Medical Hypothesis, Discovery & Innovation (MEHDI) Journals
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Visual Prognosis after Explantation of Small-Aperture Corneal Inlays in Presbyopic Eyes: A Case Series
The purpose of this study was to report visual prognosis after explantation of a small-aperture corneal inlay used for the treatment of presbyopia. This is a retrospective case series conducted at a single site in Draper, Utah, USA (Hoopes Vision). Medical records of 176 patients who had received a small-aperture corneal inlay (KAMRA™, AcuFocus Inc., Irvine, CA, USA) were reviewed. Patients who had undergone explantation of the device were identified. Uncorrected distance visual acuity (UDVA), uncorrected near visual acuity (UNVA), corrected distance visual acuity (CDVA), and manifest refraction spherical equivalent (MRSE) were measured pre-implantation, post-implantation, pre-explantation, and post-explantation of the inlay. Ten eyes from ten patients were included in this study. The explantation rate was 5.7% over 31 months, with blurry vision as the most common complaint. After explantation, six patients achieved pre-implantation UDVA, and six achieved pre-implantation UNVA. Eight of nine patients who underwent final manifest refraction achieved pre-operative CDVA. All patients had residual donut-shaped corneal haze in the stroma at the previous position of the inlay. All patients experienced improvement in haze with 20% experiencing complete resolution. The degree of stromal haze was not related to the duration of implantation. Of the subset of patients who underwent explantation of their small-aperture corneal inlay, there was persistent loss of CDVA in 10%. The majority of patients experienced some level of residual stromal haze, which may contribute to deficits in UNVA and CDVA in few patients. A hyperopic shift induced by the corneal inlay may contribute to the blurry vision these patients experienced; there was a reduction of this shift post-explantation. While this device is removable, patients should expect some post-explantation changes such as residual haze with a small subset experiencing persistent deficits in CDVA
Comparative Analysis of LASIK Flap Diameter and its Centration Using Two Different Femtosecond Lasers
The aim of this study was to compare the diameter, accuracy, variability, and centration with respect to the limbus of corneal flaps created by two femtosecond lasers, the VisuMax, and Wavelight FS200, for laser in situ keratomileusis (LASIK) and how these flaps affect visual outcomes. This is a retrospective chart review of flap morphology created during LASIK Surgery. Overall, 168 eyes underwent flap creation using the WaveLight FS200 laser, and on 189 eyes, the VisuMax laser was used. Of these total number, flap morphology was analyzed in a random sample of 158 eyes; 80 with the Visumax laser and 78 with the WaveLight FS200 laser. Intraoperative photos of the flaps taken by the Wavelight Allegretto EX500 were analyzed. Flap diameters and centration were measured using Adobe Acrobat Pro. All patients had visual acuity measurements including uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent refraction (SE) and refractive astigmatism recorded three months postoperatively. Greater than 90% of patients in both groups achieved a UDVA of 20/20 postoperatively. The mean difference between targeted and achieved flap diameter was 0.50 +/- 0.15 mm in the VisuMax group and 0.35 +/- 0.15 millimeters (mm) in the FS200 group (P<0.01). The flap diameters of the VisuMax group were more precise with a variance of 0.024 mm compared to a variance of 0.038 mm in the FS200 group (P<0.05). VisuMax flaps were more nasally displaced (log(NA/TA) = -0.21 +/- 0.10 mm) compared to the FS200 flaps (log(NA/TA) = 0.03 +/- 0.10 mm), (P< 0.01). We concluded that both the VisuMax and FS200 created flaps larger than the preoperative targeted diameter. VisuMax created corneal flaps that had a greater degree of deviation from the targeted diameter when compared to flaps from the FS200. However, there was less variance in the VisuMax flap diameter. In addition, VisuMax flaps were more nasally displaced. There were no statistically significant differences in visual outcomes when comparing the two femtosecond lasers
Ocular Surface Evaluation After the Substitution of Benzalkonium Chloride Preserved Prostaglandin Eye Drops by a Preservative-free Prostaglandin Analogue
To evaluate ocular surface changes after withdrawal of Benzalkonium chloride (BAK) in patients with glaucoma in monotherapy with BAK-preserved prostaglandin. This was a prospective observational study. All patients underwent complete ophthalmologic examination and evaluation of ocular surface. A questionnaire was filled regarding symptoms of dry eye (Ocular Surface Disease Index [OSDI]) at the beginning of study. The treatment was switched to preservative-free tafluprost for 6 weeks and after this period, all patients were re-evaluated. All patients reported improvement of symptoms. The green lissamine test showed a significant improvement of the ocular surface, with most patients classified as light dry eye (P < 0.001). A significant improvement in the score (P < 0.001) was also found, with an average of 17.95 ± 5.35 points, which classifies the patients' symptoms in the normal to light zone. Benzalkonium chloride withdrawal reduced the signs and symptoms of dry eye in patients with primary open angle glaucoma (POAG)
Ocular Accommodation, Intraocular Pressure, Development of Myopia, and Glaucoma: Role of Ciliary Muscle, Choroid, and Metabolism
Ocular accommodation is not just a mechanism for altering curvature of the crystalline lens of the eye, it also enables aqueous humor outflow through the trabecular meshwork, influencing intraocular pressure (IOP). Long term stress on the ciliary muscle from sustained near focusing may initiate myopic eye growth in children and primary open angle glaucoma in presbyopic adults. Multi-factorial studies of ocular accommodation that include measures of IOP, ciliary muscle morphology, anterior chamber depth, and assessment of nutritional intake and metabolic markers may elucidate etiology and novel strategies for management of both myopia and chronic glaucoma. Anatomy of the ciliary fibers from anterior insertion in the fluid drainage pathway to their posterior consanguinity with the vascular choroid, alters ocular parameters such as micro-fluctuations of accommodation and pulsatile ocular blood flow that are driven by cardiac contractions conveyed by carotid arteries. Stretching of the choroid has consequences for thinning of the peripheral retina, sclera and lamina cribrosa—with potential to induce retinal tears and optic nerve cupping. It is hoped that the present synthesis of relevant literature and evidence based speculations, may stimulate additional research conducted clinically oriented scientists, supported by their host institutions. Early metabolic interventions may lead to prevention or reduced severity of myopia and glaucoma. It is hoped that improved quality of life for patients and informed consumers, and reduced disability from visual impairment and blindness may result
Visual Prognosis after Explantation of a Corneal Shape-Changing Hydrogel Inlay in Presbyopic Eyes
The purpose of this case series is to report visual outcomes in patients who underwent explantation of the Raindrop® hydrogel corneal inlay. Retrospective chart review comprising four cases of explantation of the Raindrop® corneal shape-changing hydrogel inlay: pre-implantation, pre-explantation, and post-explantation values for uncorrected distance visual acuity, uncorrected near visual acuity, and corrected distance visual acuity (CDVA) were measured; keratometric and tomographic data were collected using the Pentacam system (Oculus, Inc). Three eyes were explanted for progressive haze after implantation that persisted even after removal; one eye was explanted due to poor visual acuity with no haze formation. All patients experienced decreased unaided and corrected distance visual acuity. Persistent increase in corneal thickness and mean keratometry was noted post-explantation. All four patients regained their original near visual acuities, but one patient had persistent one-line loss in CDVA. There are long lasting tomographic corneal changes following Raindrop inlay explantation. In addition, persistent increased corneal thickness could be related to semi-permanent changes in corneal structure and may account for residual haze experienced by patients. After explantation, patients may not return to baseline CDVA
Multimodal Imaging Characteristics of a Large Retinal Capillary Macroaneurysm in an Eye With Severe Diabetic Macular Edema: A Case Presentation and Literature Review
Though microaneurysms are the hallmark of diabetic retinopathy (DR), large aneurismal changes termed as ''macroaneurysms'' (MAs) may also occur in the course of chronic diabetic macular edema. MAs are usually accompanied by intraretinal hard exudates, fluid accumulation and retinal hemorrhages. Detection of MAs is clinically important as it implies that macular edema is usually chronic and therefore can be resistant to intravitreal anti-vascular endothelial growth factor injections. Multimodal imaging consisting of fluorescein angiography (FA), indocyanine green angiography (ICGA), optical coherence tomography (OCT) or OCT-angiography (OCTA) can be performed to detect and understand the nature of MA and thereby select proper treatment modality. Herein, we report multimodal imaging features of a 64-year-old woman with insulin-dependent diabetes mellitus presented with treatment naïve severe macular edema and a macroaneurysm at the right temporal macula. In conclusion, FA, ICGA and OCT seem to be far superior to OCTA to detect these lesions due to probable slow flow inside the MA
Graft Detachment After Descemet's Stripping Automated Endothelial Keratoplasty in Bullous Keratopathy and Fuchs Dystrophy
Descemet’s stripping automated endothelial keratoplasty (DSAEK) is a surgical technique for corneal transplantation in case of corneal decompensation. One of the main complications is graft detachment (GD) recoverable with Air Re-bubbling (ARB). The aim of this retrospective, interventional case series was to identify factors related to this complication in eyes operated for bullous keratopathy (BK) and Fuchs dystrophy (FD). We considered one-hundred patients who underwent DSAEK for BK or FD between January 2016 and October 2017 at Department of Ophthalmology, Policlinico Universitario of Bari, Italy. Studied parameters included physiological and pathological anamnesis of both donors and recipients and properties of donor’s lenticules and of the recipient’s corneas. Data was analyzed using One-way ANOVA with Tukey post hoc test and Chi-square test with Odds Ratio (OR) calculation. We grouped patients according to diagnosis. GD occurred in 9 eyes affected by BK and 19 by FD (p=0.003, OR = 0.25, 95% CI, 0.098-0.62). It was recovered with ARB. In BK, ARB correlated to complicated cataract extraction (p=0.04, OR = 7.83, 95% CI, 1.28 – 47.98) and aphakia (p=0.026, OR = 54.38, 95% CI, 2.51 - 11.76). In FD, ARB was associated to donor’s death for neoplasia (p=0.06, OR= 4.04, 95% CI, 1.06 – 15.37). No other differences were found. In conclusion, we could hypothesize that in FD patients, donor’s cancer therapy may play a role on altered corneal fibroblast metabolism, activating a synergetic effect between chemotherapy and genetic alteration of FD, which may lead to an altered adhesion of donor’s lenticule on recipient's stroma. In BK patients, complicated cataract extraction and aphakic status of recipients’ eye may contribute to altered adhesion of donor’s lenticule post-DSAEK
Early Miscarriage Occurring Six Days After Intravitreal Ranibizumab Injection
The aim of this case report was to describe a miscarriage which occurred 6 days after an intravitreal Ranibizumab (IVR) injection. A 24-year-old female patient with type 1 diabetes diagnosed with diabetic macular edema in her left eye planned for 3 injections of IVR at one-month intervals. She had been receiving insulin injections 3 times a day and her Hemoglobin A1C (HbA1c) was in the approximate range of 6–7%. An ophthalmologic examination revealed that the patient’s Snellen corrected distance visual acuity (CDVA) was 10/10 in her right eye and 3/10 in her left eye. The patient was unaware of her pregnancy at the time of initial injection. Two days after the first injection, she found out that she was 5 weeks pregnant. This was the first pregnancy for the patient and there were no risk factors for miscarriage rather than diabetes. Six days after the injection, she was admitted to the hospital due to severe abdominal pain and vaginal bleeding. Miscarriage was diagnosed and she underwent curettage procedure. We concluded that pregnancy tests should be administered prior to intravitreal injection for female patients of reproductive age, and patient testimony should not be the sole reason to dismiss the possibility of pregnancy.
Corneal Posterior Curvature Changes After Phacoemulsification Cataract Surgery with 2.75 mm Corneal Incision
The aim of this study was to evaluate the corneal posterior curvature changes after phacoemulsification cataract surgery, with intraocular lens implantation, with a temporal limbal self-sealing 2.75 millimeters (mm) corneal incision, using a Placido-dual rotating Scheimpflug device. In this prospective intervention study, corneal posterior curvature changes were evaluated in fifty-six patients (56 eyes). All patients underwent corneal tomography using the Galilei G2 (Ziemer Ophthalmic System AG, Port, Switzerland) preoperatively (PRE) and with two weeks (RP15), one month (RP30), and three months (RP90) after phacoemulsification cataract surgery with a temporal limbal self-sealing 2.75 mm incision. Tomographic parameters analyzed in the posterior cornea were the steep curvature (K2), flat curvature (K1), mean curvature (average K), and posterior corneal astigmatism. We did not observe any statistically significant change in the K2, K1, average K, and posterior corneal astigmatism in any postoperative follow-up measurements (RP15, RP30, RP90), showing that the postoperative values tend to be the same as the preoperative ones when measured with the Galilei G2 tomography. In conclusion, the 2.75 mm temporal limbal self-sealing corneal incision in phacoemulsification cataract surgery does not induce significant changes in the posterior corneal curvature parameters of K2, K1, average K, and astigmatism
Preliminary Outcomes of Temporary Collagen Punctal Plugs for Patients with Dry Eye and Glaucoma
The aim of this study was using a temporary collagen punctal plug as a pre-test before decision of permanent punctal closure or long-term plug use for patients with dry eye disease (DED) and primary open-angle glaucoma (POAG). This case-control study was conducted at a single office in Honolulu, Hawaii from January 2017 to August 2018. In the case group, a temporary collagen plug was used in 33 eyes of 33 patients with DED and POAG who were receiving glaucoma medications with good control. On the other hand in the control group, 33 eyes of 33 patients with DED and POAG who were receiving glaucoma medications with good control were included, but punctal plug was not used. In the case group, one of the lower lid puncta was selected for the study and a canalicular rod shape plug was inserted as a therapeutic trial to predict the efficacy of long-term punctal plug placement or punctal closure. The mean changes of intraocular pressure (IOP) and improvement in symptoms/signs of DED were compared between the two study groups. Results revealed a statistically significant IOP reduction in the case group compared to the control group. Furthermore, DED improved significantly more in the case group compared to the control group (P< 0.001). We concluded that temporary punctal plug in patients with DED and POAG can significantly improve DED and lower IOP. Therefore, we could consider permanent punctal closure or long-term plug for patients with DED and POAG who responded well to temporary punctal plug without epiphora or other complications