Medical Hypothesis, Discovery & Innovation (MEHDI) Ophthalmology Journal
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Outcomes after bilateral implantation of AcrySof IQ PanOptix trifocal intraocular lens: a prospective interventional study
Get PDFBackground: Implantation of multifocal intraocular lenses (IOLs) is becoming increasingly popular for the treatment of visual demands at various distances in patients undergoing phacoemulsification cataract surgery. We aimed to assess the visual performance and rates of photic phenomena, posterior capsule opacification (PCO), and spectacle independence in patients with bilateral implantation of the AcrySof® IQ PanOptix® multifocal IOL model TFNT00 at one and six months postoperatively.
Methods: This prospective interventional cohort study included adult patients who underwent uneventful phacoemulsification cataract surgery with bilateral implantation of AcrySof® IQ PanOptix® IOL. Uncorrected and corrected visual acuities at far, intermediate, and near distances were measured preoperatively and at the one- and six-month postoperative follow-up examinations. The rates of photic phenomena, postoperative need for near and distance spectacles, and PCO were also recorded.
Results: We included 164 eyes of 82 patients with a male-to-female ratio of 38 (46.3%) to 44 (53.7%) and a mean (standard deviation [SD]) age of 52.37 (7.62) years. There were statistically significant improvements in the visual acuities of both eyes across all distances at the one- and six-month follow-up examinations compared to the preoperative values (all P < 0.001), except for corrected near visual acuity in the right eye (P > 0.05) at six-month. We also detected significant postoperative improvements in visual acuities of both eyes across all distances at the six-month follow-up compared to values at the one-month follow-up (all P < 0.05), except for corrected near visual acuity in the right eye (P > 0.05). The photic phenomenon was reported by 12 (14.6%) of the 82 patients at the six-month postoperative follow-up. Five (6.1%) and eight (9.8%) of the 82 patients reported using spectacles for distance and near, respectively. Additionally, PCO developed in 19 (11.6%) of the 164 included eyes, although it was not clinically significant at six months.
Conclusions: The AcrySof® IQ PanOptix® IOL model TFNT00 is recommended for use, given its excellent performance in all ranges of vision, a high rate of spectacle independence, and a good safety profile. Future comparative studies with longer follow-up periods are warranted to verify superiority of its performance over that of other available multifocal IOLs
A prospective contralateral eye comparison of the tolerability of two artificial tears with different physical properties in patients with dry eye disease
Get PDFBackground: Artificial tears (ATs) are widely used in ophthalmic practice with various formulations, mainly as a treatment for dry eye, owing to their rapid ability to alleviate the signs and symptoms of this condition. We aimed to investigate drop comfort and subjective ocular symptoms after instillation of the following ATs with different physical properties: Optive® non-preservative (OUD) and Systane® Hydration non-preservative (SHUD).
Methods: This was a prospective, double-blind, randomized, contralateral eye comparison study. A rheometer and a digital pH meter were used to evaluate the viscosity and pH of both ATs prior to instillation. We recruited 36 patients with dry eye disease. Single standardized AT volumes were set using a micropipette for all patients. Ocular discomfort was assessed using the Ora Calibra™ Ocular Discomfort and 4-Symptom Questionnaire (OOD4SQ; 0 – 5 scale) before and 60 min after instillation. Drop comfort was assessed using the Ora Calibra™ Drop Comfort Scale (0 – 10 scale) immediately after AT instillation. The difference in the drop comfort score (DCS) between the two ATs and ocular discomfort scores using OOD4SQ before and 60 min after instillation of each AT were recorded and compared.
Results: The viscosities and pH of SHUD and OUD were 32.73 centipoise (cP) and 7.74 and 14.42 cP and 7.19, respectively. The mean (standard deviation) DCS was higher in the SHUD group than in the OUD group (1.83 [1.21] versus 1.67 [1.12]); however, the difference was not statistically significant (P > 0.05). There was a significant reduction in all parameters of OOD4SQ including overall discomfort, burning, dryness, grittiness, and stinging 60 min after OUD instillation (all P < 0.05), while a significant difference was only noted in dryness (P < 0.05) in the SHUD group.
Conclusions: OUD, which has a lower viscosity and pH compared to SHUD, provides less subjective sensation and better ocular comfort 60 min after instillation. Further randomized clinical trials including patients with dry eye disease of different severities, larger sample sizes, and longer follow-up periods are required to verify our findings
Intravitreal injection of methotrexate in persistent diabetic macular edema: a 6-month study
Get PDFBackground: Diabetic macular edema (DME) affects approximately 10% of patients with diabetes mellitus. This condition can cause blurred or distorted vision, which significantly affects the quality of life of these patients. We evaluated the therapeutic effects of intravitreal methotrexate (MTX) injections on persistent DME.
Methods: This prospective interventional case series included patients with confirmed persistent DME that was unresponsive to previous standard treatments. The patients underwent comprehensive eye examinations and macular imaging with optical coherence tomography (OCT). A single intravitreal MTX injection (400 µg MTX in 0.16 mL solution) was administered, followed by patient assessments at 1, 3, and 6 months after injection. Best-corrected distance visual acuity (BCDVA), intraocular pressure (IOP), macular thickness (MT), and central subfield thickness (CST) were measured at baseline and post-injection to evaluate treatment efficacy.
Results: We included 33 eyes of 30 patients with a mean (standard deviation [SD], range) age of 62.7 (8.3, 44 to 77) years, of whom 17 (56.7%) were men and 13 (43.3%) were women. All participants had type 2 diabetes mellitus, with a mean (SD, range) duration of 17.0 (6.8, 10 to 31) years. Most participants (n = 27 eyes, 81.8%) had non-proliferative diabetic retinopathy, and six eyes (18.2%) had regressed proliferative diabetic retinopathy. Four eyes (12.1%) had undergone prior macular laser photocoagulation. The mean (SD) number of prior intravitreal bevacizumab injections was 3.4 (0.8), and 29 eyes (87.8%) had received one intravitreal triamcinolone injection. During the study period, a statistically significant difference was observed in CST (P < 0.05); however, no statistically significant differences were observed in BCDVA, MT, or IOP (P > 0.05). Pairwise comparison revealed a significant decrease in CST at 6 months post-injection compared to the baseline value (P < 0.05). During the investigation period, no side effects of MTX, such as macular edema, retinal tears, vitreous hemorrhage, endophthalmitis, or vision loss, were observed.
Conclusions: A single intravitreal MTX injection significantly reduced CST in patients with persistent DME, without relevant safety concerns. However, no significant improvement in functional outcomes was observed. Therefore, there is no strong evidence to recommend its use as a treatment for pDME. Further studies, preferably randomized clinical trials with long-term follow-ups, are warranted to assess the long-term efficacy, safety, and potential benefits of intravitreal MTX for the treatment of persistent DME
Effects of artificial tears on keratocyte cell density after femtosecond laser in situ keratomileusis: a prospective, comparative, interventional, contralateral eye study
Get PDFBackground: Flap creation during laser refractive surgery restructures the anterior cornea, particularly the stroma, reducing the keratocyte cell density (KCD). This reduced density makes it challenging to completely regenerate to the presurgical phase. The aim of the present study was to investigate the effects of two types of artificial tear (AT) interventions on KCD up to 3 months after femtosecond laser-assisted in situ keratomileusis (FS-LASIK) surgery.
Methods: This prospective, double-blind, comparative, interventional, contralateral eye study recruited patients with myopia scheduled for FS-LASIK. Inclusion criteria were healthy individuals aged 19 – 25 years with moderate or high myopia, a maximum cylindrical error of - 1.25 diopters, and a maximum pupil size of 6.5 mm who had undergone FS-LASIK and completed 3 months of follow-up. Complete optometric and ophthalmologic examinations were performed. Bilateral simultaneous FS-LASIK surgery was performed using the same femtosecond laser platform as in the standard procedure. The Research Randomizer was used to determine the eye to be treated with Systane® Hydration (Alcon Laboratories, Inc., Fort Worth, TX, USA) or Systane® ULTRA (Alcon Laboratories, Inc., Fort Worth, TX, USA) AT. KCD was examined using real-time images obtained from in vivo confocal microscopy (Heidelberg Retina Tomograph 3 with the Rostock Cornea Module, HRT III RCM); Heidelberg Engineering GmbH, Heidelberg, Germany) at baseline and 1- and 3-month postoperative visits.
Results: We included 60 eyes of 30 participants with a mean (standard deviation) age of 21.34 (1.85) years and a male-to-female ratio of 1:1 who completed 3-month post-FS-LASIK surgery follow-up. KCD did not differ significantly between the two groups at any visit (all P > 0.05); nevertheless, mean KCD was initially reduced up to 1 month postoperatively and then revealed a slight increase up to 3 months postoperatively in Systane® Hydration-treated eyes and continued to reduce in Systane® ULTRA-treated eyes. Intragroup comparisons revealed that the eyes treated with ATs experienced a significant reduction in KCD between the preoperative and 1-month postoperative visits and between the preoperative and 3-month postoperative visits (all P < 0.05). Treatment-related complications were not observed.
Conclusions: Overall, KCD reduced up to 3 months post-FS-LASIK surgery. Both AT types exerted a comparable effect on postoperative KCD up to 3 months. Future studies with a more frequent administration of ATs, longer follow-up periods, and a control group are required before preliminary outcomes of the present study can be generalized
Seven-year experience in a low vision rehabilitation clinic at a tertiary referral center
Get PDFBackground: Low vision is a major public health concern worldwide. This study was aimed at describing the characteristics of patients who had visited a low-vision rehabilitation clinic.
Methods: In this retrospective study, we reviewed the medical records of patients with low vision attending a low-vision rehabilitation clinic at a tertiary referral center over 7 years. Inclusion criteria were a diagnosis of vision impairment and availability of complete records. We extracted the following data from each record: age, sex, education level, employment status, chief complaints concerning vision, associated ocular diseases, uncorrected distance and near visual acuities, best-corrected distance and near visual acuities, statuses of previous and current prescribed optical devices, and cooperation status of patients during the optometric examination.
Results: We enrolled a total of 567 patients, including 338 (59.6%) men and 229 (40.4%) women, with a mean (standard deviation) age of 40.46 (28.34) years. Most (98.4%) participants were cooperative, with a high rate of unemployment (90.5%) and low education level. Half (49.2%) of the patients had moderate visual impairment. Retinal pathologies, mainly congenital (28.4%), and age-related macular degeneration (ARMD; 26.5%) were common causes of low vision. Difficulty in reading was the most frequent complaint (22.9%), and a combination of difficulties in reading, writing, and facial recognition was recorded in 54.7% of the patients. Other functional complaints were reported by at least 5% of the patients. Our multivariate logistic regression analysis revealed that the likelihood of difficulties in performing in-house activities, reading, facial recognition and social interaction, and driving increased per 10-year increment in age, with odds ratios of 1.39, 1.31, 1.24, and 1.22, respectively (all P < 0.05). The likelihood of reporting three complaints (reading, writing, and facial recognition together) increased per 0.1-logarithm of the minimum angle of resolution increment in the best-corrected distance visual acuity of the better eye, with an odds ratio of 2.05 (P < 0.05). In addition, men were more likely to experience difficulties in driving and reading, while women were more likely to experience difficulties in facial recognition and social interaction or in-house activities (all P < 0.05). Optical devices for distance or near vision were prescribed to most patients.
Conclusions: Most patients were men and unemployed. The most common category of low vision was moderate impairment. Retinal conditions, mainly congenital ones and ARMD, were the most frequent causes. A combination of difficulties in reading, writing, and facial recognition was the most common complaint. Optometrists should address these findings during rehabilitation therapy to treat patients with low vision
Rhegmatogenous retinal detachment: an analysis of 2315 eyes over a six-year period
Get PDFBackground: Rhegmatogenous retinal detachment (RRD) is a form of retinal detachment caused by passage of fluid from the vitreous cavity into the space between the neurosensory retina and the retinal pigment epithelium via a retinal break or full-thickness defect. At our tertiary referral center, we evaluated the clinical and epidemiological features of RRD, and we herein report the frequency of related risk factors.
Methods: In this retrospective study, we reviewed the records of patients with a final diagnosis of RRD at an academic ophthalmological referral center in Isfahan, Iran, over a six-year period. We retrieved and reviewed data from the medical records of all eligible participants, including sex, age, laterality, lens status, macular status, type of RRD, location and number of breaks, type of surgery, rate of re-operation during the first year after initial surgery, and documented clinical risk factors for RRD. Clinical risk factors were categorized as the presence of myopic refractive error, ocular trauma, history of cataract surgery, history of other ocular surgeries, history of uveitis, or undetermined.
Results: We included 2315 eyes of 2229 patients with a mean (standard deviation [SD]) age of 51.1 (16.9) years and a male-to-female ratio of 1.8:1. The most common quadrants containing retinal breaks were the superotemporal quadrant (34.1%), inferotemporal quadrant (23.4%), and superonasal quadrant (10.7%). Macula-involved RRD was seen in 90% of eyes (n=2083 eyes). The most frequently identified risk factors were cataract surgery (32.9%) and myopia (22.3%) in adults, and myopia (35.0%) and ocular trauma (27.4%) in the pediatric group. Most eyes underwent pars plana vitrectomy (51.3%), whereas pneumatic retinopexy (0.7%) was the least commonly selected.
Conclusions: Our results indicate that cataract surgery and myopia are the most common risk factors for RRD in adults. Myopia and ocular trauma are the most common risk factors in pediatric patients. As observed in many studies, the characteristics of the study population, including middle age, male sex, myopia, and ocular trauma, may be associated with RRD at different rates. Further population-based longitudinal studies with larger sample sizes are required to verify these preliminary observations
Photophysical and photodynamic analysis of different formulations of riboflavin
Get PDFBackground: Riboflavin (Rb) has been used in the ophthalmological procedure known as corneal cross-linking (CXL). Pathologies requiring this treatment include keratoconus, corneal ectasia, and infectious keratitis. Rb is instilled via different molecules that are transported into the tissues. However, each vehicle imparts different properties that alter the photodynamic behavior of Rb, leading to variable concentrations of free radicals within the medium. The objective of this study was to measure the concentrations of free radicals produced by commonly used Rb formulations. To determine the free radical production level of each formulation, L-tryptophan (L-Tryp) was used as a model substrate because it can be efficiently photo-oxidized.
Methods: We investigated the photodegradation of L-Tryp and its kinetics upon light exposure. The spectra were recorded using a Shimadzu UV-1800 PC spectrophotometer and a Cary Eclipse fluorescence spectrophotometer. A high-power solid-state LED light source was used for irradiation. L-Tryp degradation was performed using a 9-W LED lamp, and steady-state photolysis was conducted in quartz cells. The observed rate constants for L-Tryp degradation were determined by analyzing the changes in absorbance and fluorescence intensity. Data analysis was performed using Origin software.
Results: We examined the characteristics of the photophysical and photodynamic action of the carriers in different commercially available Rb formulations. These included a) Rb with dextran, b) Rb without dextran, c) VibeX Rapid® (hydroxypropylmethylcellulose as a vehicle), d) Trans-Epithelial Kit (I) (sodium chloride as a vehicle), and e) Trans-Epithelial Kit (II) (benzalkonium chloride as a vehicle), using L-Tryp as a model substrate, and focusing on absorption and emission spectra. VibeX Rapid® exhibited the highest photo-degradation constant. The study affirmed the stability of Rb formulations for CXL and highlighted the efficacy of VibeX Rapid® in L-Tryp photo-oxidation and this rationalizes its current use as a CXL agent.
Conclusions: We demonstrated that formulations for transport of Rb are of crucial importance in CXL applications. Rb in the VibeX Rapid® formulation is more effective in generating photo-degradation, and this reflects its superior performance in CXL. Future experiments should be designed and conducted to quantitatively differentiate the production of free radicals. Studies involving human participants could shed light on the clinical efficacy and safety of the available Rb formulations
Myopia progression in children before and after the coronavirus disease lockdown
Get PDFBackground: The worldwide spread of the coronavirus disease (COVID-19) pandemic in 2020, followed by lockdowns, forced children to be in home confinement with increased screen time, leading to rapid progression of myopia and an increase in the prevalence of myopia. This study was aimed at determining if myopia progression seen in evidence-based practice resulted from the COVID-19 lockdown or delayed follow-ups.
Methods: A retrospective review of case sheets of patients visiting the pediatric department of a tertiary care eye hospital in Mumbai, India, was conducted from 2017 onwards. We enrolled all children with myopia who had attended at least one follow-up visit before the COVID-19 lockdown and at least one follow-up visit post-lockdown. The spherical equivalent (SEQ) of refractive error values at baseline and pre- and post-COVID-19 lockdown follow-ups (hereinafter referred to as the “first” and “second” follow-ups, respectively) were recorded. The duration between baseline and the first follow-up visit and between the first and second follow-up visits were noted.
Results: We enrolled 112 eyes of 56 children, including 35 (62.5%) boys and 21 (37.5%) girls, with a mean (standard deviation [SD]) age of 9.54 (2.82) years. The mean (SD) SEQ values at baseline and first and second follow-ups were - 4.74 (3.83), - 5.46 (3.81), and - 6.42 (3.66) D, respectively. The mean change in SEQ, mean SEQ myopia progression, and rate of myopia progression per month differed significantly between the baseline and the first follow-up visit versus between the first and second follow-ups (all P < 0.05). However, the change in myopia degree did not differ significantly between these two periods in eyes with low, moderate, or high myopia (all P > 0.05). The mean (SD) duration between the baseline and the first follow-up visit was 14.57 (5.68) months, while that between the first and second follow-ups was 27.96 (9.18) months, showing a significant difference (P < 0.05).
Conclusions: Our findings suggest that a longer gap between follow-up visits and myopia progression per month should be factored into the management of myopia. Considering that young children are more vulnerable, preventive measures and school reforms should be urgently implemented in India. Further retrospective multicenter studies with a larger sample size of eyes, including various refractive errors over a longer period, are required to verify these findings
Optical coherence tomography epithelial mapping for keratoconus screening
Get PDFLetter to the Editor
Note: letters have no abstract
Impact of flight and equivalent short-term high-altitude exposure on ocular structures and function
Get PDFBackground: Exposure to high-altitude conditions during flight or similar activities affects many aspects of visual function, which is critical not only for flight safety but for any altitude-related activity. We aimed to summarize the available literature pertaining to ocular changes during flight or equivalent short-term high-altitude exposure (e.g., hypobaric chamber, effortless ascent lasting less than or equal to 24 h) and to highlight future research priorities.
Methods: Using the PubMed/MEDLINE and Web of Science/ISI Web of Knowledge databases with structured search syntax, we conducted a systematic review of the literature spanning a 40-year period (January 1, 1983, to October 10, 2023). Articles pertaining to ocular changes during flight or flight-equivalent exposure to altitude were retrieved. The reference lists of retrieved studies were also searched, and citations of these references were included in the results.
Results: Of 875 relevant PubMed and ISI publications, 122 qualified for inclusion and 20 more were retrieved from the reference lists of initially selected records, for a total of 142 articles. Reported anterior segment changes included deterioration in tear film stability and increased dry eye incidence, increased corneal thickness, discomfort and bubble formation in contact lens users, refraction changes in individuals with prior refractive surgery, decreased intraocular pressure, and alterations in pupillary reaction, contrast sensitivity, and visual fields. Photoreceptor–visual pathway changes included alterations in both photoreceptors and neuro-transduction, as evidenced in dark adaptation, macular recovery time, reduction in visual field sensitivity, and optic neuritis (likely an element of decompression sickness). Retinochoroidal changes included increases in retinal vessel caliber, retinal blood flow, and choroidal thickness; central serous chorioretinopathy; and retinal vascular events (non-arteritic ischemic optic neuropathy, high-altitude retinopathy, and retinal vein occlusion).
Conclusions: The effect of short-term high-altitude exposure on the eye is, in itself, a difficult area to study. Although serious impairment of visual acuity appears to be rare, ocular changes, including tear film stability, contact lens wear, central corneal thickness, intraocular pressure, contrast sensitivity, stability of refractive surgeries, retinal vessels, visual fields, and macula recovery time, should be considered in civilian aviators. Our report provides guidance to climbers and lowlanders traveling to altitude if they have pre-existing ocular conditions or if they experience visual symptoms while at altitude. However, key outcomes have been contradictory and comprehensive studies are scarce, especially those pertaining to the choroid and retina. Such studies could not only deepen our understanding of high-altitude ocular pathophysiology, but could also offer valuable information and treatment possibilities for a constellation of other vision-threatening diseases