Prism Diopters Research Articles

Plication or resection combined with antagonist recession in horizontal strabismus.

Strengthening of extraocular muscles is a conventional procedure in the management of strabismus. Plication may be an alternative strengthening technique, and is less invasive than resection. This study compared plication and resection, each combined with antagonist muscle recession, in terms of success rates and changes in ocular deviation in the management of horizontal strabismus. This retrospective study recruited individuals with horizontal strabismus who underwent plication (group I) or resection (group II) coupled with antagonist muscle recession. All participants underwent a detailed baseline eye and ocular motility evaluation. Demographic and clinical data were collected, including age, sex, type of preoperative strabismus (exotropia or esotropia), baseline visual acuity, mean follow-up duration, laterality of operated eye, surgical doses of correction (resection, plication, or recession) in millimeters, preoperative strabismus magnitude in prism diopters (PD), and postoperative strabismus magnitude in PD. Successful postoperative deviation was defined as ≤10 PD. At final follow-up, the success rates and degrees of change in angle of deviation were recorded. Forty-four patients were enrolled: 19 patients in group I (plication) and 25 patients in group II (resection). The groups had comparable ages, sex ratios, types of strabismus, and preoperative and postoperative angles of deviation (all P > 0.05). Despite comparable success rates between groups (73.7% in group I versus 64.0% in group II, P > 0.05), the difference (9.7%) was marginally close to the predefined clinically meaningful difference of 10%. In the esotropia subgroup, despite comparable alignment between the plication and resection groups (P > 0.05), the difference was clinically meaningful (17.3%), and both groups had higher success rates in the esotropia subtype than in the exotropia subtype. The rate of over- or undercorrection was not statistically or clinically different in the total and in each subtype of strabismus (all P > 0.05). Success rates for unilateral and bilateral cases were similar between groups (both P > 0.05). Changes in angle of deviation were similar for individuals with esotropia and exotropia between groups (both P > 0.05). In esotropic and exotropic strabismus, plication and resection procedures combined with antagonist recession were similarly effective. However, further randomized, large-scale, longitudinal studies with clinical and subjective evaluations could comitant strabismus, squint, esotropias, primary exotropia, exodeviation, plication, resection, recession, amblyopias.

Heterophoria in multiple sclerosis patients: a proof of principle cross-sectional study.

The pathophysiology of multiple sclerosis (MS) involves inflammatory neurodegeneration in the brainstem, cerebellum, and retina. The clinical relevance of oculomotor involvement in MS, however, remains uncertain. In this cross-sectional study, we evaluated heterophoria as a (sub)clinical tool in 54 MS patients and 55 age-matched healthy controls (HCs). We quantified heterophoria in prism diopters for distance and near range with orthoptic examination. Our primary outcome was high degrees of horizontal heterophoria (HDHH) defined as measurements beyond ±2 standard deviations from the mean prism diopter of heterophoria of our HCs. More than one-third (37%, n=20/54) of MS patients but only 11% (n=6/55) of HCs were classified as HDHH [distance, MS=9% (n=5/54) versus HC=6% (n=3/55); near, MS=19% (n=10/54) versus HC=5% (n=3/55)]. Our MS patients presented more combined vertical and horizontal deviations at near range [MS 19% (n=10/54) versus for HC 7% (n=4/55)]. We observed the combination of HDHH both at distance and at near testing in 9% (n=5/54) of MS patients but not at all in HCs (n=0/55). Despite the high prevalence of heterophoria, HDHH may be an additional (sub)clinical tool of subclinical involvement in MS. Thus, orthoptic examination may be an additional tool to improve MS diagnostic procedures.

Low vision rehabilitation program in patients with myopic macular degeneration: A case series

Aims/Purpose: Patients with pathologic myopia are at risk of developing myopic macular degeneration (MMD) that leads to vision loss and irreversible visual impairment. Working age and elderly populations are affected by loss of productivity and quality of life. Low vision services should offer specialized training programs to help patients to overcome the difficulties in daily living activities. The aim of this study was to describe the results of a low vision rehabilitation program (LVR) in patients with MMD.Methods: Five patients (8 eyes) with MMD were included in the LVR at an ophthalmology clinic in Portugal. The LVR had a length of 8 weeks and was divided into two phases. The first phase included the use of prisms for image relocation (IR) with eccentric viewing exercises to stabilize the preferred retinal locus. At the second phase, training with low vision aids was performed. Best corrected visual acuity (BCVA) for distance and near, contrast sensitivity (CS), reading speed (RS) and face recognition were compared pre and post rehabilitation.Results: Patients had MMD category 3 (patchy chorioretinal atrophy) and 4 (macular atrophy) in the best eye. Vision impairment varied between mild and severe. The IR prisms varied from 2 to 6 prism dioptres. Electronic devices were the most prescribed low vision aids. At the end of the LVR, the outcomes were good in all patients. BCVA increased by two to three lines, CS increased by two to four lines, RS increased by 40 to 60 words per minute and face recognition improved in all patients.Conclusions: The LVR was beneficial, improving visual function and functional vision outcomes in all patients. LVR programs seem to be effective in patients with pathologic myopia. Longitudinal studies are necessary to ascertain the long‐term efficacy of LVR.

Surgical Outcomes and Factors Related to Their Success of Infantile Esotropia in a Tertiary Hospital: A Retrospective Study.

This study aims to evaluate the outcomes of surgical intervention for infantile esotropia at a tertiary care hospital. Medical records of patients with esotropia who underwent surgical correction at our tertiary hospital between January 2013 and June 2023 were retrospectively analyzed. Patient demographics, preoperative and postoperative ocular alignment, surgical techniques employed, complications or reoperations, and factors related to successful surgery were analyzed. The study included 77 participants with an average age of 9.54 ± 10.87 years at the time of surgery. Postoperatively, 71.4% (55/77) patients achieved successful alignment, which was defined as an ocular deviation of ≤10 prism diopters (PD), at the final follow-up. The average follow-up period was 12 months, during which no complications were noted. Reoperation was required in 15.6% (12/77) patients. Multivariate logistic regression revealed that having a smaller preoperative deviation of <50 PD positively influenced the success of strabismus surgery (adjusted odds ratio, 7.13; 95% CI, 2.04-24.86). The surgical correction of infantile esotropia in a tertiary care setting yielded favorable alignment outcomes in most cases, with no complications and a low reoperation rate. A preoperative angle of <50 PD emerged as a prognostic factor for successful surgical outcomes in this population. Further studies with longer follow-up periods are recommended to evaluate the long-term stability of these outcomes and identify additional influencing factors.

Botulinum toxin augmented surgery versus conventional surgery in the management of large-angle concomitant esotropia: A randomized clinical trial.

The surgical management of large-angle concomitant esotropia is challenging with high reoperation rates. This study aims to assess the effectiveness and safety of intraoperative botulinum toxin A (BTA) augmentation compared to surgery alone in large angle concomitant esotropia. This is a prospective randomized interventional study. Patients with large angle concomitant esotropia (≥55 prism diopter [PD]) were randomly allocated to either surgery only (Group I) or BTA augmented surgery (Group II). The surgical effect in PD/mm was calculated and compared between the study groups at all follow up intervals. Treatment was considered successful if the patients had orthotropia ± 10 PD at their final examinations. A total of 23 patients were included in the study, 11 in Group I and 12 in group II. The surgical effect was significantly greater in Group II compared to Group I at all follow up durations. The 1-year surgical effect was 32.5% greater in Group II compared to Group I (5.99 ± 0.69 vs. 4.52 ± 0.91 PD/mm, respectively, P = 0.001). The success rate was greater for Group II compared to Group I (75% vs. 63.64%, respectively), but this difference was not statistically significant (P = 0.901). Botulinum toxin augmented surgery is a good alternative to surgery alone in the treatment of large angle concomitant esotropia. BTA injection exerts a significant augmentation effect on medial rectus muscle recessions.

Unusual outcome of strabismus surgery in a case of Apert syndrome: A case report

Abstract Apert syndrome (AS) is a form of acrocephalosyndactyly, which is characterized by craniosynostosis, midfacial hypoplasia, and symmetrical syndactyly of the hands and feet. A 3-year-old female with craniosynostosis, high-arched palate, syndactyly, strabismus, and diagnosed as a case of Apert syndrome was brought to the outpatient department. Strabismus evaluation revealed 35 prism diopters of left convergent squint. Magnetic resonance imaging of the brain and orbit revealed hypoplastic extraocular muscles. A plan to carry out a bilateral medial rectus recession was made. However, intraoperatively, normal-sized muscles were found and the plan was modified to carry out only a left eye medial rectus recession of 5.5 mm. The patient was orthophoric postoperatively, indicating the unusual postoperative outcome in such a case. This report aimed to underline the challenges of managing a case of strabismus and the variable postoperative outcomes encountered in a case of Apert syndrome.

Factors Affecting Outcomes of Stereoacuity in Partially Refractive Accommodative Esotropia with Motor Success Treated by Preoperative Prism Correction and Surgery.

Favorable stereoacuity does not develop in all patients with partially refractive accommodative esotropia (PRAET) successfully aligned, and there have been few previous reports on the factors influencing stereoacuity outcomes in patients with PRAET treated with prismatic correction (PPC) and/or surgery. This study aimed to analyze factors affecting stereoacuity outcomes in patients of PRAET treated with PPC and surgery. Retrospective study. Sixty-six patients with alignment within 10 prism diopters at final visit with PPC and surgery were included. According to the final stereoacuity, patients were grouped into the fine group (≤60 arcsec (")), the coarse group (60 "<, 3000" ≤), and absent stereoacuity group. Preoperative patient characteristics were compared among three groups using analysis of variance. Comparison of final stereoacuity among three groups based on age at onset (very early: ≤6 months; early: >6 months, ≤2 years; late: >2 years) was carried out with the Kruskal-Wallis test. There were no differences in ages at initial PPC, at surgery, at final visit, durations of misalignment, of PPC, or after surgery; however, significant differences in ages at onset and initial visit were found. Age at onset in the absent group was significantly earlier than those of the fine and the coarse groups (p < 0.001 and p < 0.001, respectively). Moreover, of the 25 patients with age at onset >2 years, 18 patients (72%) showed fine or coarse stereoacuity (p < 0.001). Although stereoacuity outcomes in patients with early onset were poor despite of the finally successful alignments obtained with PPC and surgery, fine stereoacuity and coarse stereoacuity were obtained in 24% and 44% of patients with age at onset >2 years.

Abducens Nerve Palsy Caused by Cavernous Sinus Meningioma Mimicking Tolosa-Hunt Syndrome

Purpose: To report a case of abducens nerve palsy caused by cavernous sinus meningioma mimicking Tolosa-Hunt syndrome (THS).Case summary: A 59-year-female visited to the ophthalmic department for sudden onset of horizontal diplopia for 20 days. The extraocular examination showed 10 prism diopters (PD) esotropia at distant fixation and ortho at near fixation without definitive abduction limitation. At 2 months of follow-up, she showed the 25 PD left esotropia with abduction limitation of the left eye. The ocular pain and headache were newly developed. Magnetic resonance imaging (MRI) with contrast was performed and revealed the enlargement and enhancement of left cavernous sinus. THS was suspected and high dose steroid treatment was performed. The ocular findings and headache were improved after treatment. These symptoms showed waxing and waning with steroid tapering during follow-up. The follow-up MRI showed no definitive improvement of cavernous sinus lesion compared with previous study. The cavernous sinus meningioma was considered. There was no improvement of ocular motility findings during follow-up and the strabismus surgery was performed.Conclusions: The abducens nerve palsy with headache can occur caused by cavernous sinus meningioma. It may be difficult to differentiate it from THS in certain cases.

Botulinum Toxin Injection for the Treatment of Third, Fourth, and Sixth Nerve Palsy: A Meta-Analysis.

The efficacy of botulinum toxin injection for the treatment of third, fourth, and sixth nerve palsy was evaluated. PubMed, Scopus, EMBASE, Web of Science, and Google Scholar databases were searched. Data about the duration of palsy (acute vs chronic), cause of the palsy, type of toxin used, mean dose, and other background characteristics were collected. Outcome variables were success rate (defined by alleviation of diplopia or reduction in eye deviation) and standardized mean difference of prism diopter and abduction deficit before and after injection. The Joanna Briggs Institute checklist was implemented for the risk of bias assessment. The analysis included 38 articles, comprising 643 patients. The overall treatment success rate in acute and chronic nerve palsy was 79% and 33%, respectively. The success rate was not significantly different between different subgroups of age, type of botulinum toxin, pre-injection prism diopter, etiology of the palsy, duration of follow-up, and mean dose of botulinum toxin injection. However, in both acute and chronic palsy, diabetes etiology was accompanied by the highest success rate. Overall symptomatic response to botulinum injection was 84% (95% CI: 67% to 96%), whereas functional response was observed in 64% (95% CI: 47% to 79%) of the patients. The odds ratio for the success rate of treatment of palsies with botulinum toxin versus expectant management was 2.67 (95% CI: 1.12 to 6.36) for acute palsy and 0.87 (95% CI: 0.17 to 4.42) for chronic palsy. Botulinum toxin can be used for the treatment of acute third, fourth, and sixth nerve palsy, especially in patients with acute palsy and more severe tropia. [J Pediatr Ophthalmol Strabismus. 2024;61(3):160-171.].

Surgical Outcomes in Patients with Intermittent Exotropia with Siblings Who Underwent Surgery by the Same Surgeon

Purpose: We evaluated surgical outcomes in pediatric patients with intermittent exotropia with and without a family history of exotropia surgery performed by the same surgeon.Methods: We conducted a retrospective review of the medical records of pediatric patients aged ≤ 18 years who underwent surgery for intermittent exotropia between September 2015 and December 2021. We compared surgical outcomes between patients with and without a family history of exotropia surgery performed using 1:1 propensity score matching. A successful surgical outcome was defined as achieving alignment between an exodeviation of 10 prism diopters (PD) and an esodeviation of 4 PD.Results: This study included 60 patients with a family history of exotropia surgery and 60 matched controls with no such history. Notably, the log-rank test revealed no significant differences in surgical outcomes between the two groups (&lt;i&gt;p&lt;/i&gt; = 0.622). Furthermore, clinical characteristics, including the onset of exotropia, degree of ocular deviation, and age at surgery, were similar between first- and second-born siblings. Furthermore, no significant differences were observed in surgical outcomes between the two groups (&lt;i&gt;p&lt;/i&gt;= 0.540).Conclusions: Patients with a family history of exotropia surgery do not exhibit significantly different surgical outcomes compared to those with no such history. In addition, no significant differences were observed in surgical outcomes between the first- and second-born siblings.

Efficacy of anti-suppression therapy in improving binocular vision in children with small-angle Esotropia

PurposeTo evaluate the efficacy of anti-suppression exercises in children with small-angle esotropia in achieving binocular vision. MethodsA retrospective review of patients aged 3–8 years who underwent anti-suppression exercises for either monocular or alternate suppression between January 2016 and December 2021 was conducted. Patients with esotropia less than 15 prism diopters (PD) and visual acuity ≥ 6/12 were included. Patients with previous intra-ocular surgery or less than three-month follow-up were excluded. Success was defined as the development of binocular single vision (BSV) for distance, near, or both (measured clinically with either the 4 prism base out test or Worth four dot test) and maintained at two consecutive visits. Qualified success was defined as the presence of diplopia response for both distance and near. Additionally, improvement in near stereo acuity was measured using the Stereo Fly test. ResultsEighteen patients with a mean age of 5.4 ± 1.38 years (range 3–8 years) at the time of initiation of exercises were included in the study. The male female ratio was 10:8. The mean best corrected visual acuity was 0.18 LogMAR unit(s) and the mean spherical equivalent was +3.8 ± 0.14 diopters (D). The etiology of the esotropia was fully accommodative refractive esotropia (8), microtropia (1), post–operative infantile esotropia (4), partially accommodative esotropia (1), and post-operative partially accommodative esotropia (4). Patients received either office-based, home-based, or both modes of treatment for an average duration of 4.8 months (range 3–8). After therapy, BSV was achieved for either distance or near in 66.6 % of patients (95 % CI = 40.03–93.31 %). Binocular single vision for both distance and near was seen in 50 % of children. Qualified success was observed in 38.46% of patients. Persistence of suppression was observed in one patient (5.5 %). Near stereopsis improved to 200 s of arc or more in 60% of the patients. The mean esotropia reduced from 5.7 ± 4.0 PD for distance and 6.2 ± 4.66 PD for near to 2.7 ± 2.4 PD and 3.38 ± 4.7 PD respectively, at the last follow-up (p-value 0.004 and 0.006). Failure of therapy was noticed after six months of follow-up in the child with infantile esotropia. ConclusionAnti-suppression exercises may be beneficial to improve binocular vision functions in children with small-angle esotropias of variable etiologies. Recurrence of suppression after cessation of therapy is possible, warranting regular follow up.

Acquired comitant esotropias – comparison of surgical outcomes of accommodative vs non-accommodative types

ABSTRACT Purpose: To compare the motor and sensory outcomes of strabismus surgery and the factors affecting surgical success in acquired acute non-accomodative esotropia (ANAET) and partially accommodative refractive esotropia (pARET). Methods: A retrospective chart review of patients with ANAET and pARET who underwent unilateral or bilateral horizontal rectus muscle surgery between January 2020 and December 2021 was conducted. Patients with postoperative follow-up of at least six weeks were included. Patients with pattern deviation, lateral incomitance, and near-distance disparity were excluded. Motor success was defined as a postoperative deviation within eight prism diopters of orthophoria. Sensory success was defined as presence of binocular single vision (BSV) for both distance and near (Worth four dot test). The effect of factors like age at onset, age at surgery, amblyopia before surgery, duration of squint before treatment, presence or absence and magnitude of vertical deviation, preoperative angle of deviation, and spherical equivalent on the motor and sensory success in each group were analyzed and compared. Results: 38 patients with ANAET and 33 patients with pARET were included. The mean age of onset of esotropia was 8.55 ± 4.65 years and 4.39 ± 2.27 years (p < .001) and the mean age at surgery was 10.62 ± 4.99 years and 7.89 ± 2.84 years (p = .006) in the ANAET and the pARET group respectively. The mean duration of the final follow-up was 38.51 weeks in the ANAET and 48.68 weeks in the pARET group (p = .089). Patients were successfully aligned for both distance and near in 81.5% of patients in the ANAET and 78.9% of patients in the pARET group at the final follow-up (p. 0.775). A BSV for both distance and near at the final follow-up was seen in 81.2% vs 66.6% of patients in the ANAET and the pARET group respectively (p = .25). A good near stereoacuity (<120 arcsecs) was seen in 60.6% and 41.9% of the ANAET and the pARET groups respectively (p = .175). The percentage of patients in the ANAET group who had orthophoria, any esodeviation, and any exodeviation for distance at the final follow-up was 63.1%, 34.2% and, 2.6%. The percentage of patients in the pARET group in similar categories was 36.3%, 42.4% and, 21.2%. None of the demographic and preoperative factors were found to affect the surgical outcomes in the two groups. Conclusions: The motor and sensory outcomes were similar in the two groups. A higher proportion of ANAET patients remained orthophoric during the follow-up. The patients in the pARET group showed a tendency toward exodrift.

Clinical Characteristics and Outcomes after Augmented Medial Rectus Muscle Recession in Patients with Acute Acquired Comitant Esotropia

Purpose: To analyze the clinical characteristics of patients with acute acquired comitant esotropia, evaluate the outcomes of augmented medial rectus muscle recession, and propose indicators for determining the appropriate surgical dosage.Methods: Data of patients with acute acquired esotropia who underwent medial rectus recession between 2016 and 2022 were retrospectively analyzed. The amount of medial rectus muscle recession was 1-2 mm greater than for other types of esotropia. Surgical success was assessed by reference to the angle of deviation and diplopia status 6 months after surgery. We investigated the amount of additional recession required for favorable surgical outcomes, the characteristics of groups that required augmentation, and changes in surgical amount according to the deviation angle.Results: A total of 38 patients were included; the average refractive error was -3.79 ± 3.11 diopters (D). Patient age at the time of surgery was 25.6 ± 18.2 years and the preoperative deviation angle was 38.1 ± 11.5 prism diopters (PD). The amount of medial rectus muscle recession was 6.25 ± 1.4 mm, i.e., 1.2 ± 1.0 mm greater than during other surgeries. The average augmentation was 24.1 ± 18.8%. The motor surgical success rate was 92.1% and the sensory success rate was 97.4%. The required augmentation was 26.9% for those with angles of deviation &lt; 30 PD, 25.5% for patients with angles between 30 and 40 PD, and 20.0% for those with angles &gt; 40 PD. Patients who required augmentation &gt; 25% were older, and the surgical effect was greater as the angle of deviation increased.Conclusions: To ensure successful surgical outcomes of patients with acute acquired comitant esotropia, it is essential to increase the amount of medial rectus recession compared to that during other surgeries; the average augmentation was 24% in this study.

The Comparison of Long-term Surgical Results for Sensory Exotropia and Comitant Exotropia

Purpose: To compare the long-term surgical outcomes of patients with sensory and concomitant exotropia and to define the factors associated with successful surgical outcomes in those with sensory exotropia.Methods: The medical records of patients with sensory exotropia who underwent operations and were followed-up for at least 2 years were retrospectively reviewed. We enrolled patients exhibiting only best-corrected visual acuities ≤ 20/100 of the operated eyes. Surgical success was defined as a final distance deviation &lt; 10 prism diopters (PD) with the eye in the primary position. Twenty-eight patients operated upon to treat sensory exotropia and 28 who underwent operations to treat concomitant exotropia who did not differ in terms of the gaze deviation angle were matched in terms of age, sex, and the preoperative distance and near distributions; their surgical outcomes were compared. Factors affecting such outcomes were identified using a multivariate Cox’s proportional hazards model.Results: The mean follow-up times were 91.7 ± 45.8 months in the sensory and 42.6 ± 27.7 months in the concomitant exotropia groups. The cumulative probabilities of surgical success 2 years after surgery were 74.5% in the sensory and 74.4% in the intermittent exotropia groups, thus not significantly different (&lt;i&gt;p&lt;/i&gt; = 0.988). The Cox’s proportional hazard model showed that a greater difference between the preoperative distant and near deviations was associated with recurrence (&lt;i&gt;p&lt;/i&gt; = 0.091).Conclusions: The long-term surgical outcomes of patients with sensory and concomitant exotropia were comparable. A high-level near-distance disparity increased the risk of recurrence.

Binocular vision measurements with a new online digital platform: comparison with conventional clinical measures

ABSTRACT Clinical relevance New digital systems are being developed for evaluating different aspects of the visual function, such as binocularity, and it is important to know their real performance in clinical practice in order to use them appropriately. Background The aim was to compare binocular vision measures obtained with an online digital platform with conventional measures using prisms and printed tests. Methods Prospective study enrolling 49 healthy patients (mean age: 35.5 ± 13.6 years). A complete visual examination was performed including measurement of near phoria (cover test), negative fusional vergence (NFV) and positive fusional vergence (PFV) ranges (prism bar), and stereopsis (24 patients Randot Stereo Test and 25 patients TNO Random Dot Test 19th edition). These same parameters were also measured with the Bynocs system (Kanohi Eye Pvt Ltd). Bland – Altman plots were used to analyse the agreement between methods. Results Digital measurement of near phoria was significantly lower than that obtained with the cover test, with a median difference (MD) of 4.71 (−0.07–20.07) prism dioptres (pd) (p < 0.001). No significant differences were found between Bynocs and prism bar methods in NFV break (MD 2.00, range −21–26 pd, p = 0.584) and recovery points (MD 0.00, range −16–24 pd, p = .571). Near PFV were significantly lower with Bynocs (break: MD −9.00, range −38–12 pd; recovery: MD −14.00, range −43–20 pd; p < 0.001). Bynocs stereoacuity threshold was significantly lower than that obtained with TNO (p = 0.004), but significantly higher compared to Randot (p < 0.001). Large and clinically relevant confidence intervals for the comparison between digital and conventional measures were detected in Passing-Bablok analysis. Conclusions Digital measures of near phoria, NFV, PFV, and stereopsis with the Bynocs platform cannot be used interchangeably with conventional measures. The normal ranges of normality for this new tool are defined.

Postoperative outcomes for unilateral congenital trochlear nerve palsy: A retrospective cohort study

Congenital trochlear nerve palsy is the most common cause of vertical strabismus. The goal of this study was to investigate surgical outcomes after superior oblique tendon plication with or without inferior oblique recession in children and adults with unilateral congenital trochlear nerve palsy. Data and outcomes were collected in patients with a diagnosis of unilateral congenital superior oblique palsy during a retrospective single-center study conducted at the University Hospital of Tours. A reproducible, standard ophthalmological and oculomotor examination was performed pre- and postoperatively at 1 year, including presence or absence of diplopia, vertical and horizontal deviations, and compensatory head posture. Surgical success, defined as an endpoint including absence of diplopia in primary position, absence of head tilt, and vertical deviation at distance fixation<5 prism diopters (PD), was analyzed. A total of fifty-seven patients (median [IQR] age of 11 years [5-42]) were analyzed. Patients experienced a significant reduction in vertical distance and near deviations (p<0.001), compensatory head tilt (p<0.001), and diplopia after surgery (p<0.001). Surgical success was higher in adults (17/24, 70.8%) than in children (15/33, 45.5%), although this did not reach statistical significance (p=0.0657). This study suggests that plication of the superior oblique muscle tendon, with or without recession of the inferior oblique muscle, can be effective in treating unilateral congenital trochlear nerve palsy. Further studies are necessary to compare surgical procedures and investigate their efficacy in adults compared to children in the short and long term.

Comparative Analysis of Strabismus Measurement Using a Video Oculagraphy System and Alternate Prism Cover Test.

The aim of the study was to compare distance vision measurements obtained with video oculography (VOG) and an alternate prism cover test (APCT). Single-center, retrospective, and cross-sectional. Eighty-seven subjects with strabismus were included. All patients underwent an optometric examination. The measurement of strabismus in distance vision was performed with the best optical correction using the APCT and the VOG GazeLab. Subjects were divided according to the type of strabismus; 41 were esotropic and 46 were exotropic. The general comparison of APCT and VOG showed a mean difference of 0.60±2.74 prism diopters (Δ), not observing statistical differences between both methods ( P =0.059) and presenting a correlation of 0.976 ( P <0.001). Using APCT, the mean amount of esotropia for the group was 18.31±11.64 Δ and that of exotropia was 19.62±8.80 Δ. Compared with the VOG, the mean value of esotropia for the group was 18.65±11.65 Δ and that of exotropia was 19.48±8.62 Δ. The means are statistically different for the esotropia group ( P =0.005) but not for the exotropia group ( P =0.318). There was a high direct correlation between the methods of measurement for both the esotropic ( R =0.980; P <0.001) and exotropic patients ( R =0.975; P <0.001). Bland-Altman analysis shows a mean difference of 1.37±2.76 Δ for the esotropia patients and 0.31±2.66 Δ for the exotropic patients, respectively. This study demonstrated comparable results in measuring strabismus between VOG and APTC for esotropia and exotropia, with an excellent correlation between both methods and good agreement, especially in subjects with exotropia.

Preoperative visual function characteristics having an effect on the success of exotropia surgery

Background: There are individual reports on the effect of some preoperative characteristics of visual functions (like convergence, angle of deviation, presence of fusion and type of binocular vision) on the success of exotropia surgery. To date, however, it has not been established what are the major diagnosis-related prognostic factors for the success of surgery for exotropia. Purpose: To identify the preoperative characteristics of visual functions which have an effect on the success of surgery for exotropia. Material and Methods: Of the 59 exotropes (age range, 10 to 21 years) included in this study, 33 had basic constant exotropia (group 1) and 26, intermittent exotropia (group 2). Patients underwent an ophthalmological and ortoptic examination of the motor and sensory systems of the eye. Patients with surgery success (postoperative orthotropes) were compared to those who had a residual exotropia of more than 10 prism diopters (PD) postoperatively in terms of the preoperative accommodative convergence–accommodation (AC/A) ratio, near point of convergence (NPC), distance stereopsis and near stereoacuity threshold. Results: Our analysis of the preoperative NPC, AC/A ratio and stereopsis for the group with postoperative orthotropic alignment and the group with postoperative exotropic alignment found preoperative close to normal values of AC/A ratio (4.0 ± 1.65 PD/D), NPC (8.03 ± 3.02 cm), the presence of distance stereopsis and near stereopsis (passing the 200 second of arc image on the Lang II stereo card) and the absence of medial rectus hypofunction of hyperfunction in 83.05% of patients of the former group. Conclusion: Preoperative close to normal values of AC/A ratio (4.0 ± 1.65 PD/D), NPC (8.03 ± 3.02 cm), the presence of distance stereopsis and near stereopsis (passing the 200 second of arc image on the Lang II stereo card) and the absence of medial rectus hypofunction of hyperfunction can be the factors favoring the success of exotropia surgery.

Surgical outcomes of bilateral lateral rectus recession versus unilateral recession and resection for the divergence excess type of intermittent exotropia.

To compare bilateral lateral rectus recession (BLR) with unilateral recession and resection (RR) for divergence excess intermittent exotropia (IXT). Retrospective analysis of 66 patients with divergence excess IXT who underwent either BLR or RR from January 2013 to December 2020 was conducted. Data on demographics, pre- and postoperative deviations, fusion, stereopsis, control, and accommodative convergence/accommodation ratio were collected. Success was defined as esodeviation ≤5 PD (prism diopter) to exodeviation ≤10 PD with a follow-up time of at least 8.0 ± 2.0 weeks. BLR (42 cases) and RR (24 cases) groups had the same success rate (83.3%, P = 0.688) and similar reduced postoperative deviations both in distance and at near (P > 0.05). Near-distance disparity decreased significantly in both groups (P = 0.000) with no intergroup difference (P = 0.193). BLR and RR were equally effective for divergence excess IXT with comparable outcomes of both distance and near deviations.

A Novel Technique Using Paretic Superior Rectus as a Globe Suspender for Monocular Elevation Deficiency.

Surgical innovations in strabismus provide opportunities to improve visual function, eye alignment, and cosmesis in rare pediatric ophthalmological conditions. Monocular elevation deficiency is a rare and multifactorial disease in which the affected eye is equally limited in terms of elevation during adduction and abduction. We aimed to present a novel procedure for the treatment of acquired monocular elevation deficiency using the paretic superior rectus muscle as a globe suspender to resolve hypotropia. We report the case of an eight-year-old girl with left eyelid ptosis and hypotropia two months after draining a left orbital abscess. Left inferior rectus muscle recession was performed at five years, with residual left hypotropia. Ophthalmological examination revealed a best-corrected visual acuity of 20/20 OD and 20/100 OS. Severe left eyelid ptosis and poor levator function were also observed. Extraocular motility showed left hypotropia of 40 prism diopters with the left superior rectus muscle under action (-4) in the adduction and abduction positions. A force duction test negative for restrictions on the inferior rectus muscle was performed intraoperatively. To reduce the risks of the Knapp procedure, the left superior rectus muscle was split into medial and temporal halves. Double-armed sutures were secured in half, and the halves were detached from the sclera. The medial and temporal halves were reattached anteriorly to the medial and lateral rectus insertions, respectively. Eight weeks after surgery, the patient had nine prism diopters of hypotropia in the primary gaze. Ten weeks after surgery, there was no change in visual acuity. In the cover test, the patient exhibited residual left hypotropia of nine prism diopters with a restriction (-4) of elevation in adduction and abduction. The parents were pleased with the satisfactory cosmetic outcomes, and postoperative clinical photographs of the patient showed improved hypotropia and persistent minimal elevation of the left eye during adduction and abduction. Superior rectus muscle splitting and vertical transposition to the medial and lateral rectus could be safer and simpler alternatives to the Knapp procedure and may offer a lower risk of anterior segment ischemia. Further studies are required to confirm these findings.