Determining the Degree of Perceptible Static Eyelid Asymmetry and Effect of Face Inversion: A Cross-sectional Pilot Study

PURPOSE

To determine the degree of static eyelid asymmetry required to be perceptible and whether this is affected by image inversion.

METHODS

Images of 3 volunteers were digitally manipulated to have eyelid asymmetry of 0.5 mm, 1 mm, or 1.5 mm of 3 different types, upper lid ptosis, upper lid retraction, and lower lid retraction. Forty-nine laypersons stated whether the images were symmetrical or asymmetrical. A separate inversion survey, completed by 29 clinicians, consisted of symmetrical images and 1 mm asymmetrical images, with half being inverted.

RESULTS

Upper lid ptosis, upper lid retraction, and lower lid retraction were not detected by most laypeople at 0.5 mm of severity (18.9%, 6.7%, 18.9% detection, respectively) but all 3 were detected by the majority of participants once asymmetry reached 1 mm severity (65.7%, 61.8%, 51.0% detection, respectively) and rose to over 70% identification at 1.5 mm (92.2%, 73.5%, 73.5% detection, respectively). Inversion of the images led to 19.7% lower rates of correct identification of asymmetrical faces compared with images presented in the correct orientation (80.7% asymmetry identified in normal images, 61.0% inverted, p < 0.001).

CONCLUSIONS

All asymmetries were detectable by a majority of laypersons at a severity of 1 mm. Image inversion decreases a clinician's ability to detect a 1 mm asymmetry, indicating an impaired asymmetry perception in the intraoperative view. This study provides research to counsel patients with varying degrees of eyelid asymmetry.

Informed Consent In Facial Photograph Publishing: A Cross-sectional Pilot Study To Determine The Effectiveness Of Deidentification Methods

This study determined the effectiveness of three deidentification methods: use of a) a black box to obscure facial landmarks, b) a letterbox view to display restricted facial landmarks and c) a half letterbox view. Facial images of well-known celebrities were used to create a series of decreasingly deidentified images and displayed to participants in a structured interview session. 55.5% were recognised when all facial features were covered using a black box, leaving only the hair and neck exposed. The letterbox view proved more effective, reaching over 50% recognition only once the periorbital region, eyebrows, and forehead were visible. The half letterbox was the most effective, requiring the nose to be revealed before recognition reached over 50%, and should be the option of choice where appropriate. These findings provide valuable information for informed consent discussions, and we recommend consent to publish forms should stipulate the deidentification method that will be used.

Application of SPF moisturisers is inferior to sunscreens in coverage of facial and eyelid regions

Many moisturisers contain sun protection factors (SPF) equivalent to those found in sunscreens. However, there is a lack of research into how SPF moisturiser application compares to sunscreens in terms of coverage achieved and protection afforded. Previously we demonstrated that users incompletely covered their eyelid regions during routine sunscreen application. Here, we aimed to determine if SPF moisturiser users also displayed these tendencies. A study population of 84 participants (22 males, 62 females, age 18–57) were exposed to UV radiation and photographed using a tripod mounted UV sensitive DSLR camera on two separate visits. At visit one, images were acquired before and after applying either SPF30 sunscreen or moisturiser, then at visit two the study was repeated with the other formulation. Images were processed for facial landmark identification followed by segmentation mapping of hue saturation values to identify areas of the face that were/were not covered. Analyses revealed that application of moisturiser was significantly worse than sunscreen in terms area of the whole face missed (11.1% missed with sunscreen compared to 16.6% for SPF moisturiser p<0.001 paired t-test). This difference was primarily due to decreased coverage of the eyelid regions (14.0% missed with sunscreen, 20.9% moisturiser, p<0.001). Analysis of a post-study questionnaire revealed participants to be unaware of their incomplete coverage. Secondary analyses revealed improved coverage in males (p = 0.05), and, with moisturiser only, in participants with darker skin tones (p = 0.02). Together these data indicate that, despite potential advantages in terms of increased frequency of application of moisturiser, the areas of the face that are at higher cancer risk are likely not being protected, and that participants are unaware that they are at risk. As such, alternative sun-protection strategies should be promoted.

UV imaging reveals facial areas that are prone to skin cancer are disproportionately missed during sunscreen application

Application of sunscreen is a widely used mechanism for protecting skin from the harmful effects of UV light. However, protection can only be achieved through effective application, and areas that are routinely missed are likely at increased risk of UV damage. Here we sought to determine if specific areas of the face are missed during routine sunscreen application, and whether provision of public health information is sufficient to improve coverage. To investigate this, 57 participants were imaged with a UV sensitive camera before and after sunscreen application: first visit; minimal pre-instruction, second visit; provided with a public health information statement. Images were scored using a custom automated image analysis process designed to identify areas of high UV reflectance, i.e. missed during sunscreen application, and analysed for 5% significance. Analyses revealed eyelid and periorbital regions to be disproportionately missed during routine sunscreen application (median 14% missed in eyelid region vs 7% in rest of face, p<0.01). Provision of health information caused a significant improvement in coverage to eyelid areas in general however, the medial canthal area was still frequently missed. These data reveal that a public health announcement-type intervention could be effective at improving coverage of high risk areas of the face, however high risk areas are likely to remain unprotected therefore other mechanisms of sun protection should be widely promoted such as UV blocking sunglasses.

Pupillary distortion and staphyloma following trans-scleral contact diode laser cyclophotocoagulation: a clinicopathological study of three patients

PURPOSE

To search for the cause of scleral thinning and pupillary distortion following trans-scleral contact diode laser cyclophotocoagulation (TCDLC).

METHODS

We reviewed the records of 3 patients in whom there were complications of scleral thinning and pupillary distortion following TCDLC. One of the eyes was later enucleated, and we present the histopathological findings. Using the histopathological features in this patient, we discuss the possible pathogenesis of the scleral thinning and pupillary distortion.

RESULTS

Case 1 is a 46-year-old white woman who following TCDLC in an area of clinically normal sclera developed a staphyloma. Case 2 is a 52-year-old white woman who following TCDLC in an area of scarred sclera developed mild thinning. Case 3 is an 85-year-old white man who following TCDLC developed pupillary distortion, and gonioscopy revealed damage to the peripheral iris. Histological examination of case 1 revealed the staphyloma covered by a thin layer of conjunctival epithelium, collagen and vitreous condensation. We also observed cicatricial cilary body contraction causing distortion of the pupil and lens.

CONCLUSIONS

Therapeutic TCDLC can produce scarring of the iris root, anterior chamber angle, draining structures and ciliary body, and may result in pupillary distortion. Pre-existing scleral scars may predispose to scleral damage following TCDLC. We discuss a simple strategy to avoid this complication of TCDLC.