Computational method for aid in the diagnosis of sixth optic nerve palsy through digital videos.

The sixth cranial nerve, also known as the abducens nerve, is responsible for controlling the movements of the lateral rectus muscle. Palsies on the sixth nerve prevent some muscles that control eye movements from proper functioning, causing headaches, migraines, blurred vision, vertigo, and double vision. Hence, such palsy should be diagnosed in the early stages to treat it without leaving any sequela. The usual methods for diagnosing the sixth nerve palsy are invasive or depend on expensive equipment, and computer-based methods designed specifically to diagnose the aforementioned palsy were not found until the publication of this work. Therefore, a low-cost, non-invasive method can support or guide the ophthalmologist's diagnosis. In this context, this work presents a computational methodology to aid in diagnosing the sixth nerve palsy using videos to assist ophthalmologists in the diagnostic process, serving as a second opinion. The proposed method uses convolutional neural networks and image processing techniques to track both eyes' movement trajectory during the video. With this trajectory, it is possible to calculate the average velocity (AV) in which each eye moves. Since it is known that paretic eyes move slower than healthy eyes, comparing the AV of both eyes can determine if the eye is healthy or paretic. The results obtained with the proposed method showed that paretic eyes move at least 19.65% slower than healthy ones. This threshold, along with the AV of the movement of the eyes, can help ophthalmologists in their analysis. The proposed method reached 92.64% accuracy in diagnosing the sixth optic nerve palsy (SONP), with a Kappa index of 0.925, which highlights the reliability of the results and gives favorable perspectives for further clinical application.

Surgical planning of horizontal strabismus using multiple output regression tree.

Strabismus is an eye disease that affects about 0.12%-9.86% of the population, which can cause irreversible sensory damage to vision and psychological problems. The most severe cases require surgical intervention, despite other less invasive techniques being available for a more conservative approach. As for surgeries, the treatment goal is to align the eyes to recover binocular vision, which demands knowledge, training, and experience. One of the leading causes of failure is human error during the measurement of deviation. Thus, this work proposes a new method based on the Decision Tree Regressor algorithms to assist in the surgical planning for horizontal strabismus to predict recoil and resection measures in the lateral and medial rectus muscles. In the presented method, two application approaches were taken, being in the form of multiple single target models, one procedure at a time, and the form of one multiple target model or all surgical procedures together. The method's efficiency is indicated by the average difference between the value indicated by the method and the physician's value. In our most accurate model, an average error of 0.66 mm was obtained for all surgical procedures, both for resection and recoil in the indication of the horizontal strabismus surgical planning. The results present the feasibility of using Decision Tree Regressor algorithms to perform the planning of strabismus surgeries, making it possible to predict correction values for surgical procedures based on medical data analysis and exceeding state-of-art.

Transplante autólogo de músculo ocular extrínseco para tratamento cirúrgico de estrabismos sensoriais grandes / Autologous graft of extraocular muscle to treat large angle sensory strabismus

RESUMO Apresenta-se uma série de 13 casos de pacientes com estrabismo sensorial de grande ângulo submetidos à técnica cirúrgica de autotransplante da musculatura ocular extrínseca. Foi realizada a técnica de recuo-ressecção dos músculos retos horizontais, e o retalho retirado do músculo ressecado foi suturado ao músculo enfraquecido como expansor autólogo. Foram avaliadas seis exotropias e sete esotropias, com desvios médios de 75 (70-90) dioptrias prismáticas (DP). Houve melhora significativa dos desvios no pós-operatório, sendo a média pós-operatória de 10,07 dioptrias prismáticas (ortotropia a 35DP). Somente um dos casos evoluiu com inversão do desvio após procedimento cirúrgico.

ABSTRACT We report 13 cases of large angle sensory strabismus treated with autologous graft of extraocular muscle. Recession-resection procedure of the horizontal rectus muscles was performed, and the flap from the resected muscle was sutured to the weakened muscle as an autologous expander. Six cases of exotropia and seven of esotropia, with mean prism diopter deviation of 75 (range of 70-90). There was significant improvement in the postoperative deviation, and mean prism diopter of 10.07 (range of no deviation to 35). Only one patient progressed with inverted misalignment after the surgical procedure.

Treatment of lateral rectus paralysis by transposition of superior rectus to lateral rectus / Tratamento de paralisia de reto lateral pela transposição do reto superior para o reto lateral

ABSTRACT Objective: To evaluate the results of the surgical technique described by Crouch in the correction of lateral rectal paralysis (LR) esotropia. Methods: A study conducted of six patients with VI cranial nerve palsy, with more than three months, and associated contracture of the medial rectus muscle. The causes of paralysis varied in traumatic, congenital and neuropathic. The patients underwent surgical correction, performed with a technique consisting of the instillation of the superior rectus muscle (SR) and its suture above the insertion of the LR muscle, completed with Foster´s suture (suture joining, 8mm of the muscle insertion, the body of the SR and LR). The patients were followed for six months. Results: Five patients presented preoperative deviation between 30 and 50 prismatic diopter (PD), and one patient presented a deviation greater than 100 PD, and therefore, the patient required surgical reintervention due to residual deviation. The other five patients presented postoperative orthoppy, with better visual acuity and no vertical deviations. Conclusion: The surgery proposed by Crouch has been shown to be a good alternative to conventional techniques, such as Carlson-Jampolsky surgery, being a technically simpler procedure with good results.

RESUMO Objetivo: Avaliar resultados da técnica cirúrgica descrita por Crouch na correção de esotropia por paralisia do reto lateral (RL). Métodos: Estudo realizado com seis pacientes diagnosticados com paralisia de IV par craniano, com mais de três meses, e com contratura associada do musculo reto medial. As causas da paralisia variaram em traumática, congênita e neuropática. Os pacientes foram submetidos à correção cirúrgica, realizada com técnica que consiste na desinserção do músculo reto superior (RS) e sua sutura acima da inserção do músculo RL, completada com ponto de Foster (sutura unindo, a 8mm da inserção muscular, o corpo do RS e RL). Os pacientes foram seguidos por seis meses. Resultados: Cinco pacientes apresentaram, no pré-operatório, desvio entre 30 e 50 dioptrias prismáticas (DP), e um paciente apresentava desvio maior que 100DP, sendo, portanto o paciente que necessitou de reintervenção cirúrgica, por desvio residual. Os outros cinco pacientes apresentaram ortotropia no pós-operatório, com melhor da acuidade visual e sem desvios verticais. Conclusão: A cirurgia proposta por Crouch demostrou-se uma boa alternativa às técnicas convencionais, como cirurgia de Carlson-Jampolsky, sendo um procedimento tecnicamente mais simples e com bons resultados.

Identificação e análise das causas responsáveis por reoperações de estrabismo / Identification and analysis of the responsible causes for reoperations of strabismus

RESUMO Introdução: A dificuldade na obtenção de resultados previsíveis é um grande desafio atual da cirurgia corretiva de estrabismo. Os resultados não desejados podem ocorrer em cerca de 51% dos procedimentos e a dificuldade pode ser devida ao fato da cirurgia ser realizada sobre tecidos perioculares bastante moles e com difícil referência para a localização anatômicas das estruturas. Objetivo: Identificar e analisar as principais causas responsáveis por reoperações nos usuários submetidos à cirurgia corretiva de estrabismo, atendidos no Centro de Oftalmológico do HUUFMA, em São Luís-MA. Métodos: Estudo do tipo pesquisa documental retrospectiva dos registros institucionais, por meio da coleta de dados dos prontuários físicos e eletrônicos no sistema ambulatorial interno do HUUFMA. Resultados: A taxa de reoperação analisada foi de 7,31%. Foram operados 89 pacientes menores de 15 anos (72,35%), 23 na faixa de 15 a 30 anos (18,69%) e 11 pacientes maiores de 30 anos (8,94%). A média da idade dos 123 operados foi de 10,32 anos. O sexo feminino foi prevalente na população (58,53%). Conclusão: O desvio Esotrópico (ET) foi o tipo de desvio mais comum no grupo de reoperados. Os resultados inesperados e os maiores desvios foram nos pacientes com relatos de comorbidades e/ou síndromes associadas ao estrabismo, assim como o desvio horizontal congênito (Dhc) foi prevalente entre as queixas apresentadas. A anestesia geral foi mais relatada em pacientes de menor faixa etária. O tempo médio decorrido entre a primeira e a segunda cirurgia foi de 10,54 meses e houve relativa prevalência das subcorreções nas reoperações.

ABSTRACT Introduction: The difficulty in obtaining predictable results is a great challenge on the strabismus surgery field. Procedures can lead to an undesirable development in about 51% of patients, and this difficulty may be due to surgery being perfomed on soft periocular tissues in which anatomical structure can be tricky to locate. Objective: Identify and analyse the main causes of reoperation on strabismus surgery patients treated at Centro Oftamológico do HUUFMA, in São Luís-MA. Methods: A retrospective documental research based on institutional registries, through data collection from physical and eletronic patient records of HUUFMA's ambulatorial internal system. Results: The analysed reoperation rates were in about 7,31%. 89 patients under 15-year-old (72,35%), 23 patients aged between 15 to 30 (18,69%), and 11 patients over the age of 30 (8,94%) were submitted to surgery, with total number of 123 patients and mean age of 10,32 years. Female patients have prevailed in the population (58,53%). Conclusion: Esotropic deviation was the most common deviation in the reoperated group. The unexpected results and greatest deviations occurred on patients with reported comorbidities and/or syndromes associated with strabismus, such as dissociated horizontal deviation (DHD), which was prevalent among the presented complaints. General anesthesia was most reported in lower age patients. The average time elapsed between the first and the second procedure was 10,54 months, and a relative prevalence of the undercorrections occurred on reoperations procedures.

Sutura de tração permanente para tratamento de paralisia congênita de III nervo / Permanent treatment suture for the treatment of congenital nerve palsy of III nerve

Resumo A paralisia do terceiro nervo craniano representa o estrabismo paralítico de tratamento mais complexo e desafiador. Os casos de paralisia completa III par incitam o uso de certas técnicas de cirurgia de estrabismo destinadas a manter o olho voltado para a posição primária do olhar (PPO). Entretanto, as possibilidades terapêuticas são limitadas e complexas e o tratamento cirúrgico tende a hipocorreção e recorrências frequentes a longo prazo.O envolvimento completo e congênito do terceiro nervo craniano requer cirurgias para a exotropia, hipotropia e ptose.Dentre as técnicas cirúrgicas já descritas, optou-se pela realização de uma modificação da técnica cirúrgica de recuo-ressecção, que deu-se em único tempo cirúrgico, sendo suficiente para alcançar o objetivo estético. Este trabalho relata o resultado positivoda manutenção de sutura de tração à carúncula para tratamento cirúrgico de estrabismo paralítico congênito de nervo oculomotor de longa data.

Abstract Paralysis of the third cranial nerve represents the most complex and challenging paralytic squint. The cases of complete III nerve paralysis encourages the use of certain strabismus surgery techniques in order to keep eye in primary position of gaze. However, the therapeutic possibilities are limited and complex and the surgical treatment tends to hypocorrection and frequent recurrences in the long term. Complete and congenital involvement of the third cranial nerve requires surgeries for exotropia, hypotropia and ptosis. Among the surgical techniques already described, we choose a modification of the surgical technique of recession-resection, which occurred in a single surgical time, being suffice to achieve aesthetic objective. This paper reports the positive result of the maintenance of caruncle traction suture as surgical treatment of congenital III nerve paralysis.

Automatic diagnosis of strabismus in digital videos through cover test.

BACKGROUND AND OBJECTIVE: Medical image processing can contribute to the detection and diagnosis of human body anomalies, and it represents an important tool to assist in minimizing the degree of uncertainty of any diagnosis, while providing specialists with an additional source of diagnostic information. Strabismus is an anomaly that affects approximately 4% of the population. Strabismus modifies vision such that the eyes do not properly align, influencing binocular vision and depth perception. Additionally, it results in aesthetic problems, which can be reversed at any age. However, the use of low cost computational resources to assist in the diagnosis and treatment of strabismus is not yet widely available. This work presents a computational methodology to automatically diagnose strabismus through digital videos featuring a cover test using only a workstation computer to process these videos. METHODS: The method proposed was validated in patients with exotropia and consists of eight steps: (1) acquisition, (2) detection of the region surrounding the eyes, (3) identification of the location of the pupil, (4) identification of the location of the limbus, (5) eye movement tracking, (6) detection of the occluder, (7) identification of evidence of the presence of strabismus, and (8) diagnosis. RESULTS: To detect the presence of strabismus, the proposed method achieved a specificity value of 100%, and (2) a sensitivity value of 80%, with 93.33% accuracy in diagnosis of patients with extropia. This procedure was recognized to diagnose strabismus with an accuracy value of 87%, while acknowledging measures lower than 1Δ, and an average error in the deviation measure of 2.57Δ. CONCLUSIONS: We demonstrated the feasibility of using computational resources based on image processing techniques to achieve success in diagnosing strabismus by using the cover test. Despite the promising results the proposed method must be validated in a greater volume of video including other types of strabismus.

Surgical planning for horizontal strabismus using Support Vector Regression.

Strabismus is a pathology which affects about 4% of the population, causing esthetic problems (reversible at any age) and irreversible sensory disorders, altering the vision mechanism. Many techniques can be applied to settle the muscular balance, thus eliminating strabismus. However, when the conservative treatment is not enough, the surgical treatment is adopted, applying recoils or resections to the ocular muscles affected. The factors involved in the surgical strategy in cases of strabismus are complex, demanding both theoretical knowledge and experience from the surgeon. So, the present work proposes a methodology based on Support Vector Regression to help the physician with decision related to horizontal strabismus surgeries. The efficiency of the method at the indication of the surgical plan was evaluated through the average difference between the values that it provided and the values indicated by the specialists. In the planning of medial rectus muscles surgeries, the average error was 0.5mm for recoil and 0.7 for resection. For lateral rectus muscles, the mean error was 0.6 for recoil and 0.8 for resection. The results are promising and prove the feasibility of the use of Support Vector Regression in the indication of strabismus surgeries.

Computer-Aided Methodology for Syndromic Strabismus Diagnosis.

Strabismus is a pathology that affects approximately 4 % of the population, causing aesthetic problems reversible at any age and irreversible sensory alterations that modify the vision mechanism. The Hirschberg test is one type of examination for detecting this pathology. Computer-aided detection/diagnosis is being used with relative success to aid health professionals. Nevertheless, the routine use of high-tech devices for aiding ophthalmological diagnosis and therapy is not a reality within the subspecialty of strabismus. Thus, this work presents a methodology to aid in diagnosis of syndromic strabismus through digital imaging. Two hundred images belonging to 40 patients previously diagnosed by an specialist were tested. The method was demonstrated to be 88 % accurate in esotropias identification (ET), 100 % for exotropias (XT), 80.33 % for hypertropias (HT), and 83.33 % for hypotropias (HoT). The overall average error was 5.6Δ and 3.83Δ for horizontal and vertical deviations, respectively, against the measures presented by the specialist.

Computational methodology for automatic detection of strabismus in digital images through Hirschberg test.

Strabismus is a pathology that affects about 4% of the population, causing aesthetic problems, reversible at any age; however, problems that can also cause irreversible muscular alterations, and alter the vision mechanism. The Hirschberg test is one of the exams used to detect this pathology. The application of high technology resources to help diagnose and treat ophthalmological conditions is, lamentably, not commonly found in the sub-specialty of strabismus. This work presents a methodology for automatic detection of strabismus in digital images through the Hirschberg test. For such, the work was organized into four stages: (1) finding the region of the eyes; (2) determining the precise location of the eyes; (3) locating the limbus and brightness; and (4) identifying strabismus. The methodology has produced results on the range of 100% sensibility, 91.3% specificity and 94% for the correct identification of strabismus, ensuring the efficiency of its geostatistical functions for the extraction of eye texture and for the calculation of the alignment between the eyes on digital images obtained from the Hirschberg test.

Transplante autólogo de musculatura ocular extrínseca: estudo experimental em coelhos / To evaluate the feasibility of autologous extraocular muscle grafting as a sort of muscle expansion surgery

Objetivo: avaliar a viabilidade do uso de segmentos de músculos oculares extrínsecos como expansores de tendões musculares. Métodos: vinte e nove coelhos tiveram seu músculo reto superior esquerdo ressecados e o fragmento de cada um foi transplantado para o reto superior contralateral Os animais foram então examinados em diversos períodos pós-operatórios, até serem sacrificados, para que se avaliasse o desenrolar dessa técnica cirúrgica. Resultados: a secreção e a atrofia foram mínimas em ambos os grupos; já hiperemia predominou no grupo-teste, bem como a fibrose. À tração, os músculos-testes romperam-se mais facilmente. Conclusões: a técnica de transplante autólogo homotópico de músculos oculares extrínsecos provou ser viável para o alongamento muscular. A maior fibrose no grupo-teste não foi tão expressiva a ponto de inviabilizar os efeitos da cirurgia e, apesar dos músculos-testes terem se rompido mais facilmente, a força para rompê-los foi sempre maior do que aquela presente numa contração muscular normal