Unusual Case of Indolent Choroidal Alterations Mimicking Neurofibromatosis Type 1.

Indolent, non-progressive choroidal alterations can be strongly suggestive of neurofibromatosis type 1 (NF1) but are also rarely of unknown aetiology. A 63-year-old man presented for a routine examination. Comprehensive ophthalmological examination and retinal imaging was performed. Visual acuity was 20/20. The anterior segment and fundus were unremarkable. Near-infrared reflectance (NIR) with spectral-domain optical coherence tomography showed unilateral hyperreflective areas in the left posterior pole, corresponding to choroidal nodules on enhanced depth imaging and hypofluorescent areas on indocyanine green angiography. Dermatological evaluation and genetic testing for NF1 were negative. Chest computed tomography, liver function, HLA-A29, and angiotensin-converting enzyme level were negative. The patient has remained in good health and the choroidal alterations have remained non-progressive for 3 years. Choroidal alterations observed with NIR could be a manifestation of somatic mosaicism or a variation of a new unclassified correlated condition that may be better elucidated in the future, given the use of novel imaging techniques that are currently available in ophthalmology.

Effect of refractive correction on the accuracy of frequency-doubling technology Matrix.

PURPOSE: To investigate the effect of refractive correction on the reliability and accuracy of frequency-doubling technology (FDT) Matrix examinations. METHODS: Forty-eight eyes of healthy people were submitted to the FDT Matrix 30/2 threshold program. They had experience in perimetry, normal eye examination, and negative history for glaucoma and/or neurological diseases. The subjects were randomized into groups A (24 subjects) and B (24 subjects). The FDT Matrix 30/2 examinations were carried out in 3 different sessions. At the first session, groups A and B underwent the examinations with their best refractive correction. In the second session, group A underwent the FDT 30/2 examination with best refractive correction and the group B without it. In the third session, the groups were matched and followed the same protocol. The perimetric and reliability indexes and the time of examination with or without correction were considered. The Student t test was used when the distribution of the data was normal, whereas Mann-Whitney when the distribution of the data was not normal. After a Bonferroni correction, a P value <0.001 was considered as statistically significant. RESULTS: Mean deviation reduced statistically significantly when refractive correction was used (-2.65±3.71 vs. -1.41±3.51 dB; P<0.006). All the other perimetric indexes and data considered did not change significantly when the subjects did the examination with or without the refractive correction. CONCLUSIONS: The statistically significant reduction of mean deviation obtained with corrective lens showed that a better general accuracy and reliability of FDT responses was obtained with refractive correction. Pattern standard deviation constancy with or without correction confirmed that a localized defect is the first sign of visual field defect and that the absence of differences of pattern standard deviation between the 2 sessions is related to the absence of pathologic conditions in the eyes studied. Finally, as FDT Matrix is less influenced by other nonconventional perimetric techniques by refractive errors, the use of corrective lens is advisable to improve the accuracy and reliability of the results obtained and to optimize their performance.

The influence of learning effect on frequency doubling technology perimetry (Matrix).

PURPOSE: To determine learning effect in healthy patients without perimetric experience, tested with the frequency doubling technology perimetry, with the new model Matrix. PATIENTS AND METHODS: Frequency doubling technology in the 30-2 threshold mode was performed on 37 healthy subjects. Each subject was tested twice in different sessions. The test always began with the right eye (RE) and continued with the left eye (LE). To evaluate learning effect the results of the REs at the first session were compared with those of the LE. The following parameters were evaluated: foveal threshold (FT), reliability indexes, mean defect (MD), pattern standard deviation (PSD), glaucoma hemifield test (GHT), duration of examination. RESULTS: At the first session the average values of RE were FT=30.81 db, MD=-1 db, PSD=3.01 db, and duration of the examination=383.27 "and of LE were FT=30.73, MD=-0.79 db, PSD=2.97 db, and duration of examination 382.62." At the second session the average values of RE were FT=32.22 db, MD=+0.16 db, PSD 2.75 db, and duration of examination=374.97 db. The reliability was different and the GHT between the RE and LE in the first and second session was also different. CONCLUSIONS: A learning effect was observed between the first and the second sessions and the results of the GHT appeared improved. This above all should be taken into account when considering the clinical use of this test to avoid erroneous diagnostic conclusions.

Comparison between GDx VCC parameter and achromatic perimetry in glaucoma patients.

PURPOSE: To evaluate the correlation between polarimetry parameters and standard threshold perimetry indices. PATIENT AND METHODS: One hundred and eight consecutive glaucomatous patients were recruited in this study. Glaucomatous patients were classified when an abnormal visual field and/or an abnormal optic nerve head were present. One eye was chosen randomly from all the subjects. All optic nerve heads were examined with the GDx variable corneal compensator (VCC) (Laser Diagnostic Technologies, Inc, San Diego, CA) and visual fields were assessed by Humphrey Perimeter, program 24-2, SITA standard (Humphrey Instrument, Inc, San Leandro, CA). GDx VCC parameters and visual field indices were considered. Correlation coefficient was used to compare the 2 sets of data. A linear regression model was also used to calculate the independent contribution of each GDx VCC parameter and to determine which parameter was the most predictive of visual field damage. RESULTS: The mean age (+/-standard deviation) was 61+/-10.3, the average of the mean deviation (MD) was -2.31+/-3.2 dB and the mean pattern standard deviation (PSD) was 3.32+/-2.83 dB. Significant (P<0.05) correlation was found between MD and the nerve fiber indicator (NFI) (r=-0.35), the superior average (r=0.28), the Temporal-Superior Nasal-Inferior Temporal average (r=0.24) and the inferior average (r=0.21). The linear regression model found NFI to be the predictor variable of MD. Significant (P<0.05) correlation was found between PSD and the NFI (r=0.39), the superior and the inferior average (r=0.30), and the Temporal-Superior Nasal-Inferior Temporal average (r=0.29). The linear regression model found NFI to be the predictor variable of PSD. CONCLUSIONS: Some of the GDx VCC indices were significantly correlated to visual field indices in glaucomatous patients, but NFI was the best indicator of visual field damage.

Visual acuity in central and branch vein retinal occlusion in the presence of macular edema: 1 year of follow-up.

One year after laser treatment of 117 eyes with central or branch retinal vein occlusion in the presence of macular edema, visual acuity was equally improved in the central retinal vein occlusion laser-treated and branch retinal vein occlusion non-laser-treated eyes. We concluded that fluorangiographically evident ischemic areas or significant macular edema are indications for laser therapy, and that a poor long-term functional prognosis is always related to more severe macular damage at the onset.