Syndromic and non-syndromic forms of retinitis pigmentosa: a comprehensive Italian clinical and molecular study reveals new mutations.

Mutations in more than 60 different genes have been associated with non-syndromic and syndromic retinitis pigmentosa (RP), a heterogeneous group of inherited retinal dystrophies. To increase the understanding of the molecular epidemiology of the disease in Italy, we analyzed 56 patients with syndromic and non-syndromic forms of RP attending the Retinitis Pigmentosa Center of San Paolo Hospital (Milan, Italy). Patients underwent detailed clinical examination. Genomic DNA isolated from peripheral blood samples was screened for mutations in different genes according to RP form by direct sequencing analysis. The impact of novel missense mutations on protein functions was predicted by in silico analysis and protein sequence alignment. Cosegregation analysis was performed between available family members. Forty-one of the 56 probands analyzed had non-syndromic and 15 had syndromic RP forms. Putative disease-causing mutations were identified in 19 of 56 unrelated RP probands. Mutation screening identified a total of 22 different heterozygous variants. Notably, 12 of these putative pathogenic mutations have not been previously reported. New variants were found to be located on the USH2A, RPGR, EYS, and RHO genes. All 3 new variants detected in X-linked RP probands were confirmed in other affected family members. We found a positivity rate of 24.4% and 60% for probands with non-syndromic and syndromic RP, respectively. This is the first report of RPGR X-linked RP proband-ORF15 mutations in Italian patients with X-linked (XL)-RP. In addition, this is the first report of data regarding the association between EYS mutations and non-syndromic RP forms in the Italian population.

Test-retest variability of intraocular pressure and ocular pulse amplitude for dynamic contour tonometry: a multicentre study.

AIMS: To assess the test-retest variability of intraocular pressure (IOP) and ocular pulse amplitude (OPA) measurements utilising dynamic contour tonometry (DCT) and to evaluate possible influential factors. METHODS: The study included 350 consecutive subjects (175 glaucoma, 175 control; one eye per subject) from seven European centres. IOP was measured once with a Goldmann applanation tonometer (GAT) and twice by DCT (DCT1, DCT2) in a randomised sequence. OPA was also recorded for both DCT measurements. Differences (DCT1-DCT2; OPA1-OPA2; GAT-DCT1; GAT-DCT2) were assessed using the t test. The intraclass coefficient of correlation (ICC) and coefficient of variation (CoV) for DCT and OPA were calculated. RESULTS: DCT1 was 0.6+/-1.6 mm Hg higher than DCT2 (p<0.001); OPA1 was 0.1+/-0.7 mm Hg higher than OPA2 (p=0.02). Results were not influenced by randomisation test order. In both glaucoma and normal subjects, DCT and OPA showed ICC>0.90 and >0.76, and CoV=4.8-5.0% and 10.3-10.5%, respectively. DCT1 and 2 were 2.4+/-2.6 and 1.8+/-2.6 mm Hg higher respectively than GAT (p<0.001). DISCUSSION: DCT test-retest variability was almost perfect for IOP and good for OPA. Tonometry measurements with DCT tended to be overestimated compared with GAT.

The effect of pneumatic trabeculoplasty on intraocular pressure: the results of a 6-month, open-label, multicenter study.

PURPOSE: To evaluate the effects of pneumatic trabeculoplasty (PNT) in ocular hypertension and glaucoma subjects. METHODS: A total of 63 consecutive subjects, either treated (79%) or untreated (21%), with intraocular pressure (IOP) between 20 and 25 mmHg were enrolled; the eye with higher IOP (or, in case of identical IOP, worse visual field) was treated with PNT, with the fellow eye used as control. Subjects underwent a baseline evaluation the day before treatment, two PNT treatments at day 0 and 7, visits at day 1, 8, 14, and at each month until the end of the study, which lasted 6 months. Safety was addressed at all visits; an IOP curve (at 8 and 10 AM, 2 and 4 PM) was obtained at baseline and during monthly visits. RESULTS: In PNT eyes, baseline IOP was 22.2-/+1.6 mmHg. Following PNT a statistically significant reduction of IOP occurred at all visits (p<0.0001), with a mean decrease ranging from -2.7-/+2.5 (-11.9-/+10.8%) to -3.6-/+2.6 mmHg (-16.0-/+11.6%); mean reduction was 12.8-/+11.5%. Although IOP diminished also in the control eyes after baseline (p<0.05), the change in IOP was significantly higher in PNT group at each visit (p<0.05). Mild side effects were experienced by 76% of subjects and they all resolved without sequelae. CONCLUSIONS: The results suggest the effect of this procedure in reducing IOP in glaucoma and ocular hypertensive subjects.

Circadian variations in central corneal thickness and intraocular pressure in patients with glaucoma.

AIM: To analyse 24 hour variations in intraocular pressure (IOP) and central corneal thickness (CCT) in a group of glaucomatous patients. METHODS: 30 patients with primary open angle glaucoma were hospitalised and underwent circadian evaluations (at 8 pm, midnight, 4 am, 8 am, noon, and 4 pm) of supine and sitting IOP, respectively, measured using a Perkins and a Goldmann tonometer, and CCT measured using an ultrasonic pachymeter (the mean value of three measurements within 5 mum). All patients were treated with timolol 0.5% twice daily and latanoprost 0.005% once daily. RESULTS: Mean supine IOP was 15.3 (SD 3.7) mm Hg (range 10-25), with circadian fluctuations of 7.3 (3.3) mm Hg. Mean sitting IOP was 15.1 (3.9) mm Hg (range 8-26), with circadian fluctuations of 5.4 (3.1) mm Hg. Mean CCT was 534 (39) microm (range 443-637 microm) with circadian fluctuations of 16.5 (6.2) microm (range 6-31 microm). Both the within patient and within time point fluctuations in CCT were statistically significant (p<0.0001, ANOVA). CONCLUSIONS: The authors found considerable fluctuations in 24 hour IOP. The circadian fluctuations in CCT were small and, although statistically significant, did not seem to interfere with the circadian IOP assessment.

Direct costs of glaucoma and severity of the disease: a multinational long term study of resource utilisation in Europe.

BACKGROUND: Resource utilisation and direct costs associated with glaucoma progression in Europe are unknown. As population progressively ages, the economic impact of the disease will increase. METHODS: From a total of 1655 consecutive cases, the records of 194 patients were selected and stratified by disease severity. Record selection was based on diagnoses of primary open angle glaucoma, glaucoma suspect, ocular hypertension, or normal tension glaucoma; 5 years minimum follow up were required. Glaucoma severity was assessed using a six stage glaucoma staging system based on static threshold visual field parameters. Resource utilisation data were abstracted from the charts and unit costs were applied to estimate direct costs to the payer. Resource utilisation and estimated direct cost of treatment, per person year, were calculated. RESULTS: A statistically significant increasing linear trend (p = 0.018) in direct cost as disease severity worsened was demonstrated. The direct cost of treatment increased by an estimated 86 for each incremental step ranging from 455 euro per person year for stage 0 to 969 euro per person year for stage 4 disease. Medication costs ranged from 42% to 56% of total direct cost for all stages of disease. CONCLUSIONS: These results demonstrate for the first time in Europe that resource utilisation and direct medical costs of glaucoma management increase with worsening disease severity. Based on these findings, managing glaucoma and effectively delaying disease progression would be expected to significantly reduce the economic burden of this disease. These data are relevant to general practitioners and healthcare administrators who have a direct influence on the distribution of resources.

Intraobserver and interobserver reproducibility in the evaluation of ultrasonic pachymetry measurements of central corneal thickness.

PURPOSE: To assess reproducibility of central corneal thickness (CCT) measurement by means of ultrasonic pachymetry. METHODS: Fifty one volunteers underwent three sessions of CCT measurements, each consisting of three CCT measurements, performed by each of three different observers. Intra- and interobserver reproducibility was calculated by means of intraclass correlation coefficient (ICC). The expected range of variability between two independent evaluations was calculated using scatter plots of each test-retest difference against their mean. The standard deviation of the mean differences in the test-retest scores was used to describe the differences in the score spread. RESULTS: The ICC ranges of the intra- and interobserver evaluations were 0.95-0.97 and 0.89-0.95 respectively; the expected variability was < or = +/-1% and < or = +/- 2% respectively (95% confidence interval). CONCLUSIONS: The measurement of CCT by means of ultrasonic pachymetry is highly reproducible.

Clinical ability of Heidelberg retinal tomograph examination to detect glaucomatous visual field changes.

PURPOSE: To determine the agreement between Heidelberg Retinal Tomograph (HRT; Heidelberg Instruments, Heidelberg, Germany) and visual field examinations in differentiating normal from glaucomatous eyes and to evaluate the sensitivity and specificity of HRT optic disc examination in detecting eyes with glaucomatous damage. STUDY DESIGN: Cross-sectional study. PARTICIPANTS: Three hundred fifty-nine patients, for a total of 359 eyes (55 normal, 209 with ocular hypertension [OHT], and 95 with primary open-angle glaucoma). INTERVENTION: Optic disc imaging by HRT, using a 10 degrees angle view; a mean of three repeated images were analyzed using version 2.01 software. The optic disc was classified as "normal/glaucomatous" on the basis of multivariate discriminant analysis and cumulative frequency distribution (ranked-segment distribution curves). The visual field was examined using the DS 30 II program (Humphrey perimeter, Zeiss Humphrey System, Dublin, CA), with a glaucomatous visual field being defined on the basis of an abnormal glaucoma hemifield test and a statistically significant corrected pattern standard deviation less than 4 dB. MAIN OUTCOME MEASURES: Agreement between HRT and visual field examinations calculated by means of the kappa statistic and the sensitivity and specificity of HRT examination. RESULTS: The agreement between the visual field-based and HRT definition of glaucoma was fair to poor, with a kappa statistic of between 0.48 and 0.28. The sensitivity and specificity of the HRT examination were, respectively, 80% and 65%, according to Mikelberg's analysis, and, respectively, 31% to 53% and 90% to 92%, according to the analysis based on cumulative curves of normality. CONCLUSIONS: In a broad clinical setting including normal, OHT, and glaucoma patients, the HRT and visual field tests have fair to poor agreement in detecting glaucoma. The HRT demonstrated a lack of specificity when using Mikelberg's multivariate discriminant analysis and a lack of sensitivity when using cumulative frequency distribution (ranked-segment distribution) curves. These values did not change when normal or OHT patients were excluded from the analysis. In the clinical setting, caution should be used when interpreting HRT results on the basis of multivariate discriminant analysis or cumulative frequency distribution curves.

Effect of timolol, latanoprost, and dorzolamide on circadian IOP in glaucoma or ocular hypertension.

PURPOSE: To compare the around-the-clock intraocular pressure (IOP) reduction induced by timolol 0.5%, latanoprost 0.005%, and dorzolamide in patients with primary open-angle glaucoma (POAG) or ocular hypertension (OHT). METHODS: In this crossover trial, 20 patients with POAG (n = 10) or OHT (n = 10) were treated with timolol, latanoprost, and dorzolamide for 1 month. The treatment sequence was randomized. All patients underwent measurements for four 24-hour tonometric curves: at baseline and after each 1-month period of treatment. The patients were admitted to the hospital, and IOP was measured by two well-trained evaluators masked to treatment assignment. Measurements were taken at 3, 6, and 9 AM and noon and at 3, 6, and 9 PM and midnight by handheld electronic tonometer (TonoPen XL; Bio-Rad, Glendale, CA) with the patient supine and sitting, and a Goldmann applanation tonometer (Haag-Streit, Bern, Switzerland) with the patient sitting at the slit lamp. Systemic blood pressure was recorded at the same times. The between-group differences were tested for significance by means of parametric analysis of variance. The circadian IOP curve of a small group of untreated healthy young subjects was also recorded using the same procedures. To compare the circadian IOP rhythms in the POAG-OHT and control groups, the acrophases for each subject were calculated. RESULTS: When Goldmann sitting values were considered, all the drugs significantly reduced IOP in comparison with baseline at all times, except for timolol at 3 AM. Latanoprost was more effective in lowering IOP than timolol at 3, 6, and 9 AM (P = 0.03), noon (P = 0.01), 9 PM, and midnight (P = 0.05) and was more effective than dorzolamide at 9 AM, noon (P = 0.03), and 3 and 6 PM (P = 0.04). Timolol was more effective than dorzolamide at 3 PM (P = 0.05), whereas dorzolamide performed better than timolol at midnight and 3 AM (P = 0.05). An ancillary finding of this study was that in the group of healthy subjects, the pattern of IOP curve was different that in patients with eye disease. CONCLUSIONS: Latanoprost seemed to lead to a fairly uniform circadian reduction in IOP, whereas timolol seemed to be less effective during the nighttime hours. Dorzolamide was less effective than latanoprost but led to a significant reduction in nocturnal IOP. The reason for the difference in the pattern of the IOP curve of healthy subjects is currently unknown and deserves further investigation.

Myocilin Gln368stop mutation and advanced age as risk factors for late-onset primary open-angle glaucoma.

BACKGROUND: Juvenile open-angle glaucoma has been found to be associated with molecular defects in the myocilin (MYOC) gene. Most of the defects are missense mutations located in the third exon. The Gln368stop mutation has recently been found in several cases of late-onset primary open-angle glaucoma (POAG). OBJECTIVE: To study the effect of glaucoma risk in a relatively homogeneous genetic population. METHODS: A clinical study was performed in all living members of a 5-generation family. DNA analysis was performed for studying association with genetic markers and identifying the mutation. RESULTS: We identified the Gln368stop molecular defect in 19 patients with POAG, 5 patients with ocular hypertension, and 22 healthy carriers. We compared affected and unaffected carriers based on age at onset and last examination, respectively. Besides the presence of 3 young patients with POAG (<40 years old), the number of glaucomatous patients in the advanced age group increased. CONCLUSIONS: The penetrance of glaucoma increases with age in Gln368stop carriers, but some remain unaffected at advanced age and others are affected at an early age. This suggests that additional risk factors are operating within this family, which may be identified by a genome-wide linkage search in this large pedigree. CLINICAL RELEVANCE: The myocilin Gln368stop mutation shows a good genotype-phenotype correlation and should be investigated in all familiar cases of chronic POAG. This may be important for early diagnosis and periodical checkups of presymptomatic individuals belonging to these families.

A novel spontaneous missense mutation in VMD2 gene is a cause of a best macular dystrophy sporadic case.

PURPOSE: To report the molecular characterization of a novel VMD2 mutation causing a Best macular dystrophy sporadic case. METHODS: All family members underwent ophthalmologic examination and genetic testing by single strand conformation polymorphism analysis and direct sequencing of the VMD2 gene. RESULTS: A single T to G transition at nucleotide 663 was identified in one of the VMD2 gene copies of the patient, which results in a Cys to Trp substitution at position 221 in the corresponding protein (C221W). Sequence analysis of the VMD2 exon 6 of both parents of the patient did not reveal any mutation. CONCLUSION: These data confirm the involvement of the VMD2 gene in Best macular dystrophy onset, even in sporadic cases of the disease, pointing out the relevance of molecular analysis in the diagnosis of this degenerative retinal disease.

Topical lomefloxacin 0.3% twice daily versus tobramycin 0.3% in acute bacterial conjunctivitis: A multicenter double-blind phase III study.

AIMS/BACKGROUND: To evaluate in a double-masked comparative, prospective, randomized multicenter trial the efficacy of lomefloxacin 0.3% eye drops twice daily and of tobramycin eye drops 4 times daily in patients with acute bacterial conjunctivitis. METHODS: Ninety-nine subjects were enrolled: 50 were treated with lomefloxacin 0.3% eye drops twice daily and 49 with tobramycin 0.3% eye drops 4 times daily. In all patients, conjunctival swabbing and assessment of objective signs and of subjective symptoms were performed. RESULTS: There was no statistical difference for any individual sign or symptom or for the sum score of either key or other signs and symptoms at any of the examination days. The sum score of both key and other signs and symptoms decreased in both groups at day 3-4 as compared to baseline values (p < 0.0001). The decrease in both these scores continued significantly from day 3-4 to day 7-8 (p < 0.05) and was similar in the two treatment groups (p > 0.4). The lowest resistance rate was seen in lomefloxacin (3.5%) and in neomycin (7.0%), while tobramycin showed resistance in 10 out of 88 resistance strains (11.4%). CONCLUSION: Both lomefloxacin 0.3% twice daily and tobramycin 0.3% administered 4 times daily were well tolerated and showed a high degree of clinical and microbiological efficacy in the treatment of acute bacterial conjunctivitis. Lomefloxacin caused less resistance than other antibiotics evaluated.

Laser treatment of feeder vessels in subfoveal choroidal neovascular membranes: a revisitation using dynamic indocyanine green angiography.

OBJECTIVE: This study aimed to determine whether the indocyanine green angiography (ICGA)-guided laser treatment of feeder vessels (FVs) may be useful in the management of the subfoveal choroidal neovascular membranes (CNVM) in patients with age-related macular degeneration (ARMD). DESIGN: Noncomparative case series. PARTICIPANTS: The authors considered a series of 15 patients with subfoveal CNVM in whom feeder vessels could be clearly detected by means of dynamic ICGA but not necessarily with fluorescein angiography (FA). On the basis of the indications of the pilot study, the authors also studied a second series of 16 patients with FVs smaller than 85 microm. INTERVENTION: Treatment of FV using argon green laser was performed. The ICGA was performed immediately after treatment, after 2, 7, 30 days, and then every 3 months, to assess FV closure. If an FV appeared to be still patent, it was immediately retreated and the follow-up was started again. The follow-up time ranged from 23 to 34 months for the pilot study and from 4 to 12 months for the second series. MAIN OUTCOME MEASURES: The obliteration of the membrane and change in visual acuity from baseline were measured. The effect on the treatment of the number and width of the FVs, and the size and location of the membrane, also was evaluated. RESULTS: In the pilot study, the CNVM was obliterated after the first treatment in only one patient, five patients needed more than one treatment, and obliteration failed in nine patients (40% success rate). The rate of success was affected by the width and number of the FVs. The success rate in the second series of 16 patients was higher (75%). CONCLUSIONS: The success of the laser treatment of FVs depends on their width, length, and number. Dynamic ICGA, which detects smaller FVs and makes it possible to control the laser effect and initiate immediate retreatment in the case of incomplete FV closure, should be considered mandatory for this type of treatment; a comparable success rate would have been unlikely using the other currently available methods of treating subfoveal CNVMs.

Experimental short-term tolerance to perfluorodecalin in the rabbit eye: a histopathological study.

PURPOSE: Perfluorocarbon liquids are largely used in vitreoretinal surgery, but their permanence into the eye is considered harmful and early withdrawal is routinely performed by most of the surgeons. We undertook this investigation to evaluate the effects of Perfluorodecalin (PFD) tamponade following vitrectomy in the rabbit eye. METHODS: Twenty-four rabbits underwent vitrectomy of the right eye according with a standard procedure. Eighteen rabbits received PFD and 6 control rabbits received Balanced Salt Solution (BSS) as vitreous substitute. The eyes were examined with light microscopy and transmission electron microscopy after two, four and six days after tamponade and thirty days after the withdrawal of PFD. RESULTS: The tamponade lasting four or more days caused irreversible retinal damage involving the photoreceptors and retinal pigment epithelium. Peculiar impressions were formed in the inner retina at the site of the gravitational effect of PFD droplets. CONCLUSIONS: Based on the results of this study we suggest that the tamponade with PFD lasting more than two days is detrimental to the retina, at least in the case of the rabbit. Damage seems to be related only to the high specific gravity of PFD.

A novel mutation in the GLC1A gene causes juvenile open-angle glaucoma in 4 families from the Italian region of Puglia.

BACKGROUND: Primary open-angle glaucoma encompasses a complex of potentially blinding ocular diseases characterized by a normal-appearing angle of the anterior chamber, a characteristic degeneration of the optic nerve with resultant typical visual field defects, and usually, an elevated intraocular pressure. It can be subdivided into 2 groups according to the age at onset: the more prevalent chronic open-angle glaucoma diagnosed after 40 years of age, and the less common juvenile form, which occurs between 3 years of age and early adulthood. A locus for primary open-angle glaucoma (GLC1A) has been mapped to a 3-centimorgan region of the long arm of chromosome 1 (1q23-25). Recently, the myocilin (MYOC) gene, located in this chromosomal interval, has been found mutated in several patients affected by primary open-angle glaucoma. OBJECTIVE: To describe the clinical and molecular genetic features of 4 pedigrees affected by autosomal dominant juvenile open-angle glaucoma, all from the Italian region of Puglia. METHODS: Clinical study, gonioscopy, automated perimetry, and DNA analysis were performed on several members of the 4 families. RESULTS: We identified a new molecular defect (1177GACA-->T) in the third exon of the GLC1A gene. This mutation is present in all affected persons and in 2 still phenotypically normal persons. CONCLUSION: Our results are important for diagnostic purposes because it is now possible to identify asymptomatic carriers, for whom clinical surveillance for the early detection and treatment of glaucoma may be suggested.