Prophylactic juxtapapillary laser photocoagulation in pediatric morning glory syndrome

INTRODUCTION

Morning glory syndrome (MGS) is a rare congenital cavitary anomaly of the optic disc, that was first named by Kindler

in 1970 because of its resemblance to the morning glory flower. It is characterized by an enlarged and excavated optic disc with juxtapapillary chorioretinal pigment disturbance, radial retinal blood vessels, and a central white glial tuft. The prevalence of this condition is 3.6/100 000 in children, and the exact pathogenesis of MGS remains unknown

.

Juxtapapillary laser treatment alone is generally used as a supplement to vitrectomy in RD of MGS. The mechanism of laser treatment is to produce adhesion, through the thermal effect, between the retinal pigment epithelium (RPE),neuroepithelium and choroid to create a barrier to prevent subretinal fluid migration

. Prophylactic juxtapapillary laser treatment is controversial in the literature for the prevention of RD in MGS, as the likely risk of visual loss is attributed to the papillomacular bundle (PMB) injury. However, more animal and human studies have demonstrated that lasers in the region of the PMB do not cause loss of visual function

. Hence,this study aimed to report the preliminary anatomic and visual outcomes of prophylactic juxtapapillary laser treatment alone in a cohort of pediatric MGS patients from a single institution.

It should be mentioned that echography is an important method of examination for MGS. B-scan echography of all MGS eyes in this study showed excavation of the posterior pole, and no RD band was found during the entire followup period. Cennamo

reported that spectral-domain optical coherence tomography could sometimes show RD when echography could not, suggesting that echography may miss the diagnosis of RD sometimes compared to optical coherence tomography. In this study, it was indefinite whether mild subretinal fluid or intraretinal fluid existed in some cases.Despite the good RPE response of the laser in all patients, the progression of serous RD may be observed in a longer time,and the efficacy of laser adhesion as a barrier may be reduced gradually, which needs to be followed up for a longer time.

In the literature, the treatment of advanced RD in MGS is challenging. Some cases are treated when total RD occurs,which requires silicone oil or long-acting gas tamponade

. In addition, cases that have recurrent RD always need multiple interventions

. Complications of these operations are severe in the long term, such as silicone oil emulsification,keratopathy and photophobia

. Despite the reports of cases with successful retinal attachment after treatment

, the follow-up periods in these studies were not long enough,and long-term complications were ignored. In addition, the visual acuity prognosis is very poor in these conditions since RD has occurred for a long time. Considering these findings,early prophylactic treatment is actually needed to improve the anatomical and visual prognosis.

MGS could be complicated with other ocular diseases, such as persistent fetal vasculature (PFV), cataracts, microphthalmia and retinal detachment (RD). It has been reported that approximately 1/3 of those with MGS can develop RD, and a small number of cases have spontaneous resolution

. The development process of RD may result from various factors,mainly abnormal communications between the subarachnoid space and subretinal space or retinal breaks, which contribute to the migration of cerebrospinal fluid or vitreous humor to the subretinal space and the traction of preretinal glial tissues

.

氣化爐高壓氧氣切斷閥主要用于氧氣輸送管路以及氧氣吹掃管路快速關(guān)閉或者開啟。由于介質(zhì)是氧氣，具有助燃性能，閥門一旦發(fā)生熱量累積、泄漏等，容易引發(fā)燃燒甚至爆炸，從而會嚴重影響裝置的平穩(wěn)運行，因而氣化爐高壓氧氣切斷閥對閥門的密封性能、材料選擇、使用壽命等性能有非常嚴格的要求。

SUBJECTS AND METHODS

會寧縣是西北教育名縣，自恢復(fù)高考以來，全縣累計向全國大中專業(yè)院校輸送優(yōu)秀畢業(yè)生5.1萬名，其中獲得博士學(xué)位者500多人，碩士學(xué)位者近2000多人，學(xué)士學(xué)位者近2萬人。“領(lǐng)導(dǎo)苦抓，教師苦教，學(xué)生苦學(xué)，家長苦供，親友苦幫”的“五苦”精神已經(jīng)是我們這一區(qū)域的特有的教育文化。我們在班級文化建設(shè)中深入挖掘教育中可歌可泣的感人的事例，培育學(xué)生的核心素養(yǎng)。

Consecutive patients with a diagnosis of MGS from April 2015 to February 2021 were enrolled. The patients underwent comprehensive ophthalmic examinations before and after treatment. All patients were examined with binocular indirect ophthalmoscopy with a +20 D lens or slitlamp microscope by the same clinician (Zhao PQ). Widefield fundus images were taken with RetCam III (Clarity,Pleasanton, California, USA) or Optos Optomap 200Tx (Optos,PLC, Dunfermline, Scotland, UK). A/B-scan echography(CineScan, BVI Co., France) examinations were performed to measure the axial length, maximal depth and width of excavation and to evaluate the status of the whole globe. The frequencies of the probe of the A-scan and B-scan echography were 11 MHz and 10 MHz, respectively. Intraocular pressure(IOP) was measured using a non-contact tonometer (Topcon CT-90, Tokyo, Japan) or rebound tonometer (iCare, Tiolat Oy,Helsinki, Finland) every time.

The criterion for laser treatment was diagnosis of MGS without obvious RD in those aged 0-15y. Patients with refractive media opacity, PFV, tractional or rhegmatogenous retinal detachment (RRD) or without intact data were excluded. All the patients were under general anesthesia monitored by an experienced pediatric anesthesiologist. Fundus photography and fluorescein angiography (FA) were performed according to the reported literature

. All patients underwent prophylactic laser treatment alone by two experienced clinicians (Xu Y and Peng J) after fundus photos were taken. This treatment was three to five rows of confluent gray-white laser spots at 360° of the retina around the edge of the optic disc through a 520 nmwavelength, a power of 180-250 mW and a 300ms-duration laser with an indirect ophthalmoscope (Novus, Lumenis, USA).The laser spots were grid, and the intensity was moderate(Figure 1). The laser spots were given around the border of these areas, including atrophy of RPE and small folds around the optic disc (Figure 2A). The visible macular area was spared with laser carefully to protect the PMB (Figure 1).

Baseline data for age, gender, laterality of MGS and symptoms at presentation were collected.Ophthalmic evaluations, including visual acuity, axial length,IOP and ocular complications, were noted one-month, six months and after every year postoperatively.

Cranial magnetic resonance imaging (MRI) was also suggested for all patients.The main outcomes were the status of the retina and best corrected visual acuity (BCVA), which were evaluated during follow-ups.

Statistical analyses were performed using IBM SPSS Statistics, version 22.0 software (Armonk, NY:IBM Corp). Paired

-tests and Mann-Whitney

tests were used to compare the differences in several parameters between two subgroups of patients who were younger than 12 months old at the time of treatment and the others. A

value of less than 0.05 was considered statistically significant.

RESULTS

A total of 24 eyes from 22 patients were included in this study. Two (9.1%) patients underwent bilateral treatments.At the time of treatment, 13 (59.1%) patients were younger than 12 months old. The baseline data of the patients are listed in Table 1. The median age at treatment was 10.5mo(interquartile range: 7.5-19.5mo), and the mean follow-up duration was 27.7±17.5mo. Symptoms at presentation included strabismus in 6 (27.3%), decreased vision in 2 (9.1%) and routine fundus screening in 14 (63.6%) patients (Table 1). At the preoperative, postoperative one-month and postoperative six-month follow-ups, the mean ocular axial length and IOP are listed in Table 1. There was an increasing trend of the axial length with age, but no significantly shortened axial length or elevated IOP was found. Fifteen (68.2%) patients underwent cranial MRI examinations. Three of the 15 (20.0%)patients had various abnormal findings in the central nervous system, including one moyamoya, one encephalocele, and one intracranial arteriostenosis.

On fundus photography and B-scan echography at the preoperative and postoperative one-month, postoperative sixmonth and following follow-ups, the anatomic outcomes of all eyes remained stable (Figures 2 and 3). None of them developed obvious RD during the entire follow-up course.Preoperative BCVA acquired from 2 (9.1%) patients ranged from light perception to 20/200. Postoperative acuity acquired from 11 (50.0%) patients ranged from light perception to 20/125 (Table 2). Patient noncompliance limited this examination for others. No visual losses were reported from any patients or their parents.

2）通常情況下，GM（1，1）預(yù)測模型要求所采用的數(shù)據(jù)序列必須是等時間間隔的，而在實際工作中，觀測的原始數(shù)據(jù)往往是非等時間間隔的數(shù)據(jù)序列，所以，針對此種情況，需要進行數(shù)據(jù)序列的轉(zhuǎn)換，即把非等間隔序列變換成等間隔序列［3］。

No obvious ocular or systemic complications were reported during the entire follow-up course. No hemorrhage, retinal holes, cataracts or keratitis were found in any patients. No evidence of the spontaneous resolution of RD, such as new subretinal proliferation, was noted. One patient had transient conjunctivitis after treatment and recovered by using topical antibiotics. Due to the poor visual acuity and young age of most patients, visual field examinations were not performed.

This study adhered to the tenets of the Declaration of Helsinki (2008) and was approved by the Ethics Committee of Xinhua Hospital affiliated with the Shanghai Jiao Tong University School of Medicine. Written information consent was acquired from the parents of all patients.

DISCUSSION

MGS is a rare congenital cavitary anomaly of the optic disc.There was a unilateral tendency and no significant difference in occurrence between genders

, which is in agreement with the data in this study. Abnormal findings in the nervous system suggest the importance of cranial examinations for MGS patients in this study, which has also been reported in previous studies

. The median age at presentation was six months old (range: 3.0-17.3mo) in this cohort, suggesting that early fundus screening is worthwhile for early diagnosis and management.

Considering these findings, early prophylactic treatment is truly needed to improve the anatomical and visual prognosis.In the above studies, laser photocoagulation around the optic disc is generally used as a supplement to vitrectomy. However,there remains some ambiguity about the safety of lasers in the region of the PMB. Early animal and human studies suggested that there was no obvious detriment to applying a laser in the region of the PMB

. Recently, more human studies have demonstrated that laser-associated retinal damage is limited to the outer retinal layers. The immediate morphological changes of the inner retina suggested that the RPE prevents damage to the inner retina by absorbing most of the energy of the laser

. More recently, Bloch and da Cruz

reported the safety of juxtapapillary laser photocoagulation in the region of the PMB for optic disc pit maculopathy. No anatomical or perimetric findings consistent with nerve fiber layer damage in the region of laser treatment were reported in any of the patients, suggesting that lasers in the region of the PMB would not cause loss of visual function. On the other hand,it is controversial to treat the fovea directly with the laser for patients with good vision. Fovea-sparing laser treatment has been applied for diabetic macular edema

. As the macula in MGS often develops abnormally or is displaced toward the edge of the excavation, it is important to distinguish the probable site of the fovea, which truly requires some effort.Normal macula is usually yellowish on fundus photography,with a clear foveal reflection and a clear foveal avascular zone(FAZ) on fundus FA

. Therefore, despite the limitation of exactly anchoring the fovea in pediatric MGS patients, the probable whole area of the macula was dignified and spared to protect the fovea and the PMB. Pre- and postoperative visual acuities of two patients who were observed to be unaffected also supported the safety of scrupulous juxtapapillary laser photocoagulation in these patients.

It has been reported that approximately 80% of MGS could be complicated with other ocular diseases, such as PFV, cataracts,microphthalmia and RD

. As one of the most severe complications of MGS, RD has been reported to occur in 30%-38% of MGS patients

. Haik

reported that the natural course of MGS with RD occurred in 11 of 32 eyes during a mean follow-up of 10.3y. Of the 11 eyes, four had spontaneous reattachment, and two of them exhibited redetachment.Evidence of the spontaneous resolution of RD in MGS, such as new subretinal proliferation, was not observed during the follow-up period, which suggested that RD did not occur in all the patients in this study.

In the literature, the treatment of advanced RD in MGS is challenging. Harris

reported an MGS case with near total RD and a tiny retinal break treated with one vitrectomy and two fluid-gas exchanges. The retina remained attached for 14mo after the final surgery. Jo

reported an MGS case with a retinal hole and RD treated with vitrectomy and long-acting gas tamponade. The retina was redetached one month later, and silicone oil tamponade was then used. The retina retained attached for five years after the removal of the silicone oil. Recurrent RD and multiple interventions, such as in these cases, are intolerant for some patients. Sakamoto

reported two MGS cases with total RD and contractile movements treated with vitrectomy, and the retina failed to be reattached in both cases, suggesting the considerable difficulty of the treatment of these conditions. Sen

reported nine MGS cases with RD treated with vitrectomy. Silicone oil tamponade was used in 7/9 eyes, and the rate of retinal reattachment was 66%. However, the long-term complications of the surgeries were unclear. Visual improvement is quite limited in these patients.

存儲在機構(gòu)知識庫中的數(shù)字信息資源是它的核心所在。如何高效準確地獲取信息資源，并且保持數(shù)據(jù)資源持續(xù)更新，是制約機構(gòu)庫發(fā)展的關(guān)鍵因素，也是機構(gòu)知識庫建設(shè)的最重要的工作。機構(gòu)庫信息資源獲取困難制約和阻礙了機構(gòu)庫建設(shè)和發(fā)展。根據(jù)美國網(wǎng)絡(luò)信息聯(lián)盟發(fā)布的調(diào)查報告可以知道，制約高校機構(gòu)知識庫發(fā)展的關(guān)鍵因素是高校的教職工和科研人員無法及時向機構(gòu)庫提交信息，困難重重[7]。……