Pattern electroretinogram assessment during ibopamine test in ocular hypertension.

PURPOSE: To determine the change in pattern electroretinogram (PERG) amplitude during the ibopamine test in patients with ocular hypertension (OHT). METHODS: A total of 32 eyes (16 patients) with OHT (8 male, 8 female), mean age 54.19 years (range 22-76 years), mean baseline intraocular pressure (IOP) 23 ± 2 mm Hg, received a PERG assessment in both eyes every 5 minutes from baseline to 60 minutes. All the patients were pretreated by thymoxamine eyedrops to avoid the mydriatic effect of ibopamine. All the data were evaluated by descriptive statistics and paired t test. The results were considered with a significance level of p<0.05. RESULTS: All the patients enrolled matched the inclusion criteria and they did not have any local or systemic effects with the ibopamine test. The mean PERG amplitude decreased significantly from baseline after 45 minutes during the ibopamine test (paired t test = 0.05). The results were statistically not correlated with the positivity to the ibopamine test (p = 0.5). CONCLUSIONS: These data stress that, even in presence of a moderate and transient IOP increase, inner retinal function of patients with OHT may be transiently affected.

Molecular analysis of Italian patients with congenital glaucoma.

Purpose: Congenital glaucoma (CG) results from poorly understood developmental abnormalities of the aqueous drainage structures and is clinically characterized by high intraocular pressure (IOP), epiphora, corneal oedema, photophobia, blepharospasm and ocular enlargement. To date, more than 50 pathogenic mutations in the CYP1B1 gene, a member of the cytochrome P450 gene family, have been reported in CG patients. The aim of this paper was to determine the genetic defects underlying CG in Italian patients. Methods: Molecular analysis of CYP1B1 was performed on the DNA of 120 patients and the transcript region of the MYOC/TIGR gene was also studied in all the patients bearing only one mutation in CYP1B1 gene. Previously described CYP1B1 polymorphisms (R48G, A119S, L432V, D449D and N453S) were also analyzed in our patients. Results: Seventeen different variations of CYP1B1 were found in 30 of the 120 (25.0%) CG patients. Twelve of these changes had been identified in previous reports as disease-causing mutations, while L26R, P52L, A106D, A237E and F440L are described here for the first time. F440L has always been found in cis with P52L, both in patients and healthy carriers, suggesting its role as a rare polymorphism linked to the P52L, while the other new variations we found could possibly play a pathogenetic role. G61E and 1775-1801dup27 are the most frequent mutations in our patients. Two amino acid variations (A447V and R76K) were identified in MYOC/TIGR analysis. Conclusions: Our results confirm the major role of the CYP1B1 gene in congenital glaucoma and also suggest an autosomal recessive role of MYOC/TIGR in a digenic inheritance model.

Bilateral myopic photorefractive keratectomy in a 14-year-old boy.

CONTEXT: Refractive surgery has been performed for more than 10 years. Laser-assisted intrastromal keratomileusis (LASIK) and photorefractive keratectomy (PRK) may be used in accommodative esotropia either in adolescent or in adult patients. Some authors have shown that LASIK is safe, effective, and stable at 10 years follow-up post-surgery. CASE REPORT: A 14-year-old boy was admitted to our outpatient department on 08-01-2008. Together with his parents he asked for both eyes to be operated on by myopic PRK. On September 5(th) 2008 a myopic PRK was performed on his right eye and on September 12(th) 2008 on his left eye. A Bausch & Lomb Z172 excimer laser was used to perform a Planoscan procedure on both eyes. Uncorrected visual acuity was 1.0 after both procedures. The patient did not suffer pain, haze or glare in postoperative follow-up. CONCLUSION: Apart from the surgical technique, the author raises questions about the ethics of this procedure in a young boy.

Frequency Doubling Technology vs Standard Automated Perimetry in Ocular Hypertensive Patients.

BACKGROUND: Frequency doubling technology (FDT) perimetry measures contrast sensitivity. The magnocellular component of ganglion cells in human retina is isolated as a whole by the FDT stimulus. The aim of this study is to investigate the role of Humphrey Matrix threshold testing in the detection of early functional retinal impairment in ocular hypertensive patients compared to standard automated perimetry (SAP). METHODOLOGY: Forty hypertensive patients were enrolled in this longitudinal observational clinical study. Functional testing included randomly Humphrey Matrix perimetry and white-on-white Humphrey visual field perimetry. Ibopamine test was performed in all forty patients. The cut-off of 3 mmHg was considered positive for this provocative test. RESULTS: Out of 40 patients, we included 21 in ibopamine positive group and 19 in ibopamine negative group. These two groups are sex- and age-matched. In ibopamine positive group the mean increase in IOP is 4.6 mmHg (ranging from 3 to 10 mmHg). Statistics showed that correlation between FDT and SAP was statistically significant in ibopamine negative group and not statistically significant in ibopamine positive group. Only one patient, coming from IBO + group, converted from ocular hypertension to glaucoma. All the other subjects remained stable in both groups without any therapy and visual field abnormalities. CONCLUSIONS: FDT showed to be more sensitive and specific than SAP mostly in detection of early visual field impairment in ocular hypertensive patients.