The evaluation and management of vertical strabismus is more challenging and nuanced than that of horizontal strabismus. Vertical strabismus often results from a variety of restrictive or paretic causes, which can be further characterized as either acquired or congenital. In some cases, identifying the correct etiology of the strabismus can mean uncovering a potentially life-threatening condition, such as a brain tumor or stroke. The keys to identifying the correct diagnosis are, first and foremost, a careful history, and secondly, a detailed examination. The characteristics, etiologies, and evaluation of vertical strabismus will be reviewed here.

OBJECTIVE: To determine the mean difference of vertical corneal light reflex (VCLR) among healthy eyes via digital photography.
METHODS: Retrospective study.
METHODS: The study enrolled 155, healthy eyes participants, 71 males and 84 females with a mean age of 14.7 years (range 12-19 years). The participants received complete eye examinations and 2 digital photographs were taken, with the flash on, while participants fixated their eyes on a near and a distant target. Two hundred and eighty qualified photographs were analyzed by Photo-Hirschberg testing using computer software. The vertical corneal light reflex ratio (VCLRR) was calculated as the distance of the corneal light reflex (CLR) to the inferior limbus or to the pupillary border divided by the horizontal corneal diameter, defined as VCLRR1 or VCLRR2. VCLRR was analyzed using Spearman\'s correlation.
RESULTS: The mean ± SD of horizontal corneal diameter in near and distance photographs was 11.47 ± 0.62 and 11.37 ± 0.58 mm, respectively. For correlation analysis, at 1 m fixation and 6 m fixation, the number of participants within an acceptable range of vertical fusion were 94.6% and 100% of participants. The 95th percentiles (estimated as the mean ± 1.64SD) in VCLRR1 between the two eyes at near and at distance fixation were 0.0316 and 0.0272, respectively; whereas the corresponding values for VCLRR2 were 0.0309 and 0.0240, respectively.
CONCLUSIONS: The normal range of the vertical corneal light reflex ratio suggests that the Photo-Hirschberg test could be used for screening vertical strabismus cases depending on iris pigment.

Ocular skew deviation is an acute vertical misalignment resulting from the disruption of vestibular input to the interstitial nucleus of Cajal, involving the utriculo-ocular pathway, the cerebellum or the thalamus. A large percentage of skew cases associated with globe torsion and head tilt have complex or sinister etiologies, necessitating its differentiation from more common causes of acute onset vertical deviation in a sensitive and cost-efficient manner.This paper briefly reviews the anatomy and vestibular function of the inner ear, outlines the utriculo-ocular pathway, and discusses the things you need to know about skew to aid in clinical oculo-motor practice in 2022.

OBJECTIVE: To evaluate outcomes of botulinum toxin (BTX) injection of the inferior oblique (IO) muscle.
METHODS: Retrospective case series.
METHODS: Setting: Single center, ophthalmology department at Boston Children\'s Hospital.
METHODS: All patients treated with IO muscle injection of BTX (onabotulinumtoxinA) between 2010 and 2020.
METHODS: Sensorimotor evaluations at short-term (<2 months), medium-term (2-4 months), and long-term (≥4 months) intervals.
METHODS: Primary outcomes included median improvement in V-pattern strabismus and primary position hypertropia. Secondary outcomes included IO muscle overaction. Wilcoxon signed-rank tests were performed to identify differences before and after injection.
RESULTS: Record review identified 20 patients with a median age of 4.5 (range, 1-69) years. Median BTX dose injected (31 IO muscles) was 5.0 (range, 3.0-7.0) units. Indications included V-pattern strabismus (N = 8), hypertropia (N = 7), or both (N = 5). Median long-term interval was 6.4 (range, 4.1-26.6) months. Injections were concurrent with treatment of horizontal strabismus in all but 3 cases. Median V-pattern magnitude changed from 10 prism diopters (PD) preoperatively to 0 PD short-term (P = .006) and 3.5 PD long-term (P = .34). Median hypertropia changed from 8.5 PD preoperatively to 1.5 PD short-term (P = .01) and 8 PD long-term (P = .87). Median IO muscle overaction grade improved significantly at short-term (P < .001) and long-term (P = .007) intervals. There were no complications associated with the IO muscle injections.
CONCLUSIONS: BTX injection of the IO muscles can be a useful adjunct to the management of V-pattern strabismus. Intervention for primary position hypertropia may be helpful for short-term relief with no expectation of long-term benefit.

We have previously reported strabismus due to mismatch of orbital volume and globe as \'crowded orbital syndrome\' (COS). In this study we have used magnetic resonance imaging (MRI) to investigate its clinical features. This has revealed that a globe with a similar axis occupies a larger volume in the orbit in patients with COS than in controls without strabismus. This suggests that strabismus with high myopia may easily occur in those with relatively small orbits and axial elongation. In acquired esotropia and/or vertical strabismus, a mismatch of orbital volume and globe axis should be investigated with MRI.

OBJECTIVE: To identify the etiologies of isolated fourth cranial nerve palsy in Ramathibodi hospital, Thailand.
METHODS: Patients diagnosed with isolated fourth nerve palsy from January 1, 2009, through July 31, 2020 in Ramathibodi Hospital, were included in this retrospective, observational case series. The demographic data of patients, age at presentation, the etiologies of isolated fourth nerve palsy and neuroimaging results (if indicated) were recorded.
RESULTS: We identified 154 unilateral and 4 bilateral cases of isolated fourth nerve palsy. Mean age at presentation was 38.89 ± 25.71 years old. Most of the unilateral cases were congenital (57.79%), with microvasculopathy (27.92%), intracranial neoplasm (8.44%) and other etiologies. Trauma with closed head injury was the most common etiology of bilateral cases (75%), followed by ruptured arteriovenous malformation (25%). Twenty-one of the 43 (48.84%) patients with microvasculopathy fourth nerve palsy underwent neuroimaging, with normal findings, and all patients\' symptoms resolved within 6 months of symptom onset.
CONCLUSIONS: In our series, most of the isolated fourth nerve palsy cases were congenital, followed in frequency by microvasculopathy and intracranial tumor, as in many studies. In cases of microvasculopathy, the clinical signs and symptoms resolved within 6 months in all cases: observation was sufficient, with no necessity for neuroimaging. However, neuroimaging should be considered in cases with atypical presentations, such as headache, periorbital pain, or if there is rapid progression or no recovery.

Treatment of vertical strabismus will almost inevitably involve surgery when it is associated with hyperfunction of the inferior oblique muscle due to the weakness of vertical fusion (3.0-4.0 ave dptr), the presence of cyclotropy and torsional diplopia. Many operations aimed at weakening the lower oblique muscle have been described. However, they have a number of negative aspects associated with high invasiveness, difficulty of technical implementation due to the need for manipulations in the inaccessible area of the eye in proximity to the optic nerve, macular area, large vessels, as well as long duration of the operation, inability to dosage the result of the operation, low functional results. They are, to a large extent, absent in the operation of anterior transposition in which the neurofibrovascular bundle serves as the axis of rotation of the lower oblique muscle changing the vector of its action and increasing the effectiveness of treatment. Despite all the advantages of that technique, its use is still limited due to the lack of methods for controlling the amount of anterior transposition for the treatment of hyperfunction of the inferior oblique muscle, especially of small degrees.
В лечении вертикального косоглазия, связанного с наличием гиперфункции (ГФ) нижней косой мышцы (НКМ), из-за слабости вертикальной фузии (3,0—4,0 пр. дптр), наличия циклотропии и торзионной диплопии хирургический этап практически неизбежен. К настоящему времени описано множество операций по ослаблению НКМ. Однако они характеризуются целым рядом отрицательных моментов, связанных с высокой травматичностью, трудностью технического выполнения из-за необходимости манипулировать в труднодоступной области глаза вблизи зрительного нерва, макулярной зоны, крупных сосудов, с большой длительностью проведения операции, невозможностью дозировать результат операции, низкими функциональными результатами. В значительной степени этих недостатков лишена операция передней транспозиции, при которой нейрофиброваскулярный пучок служит осью поворота НКМ, вследствие чего изменяется вектор ее действия и повышается эффективность лечения. Но, несмотря на все преимущества описанной методики, ее применение по-прежнему ограничено. Это связано с отсутствием способов дозирования объема передней транспозиции для лечения ГФ НКМ, особенно малых степеней.

Vertical strabismus caused by hyperfunction of the inferior oblique muscle is a common oculomotor disorder. It is found in one third of all patients with strabismus, and in 70% of cases it is combined with esotropia. To date, there is no single approach to determining the degree of hyperfunction of the inferior oblique muscle, and the most common classifications are very subjective and inaccurate. Thus, in connection with the need to understand the severity of the disease, as well as to determine the tactics of treatment and prognosis of the surgical outcomes, it is necessary to standartize the classification of this pathology. The mechanism of action of the inferior oblique muscles of the eye is very complex and depends on the position of the eyeball at the time of their contraction. In addition to horizontal and vertical movements, they provide torsional movement. Any impairment of these muscles leads to the development of not only vertical strabismus, but excyclotropia that reduces the effectiveness of strabismus treatment. To identify all the symptoms associated with hyperfunction of the inferior oblique muscle, taking into account the peculiarities of its triple action, it is necessary to conduct a thorough diagnostic study.
Вертикальное косоглазие вследствие гиперфункции нижней косой мышцы (ГФ НКМ) является распространенным заболеванием в структуре глазодвигательных нарушений. Среди больных косоглазием оно встречается у трети пациентов, в 70% случаев сочетаясь с эзотропией. На сегодняшний день не существует единого подхода к определению степени ГФ НКМ, а наиболее распространенные классификации являются очень субъективными и неточными. Таким образом, в связи с необходимостью понимания тяжести заболевания, для определения тактики лечения и прогноза результатов хирургического лечения необходимо проведение стандартизации в классификации данной патологии. Механизм действия НКМ глаза очень сложен и зависит от положения глазного яблока в момент их сокращения. Помимо горизонтальных и вертикальных движений они обеспечивают торзионные движения. Любые нарушения этих мышц приводят к развитию не только вертикального косоглазия, но и эксциклотропии, снижающей эффективность лечения косоглазия. Для выявления всего симптомокомплекса, связанного с ГФ НКМ, учитывая особенности ее тройного действия, необходимо проводить тщательное диагностическое исследование.

UNASSIGNED: To study the effect of vertically transposing both horizontal eye muscles of one eye in the same direction on vertical strabismus.
UNASSIGNED: Retrospective analysis of 33 patients in whom vertical transposition of the medial and lateral rectus muscles was combined with a recession/resection or recession/plication procedure. Preoperative ocular alignment was compared with that 1 day and 3 months postoperatively.
UNASSIGNED: Mean preoperative vertical deviation was 7.8 ± 4.3 (median 7.5, range 3-25) prism diopters (PD) at distance and 7.8 ± 4.1 (7, 0-18) PD at near. Vertical transposition of the horizontal rectus muscles averaged 5.6 ± 1.6 mm and reduced the vertical deviation to 3.4 ± 4.2 PD (2, 0-16) at distance and 2.9 ± 3.7 PD (2, 0-14) at near. Mean effect on the vertical deviation was 0.9 ± 0.7 (0.8, -0.8 to 2.13) PD/mm at distance and 0.9 ± 0.9 (0.83, -1 to 3) PD/mm at near, it was similar in patients operated on for esotropia and for exotropia. The surgical effect on the horizontal deviation was 2.1 ± 1.1 PD/mm (distance) and 2.6 ± 1 PD/mm (near). Both the vertical and horizontal surgical dose correlated with the effect in a linear way, but the variability was greater for the vertical transposition.
UNASSIGNED: Vertical transposition of the horizontal rectus muscles in the same direction allows for correction of vertical strabismus. This procedure may be performed during primarily horizontal strabismus surgery, without operating on an additional extraocular muscle. The transposition distance correlates with the surgical effect but predictability of the effect is limited.

Aid: Familiarize themselves with the operating techniques in their own modulation to solve hypotropic states with elevation or hypotropic states with depression.
METHODS: Surgery technique “cul-de-sac” is a procedure with fixed adjustable sutures (non-absorbable suture), which are guided in parallel on both peaks original insertion of inferior rectus muscle. The node itself of suture is done in cutting the muscle and through the original insertion only leads arc suture. During „counterclockwise transposition“ procedure sec. Knapp, the horizontal rectus muscles are fixed at the straight inferior rectus muscle level. The author included their graphical diagrams.
METHODS: At the Department of Ophthalmology in the Faculty Hospital Královské Vinohrady in Prague (Czech Republic, EU) in the years 1996 - 2014 a release relaxing operation of the inferior rectus musle by the technique “cul-de-sac” on 49 eyes. Indication was double elevator palsy in 31 patients, congenital fibrosis of the extraocular muscles in 15 patients and in 3 cases, it was thyroid eye disease. “Counterclockwise transposition” procedure sec. Knapp was indicated twice for paresis of the inferior rectus muscle in 2015 and 2016. For the first time, it was a congenital form. It was detected histologically atrophy of stripped muscle with hypertrophy collagen. The second traumatic form was formed after an orbital injury.
RESULTS: We provided adequate relaxation of the inferior rectus muscle and practical restoration of eye elevation by the technique “cul-de-sac“ in 18 preschool children with the double elevator palsy and three adult patients with thyreiod eye disease. We had to restore motility to complete the procedure by classical transposition procedure sec. Knapp of both horizontal rectus muscles to the direct superior rectus muscle in elderly children and adults with the double elevator palsy, as well as in all patients with the congenital fibrosis of the extraocular muscles. Indicate the inclusion of this transposition influenced the degree of fibrotic rectus inferior muscle given by age. “Counterclockwise transposition“ procedure sec. Knapp ensured the practical disappearance hypertropie in both cases of paresis of the inferior rectus muscle. The alignment of the position of the eyes without diplopia in the direct view was ensured by prismatic correction.
CONCLUSIONS:   To release the fibrotically altered inferior rectus muscle in the double elevator palsy, the congenital fibrosis of the extraocular muscles and the thyroid eye disease, the operation of adjustable sutures was necessary in accordance with our experience with the technigue “cul-de-sac“ in its own modification. The transposition procedure sec. Knapp, either classical or “”counterclockwise” “ in its own modification, was of paramount importance for the solution of the vertical deviation of a paretic ethiology. Key words: adjustable sutures, congenital fibrosis of the extraocular muscles, double elevator palsy, thyroid eye disease, transposition procedure sec. Knapp, vertical strabismus.