Cataract surgery in setting of ocular surface disease.

PURPOSE OF REVIEW: The purpose of this article is to review the available strategies to successfully identify and manage ocular surface disease (OSD) pre, intra and post-cataract surgery. RECENT FINDINGS: Cataract surgery and OSD have an intricate relationship: the surgical procedure can induce or exaggerate OSD symptoms, while OSD can negatively impact surgical refractive outcomes and increase the rate of postoperative complications. SUMMARY: Improving the health and stability ocular surface is the key to enhance post cataract surgery refractive outcomes and avoid complications. This is pivotal for patients affected by severe OSD, but is also important for patients with minimal signs or symptoms. A correct diagnosis and a stepwise approach are the keys to improve the quality of life of such patients.

Retinal thinning in progressive supranuclear palsy: differences with healthy controls and correlation with clinical variables.

BACKGROUND: Available evidence reports conflicting data on retinal thickness in progressive supranuclear palsy (PSP). In studies including healthy controls, PSP showed either the thinning of the retinal nerve fiber layer, macular ganglion cell, inner nuclear, or outer retina layer. OBJECTIVES: The goals of the present study were to describe retinal layer thickness in a large cohort of PSP compared to healthy controls and in PSP phenotypes using spectral-domain optical coherence tomography (SD-OCT). The additional objective was to verify the relationship between retinal layers thickness and clinical variables in PSP. METHODS: Using a cross-sectional design, we examined retinal structure in 27 PSP patients and 27 controls using standard SD-OCT. Motor and cognitive impairment in PSP was rated with the PSP rating scale and the Montreal Cognitive Assessment battery (MoCA), respectively. Eyes with poor image quality or confounding diseases were excluded. SD-OCT measures of PSP and controls were compared with parametric testing, and correlations between retinal layer thicknesses and disease severity were evaluated. RESULTS: PSP showed significant thinning of the inner retinal layer (IRL), ganglion cell layer (GCL), inner plexiform layer (IPL), and the outer plexiform layer (OPL) compared to healthy controls. PSP phenotypes showed similar retinal layer thicknesses. Retinal layer thickness correlated with MoCA visuospatial subscore (p < 0.001). CONCLUSIONS: We demonstrated PSP patients disclosed thinner IRL, GCL, IPL, and OPL compared to healthy controls. Furthermore, we found a significant correlation between visuospatial abilities and retinal layers suggesting the existence of a mutual relationship between posterior cognitive function and retinal structure.

Intraocular Lens Power Calculation Without Corneal Parameters: A New Option.

OBJECTIVES: To compare different methods in calculating the corneal radius (R) to be used in case of intraocular lens power calculations when it is immeasurable. METHODS: The right eyes of 1,960 patients were randomly divided into 2 equal groups. The first group of right eyes (group A) was divided in three groups according to the axial length (AL) (≤21.99 mm, between 22 and 24.99 mm, and ≥25 mm). In these groups, the correlation between the AL and the corneal radius (R) provided three different regression formulas. The second group of right eyes (group B) was used to test the following methods of estimating the R: the regression formulas determined from group A, formula from Logan et al., formula from Stenström, the mean R calculated from group A, and the fellow eye group B. A Student paired T test was used for the statistical evaluation. RESULTS: In case of AL≤21.99, the best results have been obtained with the fellow eye R, followed by either the regression formula or the mean R from group A (mean=0.00±0.09 mm, P=0.94, mean=0.05±0.21 mm, P=0.05, mean=0.05±0.22 mm, P=0.08, respectively). In case of AL between 22 and 24.99 mm, the best results have been obtained with the fellow eye R, followed by either the regression formula or the mean R from group A (mean=-0.01±0.09 mm, P=0.38, mean=0.01±0.21 mm, P=0.12, mean=0.01±0.24 mm, P=0.18, respectively). In case of AL≥25 mm, the best results have been obtained with the fellow eye R, followed by either the regression formula or the mean R from group A (mean=-0.003±0.08 mm, P=0.94 mean=-0.004±0.25 mm, P=0.85, mean=-0.004±0.25 mm, P=0.85, respectively). CONCLUSIONS: The new calculated regression formulas seem to represent a reliable method to calculate the R when it is undetectable, as in case of corneal dystrophies.

A-scan ultrasonography and optic nerve sheath diameter evaluation in children with acute liver failure.

In this Letter to the Editor we would like to comment the article by Das and colleagues, concerning the optic nerve sheath diameter evaluation with ultrasonography in children with acute liver failure. In particular, this letter highlights several limitations in the use of B scan for such a purpose and suggests a more precise assessment with the standardized A scan technique.

Choroidal evaluation in patients under alpha-lytic therapy.

PURPOSE: To detect any choroidal thickness (CT) change in patients after alpha-lytic drugs withdrawal that could help in the cataract surgery timing decision. METHODS: Twenty-five eyes of 25 patients (mean age: 76 ± 7 years) under alpha-lytic therapy, and 25 eyes of 25 control subjects (CS) (mean age: 75 ± 7 years) without alpha-lytic therapy, both scheduled for cataract surgery in the fellow eye, were included in this observational, prospective, non-randomized study. All patients underwent EDI-OCT during the first preoperative visit and approximately 1 month (range 28-31 days) after alpha-lytic withdrawal. In the CS group, the OCT during preoperative visit and approximately 1 month after (range 28-31 days) the first examination was performed. Data normality with Kolmogorov-Smirnov test was checked and statistical evaluation with the Wilcoxon-signed rank test was performed. RESULTS: The mean subfoveal CT was 224 ± 79.7 µm during therapy and 217 ± 70.4 µm after withdrawal; 1.5 mm nasally from the fovea CT was 198 ± 83.8 µm and 194 ± 82.8 µm, respectively; and 1.5 mm temporally from the fovea CT was 217 ± 55.9 µm and 205 ± 54.4 µm, respectively. A statistically significant reduction (p < 0.05) in all the 3 measured CT points was found. In the CS no significant changes were detected (p > 0.05). CONCLUSION: No severe floppy iris syndrome was detected at the time of surgery. In these patients, CT decrease could be an important sign for cataract surgery timing decision.

Intraocular Pressure Measurements in Standing Position with a Rebound Tonometer.

Background and Objectives: It has been established that body position can play an important role in intraocular pressure (IOP) fluctuation. IOP has been previously shown to increase significantly when lying down, relative to sitting; this type of investigation has not been extensively reported for the standing (ST) position. Therefore, this study aims to look for eventual significant IOP changes while ST, sitting, and lying down. MATERIALS AND METHODS: An Icare PRO was used to measure the IOP of 120 eyes of 60 healthy individuals, with age ranging from 21 to 55 years (mean 29.22 ± 9.12 years), in sitting, supine and ST positions; IOP was measured again, 5 minutes after standing (ST-5m). RESULTS: Mean IOP difference between sitting and ST position was 0.39 ± 1.93 mmHg (95% CI: 0.04 to 0.74 mmHg) (p = 0.027); between sitting and ST-5m, it was -0.48 ± 1.79 mmHg (95% CI: -0.8 to -0.16 mmHg) (p = 0.004); between the sitting and supine position, it was -1.16±1.9 mmHg (95% CI: -1.5 to -0.82 mmHg) (p < 0.001); between the supine and ST position, it was 1.55 ± 2.04 mmHg (95% CI: 1.18 to 1.92 mmHg) (p < 0.001); between supine and ST-5m, it was 0.68 ± 1.87 mmHg (95% CI: 0.34 to 1.02 mmHg) (p < 0.001); and between ST-5m and ST, it was 0.94 ± 1.95 mmHg (95% CI: 0.58 to 1.29 mmHg) (p < 0.001). Mean axial eye length was 24.45 mm (95% CI: 24.22 to 24.69 mm), and mean central corneal thickness was 535.30 µm (95% CI: 529.44 to 541.19 µm). CONCLUSION: Increased IOP in the ST-5m position suggests that IOP measurements should be performed in this position too. The detection of higher IOP values in the ST-5m position than in the sitting one, may explain the presence of glaucoma damage or progression in apparently normal-tension or compensated patients.

Corneal Anterior Power Calculation for an IOL in Post-PRK Patients.

PURPOSE: After corneal refractive surgery, there is an overestimation of the corneal power with the devices routinely used to measure it. Therefore, the objective of this study was to determine whether, in patients who underwent photorefractive keratectomy (PRK), it is possible to predict the earlier preoperative anterior corneal power from the postoperative (PO) posterior corneal power. A comparison is made using a formula published by Saiki for laser in situ keratomileusis patients and a new one calculated specifically from PRK patients. METHODS: The Saiki formula was tested in 98 eyes of 98 patients (47 women) who underwent PRK for myopia or myopic astigmatism. Moreover, anterior and posterior mean keratometry (Km) values from a Scheimpflug camera were measured to obtain a specific regression formula. RESULTS: The mean (±SD) preoperative Km was 43.50 (±1.39) diopters (D) (range, 39.25 to 47.05 D). The mean (±SD) Km value calculated with the Saiki formula using the 6 months PO posterior Km was 42.94 (±1.19) D (range, 40.34 to 45.98 D) with a statistically significant difference (p < 0.001). Six months after PRK in our patients, the posterior Km was correlated with the anterior preoperative one by the following regression formula: y = -4.9707x + 12.457 (R² = 0.7656), where x is PO posterior Km and y is preoperative anterior Km, similar to the one calculated by Saiki. CONCLUSIONS: Care should be taken in using the Saiki formula to calculate the preoperative Km in patients who underwent PRK.