Disease Entity[edit | edit source]
Aponeurotic Blepharoptosis (or Ptosis)
Disease[edit | edit source]
Aponeurotic Ptosis is the most common type of acquired ptosis, it´s also called senile or involutional ptosis because it occurs most often in the elderly as an involutional disorder. This entity was fist described by Jones Quickert, and Wobig in 1975 who demonstrated that the levator aponeurosis appeared dehisced or disinserted from the tarsus. This disinsertion may be congenital or acquired.
Etiology[edit | edit source]
Most patients with acquired ptosis develop the condition secondary to involutional changes in the levator aponeurosis. Gradual stretching or dehiscence of this structure causes slowly progressive ptosis.
Risk Factors[edit | edit source]
Congenital aponeurotic ptosis is uncommon but this could be secondary to trauma by forceps delivery, vacuum extraction, fetal rotation, and shoulder distocia. There are multiple factors that can cause disinsertion of the levator aponeurosis, such as continuous rubbing of the eye, chronic use of contact lenses, inflammatory diseases, trauma or following eyelid or intraocular surgery. Approximately 6% of patients following cataract surgery develops ptosis.
General Pathology[edit | edit source]
The primary changes found in acquired involutional blepharoptosis include dehiscence or disinsertion of the levator aponeurosis from the tarsus, and dehiscence of the medial limb of Whitnall’s ligament.
Histopathology[edit | edit source]
In some patients have revealed a normal levator aponeurosis but a myogenic degeneration of the muscle itself, characterized by a fatty degeneration in the area of the Whitnall’s ligament. This fatty infitration has been confimed by light microscopy and appears to be a degenerative change found in adults with acquired ptosis. Müller’s muscle appeared to be grossly intact, but microscopic fibrosis with plentiful collagen fibers was observed in Müller’s muscles of patients with acquired blepharoptosis induced by prolonged hard contact lens wear.
Primary prevention[edit | edit source]
It´s focused in the treatment of all possible causes of rubbing the eye as alergic conjunctivitis, also must be carefull with the prolonged use of contact lenses, and opportunal treatment of inflammatory diseases.
Diagnosis[edit | edit source]
Symptoms[edit | edit source]
Patients with aponeurotic ptosis may present with a spectrum of symptoms ranging from visually significant obstruction to minor, visually asymptomatic cosmetic eyelid asymmetry. Visual field obstruction results in functional blockage of the superior visual field. Symptoms are often worse when reading or downgaze. Patients tend to compensate with overaction of the frontalis muscle. Persistent brow elevation may lead to frontalis fatigue or even cephalgia.
Also it´s important to look for fluctuation in symptoms of fatigue throughout the day that may indicate myasthenia gravis. In these cases, patients should also be asked about their use of statin medications, cause there have been recent reports of myasthenialike syndromes that resulted in ptosis.
Physical examination[edit | edit source]
Here are some clinical key points that should be noticed, some measurements must be interpreted whith regard and thinking in each patient as unique, cause besides exist a “normal” range all are variable depending of age, etnicity, gender, genetic, etc.
Margin reflex distance. Defined as the distance from the upper eyelid margin to the corneal light reflex in primary position. Normal distance 4-5 mm.
Vertical palpebral fissure height. Defined as the widest point between the lower eyelid and the upper eyelid. This measurement is taken with the patient fixating on a distant object in primary gaze. Normal palpebral fissure measures between 12–15 mm.
Upper eyelid crease position. Defined as distance from upper eyelid crease to the eyelid margin Normal distance is 8-9 mm in males and 9-11 mm in females. Aponeurotic defects characteristically have a high or an absent upper eyelid crease, also any asymmetry, altered contour, lack of continuity or thinning of the eyelid superior to the upper tarsal plate may indicate the presence of levator aponeurosis disinsertion.
Levator function (upper eyelid excursion). It is estimated by measuring from downgaze to upgaze with frontalis muscle function negated. Crowell Beard reported normal eyelid excursión to be between 12-17 mm The levator function is classified as Good >= 8 mm Fair 5 -7 mm Poor 4 mm
The levator muscles obey Hering’s law of equal innervation. wich means that are innervated symmetrically, resulting in equal central neural output, so in cases of bilateral asymmetrical ptosis, the less affected eyelid may maintain a normal level of elevation due to excessive innervational stimulation determined by the more ptotic eyelid. This condition can be detected prior to surgery by manually elevating the ptotic eyelid. An immediate fall of the contralateral eyelid confims the presence of bilateral, asymmetrical ptosis masked by levator “overaction.”
Myasthenia gravis should be considered in all patients with ptosis, and one may check for levator fatigability by asking the patient to alternate between upgaze and downgaze repeatedly, or by asking the patient to look in extreme upgaze for up to 1–2 min.
Visual acuity and refraction: This is important because it could change after ptosis surgery. This occurs because the weight of the upper eyelid on the cornea may affect the shape of the cornea, and hence refractive error may change after surgical repositioning of the eyelid. Corneal topography has usually demonstrated an increase in against the rule astigmatism. These changes tend to be temporary, with a decrease in refractive shift by 12 months after surgery. That´s why, one should avoid prescribing glasses to patients prior to and up to 3 months following ptosis surgery.
Elderly patients who have dermatochalasis must be assessed carefully to notice if the lower position of the eyelid is a mechanical effect of the redundant skin and/or due to an aponeurotic defect.
Pupil abnormalities, ocular, extraocular and facial movements should be normal.
Head position, chin elevation , brow position, and brow action in attempted upgaze must be appreciated as a sign of ptosis.
Bell phenomenon, corneal sensation, lagophthalmos and poor tear film quantity or quality may be explored cause a faillure in this ones may predispose a patient to complications of ptosis repair such as dryness and exposure keratitis,
Diagnostic procedures[edit | edit source]
Visual field testing with the eyelids untaped (in the natural, ptotic state) and taped (artificially elevated) helps determine the patient's level of functional visual impairment.
External full-face photography is helpfull to compare past and actual state of ptosis.
Pharmacologic testing may be helpful to exclude some clinical diagnosis like Horner síndrome (Phenyleprine 10%) or myasthenia gravis (edrophonium chloride, ice- pack, or acetylcholine receptor antibody tests)
Differential diagnosis[edit | edit source]
General treatment[edit | edit source]
Once the diagnosis of aponeurotic ptosis is made, different surgical options are available. The goal of surgery is to reattach a disinserted or dehisced aponeurosis to the superior anterior surface of the tarsus, or shorten and tighten a weak levator muscle, is usually done under local anesthesia, with or without IV sedation. Anterior levator aponeurotic-muscle reattachment or resection is effective. Some surgeons perform a posterior resection of Müller’s muscle in patients who demonstrate adequate elevation of the eyelid following instillation of topical phenylephrine. Also a small anterior, minimal dissection procedure was compared with a traditional, anterior aponeurotic approach, and results of the less invasive surgery were as efficacious as the traditional approach. The small incision procedure uses a surgical opening of about 4 mm, in contrast to the traditional 10 mm. In the study, those in the small incision group also experienced better eyelid contour outcome. Moreover, with the minimal dissection technique, operating time was significantly less overcorrection or undercorrection.
Complications[edit | edit source]
The most common complication of ptosis surgery is undercorrection which is seen after about 10–15% of cases. This patients should be observed until edema has resolved and the eyelid position has stabilized. Overcorrection should be observed until the lid position has become stable. Digital massage or “squeezing” exercises occasionally lower the eyelid, improving mild overcorrection. Surgical revision is considered in patients with persistent symptomatic ptosis or overcorrection.
Changes in corneal astigmatism can be seen in up to 72% of patients undergoing ptosis repair. It is generally with-the-rule, and in most cases regress back toward the preoperative level within 1 year.
Other potential complications are hemorrhage, infection, poor wound healing traumatize the superior oblique muscle or lacrimal gland ductules. unsatisfactory or asymmetric eyelid contour, scarring, wound dehiscence, eyelid crease asymmetry, conjunctival prolapse, tarsal eversion, and lagophthalmos with exposure keratitis.
Prognosis[edit | edit source]
The majority of ptosis procedures are successful and restore a normally functioning eyelid.
References[edit | edit source]
American Academy of Ophthalmology Orbit, Eyelids and Lacrimal System, Section 7, San Francisco, 2011 Ashok Garg, Jorge L Alio, Oculoplasty and Reconstructive Surgery, First Edition, New Delhi, India, Jaypee-Highlights Medical Publishers, Inc, 2010. Myron Yanoff, Jay S Duker, Ophtalmology. Third Edition, China, Mosby, 2009. Adam J. Cohen, David A. Wheinberg, Evaluation and Management of Blepharoptosis, First Edition, New York, USA, Springer Science+Business Media, LLC 2011. Kate Ahmad, Mark Wright, Christian J Lueck, Ptosis, Pract Neurol. 2011 ;11 (6): 332¬-340 Jack J Kanski, Brad Bowling, Clinical Ophthalmology, Seventh Edition, Barcelona, España, Elsevier 2012. Akihide Watanabe, Biji Araki, Kenji Noso, Hiroiko Kakizaki and Shigeru Kinoshita, Histopathology of Blepharoptosis Induced by Prolonged Hard Contact Lens Wear, American journal of Ophthalmology, 2006;141:1092–1096. Barbara Boughton, Assessing and Correcting Ptosis, American Academy of Ophthalmology, November 2007, http: //www.aao.org/publications/eyenet/200711/oculoplastics.cfm, accessed January 17, 2015.