinal surgery could successfully be performed after PK in all eyes of phase 2. CONCLUSION: Topical use of dextran 40 following PK produces enough clearing of the cornea to enable visualization of the fundus for further vitreoretinal procedures after the graft has been sutured.

Subretinal, viscoelastic-assisted, endoscope-guided photothermal ablation of choroidal neovascular membranes by Erbium:YAG laser.

BACKGROUND AND OBJECTIVE: The efficacy of endoscope-guided Erbium:YAG laser, assisted by viscoelastic macular detachment, in subretinal ablation of choroidal neovascular membranes (CNVs) is evaluated. PATIENTS AND METHODS: A high-repetition, midinfrared erbium:YAG laser was used subretinally to ablate CNVs in 2 patients. Ablation followed pars plana vitrectomy and macular retinal detachment using a viscoelastic substance, and was guided by a high resolution endoscope. RESULTS: Visual acuity improved from 6/90 to 6/20, six months after treatment in 1 patient, and from finger counting from 1 meter to 6/30, three months after treatment in the other. The membranes showed no angiographic signs of activity postoperatively. However, a zone of stippled hyperfluorescence appeared in both patients, corresponding with the macular detachment area. This gradually diminished in size in both patients. CONCLUSIONS: The surgical procedure was found effective in our preliminary research. The use of viscoelastic substance and endoscope is felt to contribute to the favorable outcome. The cause and significance of the retinal pigment epithelium damage are yet to be determined.

[Bilateral macular cysts secondary to electric current strike. A case report]. / Quistes maculares bilaterales inducidos por descarga eléctrica. Presentación de un caso.

OBJECTIVE: To report the clinical and tomographic findings in a case of maculopathy secondary to high-tension electric current strike. CASE REPORT: A 27-year-old male refers a reduction in his visual acuity after electric strike. Visual acuity was 0.05 in both eyes. Circular reddish macular lesions measuring 400 micro m in RE and 200 micro m in LE were evident. Optical coherence tomography (OCT) showed intraretinal foveal cysts. At the third month follow-up visit, visual acuity had improved to 0.4 in RE and 0.5 in LE. Clinical and tomographic evaluation showed a reduction of the foveal cysts. DISCUSSION: Electricity affects retinal pigment epithelium and retina by thermal denaturation. OCT provides a conclusive diagnosis.

[Phacoemulsification cataract surgery in vitrectomized eyes]. / Facoemulsificación en ojos post-vitrectomía pars plana.

OBJECTIVE: This study focuses on determining the intra- and post-operative complications stemming from technical difficulties, anatomical aspects, intraoperatory management and visual outcome of post-vitrectomized patients that undergo phacoemulsification. METHOD: In this prospective, longitudinal, observational and descriptive study phacoemulsification was performed in 25 post-vitrectomized eyes that required cataract surgery. Pre-surgical variables: sex, age, affected eye, visual accuity, underlying vitreoretinal disease, anterior segment morphological findings such as: cataract density and pupil alterations. Intrasurgical variables: characteristic of anterior chamber and pupil, phacoemulsification technique and time and the presence of complications. Post-surgical variables were also registered: visual capacity and the presence of complications. Minimum six-month follow-up period. RESULTS: The average interval between pars plana vitrectomy and phacoemulsification was 18.5 months. Silicone oil was the most frequent tamponade used in our serie (44%). Biomicroscopical findings were miosis 28% and posterior synechies 24%. The average interval of phaco time was 2.26 minutes. The intraoperative findings were fluctuations in the anterior chamber depth (24%) and anterior capsular tears (12%). The postoperative complications most frequently seen were posterior capsular plaque (28%) and corneal edema (16%). CONCLUSIONS: Phacoemulsification is a safe and effective technique in eyes after pars plana vitrectomy that require cataract surgery. The surgeon must be aware of the morphological and anatomical findings of these eyes. Visual rehabilitation will generally be determined by the presence of an underlying vitreo-retinal pathology.

[Choroidal melanoma treated with 810 nm diode laser and indocyanine green. A case report]. / Reporte de caso. Melanoma de coroides fotocoagulado con láser de diodo 810 nm coadyuvado con verde de indocianina.

CASE REPORT: A 35 year-old female with a pigmented choroidal tumor in the inferotemporal quadrant, of 3.31 x 7.64 x 5.46 mm. The patient received an intravenous injection of 25 mg of indocyanine green previous to photocoagulation of the lesion with an 810 nm diode laser. After one year follow-up the tumor showed involution demonstrated by clinical and ultrasonographic evaluation. DISCUSSION: Indocyanine green allows maximal absortion of light energy delivered by diode laser, enhancing its action by making the deepest tissues vulnerable to photocoagulation and reducing time of exposure and number of sessions.

[Septo-optic dysplasia (Morsier's syndrome): a case report]. / Displasia septóptica (síndrome de Morsier): a propósito de un caso.

CASE REPORT: We report the case of an infant with septo-optic dysplasia, or Morsier's syndrome, which is a condition affecting the central nervous system that can only be confirmed by means of neuroimaging. This syndrome involves hypoplasia of one or both optic nerves, absence of septum pellucidum, agenesis of the corpus callosum, cerebellar atrophy, ventricular dilatation and brain cysts, together with ectopic, aplastic or hypoplastic neurohypophysis. CONCLUSIONS: It is an infrequent disease and its causation is uncertain, although the predominant hypothesis suggests a genetic foundation. The mechanism by which it is transmitted by inheritance is unknown. The age of the mother is characteristically low; it is known that over half the children affected by this condition were born to mothers below the age of 20. It may be accompanied by liver damage and it is essential to establish a diagnosis and treatment as early as possible. Prognosis is general favourable.

Tomographic findings in traumatic globe evulsion caused by blunt head trauma.

Evulsion of the globe as a result of trauma is a rarity; to the best of our knowledge, only four "evulsions of the globe" have been described. We present the case of a 35-year-old Hispanic woman with traumatic evulsion of the right eye and subarachnoid haemorrhage. The management of brain injury was the priority over preservation of globe structures. We briefly describe the tomographic features of this uncommon situation and the proposed "evulsion" mechanism.

The syndrome of presumed ocular histoplasmosis in Mexico: a preliminary study.

A study to screen for the syndrome of presumed ocular histoplasmosis (SPOH) among native populations from three Mexican states was performed. Two of these states, Guerrero and Querétaro, were selected as histoplasmosis is endemic there, whereas Tlaxcala was considered a control, due to the absence of reported cases. A total of 253 individuals were submitted to ocular fundus examination to obtain evidence of SPOH. A high percentage of positive reactors to histoplasmin skin test (ST) was observed in Guerrero (83%) and Querétaro (53%), whereas in Tlaxcala positive ST were almost absent (2.04%). Only five individuals had retinal lesions, although these lesions were not characteristic of the syndrome. Stimulation of these individual's cells showed different patterns in the histoplasmin-induced lymphocyte transformation response, and two out of five individuals with retinal lesions presented a stimulated response, as well as three controls without lesions. Histocompatibility antigens (HLA) were determined in a sample of each population and no particular allele, including HLA-B7, was found to be related to SPOH as reported in the USA; however, HLA-B22 was found in three individuals who developed pulmonary histoplasmosis. Results do not provide clinical evidence or data on specific HLA risk factors, for the presence of SPOH in the population studied.

Techniques for the preservation of enucleated animal eyes in surgical training.

The main problem with using enucleated animal eyes in surgical training is that they remain fresh for such a short time. We describe a simple technique to preserve them by replacing the aqueous humor and part of the vitreous with another substance. We used 18 eyes of nine dogs (nine for the study and nine as controls), and three substances (2% methylcellulose, silicone oil, and gelatin). The methylcellulose group had the best results (including long-lasting mydriasis), preserving the eyes in which it was used in optimal surgical condition for up to 8 days, twice as long as the eyes in the control group (P less than .005).