Volume 51 ·  Issue 06 ·  2015

Strabismus is a deviation of the visual axes relative to each other and is a very common eye disease. Strabismus is not only a cosmetic disease but more importantly damage to visual acuity, binocular vision and stereopsis. There are many different strabismus forms. It is very difficult to accommodate all the different clinical forms with only one classification. Different author has different classification because of different concerns. In order to avoid clinical confusion and provide references for clinicians, literatures from mainstream domestic and international journals and new revised classification by Chinese Association for Strabismus and Pediatric Ophthalmology were reviewed in this paper. (Chin J Ophthalmol, 2015, 51: 406-407)

Strabismus is a common clinical disease in ophthalmology, with a prevalence of about 3%. There are many kinds of strabismus, and there is no perfect clinical classification method at present. Different authors and monographs at home and abroad have different degrees of differences in the classification of strabismus due to different emphases and factors considered, which often confuse beginners and non-strabismus ophthalmologists and produce certain troubles for clinical work.

In order to standardize and unify the writing of examination records and medical records of strabismus, make them in line with international standards, so as to make the analysis and clinical diagnosis of strabismus cases more clear and definite, and better promote the academic exchange of strabismus specialty, after discussion with all experts of strabismus and pediatric ophthalmology group of Chinese Medical Association Ophthalmology Branch, the English abbreviations of international commonly used terms related to strabismus and the examination recording methods were introduced^[1,2,3,4,5]The summary is summarized below.

To investigate the effect of superior oblique tucking on the status of ocular torsion.

It was a retrospective case series study. We reviewed the records of 25 patients underwent superior oblique tucking for treatment of superior oblique palsy in Tianjin Eye Hospital from January 2012 to and August 2013, among them, there were 12 patients had undergone inferior oblique myectomy or inferior rectus recession before this operation. All clinical records, including eye movement, vertical deviation, abnormal head position, Bielschowsky test et al were analyzed. Objective cyclotorsion were examined pre-operation, as well as 1, 30 days post-operation with fundus photograph. The photographs were transferred to a computer and then the fovea- disa angle (FDA) was measured by a software for drawing pictures. The difference of the two eyes was compared by the pairedt-test, and the difference of the two groups was compared by the one-way analysis of variance.

All patients had no more than 12 PD vertical deviation and significant abnormal head position before the operations. After underwent superior oblique tucking from 6 mm to 10 mm, their vertical deviation were less than 3 PD, and symptom of unacceptable abnormal head position were ameliorated or disappeared. In 25 cases of the monocular eye involvement, FDA was - 10.60°±4.93° in the affected eyes preoperatively, while it was -9.67°±5.47° in the fellow eyes. There was also no statistically significant difference between two eyes (t=0.54, P=0.59). The combined FDA in both eyes were -20.27°±6.00° and -10.53°±8.04°, -10.83°±7.38° preoperatively, 1, and 30 days after operation. The comparison of objective ocular cyclotorsion for both eyes showed significant difference pre-and post-operation (F=14.81,P<0.01).

Superior oblique tucking can correct ocular excyclodeviation effectively, and simultaneously correct little vertical deviation. It's good to ameliorate abnormal head position. (Chin J Ophthalmol,2015,51:417-423)

To evaluate the effect of integrated anteriorization of inferior oblique muscle combined with recession of superior rectus to treat large hypertropia following absence of inferior rectus.

It was a retrospective case series study. Integrated anteriorization of inferior oblique muscle means transposing inferior oblique muscle 8–10 mm posterior to the insertion directly to original insertion of inferior rectus without myotomy. We reviewed 5 patients with absence of inferior rectus muscle, who treated by integrated anteriorization of inferior oblique muscle combined with recession of superior rectus. The pre and post-operative vertical deviation in primary position, ocular motility, and abnormal head position were compared. The patients were followed up from 6 to 18 months, with average as 10.8 months.

Postoperatively, 4 patients showed orthophoria in primary position and 1 patient had 10 PD hypotropia. The infraduction deficits improved from - 3.0 to -1.6. Meanwhile, there had been an average of- 2.0 mild supraduction limitation. Abnormal head position (AHP) disappeared in 2 patients with AHP before operation. All the patients showed no change of cyclodeviation on fundus photograph. 5 patients were satisfied with the improvement of the appearance, and the follow-up results were stable, no other surgery again.

Integrated anteriorization of inferior oblique muscle combined with recession of superior rectus was an effective surgical selection to treat hypertropia with absence of inferior rectus muscle. This procedure doesn't need to cut off the inferior oblique muscle. The more convenient surgical procedure can reduce the risk of bleeding.(Chin J Ophthalmol, 2015, 51:424-428)

Brown syndrome is characterized by limitation of elevation in adduction, with complex mechanisms involving muscle, tendon, and trochlea. Here, we investigated mechanisms of Brown syndrome by magnetic resonance (MR) imaging.

It was a retrospective case series study. Fourteen patients with unilateral Brown syndrome between 3 and 54 years of age (10 cases of congenital and 4 cases with acquired disease) were included in the study. All patients underwent complete ophthalmic and orthoptic evaluation. Imaging of the ocular motor nerves at the brainstem was performed on 3D - FIESTA sequence, the orbits were imaged with FSE T1、T2WI using surface coils.

Nine of 10 with congenital Brown syndrome demonstrated hypoplasia of the superior oblique (SO) of the affected side. Abnormal low signal intensity in the trochlea area was found in one patient. Three of 4 acquired patients had a history of trauma and were demonstrated fracture of the trochlea, extensive scarring, and superior orbital fracture. One acquired case was demonstrated scarring of anterior part of the SO and hypoplasia ofthe posterior part.

Brown syndrome consists of a series of diseases. Their clinical features are quite similar while their anatomical mechanism varies in numerous ways. Therefore, based on patient's individual pathophysiology, the management in Brown syndrome should be personalized. (Chin J Ophthalmol,2015,51:429-433)

To study the thickness and width of extraocular muscles by high-resolution magnetic resonance imaging (MRI).

Cross-sectional study. Sixty eight normal subjects between 2.0 and 50.0 years of age, mean age was (21.2±2.1) (SD) years old, male 34, female 34. Extraocular muscles in the orbits were scanned with SE/T2WI coronal and oblique-coronal planes perpendicular to optic nerve, and within 1.5 mm thick planes. The thickness and width of the extraocular muscles in the maximum planes were measured in 68 normal subjects on oblique- coronal planes MR images. The vertical diameter of the medial rectus muscle and lateral rectus muscle indicated width, horizontal diameter indicated thickness. The vertical diameter of the superior rectus muscle and inferior rectus muscle indicated thickness, horizontal diameter indicated width. Vertical diameter of the muscle belly is from the top edge to the bottom edge, horizontal diameter of the muscle belly is from the innermost to the outermost edge. The differences in diameters of bilateral extraocular muscles were evaluated by the independent sample t statistical test. Superior oblique muscle was considered as a reference in each subject to calculate the ratio of the other rectus muscles and the superior oblique muscle in diameter and to compare the relationship of the extraocular muscles in the same plane.

The extraocular muscles of normal subjects were symmetrical on the two sides. There were no statistically significant differences between the bilateral extraocular muscles (medial rectus muscle, lateral rectus muscle, inferior rectus muscle and superior rectus muscle) in the thickness and width (t values respectively were 0.043, 0.025, 0.043, 0.032, 0.001, 0.601, 0.667, 0.021, 0.032, 0.005, all P>0.05). The ratio of the rectus muscles (medial rectus muscle, lateral rectus muscle, superior rectus muscle, inferior rectus muscle) and the superior oblique muscle in thickness respectively were (1.15±0.14), (1.04±0.14), (1.07±0.19), (1.39±0.22). The relationship of the thickness of extraocular muscles in the maximum planes were: inferior rectus muscle > medial rectus muscle > superior rectus muscle > lateral rectus muscle, and the thickness of 91% superior rectus muscle was close to lateral rectus muscle. The ratio of the rectus muscles (medial rectus muscle, lateral rectus muscle, superior rectus muscle, inferior rectus muscle) and the superior oblique muscle in width respectively were (1.71±0.27), (2.07±0.28), (1.62±0.29), (1.50±0.21). The relationship of the width of extraocular muscles in the maximum planes were: lateral rectus muscle> medial rectus muscle> superior rectus muscle> inferior rectus muscle.

The thickness and width of all the extraocular muscles follows a certain rule. Measurements of extraocular muscles using MRI should be done on coronal and oblique - coronal planes MRI scan simultaneously. The sizes of extraocular muscles can be assessed by observing the symmetry of the extraocular muscles on the two sides on coronal plane and the usual rule of extraocular muscles on oblique- coronal plane. (Chin J Ophthalmol, 2015,51:434-438)

To evaluate the feasibility of independently developed digital eye tracker in determining the efficacy of congenital idiopathic nystagmus (CIN) surgery.

Aprospective selfpairing study. The surgical efficacy was evaluated by independently developed eye tracker in 16 CIN patients. The null zone and the frequency, amplitude, intensity of nystagmus in various gazing position were recorded with eye tracker pre and post operatively. The consistency of null zone determined by digital eye tracker and clinical investigation were evaluated. The preoperative and postoperative rectification of horizontal and vertical nystagmus in the horizontal direction of individual patient were compared by paired samples t-test. The improvement or aggravation quantity were recorded by comparing preoperative and postoperative intensity of nystagmus every 5°within 25°.

The null zone got from digital eye tracker and clinical investigation were highly consistent (r=0.952,P<0.01). The horizontal and vertical intensity improved in 9 patients (t=2.335-6.609, P<0.05) and 5 patients (t=2.176- 5.471,P<0.05) respectively after surgery. There were 67.63% (117/173) horizontal intensity and 69.94% (121/173) vertical intensity improvement.

The independently developed digital eye tracker can quantitatively evaluate the pre and post-operative nystagmus and analyze the surgical efficacy for CIN patients. (Chin J Ophthalmol, 2015, 51:439-444)

To report the clinical results of femtosecond laser assisted lamellar keratoplasty (FS-LK).

Retrospective study. Twenty eyes of 17 patients who were treated with FS-LK were enrolled in this study. The preoperative visions were from 0.02 to 0.4. During the operation, the grafts were prepared with a depth of 400 - 600 μm according to the character of the affections.

During the follow-up period, the visions of 18 eyes (90%) were better than preoperative ones. One of them was equal to 0.8. The best corrected visual acuities of 18 eyes (90%) were better than or equal to 0.5, one of which was 1.0. The astigmatisms of 15 eyes were under 3.00 diopters at one year after operation. During the operation of two cases, the paracentral cut occurred. Two patients experienced corneal opacity, and two cases had high astigmatisms after operation. Only one eye experienced immune rejection at one year after operation.

The FS - LK appears to be a good alternative surgical method for patients with corneal diseases because of the great manipuility and excellent postoperative results, but more research is needed. (Chin J Ophthalmol, 2015, 51:445-449)

To investigate the permeability and saturation characteristics of riboflavin in sclera tissue, in order to explore a reasonable dosage regimen in sclera cross- linking.

Experimental study. Five human cadaver eyes were also included in this study, every eye was cut into seven sclera stripes and then 0.1% riboflavin solution was dripped to the sclera stripes for 5, 10, 15, 20, 25, 30minutes respectively. After that,the stripes were made into frozen sections and observed by confocal microscope. To calculate the mean fluorescence density and compare with each other. In addition, 36 New Zealand rabbits were randomly divided into group A and B groups. Each group was divided into six subgroups. In group A, 0.1% riboflavin solution was dripped to the sclera of right eye for 5, 10, 15, 20, 25 and 30 minutes respectively. In group B, 0.5% ribof lavin solution was dripped to the sclera of right eye for 5, 10, 15, 20, 25 and 30 minutes respectively. The left eye were given with physiological saline as blank check. Executed the rabbits to take out the eye and then the nose upper quadrant of the equator sclera was taken to made into frozen sections which were observed by two- photon microscope. To calculate the mean fluorescence density and compare the six subgroups in every group respectively, and compare the subgroups with the same riboflavin- applicated time between group A and B respectively.

The fluorescence intensity of sclera gradually strengthened with the longer riboflavin-applicated time, but there was no statistical difference between 20 minutes and the longer time groups (P>0.05). With the same riboflavinapplicated time in rabbit sclera, the fluorescence intensity of 0.5% concentration group was higher than 0.1% concentration group (P<0.05).

The riboflavin reached an saturation level in the sclera of human cadaver eyes and rabbit eyes after 20 minutes application. The higher concentration of riboflavinapplicated, the higher concentration of riboflavin in the rabbit sclera. (Chin J Optholmol, 2015, 51: 450-454)

To investigate changes in refractive status and ocular length in guinea pigs during the early time of myopic recovery for the causes of recovery.

Exp guinea pigs wore a-5.00 D lens on one eye from 4-18 days, which was then removed for 48 hours. At 18 and 20 days of age, each eye was evaluated for refractive status and ocular length of the eye.

The right eyes treated with -5 D lenses for 12 days developed (- 2.00±1.50) D (P=0.04) of myopia and had an increase in axial length of (0.033±0.025) mm compared to the left eyes (P=0.04). After 48 hours of recovery, the difference between the two eyes was reduced to (- 0.72±0.86) D (P=0.13), but the ocular length still had significant difference (0.031±0.022) mm (P=0.04). During the myopia recovery early period, the refractive status and ocular length changed in the same direction in the left eyes but in the opposite way in the right eyes.

Guinea pigs treated with -5.00 D lenses for 12 days developed explicit relative axial myopia. After removal of the lens for 48 hours, myopia significantly recovery can be due to the thickening of choroid and the reduction in ocular growth. (Chin J Ophthalmol, 2015, 51:455-457)