OPTICAL COHERENCE TOMOGRAPHY EVIDENCE ON THE CORRELATION OF CHOROIDAL THICKNESS AND AGE WITH VASCULARIZED RETINAL LAYERS IN NORMAL EYES.

PURPOSE: To correlate choroidal thickness (CT) and age with vascularized retinal layer and outer retinal layer thickness in normal eyes. METHODS: This was a prospective, cross-sectional study. Complete ophthalmological examination, biometry, and enhanced depth imaging spectral domain optical coherence tomography were performed. Choroidal and individual retinal layer thickness measurements were obtained. Thickness maps for all layers were evaluated using the 1 mm, 3 mm, and 6 mm early treatment diabetic retinopathy study (ETDRS) macular grid areas. RESULTS: One hundred and twenty eyes were included. Choroidal thickness correlated negatively with age in all ETDRS areas. The ganglion cell layer (GCL) in the 1 mm; the GCL and inner plexiform layer (IPL) in the 3 mm and 6 mm; and the GCL, IPL, and inner nuclear layer in the 6 mm areas correlated negatively with age and positively with CT. Retinal nerve fiber layer thickness in the 6 mm area correlated negatively with age. The retinal pigment epithelium-photoreceptor layer in all areas correlated negatively with age and positively with CT. CONCLUSION: In normal subjects, vascularized retinal layer thicknesses and outer retinal layer thickness correlate positively with CT and negatively with age. The role of neuronal versus vascular components should be considered when evaluating individual retinal layer thicknesses.

Clinical and genetic studies in a family with a new splice-site mutation in the choroideremia gene.

PURPOSE: To describe the clinical and molecular findings of an Italian family with a new mutation in the choroideremia (CHM) gene. METHODS: We performed a comprehensive ophthalmologic examination, fundus photography, macular optical coherence tomography, perimetry, electroretinography, and fluorescein angiography in an Italian family. The clinical diagnosis was supported by western blot analysis of lymphoblastoid cell lines from patients with CHM and carriers, using a monoclonal antibody against the 415 C-terminal amino acids of Rab escort protein-1 (REP-1). Sequencing of the CHM gene was undertaken on genomic DNA from affected men and carriers; the RNA transcript was analyzed with reverse transcriptase-PCR. RESULTS: The affected men showed a variability in the rate of visual change and in the degree of clinical and functional ophthalmologic involvement, mainly age-related, while the women displayed aspecific areas of chorioretinal degeneration. Western blot did not show a detectable amount of normal REP-1 protein in affected men who were hemizygous for a novel mutation, c.819+2T>A at the donor splicing site of intron 6 of the CHM gene; the mutation was confirmed in heterozygosity in the carriers. CONCLUSIONS: Western blot of the REP-1 protein confirmed the clinical diagnosis, and molecular analysis showed the new in-frame mutation, c.819+2T>A, leading to loss of function of the REP-1 protein. These results emphasize the value of a diagnostic approach that correlates genetic and ophthalmologic data for identifying carriers in families with CHM. An early diagnosis might be crucial for genetic counseling of this type of progressive and still untreatable disease.

Outer layer breaks and asymptomatic schisis detachment: clinical considerations.

BACKGROUND AND OBJECTIVE: To provide a detailed description of the clinical features that are considered forerunners of symptomatic complications in asymptomatic degenerative retinoschisis, and to show that in selected cases at this stage prophylactic photocoagulation may be a better choice than mere observation. MATERIALS AND METHODS: Forty-three eyes of 27 patients with asymptomatic bullous degenerative retinoschisis and outer layer breaks (OLBs) were studied through binocular indirect dynamic ophthalmoscopy and retinal biomicroscopy with the Goldmann 3-mirror lens, fundus drawings, and photographs where feasible. Argon laser treatment was performed on each eye: first, around the posterior border of the schisis to achieve a full-thickness retinal scar, and then on the schisis itself to promote scarring of the retinal pigment epithelium, thus avoiding retinal detachment. The follow up was 2 years minimum after treatment. RESULTS: OLBs usually involved the largest schises when multiple retinal splittings were present. Breaks were single in 18 eyes (peripheral in 16 and posterior in 2) and multiple in 25 (peripheral in 15 and posterior in 10). Overall, 23 eyes showed asymptomatic retinal detachment (schisis detachment): 20 with peripheral outer layer breaks and 3 with posterior breaks. Schisis detachment was localized to the schisis area in the first group, whereas it extended beyond the posterior boundary of retinoschisis in the latter. After treatment, no posterior progression of retinoschisis was noted nor did symptomatic retinal detachment arise. Only 1 eye had complications in the second step of the treatment that was later resolved with medical care. CONCLUSION: Prophylactic Argon laser photocoagulation can be used safely in the asymptomatic stage of bullous retinoschisis with outer layer breaks to avoid the onset of acute symptomatic retinal detachment.

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.

Comparison between discriminant analysis models and "glaucoma probability score" for the detection of glaucomatous optic nerve head changes.

PURPOSE: The aim of this study was to evaluate and compare 4 different discriminant analysis formulas and the new Glaucoma Probability Score (GPS) for the detection of morphometric optic nerve head changes in chronic open-angle glaucoma. METHODS: This is a prospectively planned cross-sectional study. Two hundred and fourteen consecutive eyes were recruited into this study. For each patient, the eyes were evaluated by a slit lamp examination, and the visual fields were assessed by a Humphrey Field Analyzer 750 (HFA, Humphrey Inc, San Leandro, CA), using the standard full threshold 24-2 (Swedish Interactive Threshold Algorithm) program. The optic nerve heads were morphometrically evaluated using the Heidelberg Retina Tomograph 3 (HRT 3, Heidelberg Engineering, Heidelberg, Germany; software version 3.0). From the HRT data, 4 discriminant analysis formulas and the GPS were considered. All data were analyzed by Student t test and Pearson r coefficient. A linear regression model was also used to determine the independent contribution of variables included in the model. Sensitivity, specificity, diagnostic precision, and receiver operating characteristic curve areas were calculated for all the 5 methods examined. kappa statistic was used to study the agreement among, and between, the 5 different methods. RESULTS: One hundred and nineteen normal eyes and 95 eyes with primary open-angle glaucoma were included in the study. No significant difference was found between the 2 study subgroups in both age and refractive error. Significant (P<0.001) correlations were found between visual field indices and the HRT parameters. Sensitivity, specificity, and diagnostic precision of the 4 formulas ranged between 50% and 99.16%. Bathija et al's formula had the highest diagnostic precision, followed by Mikelberg's formula. Using kappa statistics, kappa ranged from 0.177 to 0.528 when comparing each single discriminant formula with the GPS. CONCLUSIONS: The GPS showed similar sensitivity and specificity to the Mikelberg and Bathija formulas; this method is a promising one for differentiating between healthy and glaucomatous eyes, requiring no subjective user input.

Comparative efficacy of acetazolamide and apraclonidine in the control of intraocular pressure following phacoemulsification.

PURPOSE: The purpose of our study was to compare the effects of systemically administered acetazolamide and topical apraclonidine 0.5% in the control of intraocular pressure (IOP) following phacoemulsification of senile cataracts. SETTING: The study was conducted on patients affected by cataract and followed at the Department of Ophthalmology. METHODS: Seventy-eight eyes in 78 patients were selected. Twenty-six eyes were randomly assigned to postoperative treatment with topical apraclonidine 0.5%, 26 received oral acetazolamide and the remaining 26 received no hypotensive treatment (control group). Statistical analyses were performed mainly by means of analyis of variance. RESULTS: IOPs measured 24 h after surgery were significantly (p = 0.01) lower in the apraclonidine group compared to the control group. CONCLUSIONS: Our double-blind prospective study conducted on patients randomly assigned to treatment with apraclonidine or acetazolamide shows that the former drug is undoubtedly effective in the prevention of IOP increases following phacoemulsification. IOPs recorded in patients treated with this drug were lower than those observed in the acetazolamide and the control groups. Considering the lower risk of toxicity associated with topical administration, apraclonidine 0.5% seems to be preferable to oral acetazolamide in this postoperative setting.