Evaluation Of Blepharoptosis

    Ptosis of the upper eyelid is determined by measuring the palpebral fissure width and margin reflex distance-1 (MRDi) described by Urist and me.3 Palpebral fissure width is the distance from the central lower eyelid to the central upper eyelid margins and is measured with the patient's eyes in the primary position of gaze (Fig. 3-7). Normally, this width is about 10 mm. If it is significantly less, a ptosis should be suspected and treated.

    The MRDi is a quantitative measurement of ptosis and is determined as follows. With the eyes of the examiner and patient at the same level, an eye muscle light held between the examiner's eyes is directed at the patient. The MRD, is the number of millimeters from the light reflex on the patient's cornea to the central upper eyelid margin with the patient's eyes in the primary position of gaze; this is recorded in positive numbers (Fig. 3-8). If the ptotic eyelid covers the corneal reflex, the eyelid is raised until the reflex is seen. The number of millimeters that the eyelid must be raised is recorded as the MRDi in negative numbers. The MRD, is a more accurate measurement of the amount of ptosis than the palpebral fissure width because the latter can be altered by abnormalities of the lower eyelid, including lower eyelid retraction. The normal MRD, is 4—4.5 mm. A smaller measurement usually means ptosis of the upper eyelid.


    The palpebral fissure width on down gaze is another important measurement of blepharoptosis. The examiner uses his or her finger to fixate the patient's brow on the side being examined while raising the brow and upper eyelid on the opposite side. The patient is instructed to look to the extreme downward position of gaze while the distance between the upper and lower eyelids is measured. Normally, this distance is 2 mm or more. If the distance is 1.5 mm or less, patients frequently have difficulty reading because of the upper eyelid ptosis unless they raise their eyebrows, which is usually difficult to sustain. Olson and I showed that approximately one-third of patients with acquired ptosis of the upper eyelids have a zero palpebral fissure width on downgaze and are essentially blind unless they raise their eyebrows and thus their eyelids.

Figure 3-5 The upper eyelid creaser (Bausch & Lomb Storz® Instruments) consists of a handle and a thin, slightly curved metal extension.

Figure 3-6 A patient with upper eyelid dermatochalasis (excess skin) and poorly defined upper eyelid creases. The upper eyelid creaser is used to compress the upper eyelid skin to determine the desired position at which to reconstruct an upper eyelid crease.

Figure 3-7 The palpebral fissure width is measured over the central eyelid with the patient gazing in the primary position. This is a measurement from the central lower to the central upper eyelid, and the difference between the normal and ptotic lids determines the amount of eyelid ptosis.