Prismatic correction in the presence of acutely acquired esotropia with diplopia

Purpose. To analyze changes in binocular vision functions in patients with acutely acquired esotropia after preoperative correction by prisms. Material and methods. The study included 16 patients with acutely acquired esotropia with diplopia. Depending on the tactics of preoperative case management, two groups were distinguished. Eight patients with acutely acquired esotropia of the Bielshowsky type at the age from 12 to 35 years old (mean age, M±sd – 17.5±1.9 years). This group underwent preoperative prismatic correction of diplopia and the deviation angle, as well as eight patients with acutely acquired esotropia of the Bielshowsky type at the age from 12 to 35 years (18.5±1.9 years). Patients in this group underwent surgery without prior prismatic correction. Fresnel prisms were used to select and assign prismatic correction. The patients were monitored dynamically. Results. In the course of treatment 1 group (prismatic correction followed by surgical correction) according to the indicator of Worth's four-dot test color test, revealed a statistically significant increase in the frequency of value of the binocular single vision (p=0.041), the frequency of the presence of stereovision according to the Fly-test (p=0.013), fusion amplitude in the distance by 1.11 times (p=0.033) and near fusion amplitude by 1.15 times (p=0.003). Significant differences between the groups were observed only in the frequency of stereovision presence according to the Fly-test after treatment, which was 2.0 times higher in group 1 (p=0.041). Conclusion. Prismatic correction in combination with surgical treatment had better curative benefits than surgery itself in improving both binocular and stereoscopic visual functions. Key words: acutely acquired esotropia, diplopia, binocular vision, stereoscopic vision, Fresnel prisms

Surgical management of Helveston syndrome (Triad exotropia)

Purpose To evaluate and compare different surgical approaches for the treatment of Helveston syndrome and provide further information for preoperative planning. Methods From February 2008 to December 2018, data of 52 patients with Helveston syndrome were retrospectively reviewed. Different surgical approaches were selected based on the extent of A-pattern exotropia, dissociated vertical deviation (DVD), and both superior oblique muscle overaction (SOOA) with fundus photograph intorsion. Eye position, A-pattern, DVD, superior oblique muscle function, and binocular vision function were evaluated pre- and postoperatively. The average follow-up duration was 20.5 months. Results Nine cases underwent simultaneous horizontal deviation correction with bilateral superior rectus recession, 24 underwent simultaneous horizontal deviation correction with bilateral superior oblique muscle lengthening, and 19 underwent two stages of horizontal deviation correction with superior oblique muscle lengthening, and later bilateral superior rectus recession. A-pattern, DVD, SOOA, and fundus intorsion were all collapsed in all patients postoperatively. Forty-five patients had an orthophoric eye position with considerably aligned ocular movements postoperatively. The total success rate was 86.5%. Postoperatively, eight of the 10 patients with diplopia experienced a recovery of binocular single vision and three had a recovery of rudimentary stereopsis (Titmus 3000–400 s of arc). The compensatory head posture of patients improved significantly postoperatively. Conclusions The surgical planning of Helveston syndrome should be designed based on the degree of the A-pattern, SOOA, DVD, and the intorsion in fundus photographs, and the appropriate approach should be selected to improve patient satisfaction.

Diplopia after Isolated Inferior Orbital Wall Fracture According to the Computed Tomography Findings

Purpose: To investigate the postoperative changes in diplopia and evaluate factors that affect diplopia after isolated inferior orbital wall fracture.Methods: A retrospective study was conducted on 200 patients who underwent reconstruction surgery for isolated inferior orbital wall fracture between March 2001 and December 2020. Diplopia was categorized into peripheral, central, and full-degree types based on the history and binocular single vision. The natural course of diplopia was analyzed pre-operatively and at 1 day, 6 weeks, and 6 months postoperatively. We analyzed the orbital computed tomography images to determine fracture size (small, medium, or large), fracture site (anterior, middle, posterior, or mixed), extraocular muscle (EOM) size (swelling or deformity), EOM site (incarcerated or prolapsed), and EOM tenting.Results: Diplopia was seen in 144 out of 200 patients (72.0%) before surgery; peripheral diplopia was seen in 57 patients (39.6%), central diplopia in 46 (24.3%), and full-degree diplopia in 20 (13.9%). Pre-operative diplopia differed according to the pre-operative limitation of range of motion (LOM) (p < 0.001) and EOM site (p = 0.022). Pre-operative diplopia type differed according to the LOM direction (p = 0.018) and EOM size (p = 0.020). Diplopia persisted in 33 patients (16.5%) 6 months after the surgery. Recovery was faster in patients with peripheral diplopia compared to those with central or full-degree diplopia.Conclusions: The presence of diplopia was associated with the pre-operative LOM and EOM site but the type of diplopia was associated with LOM direction and EOM size. These factors can be used to predict the progression of diplopia in patients with isolated inferior orbital wall fracture.

Evaluation of Fusion and Stereopsis in Anisometropic Patients

Background Binocular vision has many important advantages on monocular vision as it helps in determination of the distance of an object, gives much greater depth of perception, and the ability to have stereopsis and view the world in three dimension (3D). There is an evidence that binocular vision is present in many patients with anisometropia even who have amblyopia but with grades lower than normal. Purpose This study evaluates the effect of anisometropia on BSV functions. Method sixty-four patients above 6 years with anisometropia equal to or more than 2.5D never had their vision corrected either by glasses or refractive surgeries or went on patching treatment, Anisometropic patients were devided into two groups amblyopic group (AA) and non-amblyopic group (NA) were examined for assessing their fusion by Worth four dot test and their stereopsis by fly test (Titmus stereo acuity test) by their best corrective glasses based on their cycloplegic refraction. Results Anisomyopes shows better stereopsis 62% of them and better fusion 65% of them than anisohypropes which had only 8% with good stereopsis and 32% with good fusion. However, antimetropes showed bad fusion and stereopsis as all of the five cases have amblyopia. Only 29.5% of anisomyopes have amblyopia but 68% of anisohypropes have amblyopia. As regard worth four dot test (P &lt; 0.001), as 90.6% of cases with amblyopia had suppressed eye but only 9.4 % of this amblyopic cases had normal fusion. However, in patients without amblyopia 15.6% had suppressed eyes but 84.4% had normal fusion. As regard Titmus test there was statistically significant difference between both groups (P &lt; 0.001), as 100 % of cases with amblyopia had bad stereo acuity but 28.1% of patients without amblyopia had defect in their stereo acuity. Conclusion Fusion and stereopsis as binocular single vision functions were significantly affected in AA patients with best-corrected anisometropic glasses than in NA patients.

Comparison of bilateral medial rectus recession vs recession-resection as surgery for infantile esotropia

Background: Infantile esotropia is misalignment of eyes from bifoveal fixation where surgical correction at an early age usually presents with good outcomes. Aims and Objective: To compare the surgical outcome between bilateral medial rectus recession (BMR) and recession- resection (RR) surgery in infantile esotropia. Materials and Methods: The study was conducted in Lumbini Eye Institute, Bhairahawa, from December 2017 to December 2018. Patients with infantile esotropia who underwent surgical correction were included in the study. Patients were examined pre operatively, and post operatively at day one and third month, where the angle of deviation was measured and the level of binocular single vision (BSV) was assessed. Data was entered and analyzed using the SPSS program. Results: Total 79 patients were included in the study out of which 33 underwent BMR and 46 underwent RR. The mean pre-operative angle by PBCT was 52.58 PD (SD ±15.468) in the BMR group and 47.83 PD (SD ±12.140) in the RR group. Post-operative deviation in the BMR group had angle <35 PD. In the RR group the post-operative deviation observed was <35 PD, whereas 1/46 patients had angle between 35-50 PD. All patients who had residual esotropia (ET) in either the BMR or RR group had a pre-operative angle above 50 PD. Pre-operatively 43% had fusion and rest of them had suppression. Post-operatively 40.5% had fusion, 15.2% had stereopsis and rest of them had suppression or BSV could not be assessed in them. Therefore, there was increase in BSV by 2.5% from fusion to stereopsis. Those who initially showed suppression or in whom the BSV could not be assessed pre-operatively now showed to have fusion or some stereopsis. In total there was 15.2% increase in stereopsis. Conclusion: Though cosmesis has been improved in most patients after strabismus surgery, BSV improvement was insignificant as most surgery was performed after attainment of visual maturity. No significant difference between BMR and RR was found in terms of improvement of angle of deviation and BSV.

Prismatic stage of treatment of patients in acute acquired esotropia with diplopia

Purpose. To analyze changes in binocular vision functions in patients with acutely acquired esotropia after preoperative correction by prisms. Material and methods. The study included 10 patients with acutely acquired esotropia with diplopia. Depending on the tactics of preoperative case management, two groups were distinguished: 1 - 5 patients, this group underwent preoperative prismatic correction of diplopia and the deviation angle, 2 - 5 patients, in this group underwent surgery without prior prismatic correction. Fresnel prisms were used to select and assign prismatic correction. The patients were monitored dynamically. Results. In the course of treatment 1 group according to the indicator of Worth's four-dot test color test, revealed a statistically significant increase in the frequency of value of the binocular single vision (p=0.041), the frequency of the presence of stereovision according to the Fly-test (p=0.013). Conclusion. Prismatic correction in combination with surgical treatment had better curative benefits than surgery itself in improving binocular and stereoscopic visual functions. Key words: acutely acquired esotropia, binocular vision, Fresnel prisms.

Monocular Diplopia: An Optical Correction Modality

Post-surgical or traumatic corectopia is among the rare causes of monocular diplopia. A 26-years-old student presented to the Institute with a complaint of monocular double vision in the left eye. He had a penetrating ocular injury in the left eye and subsequently, undergone for multiple ocular surgeries. Following the final intraocular lens implantation, he experienced a monocular double vision in his left eye. Upon contact lens clinic presentation, visual acuities were 20/20 in the right and 20/320 in the left eye (improved to 20/25 with pinhole). Slit-lamp examination on the left eye revealed scarring in the superior nasal quadrant of the cornea, irregular mid-dilated pupil with exposed aphakic and pseudophakic portions. A range of different optical management options were implemented to eliminate monocular diplopia and to correct refractive error. Finally, a combination of prosthetic soft contact lens and spectacle correction was able to remove diplopia and provide binocular single vision.

Elucidation of the mechanism of stereoscopic insufficiency and mental and physical fatigue caused by near vision - research and development on recovery methods

Increased exposure to video terminal display (VDT) devices is part of 21st century life, but the consequences of this are myopia and abnormal binocular single vision, which present as mental and physical fatigue. A collaborative team is investigating the mechanism underlying abnormal binocular single vision and developing a methodology for recovery. Associate Professor Satoshi Takahashi, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Japan, and the tem are looking into the interaction between binocular stereoscopic clues and monocular stereoscopic clues in binocular single vision. Their goal is to explore the effects on depth judgment and the researchers will use their findings to construct a training system that enables correct depth judgement in binocular single vision. This extensive research will involve conducting inspections on a large number of participants and developing effective methods for inspecting binocular stereoscopic function. This will lead to the development of a device that can easily diagnose the binocular stereoscopic function of the participants and enable early detection. Takahashi and the team will also explore training methods that can help individuals recover lost eye function and encourage behavioural changes that will reduce incidence of eye problems.

Connection Between Indications of Binocular Single Vision Anomalies and Punctum Proximum Among University Students of India

Purpose: To evaluate the connection between indications of binocular single vision anomalies and punctum proximum among university students of India. Method: This was a cross-sectional prospective study of 90 randomly selected subjects age ranging from18-26 years. The subjects were paramedical students studying in A.J Institute of medical science, Mangalore. After going through a detailed ophthalmic examination including standard binocular vision examination if the subject met the inclusion criteria, according to CISS questionnaire students were divided into two groups (asymptomatic and symptomatic).NPC was measured with RAF rule asking the subject to focus on a single vertical line as a target on the rule. After data collection, data were analyzed in an excel spreadsheet using, paired t-test. Result: NPC break and recovery value are more in symptomatic (9.479±0.3653 and 10.845±0.4865) subjects than asymptomatic subjects (6.033±1.3966 and 7.598±1.3921), with a highly significant difference between the two groups. Conclusion: Strong relationship was found between anomalies binocular single vision symptoms and punctum proximum (PP). The assurance of PP is useful to separate the indicative of symptomatic subjects from the asymptomatic. PP was more in symptomatic groups when compared to asymptomatic groups.