Modelling multiple outcomes in repeated measures studies: Comparing aesthetic eyelid surgery techniques

We propose a multivariate regression model to deal with multiple outcomes along with repeated measures in the context of longitudinal data analysis. Our model allows for flexible and interpretable modelling of the covariance structure within outcomes by using a linear combination of known matrices, while the generalized Kronecker product is employed to take into account the correlation between outcomes. We present maximum likelihood estimation along with extensions of the classical multivariate analysis of variance and multiple comparison hypothesis tests to deal with multivariate longitudinal data. The model and the associated multivariate hypothesis test are motivated by a prospective study conducted to compare three aesthetic eyelid surgery techniques, namely blepharoplasty, endoscopic forehead lift and endoscopic forehead lift associated with blepharoplasty. The effect of the techniques was assessed using measurements of a horizontal line through pupil centre and then three vertical lines, which go in direction to lateral canthus, middle pupil and medial canthus to the top of the brow. In this study, 30 female patients were randomly divided into three groups. Preoperative measurements were compared with postoperative measurements taken 30 days, 90 days and 10 years after the surgery. The presented multivariate model provided a better fit than its univariate counterpart. The results showed that the three surgery techniques tend to increase all considered outcomes in a long-term perspective, that is, from preoperative to 10 years postoperative evaluations. The only exception was for the outcome lateral eyebrow, for which the blepharoplasty had no significant effect.

Subbrow Lift Using Frontalis Sling to Correct Lateral Orbital Laxity

Background In order to correct upper lid laxity, upper blepharoplasty, subbrow excision, and forehead lift have been utilized. Our newly developed subbrow excision attaches the orbicularis oculi muscle to the frontalis muscle. This improves the longevity of the result without inhibiting the gliding plane of the periorbita. Method From January 2016 to July 2018, 564 patients were operated on using this technique. Among them, 41 were male and 523 were female with the average age of 59.5 years. The average size of the subbrow excision was 55 mm × 8 mm. From the upper skin incision site, the upper dissection proceeded cephalad in the subcutaneous plane just above the orbicularis oculi muscle to the point where the frontalis muscle was seen. The lower flap was created by incising the orbicularis oculi muscle 5 mm cephalad to the distal skin incision. From this 5-mm orbicularis muscle stump, the dissection proceeded caudally in a plane between the orbicularis muscle and the orbital septum. Once this flap was created, the 5-mm muscle stump was attached to the exposed frontalis muscle in a horizontal mattress fashion in three areas. The skin incision was then closed. Three months after the operation, a satisfaction survey was conducted using the Likert scale. Results The patients were followed postoperatively for at least 6 months. In all but two cases, the orbital laxity improved. However, in the brow’s lateral third where the frontalis muscle does not exist, a slight lowering of the brow had occurred. The incision healed well without any keloid or hypertrophic scars. There were no significant complications such as superior orbital nerve entrapment-related sensory problems. Conclusions Subbrow lift utilizing the frontalis muscle attachment to the lower flap orbicularis muscle is a novel method of correcting upper eyelid skin hooding. The technique does not rely on periosteal fixation. Therefore, the eyebrow gliding plane is not violated. Thus, the natural eyebrow movement is maintained. There were no cases of injury to the deep branch of the supraorbital nerve, poor wound healing, or other significant complications. Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Strategies of upper blepharoplasty in aging patients with involutional ptosis

In many aging individuals, dermatochalasis and involutional ptosis appear together. Therefore, for functional and aesthetic purposes, ptosis correction and upper blepharoplasty are performed together. The aim of this article is to investigate factors that should be considered in order to achieve good results when simultaneously performing involutional ptosis correction and upper blepharoplasty in aging patients. Involutional ptosis is usually corrected through aponeurosis advancement in mild cases. In moderate or severe ptosis, the Muller muscle and aponeurosis are used together to correct ptosis. Using the two muscles together has the advantages of reducing lagophthalmos and increasing the predictability of outcomes after surgery. Broadly speaking, the surgical method used for involutional ptosis varies depending on the specific case, but unlike congenital ptosis, it is often not necessary to perform overcorrection. In particular, if there are problems such as severe dry-eye symptoms or risk of lagophthalmos, undercorrection should be considered. When performing ptosis correction, the surgeon should be careful not to overdo skin excision; instead, limited excision should be performed. After ptosis surgery, the brow may descend and the double fold may look too small. However, in order to make the double eyelids look larger, the surgeon should consider making the double eyelid design high rather than excising an excessive amount of skin. In some cases, to obtain more natural double eyelids and favorable results, it may be necessary to perform a sub-brow lift or forehead lift before or after involutional ptosis surgery.