Factors associated with corneal astigmatism change after ptosis surgery

INTRODUCTION

Blepharoptosis, an eyelid disorder, can cause visual disturbance at any age ranging from infants as congenital ptosis to aponeurotic ptosis in the elderly. Other types included mechanical, myogenic, and neurogenic ptosis

. Patients may experience a decreased vision as the covering lid constricts the superior visual field and/or causes refractive errors, mainly corneal astigmatism.

敦禮掙扎著坐起來，一陣眩暈差點(diǎn)把他擊倒。他趕緊閉著眼向后靠在臥床的靠背上，一動(dòng)不動(dòng)，像睡著了一樣。靠背上紫紅色的金絲絨襯得他的臉卡白卡白的，胡茬子也更加分明，使得下巴看起來不是平常那種青灰色，而是深得近乎黑色了。他的上半身穿了一件淺灰色的棉質(zhì)睡衣，腰部以下搭著被子，被子的一角翻轉(zhuǎn)過來，露出比背面顏色略深的里子。被子不是很厚，比靠背略淺一些的紫色，上面點(diǎn)綴著幾團(tuán)花紋，花紋以淺綠色為主，夾雜著少許黃色，刺繡精美得讓人止不住地浮想聯(lián)翩。

Explanation have been proposed indicating the causation of corneal astigmatism in ptosis patients to be a result of eyelid pressure against the cornea, which alter the corneal shape toward with-the-rule (WTR) astigmatism

. The corneal astigmatism degree is changeable postoperatively based on several reports, some showed significant results

.Postoperative axis shift has also been reported. Wilson

demonstrated a trend of a decreased degree of WTR astigmatism in patients who underwent ptosis surgery. A similar result was reported in Savino

's study

. However,Merriam

found the opposite trend of an increased WTR astigmatism to also be possible.

“藝術(shù)人”身份是藝術(shù)家最本質(zhì)的、區(qū)別于他人的基本特征。大眾普遍意識(shí)中的藝術(shù)家通常意味著具有較高的審美能力和嫻熟的創(chuàng)作技巧，從事藝術(shù)創(chuàng)作并取得了一定成就的人。其最基本的特征首先是具有藝術(shù)天賦的，這種天賦可能體現(xiàn)在筆觸運(yùn)用上、色彩調(diào)和上，也可能體現(xiàn)在音符流動(dòng)中，詩(shī)詞歌賦、琴棋書畫，不一而足；其二是富有藝術(shù)感性，極強(qiáng)的移情通感能力，即對(duì)于美的事物的豐富的感受力和想象力，又因這種極度的感性而充滿激情，將自我感受通過藝術(shù)手段表現(xiàn)在筆觸、音符和語(yǔ)言等形態(tài)之中。正像黑格爾描述的，真正的藝術(shù)家都有一種天生自然的推動(dòng)力即將自己的情感思想即刻表現(xiàn)為藝術(shù)形象的直接的需要。

Few studies have been conducted to identify factors associated with the degree of astigmatism change after ptosis surgery

. In this study, we evaluated corneal astigmatism value of patients who underwent ptosis surgical repair to find the association between patient factors and postoperative corneal astigmatism change. The changing pattern of corneal astigmatism axis after surgery was also identified.

SUBJECTS AND METHODS

All patients underwent levator resection procedure by the same experienced surgeon, with informed consent obtained preoperatively. This study was approved by the Human Research Ethics Committee of the Faculty of Medicine Naresuan University in accordance with the Declaration of Helsinki.

This is a retrospective study evaluated patients diagnosed with congenital or acquired ptosis who underwent ptosis surgical repair at Oculoplastic Service of the Department of Ophthalmology, Naresuan University Hospital,Phitsanulok, Thailand between September 2017 and August 2019.

A comprehensive ophthalmological examination was performed. Data recorded included visual acuity, refraction,anterior segment exam, fundus exam, eye motility, and levator function.

Patient factors were identified and recorded.The data included age at operation, sex, preoperative marginreflex distance (MRD) 1, and preoperative degree and axis of corneal astigmatism. Subgroups of each factor were classified to evaluate the associations with the degree of astigmatism change at 6-week postoperatively.

Several studies attempted to compare the degree of corneal astigmatism change among various eyelid surgery procedures.A retrospective study by Zinkernagel

found a significant change of postoperative corneal astigmatism in patients who underwent ptosis surgery and blepharoplasty with reduction of the entire fat pad, in contrast to insignificant value in the groups with skin-only blepharoplasty and blepharoplastywith reduction of the medial fat pad. This study reflects the correlation between the severity of eyelid abnormality and the significant astigmatism value change postoperatively. A similar result was reported by Kim

; patients underwent levator resection exhibited more corneal curvature change compared with those who underwent blepharoplasty.

從圖2可以看出，施鉀明顯促進(jìn)了鉀素積累量的增加，與NP處理相比，施鉀處理的鉀積累量增加了35.87%～68.97%， 等施鉀量條件下，100%OF 處理的鉀積累量最小，為 156.71 kg／hm2，30%OF＋70%CF 處理的干物質(zhì)積累量最大，達(dá)到 194.89 kg／hm2，其他處理的鉀積累量處于兩者之間，且無(wú)明顯差異。……