Accuracy of the indices of MS-39 anterior segment optical coherence tomography in the diagnosis of keratoconic corneas.

PURPOSE: To determine the normative and the cut-off values of various indices available in the MS 39 Anterior Segment Optical Coherence Tomography (MS-39 AS-OCT) for keratoconus (KC) diagnosis, and to detect the accuracy of the variable available parameters. METHODS: This cross sectional observational study was conducted at Dr Rifay Ophthalmology Center, Rabat, Morocco, on 172 eyes with KC (group 1) and 248 eyes of healthy controls (group 2). Participants were screened using MS-39 AS-OCT (CSO, Firenze, Italy). The investigated indices included: keratometric indices, pachymetric indices, elevation indices, Keratoconus Summary Indices (KSI), aberration indices, and epithelial mapping evaluation. RESULTS: Most of the studied indices were significantly different between both groups (P value <0.001). Twenty two indices had Area Under the Receiver Operating Curve (AUROC) values >0.950, eight of which were from the KSI. The indices with the highest AUROC values were: Root Mean Square (RMS) for the front corneal surface at 6 mm circle (AUROC = 0.996, and best cut-off >1.69 with sensitivity of 97.67% and specificity of 97.98%) and RMS per unit of area for the front surface at 6 mm circle (AUROC = 0.996, and best cut-off >0.06 with sensitivity of 97.67% and specificity of 97.98%). Epithelial thickness-derived metrics were not among the parameters with the highest accuracy. CONCLUSIONS: This study presented the mean and the cut-off values for a plethora of parameters available in the MS-39 AS-OCT. The results of this study show that MS-39 AS-OCT is a valuable equipment for diagnosing keratoconic corneas, with a high accuracy detected for many parameters.

Relation of anthropometric measurements to ocular biometric changes and refractive error in children with thalassemia.

PURPOSE: To evaluate and correlate anthropometric, biometric, and refractive error changes in thalassemia major (TM). METHODS: One hundred children with TM and another hundred healthy controls were recruited. Height, weight, body mass index (BMI), and occipitofrontal circumference (OFC) were the anthropometric parameters recorded. Full ophthalmologic examination was performed, including best-corrected visual acuity, cycloplegic refraction, slit-lamp examination, Goldmann applanation tonometry, indirect ophthalmoscopy, keratometry (K readings), and ocular biometry. RESULTS: Compared to controls, children with TM were shorter and lighter, with a smaller BMI (p<0.001); however, no significant difference existed in OFC. Regarding ocular biometric data, patients with thalassemia had steeper mean K readings (p = 0.03), shorter axial length (AXL) (p = 0.005), shorter vitreous chamber depth (p<0.001), and thicker crystalline lens (p<0.001) than controls. Patients with thalassemia had a significant myopic shift (p = 0.003). Multiple regression analyses only showed a significant correlation between corneal astigmatism and both weight and height (ß = -0.05 and p = 0.03 and ß = 0.06 and p = 0.04, respectively). Spherical equivalent was significantly correlated to K readings, lens thickness, and anterior chamber depth (p<0.0001 for all parameters). CONCLUSIONS: Compared to controls, children with TM have significant retardation in general and ocular growth (smaller BMI and shorter AXL). Ocular growth changes probably resulted in compensatory biometric changes (steeper corneas and thicker lenses) to reach emmetropization, with an exaggerated response and subsequent myopic shift. However, growth retardation is not directly related to ocular growth changes, myopic shift, or variations in biometric parameters.

Rotating Scheimpflug Imaging Indices in Different Grades of Keratoconus.

Purpose. To evaluate accuracy of various Keratoconus (KC) screening indices, in relation to Topographic Keratoconus (TKC) grading. Setting. Al Watany Eye Hospital, Cairo, Egypt. Methods. Data of 103 normal (group 1) and 73 KC eyes (group 2), imaged by Pentacam (branded as Allegro Oculyzer), were analysed. Group 2 was divided into 2a: 14 eyes (TKC = 1, early KC), 2b: 25 eyes (TKC = 1 to 2 or 2, moderate KC), and 2c: 34 eyes (TKC = 2 to 3 up to 4, severe KC). Participants were followed up for six years to confirm diagnosis. Area under the receiver operating characteristic curve (AUROC) was calculated for evaluated curvature, elevation, and pachymetry indices with various reference shapes at different diameters. Results. When comparing normal to KC eyes, ten indices had significantly higher AUROC. Only five of them had significantly higher AUROC in early KC compared to normal corneas: Pachymetry Progression Index- (PPI-) Maximum (Max), Ambrósio's Relational Thickness- (ART-) Max, PPI-Max minus PPI-Minimum (Min), central corneal thickness (CCT), and diagonal decentration of thinnest point from the apex (AUROC = 0.690, 0.690, 0.687, 0.683, and 0.674, resp.). Conclusion. Generally, ten pachymetry and elevation-based indices had significantly higher AUROC. Five indices had statistically significant high AUROC when comparing early KC to normal corneas.

PERIPHERAL AVASCULAR RETINA WITH DISK ANOMALY AND HIGH MYOPIA: A Novel Association in a Hereditary Isolated Ocular Disorder.

PURPOSE: To describe a family pedigree with a previously undescribed association of autosomal dominantly inherited ocular abnormalities. METHODS: Case series study performed on 15 family members. Examination included history taking, visual acuity, intraocular pressure, slit-lamp, gonioscopy, indirect ophthalmoscopy (10 members), fluorescein angiography (5 members), general examination and renal ultrasound (4 members), and hemoglobin electrophoresis for the proband and another member. RESULTS: Family pedigree revealed autosomal-dominant inheritance. Visual acuity ranged from 6/36 to no light perception. Examination revealed rubeosis in 7 eyes and atrophia bulbi in 11 eyes. Indirect ophthalmoscopy for 11 eyes revealed evidence of an ocular triad of peripheral avascular retina, disk anomaly (cavitary optic disk anomaly or disk dysplasia), and tessellated fundus of high myopia. The authors also observed new vessels elsewhere with or without extensive subretinal exudations in 6 eyes. All patients with any residual vision (up to perception of light) had nystagmus. Four affected members underwent general examination, renal ultrasound, and serum creatinine level (to exclude papillorenal syndrome), and all were normal. Hemoglobin electrophoresis (to exclude sickle cell retinopathy) revealed within normal values. CONCLUSION: To the authors' knowledge, the aforementioned ocular triad has not been previously described, in association, with an autosomal-dominant pattern of inheritance.

Safety of Intracameral Injection of Minimal Bactericidal Concentration of Povidone Iodine on the Corneal Endothelium in a Rabbit Model.

PURPOSE: To investigate the safety of intracameral injection of minimum bactericidal concentration (MBC) of povidone iodine (PI) on the corneal endothelium in a rabbit model as a proposed method of prophylaxis against postoperative endophthalmitis. METHODS: We included 32 New Zealand white rabbits in the study. Twenty-four rabbits received intracameral injections of 0.1 mL of 0.25% PI, and they were sequentially killed at intervals; first, seventh, and 14th day. The control group included 4 rabbits that received intracameral injections of 0.1 mL normal saline, and 4 rabbits that underwent the same intraocular procedure without injections (sham operated). Slit-lamp examination and ultrasonic corneal pachymetry were performed before and after injections for both eyes. The corneas were histopathologically examined by light and electron microscopy. RESULTS: MBC of PI (0.25%) was toxic to rabbits' corneal endothelium as evident by histopathological changes, corneal edema, and increased corneal thickness on day 1. Signs of healing were obvious on day 7 and were almost complete on day 14, as detected by histopathology, subsidence of corneal edema, and normalization of corneal thickness. CONCLUSIONS: MBC (0.25%) of PI was found toxic to the rabbits' corneal endothelium, with progressive regeneration and complete healing within 2 weeks. To our knowledge, we are the first to use MBC of PI in intracameral injection trials. Further studies on primates, which have more comparable regenerative capacity to humans' corneal endothelium, are encouraged to evaluate their endothelial healing response.