Alterations in choroidal vascular parameters following panretinal photocoagulation using enhanced-depth imaging optical coherence tomography in diabetic retinopathy.

PURPOSE: To investigate the alteration of choroid in patients with very severe non-proliferative diabetic retinopathy (NPDR) or early proliferative diabetic retinopathy (PDR) following panretinal photocoagulation (PRP). METHODS: Thirty-nine eyes of 21 patients with very severe non-proliferative diabetic retinopathy (NPDR) (19 eyes) and early proliferative diabetic retinopathy (PDR) (20 eyes) were recruited. Enhanced-depth imaging optical coherence tomography at baseline, 1, and 6 months after PRP was employed to measure choroidal parameters including total choroidal area (TCA) and choroidal vascular index (CVI). RESULTS: In eyes with very severe NPDR, subfoveal TCA decreased non-significantly at month 1, which increased significantly at month 6 (539 ± 131µm2, 502 ± 134µm2, and 598 ± 168µm2 at baseline and months 1 and 6, respectively; P = 0.003). Subfoveal CVI increased at month 1 and then decreased at month 6 (68.25 ± 3.05, 69.74 ± 3.62, and 67.84 ± 1.77 at baseline and months 1 and 6, respectively; P < 0.001). A reverse pattern occurred in eyes with early PDR, a non-significant increase in TCA at month 1 followed by a decrease at month 6 (497 ± 95µm2, 514 ± 133µm2, and 425 ± 95µm2 at baseline and months 1 and 6, respectively; P = 0.011). CVI decreased at month 1 and remained relatively stable at month 6 (69.34 ± 3.11, 68.33 ± 3.41, and 68.50 ± 5.04 at baseline, and months 1 and 6, respectively; P = 0.023). Alteration of choroidal thickness was not statistically significant in both groups. CONCLUSION: Eyes with very severe NPDR and early PDR exhibit a reverse pattern regarding choroidal indices after PRP.

Intraocular pressure trend following myopic photorefractive keratectomy.

PURPOSE: To evaluate the intraocular pressure (IOP) trend and risk factors for IOP rise after myopic photorefractive keratectomy (PRK). PATIENTS AND METHODS: One eye of each patient undergone PRK for myopia was randomly assigned to this study. All eyes underwent tonometry by CorVis Scheimpflug Technology (CST) tonometer (Oculus Optikgeräte GmbH, Wetzlar, Germany) 1 week, 2 weeks, 1 month, 2 months, 3 months and 4 months after surgery. The eyes with IOP rise more than 5 mmHg and the risk factors were evaluated by Kaplan-Meier graph and multiple Cox regression analysis. RESULTS: A total of 348 eyes of 348 patients were enrolled in this study. Forty-three eyes (12.35%) experienced a steroid-induced IOP rise of more than 5 mmHg. Eyes with IOP rise had higher baseline IOP (Median 19 mmHg (IQR 18-22) versus Median 15 mmHg (IQR 14-16); p < 0.001). Baseline central corneal thickness (CCT) was higher in eyes without IOP rise (Median 520 µm (IQR 509-541) versus Median 535 µm (IQR 518-547); p = 0.009). In multivariate Cox regression analysis, higher baseline IOP was a risk factor for IOP rise (Hazard Ratio (HR) 1.59 (95% CI 1.43-1.77); p < 0.001) while higher baseline CCT was protective (HR 0.97 (95% CI 0.95-0.98); p < 0.001). CONCLUSION: Eyes with higher baseline IOP and lower baseline CCT are at increased risk of IOP rise after PRK and should be monitored more frequently.

The role of optical coherence tomography angiography in moderate and advanced primary open-angle glaucoma.

PURPOSE: To evaluate the relationship between structure and function in moderate and advanced primary open-angle glaucoma (POAG) and to determine the accuracy of structure and vasculature for discriminating moderate from advanced POAG. METHODS: In this cross-sectional study, 25 eyes with moderate and 40 eyes with advanced POAG were enrolled. All eyes underwent measurement of the thickness of circumpapillary retinal nerve fiber layer (cpRNFL) and macular ganglion cell complex (GCC), and optical coherence tomography angiography (OCTA) of the optic nerve head (ONH) and macula. Visual field (VF) was evaluated by Swedish interactive threshold algorithm and 24-2 and 10-2 patterns. The correlation between structure and vasculature and the mean deviation (MD) of the VFs was evaluated by a partial correlation coefficient. The area under the receiver operating characteristic curve (AUC) was applied for assessing the power of variables for discrimination moderate from advanced POAG. RESULTS: Including all eyes, whole image vessel density (wiVD) of the ONH area, and vessel density (VD) in the inferior quadrant of perifovea were the parameters with significant correlation with the mean deviation (MD) of the VF 24-2 in OCTA of the ONH and macula (r = .649 and .397; p < .05). The greatest AUCs for discriminating moderate and advanced POAG belonged to VD of the inferior hemifield of ONH area (.886; 95% CI (.805, .967)), and VD in the inferior quadrant of perifovea (.833; 95% CI (.736, .930)) without statistically significant difference (.886 Versus .833; p = .601). CONCLUSION: Among vascular parameters of the ONH area, wiVD had the strongest correlation with the MD of the VF 24-2 while VD of the inferior hemifield of the ONH area had the greatest AUC for discriminating moderate and advanced POAG. Vessel density in the inferior quadrant of perifovea had a significant correlation with the MD of VF 24-2 and also the greatest AUC for discriminating moderate and advanced POAG.

Effects of Descemet Stripping Automated Endothelial Keratoplasty on Corneal Densitometry of Cases with Long-Standing Pseudophakic Bullous Keratopathy.

Purpose: To quantify the effects of Descemet stripping automated endothelial keratoplasty (DSAEK) on corneal clarity and densitometry of patients with long-standing pseudophakic bullous keratopathy (PBK) complicated with subepithelial fibrosis. Methods: Thirty-four eyes with PBK complicated with corneal edema for more than 6 months and subepithelial fibrosis were enrolled. All subjects underwent complete ophthalmic examination and corneal densitometry module of Pentacam HR, before and 1, 3, and 6 months after DSAEK. Results: Thirteen patients were excluded due to postoperative complications or missed to follow-up visits. Finally, twenty-one patients' data were analyzed. Corneal densitometry measures significantly decreased in all three layers (anterior, central, and posterior) 3 and 6 months after surgery compared to preoperative values; however, the differences did not reach statistical significance in the 1st month. Moreover, densitometry measurements were significantly lower at month 6 compared to month 1, but not at month 3 compared to month 1. Corneal densitometry of the anterior layer was significantly higher than central and posterior layers in 2 mm and 6 mm zones preoperatively and at all postoperative visits. Corneal light backscatter of each three layers was not statistically different between 0-2 mm and 2-6 mm in all pre- and postoperative visits. Conclusions: Corneal densitometry in cases of PBK begins to improve after DSAEK in different layers in a slow and continued trend which takes up to 6 months for an effect to be seen. Interestingly, this improvement is possible even in complicated corneas with long-standing edema. Hence, corneal densitometry can be used as an objective method for quantification of the outcome of DSAEK in complicated cases of PBK.

Accuracy of different lens power calculation formulas in patients with phacomorphic glaucoma.

PURPOSE: The purpose of the study was to determine the most accurate formula for intraocular lens (IOL) power calculation among five currently used formulas in eyes with phacomorphic glaucoma (PG) undergoing cataract extraction surgery. MATERIALS AND METHODS: In this prospective interventional case series Patients diagnosed with PG were undergone uneventful phacoemulsification and IOL implantation. After 3 months, the refractive outcome for each formula was evaluated with mean prediction error (PE), mean absolute error (MAE), and the percentages of eyes within 0.25 D and 0.5 D of predicted error. RESULTS: Twenty-three patients completed the study. PEs were significantly different among the 5 formulas (P = 0.019), and Holladay I had the least error (-0.02 ± 1.11). Haigis formula had the highest hyperopic shift (0.37 ± 1.22), highest MAE (0.99 ± 0.78) and the lowest percentages of desired PEs, while the SRK II produced the greatest percentages. The overall differences in MAE between the 5 formulas were statistically insignificant (P = 0.547). CONCLUSION: In some extreme situations like patients with PG, lower generation of IOL power calculation formulas may still produce more acceptable refractive outcomes.

Closantel Retinal Toxicity: Case Report and Literature Review.

A 57-year-old shepherd was referred with a 2-week history of decreased visual acuity in both eyes. Optical coherence tomography (OCT) (Heidelberg Engineering GmbH, Heidelberg, Germany) revealed diffuse outer nuclear layer hyperreflectivity and indistinguishable external limiting membrane and ellipsoid zone. The patient announced to us that he took two 500 mg of closantel tablets (15.15 mg/kg) three days before the initiation of visual problems for sore throat as an antibiotic. Electroretinography displayed severely attenuated responses in both eyes. We decided to admit the patient with the presumed diagnosis of closantel retinal toxicity and treated him with intravenous methylprednisolone 1 g per day and intravenous erythropoietin 10000 IU twice a day, and reevaluation of the patient proved no change in his visual acuity on the third day of admission. Closantel is a veterinary drug with serious side effects in the human retina and central nervous system even in previously reported doses. Public awareness and appropriate drug labeling about its side effects could prevent accidental toxicity. OCT is a noninvasive and rapid diagnostic modality that should be done in suspected toxic retinopathy.

Sickle Cell Trait Presenting as Unilateral Proliferative Retinopathy and Macular Thinning in a Pregnant Woman.

BACKGROUND: To report a case of a pregnant woman with sickle cell trait (SCT) who presented with unilateral proliferative sickle cell retinopathy. Case Presentation. A 26-year-old otherwise healthy pregnant woman presented with the complaint of visual loss in her left eye. The funduscopic examination showed vitreous hemorrhage, sea fan neovascularization, and pale optic disc. Optical coherence tomography revealed macular inner retinal layer thinning and foveal splaying (saucerization of the foveal pit). The investigations, including hemoglobin electrophoresis, verified the diagnosis of sickle cell trait. Blood pressure, fasting blood glucose tests, and tuberculin skin tests were normal. We treated the patient by peripheral retinal photocoagulation over the area of nonperfusion. CONCLUSION: Even though the sickle cell trait is generally considered as a milder form of sickle cell disease without severe retinal manifestations, pregnancy should be considered as a trigger that can induce proliferative changes and foveal splaying in this group of patients.