Intraocular Pressure Alterations Research Articles

The Alteration of Intraocular Pressure and Ocular Pulse Amplitude by Retrobulbar Anaesthesia-A Search for Risk Factors for Serious Complications Due to Retrobulbar Anaesthesia.

Our goal was to assess the impact of retrobulbar anaesthesia on ocular pressure and perfusion development and to find out if there were systemic or biometric parameters of patients affecting them in order to understand the effect of retrobulbar anaesthesia better. Methods: Changes in intraocular pressure (IOP) and ocular pulse amplitude (OPA) using a dynamic contour tonometer (DCT) were noted before and after retrobulbar anaesthesia (RBA) in combination with five minutes of oculopression at 40 mmHg in 134 patients. Only results with a quality Q 1-3 were considered for further statistical analysis. Systemic and ophthalmic parameters were noted and their impact was tested using linear regression. Results: IOP decreased from 18.9 ± 7.2 mmHg to 15.4 ± 6.3 mmHg (n = 71, p = 0.001) after first RBA. The dosage of midazolam administered during premedication was found to increase IOP significantly after first RBA (B = 3.75; R2 = 0.38). Ocular pulse amplitude decreased significantly from 3.8 ± 1.7 mmHg to 3.0 ± 1.9 mmHg after first RBA (n = 72, p < 0.001). This change was found to be dependent on the presence of diabetes mellitus (n = 68, p = 0.048). Conclusions: IOP and OPA decrease after RBA and oculopression. Caution is needed with midazolam premedication due to potential IOP increase. Patients with diabetes and pre-existing retinal or optic nerve damage should consider alternative anaesthesia methods, such as eye drops or general anaesthesia, due to the observed decrease in OPA after RBA and oculopression.

Evaluation of lidocaine for auriculopalpebral nerve block in dogs: Onset, duration, and effects on intraocular pressure and eye examination.

Accurate intraocular pressure (IOP) measurement is essential for managing glaucoma, requiring tonometry. Local anesthesia is typically used, but nerve blocks may be needed for blepharospasm. This study investigated the efficacy of auriculopalpebral nerve block with lidocaine in achieving eyelid akinesia and its influence on IOP in dogs. In a randomized, blinded trial, 12 healthy adult mixed-breed dogs (24 eyes) received either auriculopalpebral nerve block with 2% lidocaine (n = 12 eyes) or no block (n = 12 eyes). Tetracaine drops were used for topical anesthesia in half of blocked/non-blocked eyes, and the rest of the eyes got artificial tears as control. The impact of nerve block was evaluated through assessments of menace response, palpebral reflex, and IOP before the block, after drop instillation, and at 15-min intervals until block dissipation. Auriculopalpebral nerve block provided effective eyelid akinesia in 58.5% (7/12 eyes) at 15 min, reaching 91.7% (11/12 eyes) at 30 min, indicating peak efficacy. Subsequently, the block gradually diminished, with 66.7% (8/12 eyes) and 33.3% (4/12 eyes) maintaining akinesia at 45 and 60 min, respectively. Importantly, neither auriculopalpebral nerve block nor tetracaine administration significantly affected IOP measurements (p > .05). Auriculopalpebral nerve block using lidocaine demonstrated efficient eyelid akinesia, peaking at 30 min postinjection. This technique proved to be safe with no notable alterations in IOP, suggesting its potential utility in canine ophthalmology for procedures requiring eyelid akinesia, particularly in the management of glaucoma where maintaining accurate IOP measurements is crucial for diagnosis, treatment, and monitoring the disease.

Longitudinal associations of retinal vessel morphology with intraocular pressure and blood pressure at follow-up visit-Findings from a Danish eye and vision cohort, Project FOREVER.

To characterise the retinal vasculometry of a Danish eye and vision cohort and examine associations with systolic blood pressure (BP), diastolic BP, mean arterial BP, and intraocular pressure (IOP). Longitudinal study. The retinal vasculature of fundus images from the FOREVER (Finding Ophthalmic Risks and Evaluating the Value of Eye exams and their predictive Reliability) cohort was analysed using a fully automated image analysis program. Longitudinal associations of retinal vessel morphology at follow-up visit with IOP (baseline and follow-up) and BP (follow-up) were examined using multilevel linear regression models adjusting for age, sex and retinal vasculometry at baseline as fixed effects and person as random effect. Width measurements were additionally adjusted for the spherical equivalent. A total of 2089 subjects (62% female) with a mean age of 61 (standard deviation 8) years and a mean follow-up period of 4.1 years (SD 0.6 years) were included. The mean arteriolar diameter was approximately 20% thinner than the mean venular diameter, and venules were about 21%-23% less tortuous than arterioles. BP at follow-up was associated with decreased arteriolar diameter from baseline to follow-up. After adjusting for baseline IOP, IOP at follow-up was associated with increased arteriolar tortuosity above baseline (0.59%, 95% CI 0.08-1.10, p-value 0.024). In a Danish eye and vision cohort, variations in BP and alterations in IOP over time were associated with changes in the width and tortuosity of retinal vessels. Our findings contribute novel insights into retinal vascular alterations over time.

Photocrosslinkable Sericin Hydrogel Injected into the Anterior Chamber of Mice with Chronic Ocular Hypertension Efficacy, Medication Sensitivity, and Material Safety.

(1) Background: A rise in intraocular pressure (IOP) and decreased retinal ganglion cells are frequent indicators of effective modeling of chronic ocular hypertension in mice. In this study, the sensitivity of the mouse model to pharmaceutical therapy to reduce intraocular tension was assessed, the model's safety was confirmed using a cytotoxicity test, and the success rate of the mouse model of ocular hypertension was assessed by assessing alterations in IOP and neurons in the ganglion cell layer. (2) Methods: A mouse model of chronic ocular hypertension was produced in this study by employing photocrosslinkable sericin hydrogel injection and LED lamp irradiation. The eyes of 25 C57BL/6 male mice were subjected to 405 nm UV light from the front for 2 min after being injected with 5 μL of sericin hydrogel in the anterior chamber of the left eye. IOP in the mice was measured daily, and IOP rises greater than 5 mmHg were considered intraocular hypertension. When the IOP was lowered, the intervention was repeated once, but the interval between treatments was at least 2 weeks. The right eyes were not treated with anything as a normal control group. Mice eyeballs were stained with HE, Ni-type, and immunofluorescence to assess the model's efficacy. Two common drugs (tafluprost eye drops and timolol eye drops) were provided for one week after four weeks of stable IOP, and IOP changes were assessed to determine the drug sensitivity of the mouse model of chronic ocular hypertension. Furthermore, CellTiter 96® AQueous One Solution Cell Proliferation Assay (MTS) was utilized to investigate the safety of the ocular hypertension model by evaluating the deleterious effects of photocrosslinkable sericin hydrogel on cells. (3) Results: Before injection, the basal IOP was (9.42 ± 1.28) mmHg (1 kPa = 7.5 mmHg) in the experimental group and (9.08 ± 1.21) in the control group. After injection, cataract occurred in one eye, corneal edema in one eye, endophthalmitis in one eye, iris incarceration in one eye, and eyeball atrophy in one eye. Five mice with complications were excluded from the experiment, and twenty mice were left. Four weeks after injection, the IOP of the experimental group was maintained at (19.7 ± 4.52) mmHg, and that of the control group was maintained at (9.92 ± 1.55) mmHg, and the difference between the two groups was statistically significant (p < 0.05). Before the intervention, the IOP in the experimental group was (21.7 ± 3.31) mmHg in the high IOP control group, (20.33 ± 2.00) mmHg in the tafluprost eye drops group, and (20.67 ± 3.12) mmHg in the timolol maleate eye drops group. The IOP after the intervention was (23.2 ± 1.03) mmHg, (12.7 ± 2.11) mmHg, and (10.4 ± 1.43) mmHg, respectively. Before and after the intervention, there were no significant differences in the high-IOP control group (p > 0.05), there were statistically significant differences in the timolol eye drops group (p < 0.05), and there were statistically significant differences in the tafluprost eye drops group (p < 0.05). One week after drug withdrawal, there was no significant difference in IOP among the three groups (p > 0.05). In the high-IOP group, the protein (sericin hydrogel) showed a short strips or fragmented structure in the anterior chamber, accompanied by a large number of macrophages and a small number of plasma cells. The shape of the chamber angle was normal in the blank control group. The number of retinal ganglion cells decreased significantly 8 weeks after injection of sericin hydrogel into the anterior chamber, and the difference was statistically significant compared with the blank control group (p < 0.05). After the cells were treated with photocrosslinkable sericin hydrogel, there was no significant difference in the data of the CellTiter 96® assay kit of MTS compared with the blank control group (p > 0.05). (4) Conclusions: A mouse model of chronic intraocular hypertension can be established successfully by injecting sericin in the anterior chamber and irradiating with ultraviolet light. The model can simulate the structural and functional changes of glaucoma and can effectively reduce IOP after the action of most antihypertensive drugs, and it is highly sensitive to drugs. Sericin has no obvious toxic effect on cells and has high safety.

Evaluating Intraocular Pressure Alterations during Large Muscle Group Isometric Exercises with Varying Head and Body Positions.

Performing physical exercise affects intraocular pressure, and its elevation and fluctuations are the main risk factors for glaucoma development or progression. The aim of this study was to examine the acute alterations in intraocular pressure (IOP) during four unweighted isometric exercises and to determine whether the different head and body positions taken during exercise additionally affect IOP. Twelve healthy volunteers between the ages of 25 and 33 performed four isometric exercises: wall sit in neutral head and body position, elbow plank in prone head and body position, reverse plank in supine head and body position for 1 min, and right-side plank in lateral head and body position for 30 s. Intraocular pressure was measured by applanation portable tonometry, before performing the exercise, immediately after exercise completion, and after five minutes of rest. A significant acute increase in intraocular pressure was found as a response to the performance of the elbow plank (p < 0.01), the reverse plank (p < 0.001), and the right-side plank (p < 0.001). The wall sit exercise did not reveal a statistically significant IOP elevation (p = 0.232). Different head and body positions had no significant additional influence on IOP (F (3,33) = 0.611; p = 0.613), even though the alteration in IOP was found to be greater in exercises with a lower head and body position. Our data revealed that IOP elevation seems to be affected by the performance of the elbow plank, the reverse plank, and the right-side plank; and not by the wall sit exercise. More different isometric exercises should be examined to find ones that are safe to perform for glaucoma patients.

Comparison of Corneal Endothelial Parameters and Intraocular Pressure Alterations After Uneventful Cataract Surgery with 1.8% and 3% Sodium Hyaluronate

Comparison of Corneal Endothelial Parameters and Intraocular Pressure Alterations After Uneventful Cataract Surgery with 1.8% and 3% Sodium Hyaluronate

Ocular Treatments Targeting Separate Prostaglandin Receptors in Mice Exhibit Alterations in Intraocular Pressure and Optic Nerve Lipidome.

Background: Prostaglandin (PG) receptor agonists are the first-line eyedrop medication treatment for glaucoma. The pathophysiology of this disease is not completely known, and elevated intraocular pressure (IOP) is the key risk factor. The membranes of the axons (of the retinal ganglion cells) passing through the optic nerve (ON) head experience significant damage. Lipids are an essential component of the cell's membranes, and their profile changes owing to neurodegeneration. In this investigation, three agonists for distinct PG receptors were used to lower IOP and to determine their effect on the ON lipids. We utilized DBA/2J mice as a model of progressive IOP increase and C57BL/6J mice as a model of ON crush. Methods: DBA/2J and C57BL/6J mice were treated daily for 2 weeks with Latanoprost, PF-04217329, or Rivenprost. The IOP was measured every 2 days and pattern electroretinogram was conducted for DBA/2J throughout the study. Lipidomics of ONs were performed for each model and treatment group. Results: Of the tested compounds, Latanoprost and Rivenprost were the most effective agents decreasing IOP in DBA/2J mice. Triglyceride levels increased in the ONs of DBA/2J mouse model, but phosphatidylethanolamine levels underwent highest level changes in the C57BL/6J mouse model when treated with Latanoprost. Conclusions: Topical ocular FP- and EP4-receptor agonists appreciably lowered IOP in the DBA/2J mice representing pigmentary glaucoma. The observed changes in ON lipidomics in the different models of neurodegeneration suggest possible use of such measures in the development of more effective medicines for both IOP reduction and ON protection.

Commentary: Decoding the intraocular pressure conundrum surrounding the core of COR.

The concept of intraocular pressure (IOP) gained popularity around the 19th century. It was during that time when Albrecht von Graefe developed the first IOP measuring instrument, the Maklakoff applanation tonometer, in 1865. Somewhere around the 10th century, it started off as an assessment of the firmness of the eyeball.[1] Currently, we possess cutting-edge technology like dynamic contour tonometry to provide in vivo IOP measurements. IOP control is an important component of glaucoma management, and therein lies the importance of accurate IOP measurement and documentation. Consensual Ophthalmotonic Reaction The concept of consensual ophthalmotonic reaction (COR) has been a point of debate for several decades now.[2] There have always been claims for and against this phenomenon. Though inconclusive, this theory needs to be taken into account in view of the sensitive nature of the disease. The accompanying article represents the largest evaluation to date of the untreated fellow eye response after unilateral trabeculectomy. The author’s suggestion raises the possibility of a real risk of IOP increase in the fellow eye following ipsilateral glaucoma surgery.[3] Nearly a third of patients needed an intervention to control IOP in the entire study population. COR – The Gray Area Surrounding the How and Why The authors of the accompanying article report that contralateral eye IOP was increased following ipsilateral glaucoma surgery. However, some works of literature have reported conflicting results and noted a drop in IOP, while some agreed.[4–7] The pathophysiology for this increase or decrease of IOP following ipsilateral glaucoma surgery is unclear and not well known. Possible Hypothesis and Postulations Surrounding COR Several hypotheses have been made to explain COR, but all are not entirely accepted. Some suggest that topical medication either works on the fellow eye via the bloodstream or acts centrally on IOP control mechanisms after systemic absorption. Smith et al. disproved it with the use of pindolol and stated that the IOP falls after topical and intravenous administration of pindolol.[8] Pindolol treatment is used to help decrease IOP in the contralateral untreated eye, which is unlikely to have resulted from systemic absorption of the drug. This theory can also not explain the COR seen in mechanical alteration of IOP, such as following laser trabeculoplasty and tonography. Leplat hypothesized the existence of a nervous mechanism that causes changes in IOP in one eye to provoke a reflex alteration in pressure in the contralateral eye.[9] Moreover, the Collaborative Initial Glaucoma Treatment Study (CIGTS) showed a moderate drop in IOP in the contralateral eye, but the findings were not statistically significant and were found to be transient. Hence, it is inferred that this COR does not warrant any clinical management.[10] It is postulated that post-trabeculectomy, the increased IOP in the fellow eye could be due to a reflex increase in aqueous humor production, an effort of the eyes to compensate for the low IOP of the operated eye. The ocular central nervous system (CNS) reflex mechanism would trigger an increase in aqueous production both in the ipsilateral and the contralateral eyes, resulting in a buildup of IOP in the contralateral eye. It is also possible that the IOP fluctuations in the nonsurgical eye are due to changes in the blood flow or circulation to the eye or due to the body’s overall response to the surgery.[4] COR and Minimally Invasive Glaucoma Surgery Though trabeculectomy has been the gold standard for the past few decades, minimally invasive glaucoma surgery (MIGS) is now taking up space in the world of glaucoma. Currently, there is a paucity of data regarding the efficacy of MIGS, but it is a sought-after mode of treatment. So, studies also need to focus on COR in MIGS patients to see if any similar responses are seen in that category. Conclusion Changes in IOP are possible after glaucoma surgery due to a multitude of factors coming into play, suggesting that the fellow eye needs to be carefully monitored after glaucoma surgery in one eye. In many instances, the fellow eye is often the one with useful vision. Failure to recognize and monitor IOP changes carefully may unnecessarily delay treatment and appropriate management of these eyes. In addition, fellow eyes already damaged by glaucomatous processes may be at significant risk of glaucoma progression due to higher IOP levels. Although the evidence for the existence of COR is strengthened, larger studies with more patients in each glaucoma category may shed light on its exact biological role.

Development of eye phantom for mimicking the deformation of the human cornea accompanied by intraocular pressure alterations

Comparative studies between artificial eyeball phantoms and in-vivo human subjects were carried out to better understanding the structural deformation of the cornea under varying intraocular pressure (IOP). The IOP-induced deformation and the tension of the cornea were measured by using an optical coherence tomography and noncontact tonometer readings, respectively. The dependence of the central cornea thickness (CCT) and corneal radius of curvature (CRC) on the IOP differed significantly between the full eyeball phantom (FEP) and cornea eyeball phantom (CEP) models. While the CCT changes were very similar between the two models, the relation between the CRC and the IOP was dependent on the type of eye phantom. For the CEP, the CRC drastically decreased as internal pressure increased. However, we found that the changes in the CRC of FEP was dependent on initial CCT under zero IOP (CCT0). When CCT0 was less than 460 μm, the CRC slightly decreased as IOP increased. Meanwhile, the CRC increased as IOP increased if CCT0 was 570 μm. A constitutive mechanical model was proposed to describe the response of the cornea accompanied by the changes in IOP. In vivo measurements on human subjects under both noninvasive and invasive conditions revealed that the relation between the CRC on the IOP is much closer to those observed from FEP. Considering the observed structural deformation of human cornea, we found that FEP mimics the human eye more accurately than the CEP. In addition, the tonometry readings of IOP show that the values from the CEP were overestimated, while those from the FEP were not. For these reasons, we expect that the FEP could be suitable for the estimation of true IOP and allow performance testing of tonometers for medical checkups and other clinical uses.

Machine learning identifying peripheral circulating metabolites associated with intraocular pressure alterations

AimsTo identify blood metabolite markers associated with intraocular pressure (IOP) in a population-based cross-sectional study.MethodsThis study was conducted in a multiethnic Asian population (Chinese, n=2805; Indians, n=3045; Malays, n=3041 aged...

Impact of Ocular Complications on Visual Outcomes in Adult Patients With Uveitis.

BackgroundIn this study, we aimed to assess the impact of ocular complications on visual outcomes in uveitis.MethodologyWe conducted a retrospective cohort study of 474 uveitis patients (655 eyes) with a mean age of 52.4 years who were followed for a median of 32 months (range: 8-80 months).ResultsAt least one ocular complication was found in 317 eyes (48.4%), 161 of which were present at the time of diagnosis (prevalent complication). Although having an ocular complication was associated with a mean loss of 1.7 Early Treatment Diabetic Retinopathy Study (ETDRS) lines, the best-corrected visual acuity increased at the end of the study. Complications causing a decrease of ≥2 ETDRS lines were prevalent macular and peripheral retinal diseases, as well as new-onset corneal lesions, intraocular pressure alterations, and peripheral retinal diseases.ConclusionsThe impact of the most frequent complications (cataract and macular edema) did not reach two ETDRS lines. Macular diseases at presentation were the main risk factor for visual loss at the end of follow-up.

Effect of pupil dilation on intraocular pressure in preterm and term infants.

To evaluate the effect of pupil dilation on intraocular pressure in preterm and term newborns. This prospective study involved 55 eyes of 28 preterm infants and 38 eyes of 20 term infants. The infants were divided into two groups according to their gestational ages at birth as follows: preterm group, &lt;37 weeks and term group, ≥37 weeks. Pupil dilation was attained with tropicamide 0.5% and phenylephrine 2.5%. Intraocular pressure measurements were performed with Icare PRO (Icare Finland Oy, Helsinki, Finland) before and after pupil dilation. A paired t test was used to compare the measurements before and after pupil dilation. The mean intraocular pressure change was -1.04 ± 3.03 mmHg (6.20/-11.40 mmHg) in the preterm group and -0.39 ± 2.81 mmHg (4.60/-9.70 mmHg) in the term group. A statistically significant difference in intraocular pressure was observed only in the preterm group after pupil dilation (p=0.01). An unexpected alteration in intraocular pressure in newborns may occur after pupil dilation, especially in preterm infants.

Mutational analysis of CYP1B1 (rs56010818) variant in primary open angle glaucoma (POAG) affected patients of Pakistan.

BackgroundPrimary open angle glaucoma (POAG) occurs due to the discrepancies in the angle of anterior chamber characterized by the alterations in intraocular pressure, optic nerves head changes and central loss of visual field. In molecular research, CYP1B1 mutations modulates an integral role in association with glaucoma. Current study was undertaken to reveal the homozygous and heterozygous patterns of CYP1B1 c.1169 G > A variant (rs56010818) in POAG patients of Pakistan.MethodsAfter consent, total n = 88 POAG patients undergone through standard ophthalmological investigations before their recruitment in this study. The blood samples were utilized for DNA isolation. The genotyping of CYP1B1 c.1169 G > A variant was carried out by Sanger sequencing. The mutational patterns and its association with clinical variables were demonstrated by statistical and bioinformatic tools.ResultsIt was evident that the frequencies of heterozygous G/A and homozygous mutants A/A genotypes were higher in males (36.5%, 7.7%) than females (30.6%, 2.8%) of POAG population. Furthermore, the juvenile patients exhibit high manifestation of carrier genotype (66.6%) in comparison to adult patients (31.7%). The results also indicated the significant relationship of intraocular pressure with homozygous mutant A/A genotype of CYP1B1 variant in POAG patients (p < 0.05).ConclusionsOur study provided the mutational data of CYP1B1 R390H variant and the patterns of homozygosity and heterozygosity along with clinical associations. Overall, this study revealed the genetic predisposition of CYP1B1 c.1169 G > A variant in the patients of POAG in Pakistan. The findings could be helpful for genetic screening and in-depth understanding of underlying causes in the pathogenesis of POAG.

Effects of General Anesthesia on Intraocular Pressure in Rabbits.

Measurement of intraocular pressure (IOP) is a standard procedure in ophthalmic research in animals, specifically in glaucoma research, and the control of IOP is essential during certain veterinary ophthalmic surgeries. We evaluated the effect of isoflurane on IOP in the clinically healthy laboratory rabbits and tested a way to minimize the alteration of IOP during isoflurane anesthesia. After measurement of the baseline IOP in each eye of 9 awake New Zealand white rabbits, animals were anesthetized by using either: (1) isoflurane without premedication, (2) a combination of ketamine and xylazine, or (3) isoflurane inhalation after an injection of ketamine-xylazine premedication. Isoflurane led to a sustained increase in IOP of approximately 12 mm Hg. In contrast, ketamine and xylazine decreased IOP by nearly 5 mm Hg (all values compared with baseline measurements in awake, unrestrained animals). The observed decrease in IOP after ketamine-xylazine anesthesia is consistent with anesthetic effects generally seen during anesthesia in other studies. The increased IOP after isoflurane anesthesia in rabbits in this study was an unexpected result that appears to be specific to this combination of anesthetic and animal species. Premedication with ketamine-xylazine diminished the effect of isoflurane inhalation on IOP. These results should be considered in the design of ophthalmic research studies using rabbits and in intraocular surgery where IOP stability is desired.

Safety and tolerability evaluation after repeated intravitreal injections of a humanized anti-VEGF-A monoclonal antibody (PRO-169) versus ranibizumab in New Zealand white rabbits

BackgroundTo evaluate the retinal toxicity after repeated intravitreal injections of a humanized anti-VEGF-A monoclonal antibody (PRO-169) versus ranibizumab in New Zealand white (NZW) rabbit eyes.MethodsNZW rabbits were injected intravitreally with PRO-169 (n = 12), 1.25 mg/0.05 ml or ranibizumab (n = 12), 0.5 mg/0.05 ml into the right eye (OD), whereas the left eye (OS) of each rabbit was used as control. Three consecutive injections were administered at 30-days intervals. An electroretinogram (ERG) was recorded 30 days after each injection. Clinical examination was conducted before and after injections, including intraocular pressure determination and eye fundus exploration. Eyes were enucleated and retina, cornea, conjunctiva, ciliary body and optic nerve were prepared for histopathology assessment.ResultsERG of the experimental and control eyes in PRO-169 and ranibizumab groups were similar in amplitude and pattern throughout the follow-up period. Clinical examination found no alterations of intraocular pressure (IOP). No retinal damage was observed in both, the experimental and control eyes, of all the rabbits. The histopathologic studies showed similar results in both groups, showing no signs of structural damage.ConclusionsOur study did not find evidence of retinal toxicity from a repeated intravitreal injection of PRO-169 or ranibizumab (Lucentis®) in NZW rabbits. These findings support intravitreal PRO-169 as a safe candidate to develop as a future alternative for the treatment of retinal neovascularization diseases.

Evaluation of effects of positive airway pressure treatment on retinal fiber thickness and visual pathways using optic coherence tomography and visual evoked potentials in the patients with severe obstructive sleep apnea syndrome.

Hypoxia during sleep in obstructive sleep apnea syndrome (OSAS) increases intracranial pressure, decreases cerebral perfusion pressure, and alters vascular supply to the optic nerve. Pattern visual evoked potential (pVEP) has revealed that it causes alterations in the optic nerve, and optic coherence tomography has shown that it causes alterations in the retinal and macular layers. To detect and compare possible alterations in macula and peripapillary retinal nerve fiber thickness (pRNFL) using OCT and in the optic nerve pathways using pVEP before and after positive airway pressure (PAP) in the patients with severe OSAS. Thirty patients who were diagnosed as having severe OSAS in the neurology-sleep outpatient clinic and 30 healthy control subjects were included in the study. Ophthalmic examinations were performed prior to (month 0) and after (month 6) PAP treatment, and pVEP (peak time [PT] and amplitude) and OCT parameters (peripapillary retinal-macular layers) were compared. In the comparison between the severe OSAS (before treatment) and control groups, thinning was found in pRNFL (average, nasal, inferior) and in the macular layers (external and internal superior quadrants) (p < 0.05). pVEP investigation revealed increased PT in P100 and N145 waves and decreased amplitude of N75-P100 waves. In the comparisons before and after PAP treatment, a decrease in PT of N75 and P100 waves and increase in N75-P100 amplitudes were found. In the pRNFL, significant thickening was found in the layers with thinning before treatment, whereas no significant thickening was found in macular layers, except for the fovea. It was shown that PAP treatment in patients with severe OSAS prevents hypoxia without causing alterations in intraocular pressure and thus reduces inflammation and causes thickening in the pRNFL and macular layers.

Germany: Longitudinal analysis of intraocular pressure in healthy eyes

Purpose: The knowledge of physiology of intraocular pressure (IOP) is important for the interpretation of pathophysiological alterations of IOP in glaucoma patients. Thus, the purpose of this study...

One-year results of gonioscopy-assisted transluminal trabeculotomy: Evaluation of prognostic factors.

To present the results and complications of gonioscopy-assisted transluminal trabeculotomy in adults with open-angle glaucoma using our different approaches during and after surgery. A retrospective comparative study was designed. Patients with regular 12-month follow-up history were included. Two groups were defined: group 1 comprised patients with open-angle glaucoma who underwent gonioscopy-assisted transluminal trabeculotomy surgery alone; group 2 included patients with open-angle glaucoma who underwent combined gonioscopy-assisted transluminal trabeculotomy and cataract extraction. A 30% reduction in preoperative intraocular pressure or postoperative intraocular pressure below 18 mm Hg was considered as surgical success. The success rate, alteration in intraocular pressure, alteration in best-corrected visual acuity, alteration in the need for antiglaucomatous medications, surgical complications, and the need for additional glaucoma surgery were evaluated and compared between the groups. Multivariate logistic regression analysis was used to show the association between the surgical success and possible prognostic factors. A total of 37 eyes fulfilled the inclusion criteria and were analyzed in this study. An overall mean decrease in intraocular pressure of 11.3 ± 9.3 mm Hg was shown at 12 months (p < 0.001). The medication-free surgical success rate was 37.8% (14/37), and the surgical success rate with medication was 91.8% (33/37) at 12 months. Surgical outcomes were similar between patients who underwent gonioscopy-assisted transluminal trabeculotomy alone and those who had combined gonioscopy-assisted transluminal trabeculotomy and cataract extraction (p > 0.05). The most common postoperative complication was hyphemia (89.1%). There were no complications that threatened best-corrected visual acuity. Multivariate logistic regression analysis revealed one significant association between the presence of blood in Schlemm's canal and surgical success (odds ratio = 1.47; 95% confidence interval = 1.25-1.68; p = 0.047). This study showed that the gonioscopy-assisted transluminal trabeculotomy procedure is an effective and minimally invasive form of glaucoma surgery. Its effect was related to intraoperative blood in Schlemm's canal.

Densiron 68 heavy silicone oil in the management of inferior retinal detachment recurrence: analysis on functional and anatomical outcomes and complications.

To assess the efficacy and safety of a heavy silicone oil (Densiron 68) in the management of inferior retinal detachment recurrence. A retrospective non-comparative consecutive case series study. Forty-nine cases of complex inferior retinal detachment were treated using Densiron 68 heavy silicone oil (HSO) as the endotamponade. Our main purpose was anatomic reattachment following Densiron 68 removal. Functional outcomes, rate of recurrences, the presence of inflammatory complications and intraocular pressure alterations were evaluated. Forty-nine patients affected by complex retinal re-detachment were recruited. The mean follow-up was 7.6 (±1.5) mo. The mean best corrected visual acuity after Densiron 68 removal was 0.95 logMAR, standard error (SE: 0.068). Retinal reattachment was 61.2% after first surgery and 81.6% after second surgery. Nineteen cases (38.8%) had recurrences when intraocular heavy silicon oil was in situ, 26.3% (5 cases) of which involved the inferior retina. Densiron 68 efficiently fills the inferior retinal periphery and might lower the risk of inferior proliferative vitreoretinopathy development, in particular after a standard silicon oil tamponade that reduces the proliferative process in the upper quadrants of the retina.

The Effects of Intravitreal Ranibizumab, Aflibercept or Dexamethasone Implant Injections on Intraocular Pressure Changes.

BackgroundThe aim of this study was to compare the alterations in intraocular pressure (IOP) values during the early postoperative period after intravitreal ranibizumab, aflibercept, or dexamethasone implant injections.Material/MethodsIn this retrospective study, a total of 188 patients were grouped into 3 groups: the ranibizumab group, the aflibercept group, and the dexamethasone group. Ocular axial length (AXL) and anterior chamber depth (ACD) were measured in the pre-injection period. IOP was measured just before the injection at 1 minute,10 minutes, 1 hour, 1 day, and 1 month after injection.ResultsThere was a transient peak in the ranibizumab group and the aflibercept group at 1 minute that started to decrease at 10 minutes and IOP values returned to preoperative values at approximately 1 hour. Similar alterations were also determined for the dexamethasone group with a lesser increase noted. In the correlation analysis, only alterations in IOP levels at 1 minute were negatively correlated with preoperative AXL values. There was not any correlation between preoperative AXL or ACD values and IOP alterations at any other time points.ConclusionsThere was a sudden, transient increase in IOP values after intravitreal ranibizumab or aflibercept injections; which return to normal values in a short time without requirement of any medical treatments. This transient peak was determined to be negatively correlated with the preoperative AXL.