Comparison of ICare tonometer with Goldmann applanation tonometer in glaucoma patients

PURPOSE

To compare the intraocular pressure (IOP) readings taken with the new ICare tonometer and with the Goldmann applanation tonometer (GAT) and to evaluate the influence of central corneal thickness (CCT) on the IOP measurements.

PATIENTS AND METHODS

One eye of 178 consecutive patients with primary open-angle glaucoma underwent ultrasonic CCT measurement, followed by IOP evaluation with the GAT and with the ICare tonometer. The deviation of ICare readings from GAT values, corrected according to the Doughty and Zaman formula, was calculated and correlated to CCT by a linear regression model. The agreement between the 2 devices was assessed by use of the Bland-Altman method.

RESULTS

The average CCT was 552+/-39 mum. The mean IOP and the mean corrected IOP with GAT were 19.4+/-5.4 mm Hg, and 18.5+/-5.7 mm Hg, respectively. The mean ICare IOP reading was 18.4+/-5.2 mm Hg. The deviations of ICare readings from corrected GAT values were highly correlated with CCT values (r=0.63, P<0.01). Linear regression analysis showed that a CCT change of 10 mum resulted in an ICare reading deviation of 0.7 mm Hg. The Bland-Altman scatter-plot showed a reasonable agreement between the 2 tonometers.

CONCLUSIONS

The ICare tonometer can be useful in a routine clinical setting. The IOP readings are quite in accordance with those obtained by GAT. The measurements seemed to be influenced by CCT variations, and thus pachymetry should always be taken into consideration.

Short-term effect of intravitreal injection of Ranibizumab (Lucentis) on intraocular pressure

PURPOSE

To investigate short-term effect on intraocular pressure (IOP) after intravitreal injection of ranibizumab (Lucentis) (IVIL).

MATERIALS AND METHODS

This prospective study included 1 eye of 54 patients (64+/-12 y) with wet age-related macular degeneration treated with IVIL. IOP measurements with TonoPen were taken: immediately before and 5 seconds, 5, 10, 15, 30, 60 minutes, and 1 day after IVIL. Axial length (with ultrasound biometry) was assessed in 24 eyes. The analysis included IOP difference at various time points and between phakic and pseudophakic eyes and the relationship between axial length and IOP increases after 5 seconds.

RESULTS

Mean IOP were 16.3+/-3.0 mm Hg (range: 12.0 to 21.3), 44.1+/-10.6 (22.0 to 59.3), 29.0+/-9.6 (15.0 to 49.0), 25.8+/-7.9 (16.0 to 45.0), 23.7+/-6.6 (15.7 to 39.0), 21.9+/-5.6 (14.7 to 37.0), 18.8+/-6.1 (10.0 to 35.0), and 16.1+/-3.0 (11.0 to 21.0), respectively, for time points immediately before, 5 seconds, 5, 10, 15, 30, 60 minutes, and 1 day after IVIL. Differences between before IVIL and after IVIL IOP were statistically significant after 5 seconds, 5, 10, 15, and 30 minutes (P=0.0001); however, were not significant after 1 hour (P=0.064) and 1 day (P=0.449). Differences between phakic and pseudophakic eyes were not significant (P>0.05). The relationship between shorter axial length and IOP increase after 5 seconds was significant (linear regression analysis; R=0.28, P=0.007).

CONCLUSIONS

IVIL causes a considerable short-term transient rise in IOP. The IOP increase after IVIL can be statistically significant at 0 to 30 minutes after injection in both phakic and pseudophakic eyes, and tends to be greater in shorter eyes.

Corneal Deformation Parameters Provided by the Corvis-ST Pachy-Tonometer in Healthy Subjects and Glaucoma Patients

PURPOSE

To evaluate precision and accuracy of Corvis-ST, a new noncontact tonometer equipped with a high-speed Scheimpflug technology, which measures intraocular pressure (IOP), central corneal thickness (CCT), and corneal deformation parameters (CDPs). Relationships among IOP, CCT, and CDPs were also assessed.

MATERIALS AND METHODS

This prospective, randomized study included 1 eye of 164 subjects (79 controls and 85 glaucoma patients), which underwent IOP measurements taken 3 times with Goldmann applanation tonometry (GAT) and Corvis-ST in random order. Precision was evaluated using intraclass correlation coefficients. Intermethod agreement was assessed using Bland-Altman method. Relationships amongst IOP, CCT and CDPs were evaluated using linear regression analysis.

RESULTS

Corvis-ST intraclass correlation coefficients ranged between 0.95 and 0.99 for IOP and CCT; between 0.17 and 0.97 for CDPs. Mean (GAT-Corvis-ST) IOP was 1.4±2.7 mm Hg, which appeared related to IOP and CDPs (P<0.05). CDPs significantly differed between glaucoma patients and controls (P<0.05). GAT and Corvis-ST IOP was related to CCT (P<0.05) and CDPs (P<0.001).

CONCLUSIONS

Corvis-ST precision was excellent for IOP and CCT; moderate for CDPs. Corvis-ST underestimated GAT IOP, especially at higher IOP and at lower corneal deformability levels. GAT and Corvis-ST IOP increased in thicker and less deformable corneas. Glaucoma patients showed significantly less deformable corneas than controls.

Comparisons between Pascal dynamic contour tonometry, the TonoPen, and Goldmann applanation tonometry in patients with glaucoma

PURPOSE

To compare intraocular pressure (IOP) measurements taken with Pascal dynamic contour tonometry (DCT), the TonoPen and the Goldmann applanation tonometry (GAT). The influence of central corneal thickness (CCT) on IOP measurements taken with Pascal DCT and the TonoPen was evaluated.

METHODS

One eye in each of 101 consecutive patients with primary open-angle glaucoma (POAG) underwent ultrasonic CCT measurement and IOP evaluation with GAT, Pascal DCT and the TonoPen in random order. The agreement between results from Pascal DCT and the TonoPen and those of GAT was assessed using the Bland-Altman method. The deviation of Pascal DCT and TonoPen readings from GAT values, corrected for CCT, was calculated and correlated to CCT using a linear regression model.

RESULTS

The mean of the differences in IOP measurements was 3.2 +/- 2.4 mmHg for Pascal DCT minus GAT readings and 0.5 +/- 4.5 mmHg for TonoPen minus GAT readings. The 95% confidence interval of differences in IOP measurements was higher between TonoPen and GAT readings (- 6 to 7 mmHg) than between Pascal and GAT readings (0.1-6.8 mmHg). Pascal DCT significantly overestimated IOP compared with GAT, especially for higher IOP readings. Bland-Altman scatterplots showed reasonable inter-method agreement between Pascal DCT and GAT measurements, and poor agreement between TonoPen and GAT measurements. The deviations of Pascal DCT and TonoPen readings from the corrected GAT values were both highly correlated with CCT values (linear regression analysis, p < 0.0001). The mean change in measured IOP for a 10-microm increase in CCT was 0.48 mmHg for Pascal DCT and 0.74 mmHg for the TonoPen.

CONCLUSIONS

Agreement with GAT measurements was higher for Pascal DCT than for TonoPen readings; however, Pascal DCT significantly overestimated IOP values compared with GAT. Measurements of IOP obtained with both Pascal DCT and the TonoPen appeared to be influenced by CCT, and this influence appeared to be greater for the latter.

Comparison of iCare tonometer and Goldmann applanation tonometry in normal corneas and in eyes with automated lamellar and penetrating keratoplasty

PURPOSE

To compare intraocular pressure (IOP) measurements with Goldmann applanation tonometry (GAT) and iCare tonometry in normal and post-keratoplasty corneas and to assess the influence of central corneal thickness (CCT), corneal curvature (CC), and corneal astigmatism (CA) on IOP.

METHODS

This prospective cross-sectional study included one eye of 101 subjects with normal corneas (58 healthy subjects, 43 glaucoma); and 90 post-keratoplasty patients: 34 penetrating keratoplasties (PK); 20 automated-lamellar-therapeutic keratoplasties (ALTK); 19 Descemet-stripping-automated-endothelial keratoplasties (DSAEK); 17 edematous grafts. All subjects underwent GAT and iCare IOP measurements in random order, and CCT, CC, and CA evaluation. The Bland-Altman method and multivariate regression analysis were used to assess inter-tonometer agreement and the influence of CCT, CC, and CA on IOP.

RESULTS

iCare significantly underestimated IOP in all groups compared with GAT (GAT minus iCare of 3.5±3.5 mm Hg, P<0.001), but overestimated IOP in the edematous grafts (GAT minus iCare of -6.5±1.9 mm Hg, P<0.001). In normal corneas, both tonometer measurements were directly related to CCT values; iCare readings appeared inversely related to CC. There was no significant relationship between IOP and CCT, CC and CA in post-keratoplasty eyes, except between CC and iCare measurements for PK eyes.

CONCLUSIONS

The agreement between GAT and iCare was clinically acceptable in control, ALTK and DSAEK groups, and poor in PK and edematous grafts eyes. In normal corneas, GAT was significantly affected by CCT; iCare was influenced by CCT and CC. The iCare appeared less influenced by corneal edema when compared with GAT. High IOP readings taken with both tonometers in grafts should raise suspicion of true elevated IOP.

Comparison between GDx VCC scanning laser polarimetry and Stratus OCT optical coherence tomography in the diagnosis of chronic glaucoma

PURPOSE

To compare the abilities of scanning laser polarimetry with the variable corneal compensator (GDx VCC) with those of optical coherence tomography (Stratus OCT) in discriminating between healthy and early-to-moderate perimetric glaucomatous eyes.

METHODS

A total of 95 glaucomatous patients (mean deviation - 3.7 +/- 3.0 dB, pattern standard deviation 4.5 +/- 2.7 dB) and 62 control subjects underwent imaging by the GDx VCC and Stratus OCT using both optic nerve head (ONH) and retinal nerve fibre layer (RNFL) scan protocols. One eye per patient was considered. Sensitivity at > or = 90% specificity and area under the receiver operating characteristic curve (AROC) were calculated for each GDx VCC and Stratus OCT index.

RESULTS

The largest AROCs with Stratus OCT were associated with cup : disc area ratio (0.88) for ONH scan indices, and with average thickness (0.84) for RNFL scan indices. The nerve fibre indicator provided the greatest AROC for the GDx VCC indices (0.85).

CONCLUSIONS

Both the GDx VCC and Stratus OCT instruments were shown to be useful in the detection of glaucomatous damage. The best performing indices for the GDx VCC and Stratus OCT with both ONH and RNFL scans gave similar AROCs, showing a moderate sensitivity in early-to-moderate glaucoma patients.

Frequency doubling technology perimetry with the Humphrey Matrix 30-2 test

PURPOSE

To assess the Humphrey Matrix 30-2 test in detecting functional glaucomatous damage.

PATIENTS AND METHODS

One eye in each of 60 healthy individuals, 108 patients with ocular hypertension (OHT), and 150 patients with preperimetric (48) or perimetric (102) high-tension primary open-angle glaucoma (POAG) were considered. Visual fields were assessed by the standard automated perimetry (SAP) Humphrey Field Analyzer 30-2, frequency doubling technology (FDT) N-30, and Humphrey Matrix 30-2 tests. Significantly abnormal points in the pattern deviation probability plot, testing time, sensitivity, specificity, and area under the receiver operating characteristic curve of the FDT tests were evaluated.

RESULTS

FDT revealed a significantly greater percentage of depressed points than did SAP in OHT and preperimetric POAG eyes. The FDT-N-30 test showed a significantly greater percentage of areas with P < 5% in the OHT, preperimetric POAG, and early POAG groups. The Matrix-30-2 test provided an area under the receiver operating characteristic curve slightly lower than the FDT-N-30 test in the preperimetric POAG group, and significantly greater in the perimetric POAG group.

CONCLUSIONS

FDT perimetry appeared more sensitive than SAP in detecting early glaucomatous VF loss. The FDT-N-30 test showed a slightly higher ability to detect early glaucomatous damage in patients at risk for the development of glaucoma, whereas the Matrix-30-2 test provided a more detailed characterization of the glaucomatous VF loss pattern, although it required 30% more time.

How to Measure Intraocular Pressure: An Updated Review of Various Tonometers

Intraocular pressure (IOP) is an important measurement that needs to be taken during ophthalmic examinations, especially in ocular hypertension subjects, glaucoma patients and in patients with risk factors for developing glaucoma. The gold standard technique in measuring IOP is still Goldmann applanation tonometry (GAT); however, this procedure requires local anesthetics, can be difficult in patients with scarce compliance, surgical patients and children, and is influenced by several corneal parameters. Numerous tonometers have been proposed in the past to address the problems related to GAT. The authors review the various devices currently in use for the measurement of intraocular pressure (IOP), highlighting the main advantages and limits of the various tools. The continuous monitoring of IOP, which is still under evaluation, will be an important step for a more complete and reliable management of patients affected by glaucoma.

Probing glaucoma visual damage by rarebit perimetry

AIM

To compare rarebit perimetry (RBP) with standard achromatic perimetry (SAP) in detecting early glaucomatous functional damage.

METHODS

43 patients with ocular hypertension (OH), 39 with early primary open angle glaucoma (POAG), and 41 controls were considered. Visual fields were assessed using the Humphrey field analyser (HFA) 30-2 and RBP tests. Differences among the groups were evaluated using Student-Newman-Keuls and chi(2) tests. Correlation between HFA and RBP parameters was assessed using the Pearson's correlation coefficients and regression analysis. Sensitivity and specificity of RBP in detecting early glaucomatous visual damage were calculated with different algorithms.

RESULTS

RBP-mean hit rate (MHR) was respectively 88.6% (SD 4.8%) in controls; 79.1% (10.9%) in the OH group; 64.3% (13.8%) in the POAG group (differences statistically significant). Good correlation in the POAG group was found between HFA-mean deviation and RBP-MHR. Largest AROC (0.95) and optimal sensitivity (97.4%) were obtained when an abnormal RBP test was defined as having (at least 1): MHR <80%; >15 areas with a non-hit rate of >10%; > or =2 areas with a non-hit rate of >50%; at least one area with a non-hit rate of > or =70%.

CONCLUSIONS

The RBP appeared to be a rapid, comfortable, and easily available perimetric test (requiring only a PC device), showing a high sensitivity and specificity in detecting early glaucomatous visual field defects.

Human adipose-derived stem cells for the treatment of chemically burned rat cornea: preliminary results

PURPOSE

Adipose-derived stem cells (ADSC) are multipotent, safe, non-immunogenic and can differentiate into functional keratocytes in situ. The topical use of ADSC derived from human processed lipoaspirate was investigated for treating injured rat cornea.

METHODS

A total of 19 rats were used. Six animals initially underwent corneal lesion experiments with 0.5 N NaOH (right eye) and 0.2 N (left). The 0.2 NaOH protocol was then used in 13 rats. All 26 eyes of 13 rats eyes received topical azythromycin bid for 3 d and divided into five treatment groups (n = 5 eyes/group), which included: control, stem cells, serum, stem + serum and adipose (raw human lipoaspirate). The four treatment groups received topical treatment three times daily for 3 d. Stem cells were isolated and harvested from human lipoaspirate. Topical eye drops were prepared daily with 1 × 10(5) cells/treatment. Fluorescein positive defect area and light microscope assessment was performed at 20, 28, 45, 50 and 74 h. Animals were sacrificed at 74 h for histological evaluation. Data were statistically analyzed for differences amongst groups.

RESULTS

The stem cell-treated eyes had significantly smaller epithelial defects at each time point compared to control- and adipose-treated eyes (p < 0.05). This group showed slightly better epithelium healing than the serum and combined group, yet not significantly different. Histology showed that stem cell-treated corneas had complete re-epithelization, with less inflammatory cells and limited fibroblast activation structure compared with the control eyes.

CONCLUSIONS

Our preliminary results show that topical treatment with ADSC seems to improve corneal wound healing.

Comparison between laser scanning in vivo confocal microscopy and noncontact specular microscopy in assessing corneal endothelial cell density and central corneal thickness

PURPOSE

To compare central corneal thickness (CCT) and endothelial cell density (ECD) with laser scanning confocal microscope Heidelberg Retina Tomograph (HRT) II Rostock Corneal Module and noncontact specular microscope Tomey EM-3000 and to assess intra- and interobserver agreement in normal corneas.

METHODS

This prospective study included 48 normals (69.6 ± 7.2 years, range: 55-80 years) who underwent CCT and ECD with both Tomey and HRT 3 times by 2 independent observers. Measurement differences between instruments, agreement between devices, and test-retest variability (TRV) were determined.

RESULTS

Mean CCTs with Tomey and HRT were 529.4 ± 35.4 and 536 ± 37.6 μm (P = 0.06), respectively; average ECDs with Tomey and HRT were 2473.5 ± 242.2 and 2539.7 ± 338.6 cells per square millimeter (P = 0.04), respectively. The mean of the differences (HRT minus Tomey) was 6.5 ± 17 μm for CCT and 65 ± 135.1 cells per square millimeter for ECD. Differences between instruments were not related to CCT (P = 0.35), whereas significantly increased with increasing ECD (P = 0.0001). Intraexaminer TRV for Tomey and HRT were 3.9 ± 3.7 and 22.2 ± 18.4 μm for CCT and 73 ± 63.4 and 152.2 ± 148.4 cells per square millimeter for ECD, respectively; interexaminer TRV was 4.6 ± 4.2 and 23.8 ± 17.3 μm for CCT and 84.9 ± 72.3 and 159.8 ± 149.8 cells per square millimeter for ECD.

CONCLUSIONS

HRT II Rostock Corneal Module and the Tomey EM-3000 showed an overall good intermethod agreement. HRT showed a tendency to slightly overestimate CCT measurements, significantly underestimate ECD measurements in eyes with a reduced cell density (< 2290 cells per square millimeter), and overestimate ECD in eyes with a high cell density. Both instruments showed low intra- and interobserver TRV for both CCT and ECD measurements, which tended to be less for Tomey.

Glioblastoma Immunotherapy: A Systematic Review of the Present Strategies and Prospects for Advancements

Glioblastoma (GBM) is characterized by aggressive growth and high rates of recurrence. Despite the advancements in conventional therapies, the prognosis for GBM patients remains poor. Immunotherapy has recently emerged as a potential treatment option. The aim of this systematic review is to assess the current strategies and future perspectives of the GBM immunotherapy strategies. A systematic search was conducted across major medical databases (PubMed, Embase, and Cochrane Library) up to 3 September 2023. The search strategy utilized relevant Medical Subject Heading (MeSH) terms and keywords related to "glioblastomas," "immunotherapies," and "treatment." The studies included in this review consist of randomized controlled trials, non-randomized controlled trials, and cohort studies reporting on the use of immunotherapies for the treatment of gliomas in human subjects. A total of 1588 papers are initially identified. Eligibility is confirmed for 752 articles, while 655 are excluded for various reasons, including irrelevance to the research topic (627), insufficient method and results details (12), and being case-series or cohort studies (22), systematic literature reviews, or meta-analyses (3). All the studies within the systematic review were clinical trials spanning from 1995 to 2023, involving 6383 patients. Neuro-oncology published the most glioma immunotherapy-related clinical trials (15/97, 16%). Most studies were released between 2018 and 2022, averaging nine publications annually during this period. Adoptive cellular transfer chimeric antigen receptor (CAR) T cells were the primary focus in 11% of the studies, with immune checkpoint inhibitors (ICIs), oncolytic viruses (OVs), and cancer vaccines (CVs) comprising 26%, 12%, and 51%, respectively. Phase-I trials constituted the majority at 51%, while phase-III trials were only 7% of the total. Among these trials, 60% were single arm, 39% double arm, and one multi-arm. Immunotherapies were predominantly employed for recurrent GBM (55%). The review also revealed ongoing clinical trials, including 9 on ICIs, 7 on CVs, 10 on OVs, and 8 on CAR T cells, totaling 34 trials, with phase-I trials representing the majority at 53%, and only one in phase III. Overcoming immunotolerance, stimulating robust tumor antigen responses, and countering immunosuppressive microenvironment mechanisms are critical for curative GBM immunotherapy. Immune checkpoint inhibitors, such as PD-1 and CTLA-4 inhibitors, show promise, with the ongoing research aiming to enhance their effectiveness. Personalized cancer vaccines, especially targeting neoantigens, offer substantial potential. Oncolytic viruses exhibited dual mechanisms and a breakthrough status in the clinical trials. CAR T-cell therapy, engineered for specific antigen targeting, yields encouraging results, particularly against IL13 Rα2 and EGFRvIII. The development of second-generation CAR T cells with improved specificity exemplifies their adaptability.

In vivo analysis of conjunctiva in canaloplasty for glaucoma

AIM

To assess the epithelial features of the bulbar conjunctiva using in vivo confocal microscopy in patients with glaucoma undergoing canaloplasty.

METHODS

Thirty consecutive patients with glaucoma were enrolled. Canaloplasty was considered successful if the preoperative intraocular pressure (IOP) was reduced by one-third. The conjunctiva was examined using confocal laser-scanning microscopy 1 week before (baseline) and 12 weeks after surgery. The mean density (MMD, cysts/mm(2)) and mean area (MMA, μm(2)) of conjunctival microcysts and IOP were measured. Anterior segment optical coherence tomography was performed to evaluate post-operative trabecular distension and scleral modifications at the surgery site.

RESULTS

Twelve weeks after surgery, canaloplasty was successful in 23 patients (group 1) but unsuccessful in 7 (group 2). At baseline, IOP was 28.1±2.98 and 28.3±2.81 mm Hg, MMD was 10.61±4.31 and 11.35±5.6 and MMA was 2845.02±411.85 and 2700.56±518.85 in groups 1 and 2, respectively (p>0.05). Twelve weeks after canaloplasty, mean IOP was 13.2±4.48 (p<0.05) and 24.6±3.48 mm Hg in groups 1 and 2, respectively. In group 1, MMD and MMA were 37.86±21.4 and 11997.84±8630.35, respectively, a fourfold increase compared to baseline (p<0.001); no significant differences were found in group 2. Conjunctival bleb was not documented in any case.

CONCLUSIONS

Conjunctival microcysts were evident in all glaucomatous eyes prior to surgery, and tended to increase in density and surface area after successful canaloplasty. These findings indicated enhanced aqueous humour filtration across the sclera and conjunctiva after canaloplasty.

Adipose Derived Stem Cells for Corneal Wound Healing after Laser Induced Corneal Lesions in Mice

The aim of our study was to assess the clinical effectiveness of topical adipose derived stem cell (ADSC) treatment in laser induced corneal wounds in mice by comparing epithelial repair, inflammation, and histological analysis between treatment arms. Corneal lesions were performed on both eyes of 40 mice by laser induced photorefractive keratectomy. All eyes were treated with topical azythromycin bid for three days. Mice were divided in three treatment groups (n = 20), which included: control, stem cells and basic serum; which received topical treatment three times daily for five consecutive days. Biomicroscope assessments and digital imaging were performed by two masked graders at 30, 54, 78, 100, and 172 h to analyze extent of fluorescein positive epithelial defect, corneal inflammation, etc. Immunohistochemical techniques were used in fixed eyes to assess corneal repair markers Ki67, α Smooth Muscle Actin (α-SMA) and E-Cadherin. The fluorescein positive corneal lesion areas were significantly smaller in the stem cells group on days 1 (p < 0.05), 2 (p < 0.02) and 3. The stem cell treated group had slightly better and faster re-epithelization than the serum treated group in the initial phases. Comparative histological data showed signs of earlier and better corneal repair in epithelium and stromal layers in stem cell treated eyes, which showed more epithelial layers and enhanced wound healing performance of Ki67, E-Cadherin, and α-SMA. Our study shows the potential clinical and histological advantages in the topical ADSC treatment for corneal lesions in mice.

Pulsar perimetry in the diagnosis of early glaucoma

PURPOSE

To assess the ability of Pulsar perimetry (Pulsar) in detecting early glaucomatous visual field (VF) damage in comparison with Frequency Doubling Technology (FDT), Scanning Laser Polarimetry (SLP, GDx VCC), and Heidelberg Retina Tomography (HRT).

DESIGN

Prospective observational cross-sectional case study.

METHODS

This multicenter study included: 87 ocular hypertensives (OHT); 67 glaucomatous optic neuropathy (GON) patients; 75 primary open-angle glaucoma (POAG) patients; and 90 normals. All patients underwent standard automated perimetry (SAP) HFA 30-2, Pulsar T30W, FDT N-30, HRT II, and GDx VCC. Area under Receiver Operating Characteristic Curves (AROCs) for discriminating between healthy and glaucomatous eyes and agreement among instruments were determined.

RESULTS

The best parameters for Pulsar, FDT, HRT, and GDx were, respectively: loss variance square root; no. of areas with P< 5%; Cup-Shape-Measure; and Nerve Fiber Indicator (NFI). In detecting POAG eyes, Pulsar (AROC, 0.90) appeared comparable with FDT (0.89) and significantly better than HRT (0.82) and GDx (0.79). For GON, Pulsar ability (0.74) was higher than GDx (0.69) and lower than FDT (0.80) and HRT (0.83). The agreement among instruments ranged from 0.12 to 0.56. Pulsar test duration was significantly shorter than SAP and FDT (P< .001).

CONCLUSIONS

Pulsar T30W test is a rapid and easy perimetric method, showing higher sensitivity than SAP in detecting early glaucomatous VF loss. Its diagnostic ability is good for detecting early perimetric POAG eyes and fair for GON eyes. Pulsar performance was comparable with FDT, HRT, and GDx, even if the agreement between instruments was poor to fair.

Perceived spatial frequency of sinusoidal gratings

PURPOSE

The "frequency-doubling" effect or illusion, in which the apparent spatial frequency of a grating appears to be doubled, is produced when a low spatial frequency sinusoidal grating is counterphase flickered at a high temporal frequency. This study examines changes in apparent spatial frequency of sinusoids of various spatiotemporal content after equating them for detectability.

METHODS

Detection contrast thresholds were determined for various spatiotemporal gratings. The perceived spatial frequency was then evaluated using stimuli that were four and six times detection threshold. Match ratios were determined for each spatiotemporal combination, whereby the periodicity of a stationary sinusoid was matched with that of a counterphase flickered grating. The same matching task was repeated under different matching task instructions for five randomly chosen spatiotemporal combinations.

RESULTS

Match ratios were fractional for many spatiotemporal combinations. Apparent spatial frequency ranged from less than veridical to greater than double depending on observer and spatiotemporal stimulus content. The effect of task instruction on match ratios was very small, yet significant.

CONCLUSIONS

The appearance of fractional spatial frequency percepts draws into question the notion that frequency-doubling is solely generated by spatially non-linear Y-type magnocellular ganglion cells.

Innovative Strategies for Drug Delivery to the Ocular Posterior Segment

Innovative and new drug delivery systems (DDSs) have recently been developed to vehicle treatments and drugs to the ocular posterior segment and the retina. New formulations and technological developments, such as nanotechnology, novel matrices, and non-traditional treatment strategies, open new perspectives in this field. The aim of this mini-review is to highlight promising strategies reported in the current literature based on innovative routes to overcome the anatomical and physiological barriers of the vitreoretinal structures. The paper also describes the challenges in finding appropriate and pertinent treatments that provide safety and efficacy and the problems related to patient compliance, acceptability, effectiveness, and sustained drug delivery. The clinical application of these experimental approaches can help pave the way for standardizing the use of DDSs in developing enhanced treatment strategies and personalized therapeutic options for ocular pathologies.

Rarebit perimetry in normal subjects: test-retest variability, learning effect, normative range, influence of optical defocus, and cataract extraction

PURPOSE

To study normative ranges, learning effect (LE), test-retest variability (TRV), and influence of blur and cataract in normal subjects by using rarebit perimetry (RBP).

METHODS

Seventy-five normal subjects underwent visual field (VF) testing with standard automated perimetry (SAP) and RBP. LE and TRV for RBP were assessed in repeated examinations conducted on four different days. LE was evaluated by comparing results from the first with those of the other three sessions. TRV was studied by calculating differences between retest for each combination of single tests. The blur effect was evaluated by repeated tests with spherical lenses added to the optimum refractive correction (+/-1.00 to +/-6.00 D). The cataract effect was studied in 23 subjects who underwent RBP 1 week before and 1 month after cataract surgery. Mean hit rate (MHR) and mean miss rate (MMR) were analyzed for single areas and test duration.

RESULTS

The mean MHR was 91% +/- 5.7% (range, 78%-99%); the mean MMR ranged from 4.0% to 13.8%. MHR significantly decreased with age (mean, 0.21%/year). Mean test time was 268 +/- 34.1 seconds. No significant LE was observed. TRV was significantly higher in the central VF zone and in elderly subjects. MHR increased with refractive blur and significantly decreased after cataract surgery. Effects of blur and cataract extraction were significantly higher in the central VF zone, especially in elderly subjects.

CONCLUSIONS

RBP is a rapid and easily accessible VF test. RBP testing did not show a significant LE; however, inter- and intrasubject variability were consistent. Blur and media opacities may give false-positive results in RBP, especially in the central VF, and should be considered.

Stem cell therapy in ocular pathologies in the past 20 years

Stem cell therapies are successfully used in various fields of medicine. This new approach of research is also expanding in ophthalmology. Huge investments, resources and important clinical trials have been performed in stem cell research and in potential therapies. In recent years, great strides have been made in genetic research, which permitted and enhanced the differentiation of stem cells. Moreover, the possibility of exploiting stem cells from other districts (such as adipose, dental pulp, bone marrow stem cells, etc.) for the treatment of ophthalmic diseases, renders this topic fascinating. Furthermore, great strides have been made in biomedical engineering, which have proposed new materials and three-dimensional structures useful for cell therapy of the eye. The encouraging results obtained on clinical trials conducted on animals have given a significant boost in the creation of study protocols also in humans. Results are limited to date, but clinical trials continue to evolve. Our attention is centered on the literature reported over the past 20 years, considering animal (the most represented in literature) and human clinical trials, which are limiting. The aim of our review is to present a brief overview of the main types of treatments based on stem cells in the field of ophthalmic pathologies.

Impact of intraoperative radiotherapy on cosmetic outcome and complications after oncoplastic breast surgery

Breast cancer is one of the most common tumors in the population worldwide. Conservative breast surgery (CBS) is one of the preferred surgical options, because both the oncologic and esthetic needs of the patient can be addressed. CBS surgical outcomes tend to be more effective with reduced chances of disease recurrence when radiotherapy (RT) treatment is considered as an adjunct treatment, either applied during surgery (IORT) and/or after (EBRT). The purpose of our study was to compare surgical outcomes between IORT and EBRT after CBS. In the past 5 years, we performed CBS in 489 patients in our clinic. Of these patients, 83 underwent adjunct treatment with IORT and 109 were treated with EBRT in accordance with our university approved clinical protocol. Surgical outcomes, early complication rates, and esthetic results were compared between these two groups of CBS patients, with a mean follow-up time of 17 months. IORT allowed breast irradiation treatment to be performed without effecting overlying skin, thus cosmetic outcomes tended to be favorable. Esthetic postoperative results assessed with the Breast Cancer Conservation Treatment (BCCTcore) software showed that the differences between IORT and EBRT were not statistically significant (including those patients that underwent further oncoplastic techniques after EBRT). The disease recurrence rates between the two groups were not significantly different. IORT is a safe, fast, and feasible technique that provides effective and comparable CBS outcomes for patients with breast cancer.

Pupil size influence on the intraocular performance of the multifocal AMO-Array intraocular lens in elderly patients

PURPOSE

To study the relationship between pupil size and AMO-Array multifocal intraocular lens (MIOL) performance in a population of elderly patients.

METHODS

This prospective trial included 62 patients (mean age 76 years; range 70 to 86) undergoing bilateral cataract phacoemulsification and MIOL (AMO-Array SA-40N, Allergan) implantation. Patients were divided into two groups based on preoperative pupil diameter: small pupil group (pupil size of 2.5-2.9 mm; 45 subjects) and large pupil group (pupil size of 3-5 mm; 17 subjects). The analysis included uncorrected (UC) and best-corrected (BC) near and distance visual acuity (VA), spectacle dependence, and photic phenomena complaints (postoperative follow-up 16.6+/-6.2 months; range 11-26 months).

RESULTS

Patients in the small pupil group showed postoperatively significantly higher distance UCVA and BCVA, but lower near UCVA compared to those in the large pupil group (Mann-Whitney test, p< or = 0.02). Patients with small pupils also tended to: be more (not statistically significant) spectacle independent for distance (73.3% versus 47.1%) and spectacle-dependent for near vision (55.6% versus 28.4%); report significantly less photic phenomena complaints (37.8% versus 93.1%, chisquare test, p<0.001); and, more satisfied with the surgery (95.5% versus 76.5%). Posterior capsular opacification (PCO) was observed in 19.4% of the patients.

CONCLUSIONS

Bilateral AMO-Array MIOL implantation in elderly patients seems to be an effective and safe surgical procedure that improves distance and near UCVA, providing spectacle independence in many cases. The use of these MIOLs, however, can induce photic phenomena and cause PCO. Patients with small preoperative pupils (<3 mm) presented less photic phenomena complaints and expressed a higher visual outcome satisfaction after surgery.

Discrimination between normal and early glaucomatous eyes with scanning laser polarimeter with fixed and variable corneal compensator settings

PURPOSE

To evaluate the ability of scanning laser polarimetry (SLP) with a fixed corneal polarization compensator (GDx-FCC Nerve Fiber Analyzer) compared to one with a variable one (GDx-VCC) in the discrimination between healthy and early glaucomatous eyes.

METHODS

Forty patients with early glaucomatous visual field defects, having a mean deviation of 3.1-/+1.6 dB and a pattern standard deviation of 3.1-/+0.9 dB, and 40 controls underwent both GDx-FCC and GDx-VCC. One eye per patient was considered. The cut-off point, taken as the value dividing healthy from glaucomatous eyes with highest probability, was determined for each GDx parameter. Linear discriminant functions (LDFs) were separately developed for GDx-FCC and GDx-VCC parameters. Sensitivity, specificity, and area under the receiver operating characteristic curve (AROC) for discriminating between healthy and glaucomatous eyes were calculated for each GDx parameter, both according to the GDx normative database and after the selection of new cut-off points, and for the LDFs.

RESULTS

All software-provided parameters showed low sensitivity and high specificity. The selection of new cut-off points improved the performance of all GDx parameters: VCC parameters performed better than FCC parameters; the largest AROCs were associated with the superior/nasal ratio for the GDx-FCC (0.86) and with the Number for the GDx-VCC (0.87). The LDFs provided an AROC of 0.89 with both the GDx-FCC and the GDx-VCC parameters.

CONCLUSIONS

The GDx-VCC showed a higher ability in the early diagnosis of glaucoma when compared with the GDx-FCC. The individuation of the right cut-off point of selected parameters with both GDx settings performed better than the software-provided parameters, and comparably to the GDx parameters-based LDFs.

Non-conventional perimetric methods in the detection of early glaucomatous functional damage

PURPOSE

To compare the ability of frequency-doubling technology (FDT), rarebit perimetry (RBP), and pulsar perimetry (PP) in detecting early glaucomatous functional damage.

METHODS

This prospective observational cross-sectional case study included 52 patients with early primary open-angle glaucoma (mean deviation -2.3+/-1.1 dB; pattern standard deviation 3.0+/-1.2 dB) and 53 healthy controls. Visual field (VF) testing included standard automated perimetry (SAP) Humphrey Field Analyzer 30-2, FDT N-30, RBP (version 4.0), and PP T30W. One eye per patient was considered. Sensitivity at fixed specificities and area under the receiver operating characteristic curve (AROC) for discriminating between healthy and glaucomatous eyes were calculated and compared.

RESULTS

The parameters associated with the largest AROC, which were not statistically different (Hanley-McNeil method, P0.42-0.71) were as follows: number of locations in the pattern deviation probability (PDP) plot with P<5% for FDT (0.93); mean hit rate for RBP (0.95); and mean defect for PP (0.94). PP test duration was significantly shorter than FDT and RBP (P<0.002).

CONCLUSIONS

FDT, PP, and RBP are useful non-conventional VF methods in detecting early glaucomatous VF defects with similar AROCs. The methods were rapid and easy, and PP took less than half the time than SAP. These non-conventional testing may prove to be useful in providing additional information in the diagnosis of glaucoma suspect with normal SAP results, in the therapeutic decision-making process of early glaucomatous patients, and in subjects unable to perform VF testing with SAP.

Nerve fibre layer analysis with GDx with a variable corneal compensator in patients with multiple sclerosis

PURPOSE

To evaluate the ability of GDx with variable corneal compensator (VCC) compared to visual-evoked potentials (VEPs) and standard automated perimetry (SAP) in the detection of early optic nerve damage in patients with multiple sclerosis (MS).

METHODS

46 eyes of 23 MS patients were included. Ten of them had a history of acute retrobulbar optic neuritis. A control group of 20 normal subjects was also included. All subjects underwent a complete ophthalmological examination and testing with SAP, GDx VCC and VEPs.

RESULTS

19 eyes (41.3%) were abnormal with GDx VCC compared to 38 eyes (82.6%) with SAP and 31 (64.4%) with VEPs. In the optic neuritis group, 9 eyes (69.2%) had optic nerve pallor; SAP was abnormal in 8 of these eyes (61.5%) while VEPs and GDx VCC were abnormal in 6 eyes (46.1%). 2/20 eyes (10.0%) in the control group gave a false-positive abnormal result with SAP. GDx VCC and VEP were normal for all the eyes in the control group.

CONCLUSIONS

GDx VCC is less able to detect early defects in MS patients compared to the currently used standard techniques of SAP and VEPs.

Test-retest variability of intraocular pressure and ocular pulse amplitude for dynamic contour tonometry: a multicentre study

AIMS

To assess the test-retest variability of intraocular pressure (IOP) and ocular pulse amplitude (OPA) measurements utilising dynamic contour tonometry (DCT) and to evaluate possible influential factors.

METHODS

The study included 350 consecutive subjects (175 glaucoma, 175 control; one eye per subject) from seven European centres. IOP was measured once with a Goldmann applanation tonometer (GAT) and twice by DCT (DCT1, DCT2) in a randomised sequence. OPA was also recorded for both DCT measurements. Differences (DCT1-DCT2; OPA1-OPA2; GAT-DCT1; GAT-DCT2) were assessed using the t test. The intraclass coefficient of correlation (ICC) and coefficient of variation (CoV) for DCT and OPA were calculated.

RESULTS

DCT1 was 0.6+/-1.6 mm Hg higher than DCT2 (p<0.001); OPA1 was 0.1+/-0.7 mm Hg higher than OPA2 (p=0.02). Results were not influenced by randomisation test order. In both glaucoma and normal subjects, DCT and OPA showed ICC>0.90 and >0.76, and CoV=4.8-5.0% and 10.3-10.5%, respectively. DCT1 and 2 were 2.4+/-2.6 and 1.8+/-2.6 mm Hg higher respectively than GAT (p<0.001).

DISCUSSION

DCT test-retest variability was almost perfect for IOP and good for OPA. Tonometry measurements with DCT tended to be overestimated compared with GAT.