Jaime Roizenblatt

Iris recognition as a biometric method after cataract surgery

BackgroundBiometric methods are security technologies, which use human characteristics for personal identification. Iris recognition systems use iris textures as unique identifiers. This paper presents an analysis of the verification of iris identities after intra-ocular procedures, when individuals were enrolled before the surgery.MethodsFifty-five eyes from fifty-five patients had their irises enrolled before a cataract surgery was performed. They had their irises verified three times before and three times after the procedure, and the Hamming (mathematical) distance of each identification trial was determined, in a controlled ideal biometric environment. The mathematical difference between the iris code before and after the surgery was also compared to a subjective evaluation of the iris anatomy alteration by an experienced surgeon.ResultsA correlation between visible subjective iris texture alteration and mathematical difference was verified. We found only six cases in which the eye was no more recognizable, but these eyes were later reenrolled. The main anatomical changes that were found in the new impostor eyes are described.ConclusionsCataract surgeries change iris textures in such a way that iris recognition systems, which perform mathematical comparisons of textural biometric features, are able to detect these changes and sometimes even discard a pre-enrolled iris considering it an impostor. In our study, re-enrollment proved to be a feasible procedure.

Leber's Congenital Amaurosis with Associated Nephronophthisis

The authors present a case of a 15-year-old girl with Lebers congenital amaurosis with associated nephronophthisis. The main findings in this case are: congenital blindness; enophthalmos; photophobia; nystagmus; keratoconus; cataracts; pigmentary degeneration in the fundus of both eyes; progressive uremia with absence of hematuria, proteinuria, pyuria, and glycosuria; low urinary density, normal lipidic profile; osteoporosis; absence of edema; polydipsia; polyuria; and a history of consanguinity between her parents. Tranmission of this entity allows an autosomal recessive pattern.

Median cleft face syndrome or frontonasal dysplasia: a case report with associated kidney malformation.

The authors present a case of an 11-month-old girl with the medial cleft face syndrome and the following malformations: ocular hyperterolism, primary telecanthus, cleft nose with absent tip, broad nasal root, complete absence of the left upper lid, and abnormal hair-line implantation in the corresponding frontal region, high arched palate, neurosensorial deafness and agenesia of the right kidney. The authors propose that the eyelid is responsible for the area of hair growth suppression around the eyes. This is the first case report of median cleft face syndrome associated with renal agenesia.

Merosin-positive congenital muscular dystrophy in two siblings with cataract and slight mental retardation

We report on two siblings that have been followed for 14 years, with merosin-positive congenital muscular dystrophy (CMD), cataract, retinitis pigmentosa, dysversion of the optic disc, but no cerebral anomalies, except for microcephaly and slight mental retardation (MR). The younger child had three generalized seizures easily controlled by anticonvulsant therapy. Both children presented hypotonia from birth, delayed psychomotor development, generalized muscular weakness, and atrophy and joint contractures of knees and ankles. The course of the disease, apparently static during the first 10 years of life, became progressive during the second decade with loss of deambulation by the age of 13. Creatine kinase was increased in both children. Bilateral cataract was diagnosed at 6-months of age. In spite of the occurrence of microcephaly, MR was slight and the siblings acquired reading and writing skills after the aged 10. Head magnetic resonance imaging showed normal results in both siblings. The classification of these cases within the broad spectrum of CMD is difficult since most of the known muscle-eye-brain syndromes generally show severe MR and brain anomalies. We consider these cases as corresponding to the rarer syndromes of merosin-positive CMD with associated features such as cataract and MR that were particularly emphasized during the 50th ENMC International Workshop on CMD [Dubowitz V. Workshop report: 50th ENMC International workshop on congenital muscular dystrophy. Neuromusc Disord 1997;7:539-547]. Further genetic, pathological, neuroradiological, and immunocytochemical studies will be necessary for better elucidation of the classification and pathogenesis of CMD.

Termoterapia transpupilar como opção terapêutica para hemangioma circunscrito de coróide: relato de caso

The authors describe a case of a circumscribed choroidal hemangioma with secondary retinal detachment treated with transpupillary thermotherapy using diode laser. The settings were: 900 mW power, 4.2 mm spot, for 3 minutes, QuadrAsphericO lens (Volkâ) with a magnification factor of 1.97. One month later, there was a significant shrinkage of the hemangioma with full recovery of vision in this eye. The authors discuss some aspects of this method, which seems promising in treatment of this vascular tumors.

Quantification of ocular inflammation with technetium-99m glucoheptonate

Histological and morphometric evaluation of ocular inflammation is difficult, particularly when there is extensive ocular involvement with abscess formation and necrosis. A quantitative imaging procedure applicable to humans would be important clinically. To establish such a procedure, turpentine-induced ocular inflammation was obtained by subconjunctival injection in the right eye of 55 rabbits. The left eye was used as control and injected with a volume of saline equal to the volume of turpentine in the right eye. Volumes of turpentine or saline were 0.02, 0.04, 0.06, 0.2 and 0.6 ml, and the rabbits were divided into groups 1–5, according to these volumes. Imaging was performed 48 h after turpentine injection and 6 h after intravenous injection of 10 mCi of technetium-99m glucoheptonate (99mTc-GH). An inflammatory reaction index (IRI), defined as the ratio of counts of the right eye divided by counts of the left eye, was used. IRIs were proportional to the degree of inflammation and allowed the distinction of 3 subgroups: one represented by group 4, one by group 5 and one by groups 1, 2 and 3. This method of quantification of ocular inflammatory processes using 99mTc-GH is original, rapid, non-invasive, reproducible and safe, although unable to differentiate inflammatory processes caused by doses of turpentine which are very small and close to each other. It is conceivable that its application to humans will bring new insight into the ocular inflammatory process and response to therapy.