Retinopathy of Prematurity-assist: Novel Software for Detecting Plus Disease

PURPOSE: To design software with a novel algorithm, which analyzes the tortuosity and vascular dilatation in fundal images of retinopathy of prematurity (ROP) patients with an acceptable accuracy for detecting plus disease. METHODS: Eighty-seven well-focused fundal images taken with RetCam were classified to three groups of plus, non-plus, and pre-plus by agreement between three ROP experts. Automated algorithms in this study were designed based on two methods: the curvature measure and distance transform for assessment of tortuosity and vascular dilatation, respectively as two major parameters of plus disease detection. RESULTS: Thirty-eight plus, 12 pre-plus, and 37 non-plus images, which were classified by three experts, were tested by an automated algorithm and software evaluated the correct grouping of images in comparison to expert voting with three different classifiers, k-nearest neighbor, support vector machine and multilayer perceptron network. The plus, pre-plus, and non-plus images were analyzed with 72.3%, 83.7%, and 84.4% accuracy, respectively. CONCLUSIONS: The new automated algorithm used in this pilot scheme for diagnosis and screening of patients with plus ROP has acceptable accuracy. With more improvements, it may become particularly useful, especially in centers without a skilled person in the ROP field.

Optical coherence tomographic findings in highly myopic eyes

Optical coherence tomography [OCT] had enhanced our understanding of changes in different ocular layers when axial myopia progresses and the globe is stretched. These findings consist of dehiscence of retinal layers known as retionoschisis, paravascularinner retinal cleavage, cysts and lamellar holes, peripapillary intrachoroidal cavitation, tractional internal limiting membrane detachment, macular holes [lamellar and full thickness], posterior retinal detachment, and choroidal neovascular membranes. In this review, recent observations regarding retinal changes in highly myopic eyes explored by OCT are described to highlight structural findings that cannot be diagnosed by simple ophthalmoscopy

Surgical management in advanced stages of retinopathy of prematurity; our experience

Retinopathy of prematurity is a potentially blinding condition. In this article we describe the surgical management for advanced stages of the disease [stages 4 and 5]. Indications, options and alternative techniques are described through a review of articles and our personal experience

Retinopathy of prematurity: Single versus multiple-birth pregnancies

To compare the frequency and severity of retinopathy of prematurity [ROP] among singleton and multiple-birth neonates referred to Farabi Eye Hospital, Tehran-Iran. In this retrospective study, records of 99 consecutive neonates from multiplegestation pregnancies including 68 twins, 26 triplets and 5 quadruplets who were screened for ROP from 2002 to 2004 were reviewed. The frequency, severity and risk factors for ROP were determined and compared to a group of singletons who were matched in terms of gender, birth weight [BW], gestational age [GA], oxygen therapy, respiratory distress syndrome, blood transfusion, sepsis and phototherapy. ROP was present in 12.1% of multiple-birth neonates as compared to 15.1% of singletons [P=0.53]. Threshold ROP was present in 6.1% of multiple-birth neonates versus 7.1% of singletons [P=0.62]. ROP was detected in 60% of quadruplets versus 9.6% of twins and triplets; threshold disease was observed in 40% of quadruplets as compared to 4.2% of twins and triplets [P<0.03]. However, considering the effect of BW and GA, logistic regression analysis revealed no statistically significant difference in the frequency and severity of ROP among subgroups of multiple-gestation pregnancies. There was no significant difference between multiple-birth neonates and matched singletons in terms of frequency and severity of ROP. Any apparent higher rate may be due to independent risk factors such as low birth weight and gestational age rather than multiple pregnancies per se. Screening for ROP in multiple gestation births may be conducted according to standard protocols applied for singletons

Efficacy of memantine in acute non-arteritic ischemic optic neuropathy

Evaluation of efficacy of Memantine [N-Methyl-D-Aspartate Receptor Antagonist] on visual function of patients with acute non-arteritic ischemic optic neuropathy [NAION]. The study was conducted as interventional case series from November 2005 through November 2006 in Farabi Eye Hospital. Twenty-two patients with acute NAION of less than 8 weeks duration entered the study. Memantine was prescribed with a dose of 5 mg per day for the first week and 10 mg per day for the following two weeks. Baseline best corrected visual acuity [BCVA]; visual evoked potential [VEP] and visual field was done for all patients. BCVA recording repeated 3 weeks, 3 and 6 months later. VEP and perimetry repeated 3 months after treatment. After 3 weeks, 3 and 6 months, BCVA improved -0.32 +/- 0.40 LogMAR, -0.51 +/- 0.49 and -0.51 +/- 0.49, respectively [P=0.005, P=0.001 and P=0.001, respectively]. VEP recordings after 3 months, demonstrated -8.61 +/- 14.51 db mean decrease in implicit time [P=0.019]. Amplitude of voltage did not show significant difference with baseline [P=0.10]. Perimetry results after 3 months showed that mean deviation [MD] improved 2.77 +/- 3.94 db [P=0.016]. Memantine resulted in significant improvement of BCVA 3 weeks, 3 and 6 months after treatment of acute NAION. Memantine also resulted in significant decrease of implicit time and significant improvement of mean deviation in VEP and perimetry after 3 months

Intravitreal bevacizumab versus combined bevacizumab and triamcinolone acetonide for neovascular age-related macular degeneration

To compare the short-term outcomes of intravitreal bevacizumab [IVB] with the combination of IVB and intravitreal triamcinolone acetonide [IVB/IVT] for treatment of neovascular age-related macular degeneration [AMD]. This randomized clinical trial was performed on 92 eyes of 90 patients with subfoveal and juxtafoveal choroidal neovascularization [CNV] secondary to AMD. The eyes were randomly assigned to receive IVB 1.25 mg alone [53 eyes] or in combination with IVT 2 mg [39 eyes]. Best-corrected visual acuity [BCVA] and fundus autofluorescence were assessed, and fluorescein angiography [FA] and optical coherence tomography [OCT] were performed at baseline and repeated 6 weeks after treatment. Mean age was 70.6 +/- 8.7 [range 50-89] years and 57.7% of the patients were male. BCVA improved from 1.03 +/- 0.40 to 0.93 +/- 0.38 logMAR [P=0.001] in the IVB group and from 1.08 +/- 0.33 to 0.91 +/- 0.38 logMAR [P=0.008] in the IVB/IVT group. There was a trend toward greater visual improvement with combined therapy [P=0.06]. BCVA improvement was greater in eyes with +1 versus those with +2 [P=0.049] and +3 [P < 0.001] fundus autofluorescence at baseline. Mean decrease in central macular thickness was 113 +/- 115 micro m [P < 0.001] in the IVB group versus 53.96 +/- 125 micro m [P=0.008] in the IVB/IVT group with no intergroup difference [P=0.38]. FA showed decreased leakage in 57.4%, increased leakage in 12.8% and no change in 29.8% of patients in the IVB group. Corresponding figures were 60.0%, 5.7% and 34.3% in the IVB/IVT group [P=0.556]. Addition of triamcinolone acetonide to bevacizumab for treatment of neovascular AMD does not seem to significantly increase its short-term efficacy. More severe fundus autofluorescence appears to be predictive of poorer response to treatment