Analysis of Corneal Distortion after Myopic PRK.

The purpose of the study is to evaluate the corneal biomechanical properties (CBP) and their behaviors after myopic refractive surgery both with Ocular Response Analyzer (ORA) and Corvis ST (CST). This retrospective study included 145 eyes of 145 patients with a mean age of 33.13 ± 9.24 years, who underwent myopic photorefractive keratectomy (PRK) for a refractive defect, measured as spherical equivalent, of mean -4.69 ± 2.04 D and have been evaluated before surgery and at 1, 3 and 6 months follow-up. Corneal hysteresis (CH) and corneal resistance factor (CRF) values significantly decreased after 1 month and remained statistically stable during further follow-ups. CST parameters had a different evolution: only second applanation time (AT2) differences showed a significant variation after 1 month that did not statistically change over time. Highest concavity deformation amplitude (HCDA), highest concavity peak distance (HCPD), first applanation time (AT1) and velocity (AV1) showed continuous significant differences both after 3 and after 6 months. This study suggests that after central surface ablation surgery, such as myopic PRK, corneal shape is remodeling, and its deformation parameters are going to change even at 6 months follow-up. This indicates that it should be important to evaluate refractive surgery patients during a longer follow-up because this could allow earlier diagnosis and better management of late-onset complications.

Morphological and Functional Evaluation of Oral Citicoline Therapy in Chronic Open-Angle Glaucoma Patients: A Pilot Study With a 2-Year Follow-Up.

Aims: To study the neuroprotective effect of oral citicoline (CT) therapy in primary open-angle glaucoma (POAG). Methods: This study included one eye each of 60 POAG patients. Patients were randomly divided into two groups (A and B) of 30 participants each. Only patients of group A were administered with CT therapy. Age, sex, and disease duration were matched between groups. Despite a stable intraocular pressure (IOP), a slow disease progression-assessed by standard automated white-on-white perimetry (SAP) in the previous 3 years-occurred in all patients. All patients underwent a complete eye examination, including IOP measurement, SAP, retinal nerve fiber layer (RNFL) thickness, and ganglion cell complex (GCC) thickness measurements with optical coherence tomography (OCT), before starting CT treatment and at 6, 12, 18, and 24 months' follow-up. Parameter differences between groups were evaluated at each eye check. Results: After 18 months, mean values of SAP mean deviation (MD) of group A were significantly (p = 0.039) higher (-7.25 db) than those of group B (-8.64 db). Moreover, they appeared stable in the following visits, whereas in group B, mean MD values continued to significantly (p < 0.001) decrease (-9.28 db) over time. Mean RNFL and GCC thickness in group A were significantly (p < 0.01) higher (70.39 and 71.19 µm, respectively) than in group B (64.91 and 65.60 µm, respectively) after 12 months of CT therapy. Furthermore, they appeared to be stable over the later visits, whereas they thinned significantly (p < 0.001) over time in group B. Conclusion: These findings suggest that CT therapy seems to be effective in slowing POAG progression. Further studies on a larger population and with a longer follow-up are needed to confirm this pilot investigation.

The number of implants required to support a maxillary overdenture: a systematic review and meta-analysis.

PURPOSE: The number of implants needed to support a maxillary overdenture is still a controversial issue. The aim of this systematic review was to investigate the number of implants required to support a maxillary overdenture in order to obtain optimal treatment outcomes in terms of implant survival, overdenture longevity and patient satisfaction. STUDY SELECTION: Pubmed and EMBASE databes were systematically searched and complemented by hand searching from 2000 to 2017. The Prisma statement and a PICOS approach were adopted. All selected articles provided at least two-year follow-up and 10 totally edentulous patients. Survival rate of implants and overdentures were statistically analyzed according to number of implants and according to splitting technique, employing non-parametric Fisher Test for unpaired data. For the pooled analysis of implant failures, the odds ratio between group of 4 splinted implants and group of more than 4 splinted was calculated. RESULTS: A total of 28 articles were included. Data analysis of the included studies showed that the survival rate of implants appeared higher in ≥ 4 implants group, whereas the high survival rate of overdentures and patient satisfaction were not significantly influenced by the number of implants. CONCLUSIONS: The findings of our analysis indicate that overall the most frequent tendency is to place at least four implants, splinted or unsplinted, in order to ensure a higher survival rate of implants. However, the relationship between overdenture survival, the patient's quality of life, and the number of implants required to support a maxillary overdenture has yet to be clarified.

Corneal confocal microscopy alterations in Sjögren's syndrome dry eye.

PURPOSE: To evaluate light backscattering (LB) in corneal layers in patients with primary Sjögren's syndrome dry eye (SSDE) utilizing in vivo corneal confocal microscopy (IVCM) and to determine the eventual association with the lacrimal functional test values. METHODS: A complete ophthalmic evaluation, Schirmer test with and without stimulation, break-up time (BUT) and IVCM were performed on 55 patients affected by SSDE and in an age- and sex-matched cohort of healthy participants (HP). Light backscattering, measures as light reflectivity unit (LRU), detected by IVCM at Bowman's membrane (BM) at 50 µm, at 100 µm and at 200 µm deeper than BM was compared in the two groups. The correlations between LB values and lacrimal function results were evaluated. RESULTS: In patients affected by SSDE, LB was significantly higher (p < 0.001) in each corneal layer examined (+14 ± 6.33 LRU at BM), compared with HP. A good reverse correlation between the light reflectivity measures at BM with Schirmer test with (r = -0.91) and without (r = -0.90) stimulation and BUT (r = -0.88) was found. Correlations were lower in the deeper corneal layers. CONCLUSION: Even if our results should be confirmed in further studies with a larger population, these findings show that IVCM is a device able to detect alterations in corneal layers in SSDE patients related to the lacrimal function. Light backscattering (LB) could be very useful for clinical diagnosis and management of SSDE.

Central corneal thickness evaluation in healthy eyes with three different optical devices.

PURPOSE: To compare corneal pachymetry values measured by three different optical devices: Orbscan II, Pentacam HR and Sirius in healthy eyes. METHODS: The central corneal thickness (CCT) of 102 eyes of 102 healthy subjects (mean age of 33.09 ± 8.72 years and mean refractive defect -4.11 ± 4.74 D) was measured by three different physicians using Orbscan II, Pentacam HR and Sirius. The normality of the distribution was evaluated by with Kolmogorov-Smirnov test. The correlations between CCT obtained from each device and refractive defect and age were evaluated using the Pearson test. The differences were evaluated by the Student paired t-test using SPSS 18.0 (IBM Corp. Armonk, New York). RESULTS: Orbscan II provided significant (p < 0.0001) lower CCT measurements then both Pentacam HR (-13.66 ± 16.53 µm) and Sirius (-15.18 ± 17.16 µm); Sirius showed values slightly higher than Oculus Pentacam HR (+1.52 ± 6.21 µm) that appeared to be statistically significant (p < 0.015). CONCLUSIONS: The measurement of CCT by Sirius and Pentacam HR provides similar results. By contrast, the results obtained by Orbscan II are different from those obtained from both Sirius and Pentacam HR.

Evaluation of corneal deformation analyzed with Scheimpflug based device in healthy eyes and diseased ones.

This study was designed to evaluate the correlation between corneal biomechanical and morphological data in healthy eyes, eyes that underwent myopic photorefractive keratectomy (PRK), keratoconus affected eyes, and keratoconus affected eyes that underwent corneal collagen crosslinking (CCC). Complete clinical eye examination of all eyes was followed by tomographic (Pentacam, Oculus, Wetzlar, Germany) and biomechanical (Corvis ST, Oculus, Wetzlar, Germany) evaluation. Differences among Corvis ST (CST) parameters in the different groups have been performed. Linear regression between central corneal thickness (CCT), intraocular pressure (IOP), and anterior corneal curvature measured with Sim'K (KM), versus corneal deformation parameters measured with Corvis ST in the different groups, has been run using SPSS software version 18.0. We evaluated 64 healthy eyes of 64 patients with a mean refractive error of -0.65 ± 1.68 D (measured as spherical equivalent), 17 eyes of 17 patients that underwent myopic PRK for a mean refractive defect of -4.91 ± 2.05 D (measured as spherical equivalent), 16 eyes of 16 patients affected by keratconus (stage 2-3 of Amsler Classification), and 13 eyes of 13 patients affected by keratoconus that underwent CCC. Our data suggest that corneal curvature would have a greater influence on corneal deformation than CCT; in fact KM values are more strongly associated with more CST parameters both about corneal change in shape and both about the corneal ability to come back at original shape.