Vitreous Changes Research Articles

Characteristics of posterior precortical vitreous pockets visualized by swept-source OCT and en face OCT

To determine the characteristics of posterior precortical vitreous pockets (PPVPs) and to observe vitreous changes in myopic eyes by swept-source optical coherence tomography (SS-OCT) and en face imaging in a cohort of the Chinese Han population. This was a cross-sectional study. Volunteers (235 participants, 374 eyes) received an SS-OCT examination. The heights and widths of the PPVPs were measured by SS-OCT. The area of the PPVPs was measured on en face images. The relationships between PPVP size and sex, age, axial length (AL) and spherical equivalent (SE) were evaluated. The mean width and height were 6711.64 ± 1241.87 μm and 662.47 ± 326.39 μm, respectively. The area of the PPVPs was 30.296 ± 9.114 mm2. Boat-shaped, oval, and hook-shaped PPVPs were observed in 73.26%, 21.12%, and 5.62% of all eyes, respectively; 73.53% of all PPVPs had channels communicating with Cloquet’s tubes. There was a significant difference in the PPVP width among the participates over and under 50 years old (t = -2.508, P = 0.031). Age had a positive correlation with the PPVP width (r = 0.53, P = 0.001). The PPVP height showed significant differences among the different myopia groups (F = 3.618, P = 0.013). SE had a negative correlation with the PPVP height (r = -0.176, P = 0.001). However, there were no correlations between the AL and the width, height or area of the PPVPs (P = 0.117; P = 0.334; P = 0.057, respectively). Age and myopia affect the size of PPVPs. SS-OCT greatly facilitates visualization of the complex structure of the vitreous.

Association of thrombotic microangiopathy with interferon therapy for hepatitis B: a case report

BackgroundThrombotic microangiopathy is characterized by microangiopathic hemolytic anemia, thrombocytopenia, and organ injury. The pathological features include vascular damage that is manifested by arteriolar and capillary thrombosis with characteristic abnormalities in the endothelium and vessel wall. Thrombocytopenia is one of the common adverse effects of interferon therapy. However, a more serious but rare side effect is thrombotic microangiopathy.Case presentationWe report the case of a 36-year-old Asian male patient with clinical manifestations of hypertension, blurred vision, acute renal failure, thrombocytopenia, and thrombotic microangiopathy. Renal biopsy showed interstitial edema with fibrosis, arteriolar thickening with vitreous changes, and epithelial podocytes segmental fusion. Immunofluorescence microscopy showed C3(+), Ig A(+) deposition in the mesangial region, which was pathologically consistent with thrombotic microangiopathy renal injury and Ig A deposition. The patient had a history of hepatitis B virus infection for more than 5 years. Lamivudine was used in the past, but the injection of long-acting interferon combined with tenofovir alafenamide fumarate was used since 2018. The comprehensive clinical investigation and laboratory examination diagnosed the condition as thrombotic microangiopathy kidney injury caused by interferon. After stopping interferon in his treatment, the patient’s renal function partially recovered after three consecutive therapeutic plasma exchange treatments and follow-up treatment without immunosuppressant. The renal function of the patient remained stable.ConclusionsThis report indicates that interferon can induce thrombotic microangiopathy with acute renal injury, which can progress to chronic renal insufficiency.

Retinal and Vitreous Changes Associated with Spontaneous Improvement in Myopic Macular Schisis

PurposeTo describe the retinal and vitreous changes in eyes showing myopic macular schisis (MMS) improvement when vitrectomy was not performed and identify triggering factors. DesignRetrospective observational study. SubjectsPatients with non-operated myopic macular schisis MethodsThe records of patients with MMS who were followed without performing surgery for more than 6 months were retrospectively reviewed, and the eyes showing an anatomical improvement were included. MMS evolution was analyzed quantitatively (central foveal thickness [CFT], parafoveal thickness, maximum height) and qualitatively (presence/absence of foveal detachment, lamellar hole, epiretinal membrane, choroidal neovascularization, inner and outer retinoschisis, vitreous status) at baseline and at the final visit. An anatomical improvement was defined as a decrease in CFT by at least 50 μm. Main outcome measureThe rate anatomical improvement of MMS without performing vitrectomy and the morphological changes observed in these cases. ResultsIn a cohort of 74 non-operated eyes with MMS, MMS improved in 14 eyes (19%) after a mean follow-up of 55 ± 38 months (range: 8-138). In these improved cases, the mean decrease in CFT was 153 ± 166 μm (range: 24-635, p=0.005) and a complete resolution of MMS was observed in 9 eyes (64%). In 9 eyes (64%), the improvement was associated with visible vitreous changes in the macular area on the OCT scans. The mean visual acuity, which was already good at baseline (20/50, 0.4 ± 0.2 LogMAR), increased at the last visit (20/40, 0.3 ± 0.3 LogMAR) but without reaching significance. ConclusionThis long-term follow-up analysis showed that almost 20% of MMS in eyes without indication for surgery could improve over time. In most cases, the improvement was associated with an apparent resolution of vitreous tensions.

Anterior Vitreous Objective Assessment in Uveitis: An Anterior Segment Swept Source Optical Coherence Tomography Study

ABSTRACT Purpose To assess inflammatory changes in the anterior vitreous (AV) using a swept source anterior segment optical coherence tomography (SS-ASOCT) and to correlate them with uveitis features and clinical grading of intraocular inflammation. Methods 140 eyes from 96 patients were included in this observational, cross-sectional study: 40 ACTIVE uveitis, 40 INACTIVE uveitis and 60 CONTROLS. All eyes underwent intraocular inflammation clinical grading (anterior chamber (AC) cells counting and vitreous haze evaluation) and AV imaging with SS-ASOCT. Cells seen in the AV on OCT were manually counted using imageJ. Vitreous reflectivity variation was indirectly measured by calculating the vitreous/iris pigment epithelium (VIT/IPE) relative intensity. These OCT-based parameters were compared across the groups and correlated with inflammation clinical grading. Results The mean [SD] number of AV OCT cells was significantly higher (both p < 0.001) in ACTIVE uveitis (12[9.8]) compared to INACTIVE uveitis (4.5[3.5]) and CONTROLS (4[3.1]). In ACTIVE uveitis the number of AV OCT cells was significantly and positively correlated with the AC cells (p = 0.04), the VIT/IPE relative intensity (p = 0.0002), the uveitis anatomical classification (INTERMEDIATE UVEITIS, p = 0.02) and the vitreous haze clinical grading (p < 0.0001). The mean[SD] VIT/IPE relative intensity of the AV increased from CONTROLS (0.12[0.01]) to INACTIVE uveitis (0.15[0.01]) to ACTIVE uveitis (0.17[0.02]), but with no statistically significant differences. Conclusions We were able to visualize and objectively evaluate changes occurring in the AV in eyes with uveitis by means of a commercially available SS-ASOCT. OCT-cells in the AV could represent an adjunctive tool in the objective evaluation of intraocular inflammation.

Evaluation of eye and serum findings in different waters in rabbits by drowning and submersion modeling.

This study investigated serum, vitreous, and anterior chamber fluid electrolyte changes, corneal thickness (CT), corneal volume (CV), anterior chamber volume (ACV), and anterior chamber depth (ACD) as an auxiliary diagnostic method in the identification of drowning in fresh or salt water. The study used 35 healthy, adult, male, white New Zealand rabbits, seperated into five groups (control, saltwater drowning (SWD), saltwater immersion (SWI), freshwater drowning (FWD), freshwater immersion (FWI)). CT, CV, ACV, and ACD measurements were made with Pentacam topography at 0, 2, and 4 h in all groups. Magnesium (mg), sodium (Na), and chlorine (Cl) were measured in the blood at 0 and 2 h, and in blood, vitreous fluid, and humor aqueous at 4 h. It was determined that CT, CV, ACV, and ACD are not of great value in drowning diagnosis and are affected by the fresh or salt water rather than drowning. Vitreous Na, Cl, and Mg levels are ineffective in determining drowning after one h. Anterior chamber fluid may provide valuable information in the differentiation freshwater - saltwater drownings at the 4th h in corpses retrieved from water. Anterior chamber fluid Na and Cl levels, especially in corpses removed from salt water, can be an easily used test that can help diagnose drowning.

Peripheral Lattice Degeneration Imaging with Ultra-Widefield Swept-Source Optical Coherence Tomography.

To investigate a series of peripheral lattice degeneration cases using an ultra-widefield (UWF) swept-source optical coherence tomography (SSOCT) system (Silverstone, Nikon Healthcare Japan, Inc, Tokyo, Japan). From 1st August, 2022 to 31th July, 2023, nineteen eyes of 16 patients with peripheral lattice degeneration were included. They all underwent a UWF-SSOCT examination. Anatomy of retina, vitreous, and associated pathologic changes were assessed. UWF-SSOCT showed various anatomical changes of retina and vitreous in patients with lattice degeneration. Of fifteen eyes of 12 patients whose UWF-SSOCT images were clearly obtained, 8 eyes showed regional retinal thinning, 7 eyes showed vitreous traction, 2 eyes showed detached vitreous, 3 eyes showed retinal break. UWF-SSOCT can be a useful tool to understand anatomical changes and pathophysiology of peripheral lattice degeneration.

Association of Different Type of Refractive Errors with Parental Cousin Marriages

Refractive errors are the major reason of visual impairment and its prevalence has increased over time. Refractive errors affect ocular structures as corneal shape, eye’s axial length, vitreous changes and retinal dystrophies. Uncorrected and high degree of refractive errors are the leading cause of blindness worldwide. Due to several mechanism, there is an increased risk of refractive errors with parental cousin marriages. Objective: To find association of different types of refractive errors in patients with positive history of parental consanguinity, and to evaluate that which type of refractive error is more compromised. Methods: A cross-sectional study accompanied 175 patients having positive history of consanguinity age between 14-35 years was performed at the University of Lahore, Teaching Hospital Pakistan during September 2020 to January 2021. Using non probability convenient sampling technique 175 individuals were evaluated for refractive error type with positive parental consanguinity. To measure distance visual acuity of patients, Standard Snellen chart at (6m) was used. Data were recorded by asking the patients to fill a self-made Performa. Results: Myopic refractive error is most common type of error with consanguinity patients as compare to hyperopic patients. Second most common error occurs myopic astigmatism. Hypermetropia was seen very less with consanguinity history. Refractive errors in total families found 68% with myopia and myopic astigmatism 40%. Conclusions: Refractive errors found more with consanguinity history as compare to patients with absence of consanguinity history.

Determination of postmortem interval and cause of death: Do the levels of biochemical parameters in vitreous humor provide an additional assistance to medico legal expert?

An upward rise has been observed in the pattern of unnatural deaths in the recent years and the same has been found during the post mortem examination. During the trial in the court of law prosecution as well as defense require the time passed death before examination and the cause of death in particular circumstances, as it is mandatory to fix the exact duration either to punish the guilty or NOT to punish the innocent. Vitreous humor is different from other body fluids as it has relative stability in its composition so as also biochemical parameters. It was further hypothesized that postmortem vitreous humor biochemistry closely mimics antemortem serum biochemistry and may be a useful aid in establishing postmortem diagnoses. Various studies have been carried out on vitreous electrolyte concentration changes to arrive at postmortem interval. Many workers found the importance of potassium in the determination of postmortem interval, whereas among all the biochemical parameters, vitreous potassium is found to be more useful to find out time since death. Postmortem biochemical analysis of vitreous humor may be helpful in the establishment of antemortem disease or metabolic disorder. The present study was carried out jointly in department of Forensic Medicine and Toxicology and department of Biochemistry of Surat Municipal Institute of Medical Education &amp; Research (SMIMER), Surat. A total of 100 subjects were taken up for this study. The samples were collected from dead bodies during postmortem examination with all aseptic precautions. A detailed performa was made with all the details of age, sex, length, weight and date and time of admission, date and time of death and manner of death such as suicide, homicide, sudden death and accidents was recorded. Cases below 15 years of age were not considered in this study. Out of 100 cases there were 24 (24%) females and 76 (76%) were males, out of these 56% were between 15-35 years, 32% were of 36-55 years, 9% were of 56-65 years, and 3% were of 66-77 years age group. According to the manner of death 50 subjects were of accident, 26 subjects were of sudden death, 21 subjects were of suicide and 3 subjects were of homicide. According to time interval between sample collection and time of death, 47 subjects were of 0-24 hours, 36 subjects were of 24-48 hours, 11 subjects were of 48-72 hours and 6 subjects were of 72-96 hours. In present study we observed that there is definitive correlation between time of death and changes in level of these biochemical parameters. This was a preliminary study in this region and can be considered as a pilot study. The levels of vitreous Potassium have been found to be significantly altered as the time progresses after death. A progressive decrease in sodium/potassium and increase in potassium/ calcium ratios was also observed.

Retinal detachment secondary to bungee jump.

Here, the authors report a case of a 28-year-old myopic male with Left-Eye retinal detachment secondary to a bungee jump. In recent years, a few case reports have archived a variety of visual injuries caused by bungee jumping. But only few literatures have reported the event of retinal detachment related to bungee jumping. Patients with moderate to high myopic refractive error may have different vitreous and retinal changes, like vitreous degeneration, lattice degeneration, and peripheral retinal tears. The authors accept that these retinal findings are more related to the vitreoretinal traction mechanism leading to retinal detachment in bungee jumping. This case highlights that retinal detachment secondary to a bungee jump is a rare but serious ocular manifestation, and bungee jumping should be considered a risk factor for retinal detachment in predisposed patients.

Age-related changes in human vitreous

There are two main age-related changes that can occur in the vitreous body of healthy individuals throughout life: liquefaction (synchesis) and aggregation of collagen fibrils into dense bundles (syneresis). Progressive age-related degradation leads to posterior vitreous detachment (PVD). At present many classifications of PVD exist, in which authors relied either on the morphological features, or on the differences in pathogenesis before and after widespread use of OCT. The course of PVD can be either normal or anomalous. Physiological PVD induced by age-related vitreous changes progresses in specific stages. The review emphasizes that PVD can occur initially not only in the central zone of the retina, but also on the periphery with further spread to the posterior pole. Anomalous PVD can lead to various negative effects on the retina, as well as on the vitreous as a result of traction in the area of vitreoretinal interface.

Окт диагностика скрытого клапанного разрыва при задней отслойке стекловидного тела

Changes in the posterior vitreous that look like hyperreflective dots are considered as a predictor of peripheral retinal breaks in acute posterior vitreous detachment (PVD), along with Shafer's sign, intraretinal and vitreous hemorrhages. Some of peripheral breaks in acute PVD remain unnoticed at the initial ophthalmoscopic examination due to poor visualization. We report a clinical case of an invisible peripheral retinal flap tear detection with overview wide-field OCT (RTVue XR Avanti, Line mode –12 mm) scanning by «sliding» method in the area of retinal hemorrhage in presence of multiple hyperreflective dots in the vitreous during acute symptomatic PVD. Key words: acute PVD; invisible flap tear; wide-field OCT; retinal hemorrhage; stardust sign; hyperreflective dots.

A rare combination of monogenic connective tissue diseases — Marfan and Stickler syndromes — in one patient

As DNA sequencing techniques have been used more widely in clinical practice, there have been reports of a combination of hereditary diseases in a single patient. Cases of combining diseases with similar clinical symptoms present a particular difficulty for diagnosis. We observe a child who has been identified to have a combination of autosomal dominant diseases associated with connective tissue involvement — Marfan and Stickler type 1 syndromes. Common symptoms of both diseases were as follows: marfanoid habitus, arachnodactyly, kyphoscoliosis, chest deformity, involvement in the process of joints (hypermobile syndrome) and eyes. Marfan syndrome was evidenced by dissociation of mass-growth parameters at birth, tallstature, “Gothic” palate, crowded teeth, aortic dilation at the level of Valsalva sinuses and its ascending part. Type 1 Stickler syndrome was indicated by high-grade myopia, degenerative vitreous changes requiring vitrectomy, flat face, mandibular micrognathia, latent cleft of the soft and hard palate, grade 1 bilateral conductive hearing loss, mild cognitive failure. The diagnosis of both diseases was confirmed by the detection of de novo heterozygous mutations in the FBN1 gene (c.5060_5061 delGCinvAA, p. Cys1687) and COL2A1 gene (c.4074+1G&gt;A). Establishing a final diagnosis is of great importance for predicting the course of the disease and genetic counseling of the proband and their relatives.

IMAGING THE VITREOUS WITH A NOVEL BOOSTED OPTICAL COHERENCE TOMOGRAPHY TECHNIQUE: Posterior Vitreous Detachment.

To evaluate the anatomic changes in the vitreous associated with evolving posterior vitreous detachment over the macula. A novel scanning method by which four A-scans at each position were averaged before the Fourier transform that boosted the image quality sufficiently such that frame averaging could occur. B-scans and volume rendered images of eyes with evidence of any partial separation of the vitreous in the macular regions were evaluated. There were 43 eyes of 23 subjects with particular attention paid to the findings of seven eyes with various stages of posterior vitreous detachment occurring over the macula. In eyes from young subjects with no vitreous degeneration, the outer vitreous showed a diffuse, poorly defined increase in reflectivity in the region where the vitreous cortex was expected to be. In eyes with vitreous degeneration, there was a hyperreflective zone, called the cortical vitreous condensation, that coursed parallel to the curvature of the retina. The posterior vitreous face elevated from the retina with either a well-defined, smooth outer surface, consistent with the posterior vitreous membrane, or a poorly defined flocculent outer border. The cortical vitreous near the fovea was thin and in eyes in the process of posterior vitreous detachment had visible tears. In more advanced eyes, a circular dehiscence of the cortical vitreous in the central macula occurred with herniation of the vitreous gel through the hole. The methodology produced images of unprecedented clarity that highlighted several newly described details concerning the vitreous changes associated with posterior vitreous detachment over the macula.

Silicone Oil Tamponade-Retina Contact in Highly Myopic Eyes With and Without Encircling Bands: A Computational Fluid Dynamics Study.

PurposeTo investigate the behavior of silicone oil (SiO) at a steady equilibrium and during saccades in pseudophakic highly myopic eyes with posterior staphyloma with and without an encircling band and compare it to behavior in emmetropic eyes. The SiO–retina contact area and shear stress were calculated by computational fluid dynamics.MethodsA numerical model of an emmetropic eye and a myopic eye with and without scleral band underwent a saccade of 50°/0.137 s. The vitreous chamber surface was divided into superior and inferior 180° sectors: lens, pre-equator, post-equator, and macula. SiO–retina contact was evaluated as a function of fill percentages between 80% and 90% for standing, 45° upward tilt, and supine patients. Maximum and average shear stress were calculated.ResultsOverall, SiO–retina contact ranged between 40% and 83%; fill percentage varied between 80% and 95%. Neither the encircling scleral band nor the staphyloma significantly affected the SiO–retina contact area, although the presence of a scleral band proved disadvantageous when gazing 45° upward. The inferior retina–SiO contact remained below 40% despite 95% SiO fill. The SS significantly increased at the scleral band indentation and decreased elsewhere. The staphyloma greatly reduced shear stress at the macula.ConclusionsThe presence of a myopic staphyloma reduces shear stress at the macula but does not alter SiO–retina contact significantly. The apposition of a 360° scleral band may reduce SiO–retina contact at least in some postures and increases the SS at the indentation.Translational RelevanceAssessing SiO–retina contact when vitreous chamber geometry changes according to pathologic or iatrogenic modifications allows accurate prediction of real-life tamponade behavior and helps explain surgical outcomes.

Long-term follow-up of a case of Coats disease in a 10-year-old boy with spontaneous peeling of preretinal macular fibrosis: a case report

BackgroundCoats disease is a retinal vascular disorder characterized by aneurysms and telangiectasias. Macular fibrosis is a complication of Coats disease that results in vision loss. Macular fibrosis rarely develops in the natural course and often occurs after treatment with intravitreal bevacizumab, photocoagulation, or cryotherapy. Here, we have described an unusual case of spontaneous peeling of preretinal macular fibrosis in a patient with untreated Coats disease.Case presentationA 10-year-old Japanese boy presented with vision loss in his left eye. The patient’s left visual acuity was 20/28. Fundus examination of his left eye revealed thick preretinal macular fibrosis around the optic disc and macula. In addition, retinal telangiectasis, microaneurysms, hard exudates, and retinal hemorrhages were observed in the left peripheral temporal retina. We diagnosed his condition as Coats disease with preretinal macular fibrosis. Two months later, optical coherence tomography revealed preretinal macular fibrosis detachment at the foveal lesion without any treatment. During follow-up, preretinal macular fibrosis at the macular lesion was completely detached. Further, posterior vitreous detachment was observed and the shape of the macula and the patient’s left visual acuity had improved.ConclusionsIn our case, both formation and spontaneous peeling of preretinal macular fibrosis occurred without any treatment for Coats disease, which is an unusual finding. Vitreous changes might have occurred during the natural clinical course, causing subsequent posterior vitreous detachment and resulting in spontaneous peeling of fibrosis.

Анатомическая характеристика стекловидной камеры и хрусталика у плодов в промежуточном плодном периоде онтогенеза человека

Purpose. To give an anatomical characteristic of the vitreous chamber and lens in fetuses in the intermediate fetal period of human ontogenesis. Material and methods. The study was conducted on 50 fetuses of both sexes (50 % male, 50 % female) aged from 14 to 27 weeks, which make up the collection of the Department of Human Anatomy of the Russian Ministry of Health. The following methods were used in the study: the method of sawing according to N.I. Pirogov in modification, the histotopographic method. Results. The area of the vitreous chamber in the intermediate fetal period of human ontogenesis in the first, second and third age groups averages: 33.15 ± 7.12 mm², 42.06 ± 9.95 mm², 48.07 ± 8.95 mm² . The volume of the vitreous chamber in the intermediate fetal period of human ontogenesis in the first, second and third age groups is: 101.11 ± 12.31 mm 3, 153.89 ± 15.64 mm 3and 216.61 ± 38.45 mm³, respectively. During the intermediate fetal period of human ontogenesis, the ratio of the area of the lens and the vitreous chamber changes, so at the beginning of the period it is equal to 1:4, in the middle of the period – 1:3 and by the end of the period – 1:2. Conclusion. The vitreous chamber in the intermediate fetal period of human ontogenesis is formed and actively grows from the first to the second age group (volume increases by 34 %, area – 21 %). During the intermediate fetal period of human ontogenesis, the volume of the vitreous chamber decreases from 92 % to 78 %, due to an increase in the volume of the lens from 8 % to 22 %. Keywords: intermediate fetal period, the eyeball, vitreous chamber, lens.

(Retracted) Estimation of human age by features of face and eyes based on multilevel feature convolutional neural network

Age estimation can be effectively used in security, human–computer interaction, entertainment, and audio-visual fields. However, current face-based age recognition algorithms are not highly accurate due to factors, such as face makeup and plastic surgery. Among the various feature points of a human face, the eyes are the most difficult part to be modified. And with the changes of age, the lens, cornea, and vitreous of eyes will also change accordingly. Therefore, we believe that paying attention to the local feature of the eye can improve the accuracy of age estimation to a certain extent. The multilevel feature convolutional neural network (MLFCNN) is proposed, which values eyes features and combines them with face features to jointly estimate human age. MLFCNN performs two rounds of estimation based on extracted features. First, the age range of the sample is estimated as the age group, and then on this basis, the fine age of the sample is further estimated. Field tests show that the mean absolute error of MLFCNN is 2.87, which is lower than other network models tested. When the MLFCNN estimated age did not differ more than 4 years from the actual age of the sample, the network predictions were considered correct (i.e., the tolerable age error was 4). The age estimation accuracy of MLFCNN under this condition was 91.14%. And 98.32% accuracy can be reached when the tolerable age error is 6. Ablation experiments verify that the fusion of ocular features and facial features can improve the performance of the age estimation network. In addition, it can still maintain a good performance under small training dataset.

Determining posterior vitreous structure by analysis of images obtained by AI-based 3D segmentation and ultrawidefield optical coherence tomography

AimsTo determine the three-dimensional (3D) structure of the vitreous fluid including the posterior precortical vitreous pockets (PPVP), Cloquet’s canal and cisterns in healthy subjects by AI-based segmentation of the vitreous...

Posterior vitreous detachment and paravascular retinoschisis in highly myopic young patients detected by ultra-widefield OCT

The purpose of this study was to determine the relationship between a posterior vitreous detachment (PVD) and retinoschisis (RS) in 73 highly myopic (HM) young patients age 16.4 ± 6.9 years and 24 non-HM children age 8.4 ± 1.5 years. The presence of the paravascular retinal abnormalities was determined in the images obtained by a ultra-widefield OCT (UWF OCT) instrument with an image field of 23 × 20 mm. The results showed that a partial PVD was detected in 15 (21%) of the HM patients, and the number increased significantly with increasing age (P = 0.02). PVDs of any type were not found in the non-HM eyes. The number of microvascular folds also increased with age in the HM patients (P = 0.03). Medium-reflective columnar tissues were present between the detached vitreous and inner retinal surface in 4 (5%) eyes of the HM patients. Myopic RS was found in 3 (4%) HM patients in the paravascular area but not in the macular area. These results suggest that early partial PVD may play a role in pathological and proliferative vitreous changes of HM eyes. An intense vitreoretinal traction with bridging tissues may cause the various paravascular retinal abnormalities. In HM eyes, paravascular RS is already present at an early age which may progress to macular RS with aging.

Retinal image size in pseudophakia.

Approaches are developed to determine relative retinal magnifications in anisometropic patients undergoing cataract surgery; these can be used to balance between full spectacle corrections with equal intraocular lens (IOL) powers and a pure IOL power correction. The analysis started from the original and pseudophakic Navarro eye models, where in the latter case an IOL replaced the natural lens. A third model was a simplified Navarro-IOL model with a single surface cornea and a thin lens. These models were manipulated by altering vitreous length, corneal power and lens position. Retinal image sizes were determined for both full IOL corrections and full spectacle corrections by raytracing and approximate equations. Relative magnification (RM) was determined as the ratio of retinal image size of an eye to that of the appropriate standard eye. For raytracing and full IOL correction, vitreous length led to RM change of 5%/mm, while for corneal power and IOL position this was -0.4%/D and 1.4%/mm, respectively. For raytracing and spectacle correction, effects were 0%/D (vitreous depth), -1.6%/D (corneal power) and +1.0%/mm (IOL position). For full IOL correction, the approximate RM calculations were highly accurate. For spectacle correction, the approximate RM calculations were exact for vitreous length changes, reasonably accurate for corneal power changes but very inaccurate for changes in anterior chamber depth. Relative magnification approximations may be useful to assess the risk of aniseikonia in anisometropic patients targeted for postoperative emmetropia. Some of these patients would be corrected best by a combination of spectacles and IOLs.