Avaliação de parâmetros métricos oculares pela fotografia digital da face: uso do diâmetro da íris como unidade de referência

Miot, Hélio Amante; Pivotto, Daniel Rosito; Jorge, Edson Nassib; Mazeto, Gláucia Maria Ferreira da Silva

doi:10.1590/s0004-27492008000500013

Cited by 6 publications

(2 citation statements)

References 17 publications

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“…Oculometric variables (Figure 1), such as MAR (mediopupilar aperture), PF (horizontal palpebral fissure), MH (medial aperture height, tangential to iris), LH (lateral aperture height, tangential to iris), RL (distance of iris edge to the lateral boundary of palpebral fissure), and HIP (distance from the highest point of iris to the lateral limit of the palpebral fissure), were calculated according to the size in pixels of each structure. The lengths were expressed according to individual horizontal iris diameter (DI) 13,14. Secondary variables were also calculated: lateral-medial aperture ratio (L/M) and product of medial aperture and palpebral fissure (MAxPF).…”

Section: Methodsmentioning

confidence: 99%

Comparative Evaluation of Oculometric Variables in Graves’ Ophthalmopathy

Miot

Fernandes

Jorge

et al. 2009

Clinics

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OBJECTIVESTo estimate oculometric parameters of Graves’ ophthalmopathy in comparison to healthy eyes using digital photography and digital image analysis.INTRODUCTION Graves’ ophthalmopathy is the main cause of eye proptosis. Because these protrusions cause clinically perceived distortions in orbital architecture, digital photographs can be used to detect and quantify these changes.METHODSWe carried out a cross-sectional study comprising 12 healthy volunteers and 15 Graves’ ophthalmopathy patients with the purpose of evaluating the use of simple, non-invasive digital photography to estimate oculometric parameters of Graves’ ophthalmopathy and compare them with the parameters of unaffected eyes.Facial photographs of cases and controls were taken in a standardized manner. Oculometric parameters were compared between the groups and then correlated to proptometer measures.RESULTSAll estimated oculometric variables showed significant differences between the groups, in particular with regard to mediopupilar aperture, lateral height, distance from the iris edge to the lateral boundary of the palpebral fissure, and distance from the higher point of the iris to the lateral limit of the palpebral fissure. The product of medial aperture and horizontal palpebral fissure also revealed greater discrepancy between the groups. Proptometer measures showed significant linear correlation between the distance from the iris edge to the lateral boundary of the palpebral fissure and between the distance from the higher point of the iris to the lateral limit of palpebral fissure (p<0.05).CONCLUSIONSComparative analysis of oculometric parameters in Graves’ ophthalmopathy suggests that eye proptosis is related to an asymmetric increase in lateral oculometric measures. Standardized digital photographs can be used in clinical practice to objectively estimate oculometric parameters of Graves’ ophthalmopathy patients.

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Section: Methodsmentioning

confidence: 99%

Comparative Evaluation of Oculometric Variables in Graves’ Ophthalmopathy

Miot

Fernandes

Jorge

et al. 2009

Clinics

Self Cite

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“…Although clinical facial photography should follow some standard rules (e.g., adequate lighting and adjusting the patient’s posture to neutral head position (NHP)), the photograph magnification will differ depending on various variables. When an image is captured of an object, depending on the camera's features (e.g., the focal length of the lens) and the photographic technique (e.g., the distance between the camera and the object), the resulting photograph can be smaller or larger than the object itself 10 . Therefore, measuring the distance between two facial landmarks on the facial photograph would not provide us with the actual measurement of that distance on the face.…”

Section: Introductionmentioning

confidence: 99%

A deep learning framework to scale linear facial measurements to actual size using horizontal visible iris diameter: a study on an Iranian population

Pirayesh,

Hassanzadeh-Samani,

Farzan

et al. 2023

Sci Rep

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Digital images allow for the objective evaluation of facial appearance and abnormalities as well as treatment outcomes and stability. With the advancement of technology, manual clinical measurements can be replaced with fully automatic photographic assessments. However, obtaining millimetric measurements on photographs does not provide clinicians with their actual value due to different image magnification ratios. A deep learning tool was developed to estimate linear measurements on images with unknown magnification using the iris diameter. A framework was designed to segment the eyes’ iris and calculate the horizontal visible iris diameter (HVID) in pixels. A constant value of 12.2 mm was assigned as the HVID value in all the photographs. A vertical and a horizontal distance were measured in pixels on photographs of 94 subjects and were estimated in millimeters by calculating the magnification ratio using HVID. Manual measurement of the distances was conducted on the subjects and the actual and estimated amounts were compared using Bland–Altman analysis. The obtained error was calculated as mean absolute percentage error (MAPE) of 2.9% and 4.3% in horizontal and vertical measurements. Our study shows that due to the consistent size and narrow range of HVID values, the iris diameter can be used as a reliable scale to calibrate the magnification of the images to obtain precise measurements in further research.

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Defining Temporal Hairline Landmarks

Nagarkar

Cheng

2017

Plastic &Amp; Reconstructive Surgery

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Brow dermoids are benign pediatric neoplasms. Endoscopic resection requires incisions placed within the temporal hairline, which is often difficult to reliably locate in infants. The authors studied adult and pediatric patients to define the location of the hairline in relationship to simple facial landmarks. Adult and pediatric patients who were seen in preoperative consultation for facial surgical procedures were identified and included in the study. Patients with a history of facial trauma, surgery, or congenital anomalies were excluded. Digital photographs were analyzed to measure corneal white-to-white diameter. Lines were drawn connecting the tragus to the lateral canthus and from the inferiormost aspect of the earlobe bisecting the first line (line A). The maximal distance between line A and the temporal hairline was recorded. One hundred sixteen patients met the inclusion criteria, 81 adults and 35 pediatric patients. Average age was 55.9 years in adults and 3.2 years in the pediatric group. Measurements were normalized to the corneal diameter. Average temporal hairline distance from line A was 25.0 mm in adults and 21.8 mm in the pediatric group. Hairline position was not correlated with age or sex. The temporal hairline can be reliably located relative to a line drawn from the inferior aspect of the earlobe to the midpoint of the line connecting the lateral canthus and tragus. The temporal hairline is within 30 mm of this line. When designing a temporal hairline incision in infants, it can be safely placed 30 mm or more posterior to this line to ensure a well-hidden scar.

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Avaliação de parâmetros métricos oculares pela fotografia digital da face: uso do diâmetro da íris como unidade de referência

Cited by 6 publications

References 17 publications

Comparative Evaluation of Oculometric Variables in Graves’ Ophthalmopathy

Comparative Evaluation of Oculometric Variables in Graves’ Ophthalmopathy

A deep learning framework to scale linear facial measurements to actual size using horizontal visible iris diameter: a study on an Iranian population

Defining Temporal Hairline Landmarks

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