Journal of Ophthalmic and Vision Research
Volume:17 Issue: 3, Jul_Sep 2022

Corneal irregularities can lead to high order aberrations (HOAs) and may influence the outcomes in terms of intraocular lens (IOL) selection and visual acuity assessment. The aim of this study was to evaluate the visual acuity and satisfaction after IC-8 implants in patients characterized by corneal irregularities and HOAs who could not undergo refractive surgery due to the poor residual thickness of the cornea or other conditions such as astigmatism secondary to previous radial keratotomy.

This descriptive, retrospective cohort study was conducted on nine eyes in six patients affected by corneal irregularities and HOAs who had undergone IC-8 IOL implantation. The primary endpoint was the best-corrected visual acuity (BCVA), the subjective visual function, and the visual field.

Nine eyes of six patients (three bilateral implantation) were enrolled. For each patient, BCVA, vision, and lifestyle quality were evaluated. In all patients, we noticed an improvement in all parameters without visual field defects.

Our work encourages the use of the IC8 lens to improve visual acuity in patients with irregular corneas and HOAs who cannot be treated with customized refractive surgery. Patients experience a subjective improvement of their quality of vision and also more self-confidence in their daily life. IC-8 lenses do not interfere with the visualization of retinal fundus and there is no impairment of the visual field detected by patients.

To report eye bank records for pediatric keratoplasty in Iran between 2006 and 2019.

In a retrospective study, all electronic records of the Central Eye Bank of Iran for pediatric keratoplasty between April 2006 and March 2019 were analyzed in terms of indications for keratoplasty, surgical techniques, their corresponding trends, and post-transplantation graft clarity.

Our database included 2178 eyes from 2050 pediatric cases. The leading indications for keratoplasty included acquired nontraumatic diseases (75.8%), congenital abnormalities (12.7%), corneal regraft (8.3%), and acquired traumatic diseases (3.2%). Keratoconus was the most common acquired nontraumatic cause (58%) and more common in the age group >12 years than those ≤12 years (P < 0.001). Congenital corneal abnormalities and regrafts were more common in the age group ≤12 years (both P < 0.001). The most common surgical technique was penetrating keratoplasty (PKP, 90.9%) followed by deep anterior lamellar keratoplasty (DALK, 7.3%), Descemet stripping automated endothelial keratoplasty (DSAEK, 1.1%), anterior lamellar keratoplasty (0.5%), and keratolimbal allograft transplantation (0.2%). DSAEK was more common in the age group ≤12 years (P = 0.002), which, unlike PKP and DALK, showed a significant ascending trend over the 14-year period (P = 0.018). Post- transplantation graft clarity was 96.8%.

Keratoconus was the leading indication for pediatric keratoplasty in Iran. Although PKP was the predominant keratoplasty procedure for the treatment of pediatric corneal disorders, it showed a significant descending trend over the 14 years.

To determine the diagnostic accuracy of Pentacam Cataract Grading Scale (PCGS) versus the Lens Opacities Classification System (LOCS III) in scaling pure age-related cataract.

Between April 2016 and May 2017, eyes of 281 patients were evaluated for grading of lens opacity. We used LOCS III and PCGS. Patients with pure age-related cataract with no previous history of eye surgery, eye trauma, or chronic systemic disease between 50 and 95 years of age were included. The examination of the patients was done, using slit lamp and LOCS III grading chart. The second examination was done a week later, using Oculus Pentacam. Next, we graded them using a PNS grading score. Spearman’s rank correlation and a Bland-Altman Plot were implemented for analysis using MedCalc 14. 8.1. P < O.05 was considered as statistically significant.

Three hundred eyes were examined. Of them, 189 patients were male, and patients between 70 to 80 years old were the most common group. The correlation between grades of two methods was 0.47 (P < 0.001). Results of the Bland-Altman plot showed a moderate alignment between the two methods.

The association between LOCSIII and PCGS is not so favorable, however, it is an economical and effective method to assess lens opacities is LOCSIII. PCGS can be used in early diagnosis. For a definitive diagnosis and appropriate therapeutic intervention, an ophthalmological examination is needed.

To compare the accuracy of various intraocular lens power formulas for two monofocal hydrophobic foldable lenses, the AcrySof SN60WF and the Tecnis ZCB00.

This retrospective study included 409 eyes from 409 patients who underwent uncomplicated cataract surgery (299 eyes with SN60WF and 110 eyes with ZCB00). Biometry was performed for all eyes with an IOLMaster 700. Predicted refraction from five different IOL power formulas (Barrett Universal II, Haigis, Hoffer-Q, Holladay 2, and SRK/T) was compared to postoperative refraction at one to three months for the following axial length strata: short eyes (<22.5 mm), medium eyes (22.5–25.5 mm), and long eyes (>25.5 mm).

In patients with medium eyes, there were no significant differences in the mean absolute error (MAE) and the percentage of eyes within ±0.5 D (%±0.5 D) between both IOLs. In short eyes, although MAE was similar between both lenses, %±0.5 D was significantly higher for Barrett Universal II in ZCB00 than in SN60WF (P = 0.01) while Hoffer-Q and Holladay 2 performed equally for both lenses. In long eyes, ZCB00 had a higher MAE than SN60WF for Barrett Universal II, Haigis, and Hoffer-Q. Additionally, in long eyes, the percentage of eyes within %±0.5 D was significantly higher for SN60WF than ZCB00 for all formulas (P < 0.001).

Although there were no significant differences in the formula accuracy between these two lenses in medium eyes for all formulas and in short eyes for most formulas, the accuracy decreased significantly in long eyes for ZCB00 compared to SN60WF. The effect of IOL model on the postoperative outcomes should be further investigated.

To estimate the power of an implanted intraocular lens (IOL) by measuring IOL thickness using anterior segment optical coherence tomography (AS-OCT) and to assess the repeatability of measurements.

Ninety-seven eyes were studied one month after uneventful phacoemulsification within the bag Acrysof SA60AT IOL implantation (range +11 to +35). All eyes had postoperative refraction of ±0.5 D of target refraction. AS-OCT was used to measure the central thickness of the IOL. Correlation between labelled IOL power and central IOL thickness as well as the measure of repeatability, for example, intraclass correlation coefficient (ICC), were evaluated. IOL thicknesses were also calculated using a formula and compared with AS-OCT derived measurements.

IOL thickness correlated significantly with labelled IOL power (R2 = 0.985, P < 0.001). The regression equation (IOL Power = [0.04 × IOL thickness in micron] – 7.56) indicates 25 microns of central IOL thickness change per 1D power change. Over the studied range, IOL power could be estimated with a precision of 0.85 ± 0.02 D (95% confidence interval: 0.83–0.94D). ICC for repeated measurements was 0.999. There was a significant correlation between calculated and measured (AS-OCT) IOL thickness (R2 = 0.984, P < 0.001).

Central IOL thickness measurements with the AS-OCT are highly repeatable and closely correlated with the labelled IOL power, which can predict the IOL power with ±0.85 D from the actual power. This method can be helpful in cases of postoperative IOL surprise.

To assess the changes in optic nerve head and macular microvascular networks after acute intraocular pressure (IOP) rise in healthy eyes versus the eyes of diabetic patients.

In this prospective, interventional, comparative study, 24 eyes of 24 adults including 12 eyes of healthy nondiabetic subjects and 12 eyes with mild or moderate non-proliferative diabetic retinopathy (NPDR) were enrolled. IOP elevation was induced by a suction cup attached to the conjunctiva. IOP and optical coherence tomography angiographic (OCTA) images of the optic disc and macula were obtained before and immediately after the IOP rise.

Baseline and post-suction IOPs were not significantly different between the two groups (all P > 0.05). The mean IOP elevation was 13.93 ± 3.41 mmHg among all eyes and was statistically significant as compared to the baseline in both groups (both P < 0.05). After IOP elevation, healthy eyes demonstrated a reduction in the vessel density in the whole image deep and superficial capillary plexuses and parafoveal deep capillary plexus (DCP) (all P < 0.05). In diabetic retinopathy, foveal vessel density at DCP decreased significantly following IOP rise (P = 0.003). In both groups, inside disc vessel density decreased significantly after IOP rise (both P < 0.05), however, no significant change was observed in peripapillary vessel density (both P > 0.05).

Acute rise of IOP may induce different levels of microvascular changes in healthy and diabetic eyes. Optic disc microvasculature originating from the posterior ciliary artery may be more susceptible to IOP elevation than that of retinal microvasculature.

To evaluate the effect of periocular topical triamcinolone cream on intraocular pressure.

A retrospective chart review identified 57 patients, 114 eyes using triamcinolone cream (0.1%, 0.025%) with subsequent intraocular pressure (IOP) checks at three follow-up visits. Descriptive, univariate, and multivariate analyses were performed to assess effects of age, therapy duration, consecutive weeks on steroid, prescription strength, time of day, and method of measurement on IOP levels. Generalized Estimating Equations were used in regression models to account for correlation of eyes within subjects and across visits.

We identified 57 patients using triamcinolone cream for allergic or eczematous dermatitis of the eyelid. Prescription strengths were 0.025% or 0.1% and patients were followed for a median of 4.9 months. Measurements of IOP at baseline did not change as compared to all IOP measurements at follow-ups and did not change with steroid strength. The mean change in IOP at all follow-up visits was 0.07 mm Hg (95% confidence interval [CI]: –0.36, 0.50). After adjustment for the method of tonometer and the patient’s age, the mean change was 0.03 mm Hg (95% CI: –0.68, 0.73, P = 0.93). Prescription strength and consecutive weeks of therapy were not associated with IOP. Two patients experienced a significant elevation in IOP of >10 mm Hg, one through the concomitant consequences of systemic corticosteroids usage and the other through prolonged topical application.

In patients taking periocular triamcinolone cream, there was no clinically meaningful change in mean IOP between baseline and follow-up visits, and IOP measurements were not related to variances in prescription strength or duration of therapy.

To evaluate the therapeutic response of retinal vein occlusion (RVO) to intravitreal bevacizumab (IVB) with and without concomitant vitamin D supplementation.

Seventy eyes of 68 patients with macular edema associated with branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO) received three monthly IVB injections. Patients with serum 25-hydroxyvitamin D (25(OH) D) higher than 30 ng/ml were considered as the sufficient group. Cases with serum 25(OH) D levels below 30 ng/ml were randomized into the treatment and control groups. The control group received 50,000 IU of oral vitamin D, weekly for two months. One month after the last IVB injection, best-corrected visual acuity (BCVA) and central macular thickness (CMT) were measured and compared with the preinjection values.

While 43 eyes (61.4%) of 42 patients had BRVO, 27 eyes (38.6%) of 26 patients had CRVO. In BRVO patients, changes of CMT and BCVA were not significantly different between the sufficient, control, and treatment groups (P = 0.58 and 0.64, respectively). In the CRVO group, CMT reduction in the control group was significantly less than the sufficient and treatment groups (P = 0.048). In addition, improvement of BCVA in the control group was significantly less (P = 0.036) than the sufficient and treatment groups.

Oral vitamin D supplement therapy may improve anatomical and functional outcomes in patients with CRVO and vitamin D deficiency.

In this case–control study, we measured visual acuity, objective refraction, ocular biometric parameters, and strabismus in premature cases classified according to the following categories: argon laser-treated retinopathy of prematurity (ROP), untreated spontaneously regressed ROP, no ROP, and full- term controls.

Cases with a history of prematurity at six years of age were categorized into the following groups: patients with a history of treated type 1 ROP using argon laser (group I), untreated spontaneously regressed ROP (group II), and no history of ROP (group III). Group IV included age-matched healthy full-term controls. Funduscopy was performed for all the cases and the control group.

In total, 24 eyes of 12 laser-treated ROP cases, 186 eyes of 93 spontaneously regressed ROP patients, 74 eyes of 37 premature cases with no history of ROP, and 286 eyes of 143 controls were included in the study. The mean spherical equivalent in the treated cases was not significantly different from that in the untreated cases and patients in group III. However, the average cylindrical power was significantly different among the groups (P < 0.004). Furthermore, anisometropia (≥1.5 diopters) was diagnosed with a higher rate in the treated cases (P = 0.03). The corneal curvature of the laser-treated eyes was significantly steeper and the axial length was significantly shorter than those in the other groups (P < 0.002 and P < 0.001, respectively, for multivariate analysis). Strabismus was found in three treated patients (25%). Additionally, there were three treated eyes (12.5%) diagnosed with macular dragging.

Premature cases including those who had a history of argon laser- treated ROP and those with untreated spontaneously regressed ROP showed acceptable long-term visual and refractive outcomes along with a fairly low rate of ocular disorders.

To assess the safety and efficacy of subthreshold micropulse laser (SML) photo-stimulation in the management of persistent subfoveal fluid (PSF) after surgery for rhegmatogenous retinal detachment (RRD).

In this pilot study, 11 eyes of 11 patients (8 men, 3 women) with long- lasting (12–18 months) PSF after surgery for RRD were evaluated before and after photostimulation with subthreshold micropulse yellow laser. Ophthalmic examination included best-corrected visual acuity (BCVA), Amsler grid test, ophthalmoscopy, autofluorescence (AF), and optical coherence tomography (OCT) with measurement of central point foveal thickness (CPFT). Primary outcome was subfoveal fluid resolution and secondary outcome was BCVA improvement.

The mean CPFT and BCVA were, respectively, 436.8 ± 28.8 μm and 0.25 ± 0.1 μm decimal equivalent (DE) before photostimulation and 278 ± 54.4 μm and 0.57 ± 0.2 μm DE after photostimulation, a statistically significant difference (P < 0.001). Nine (81.8%) eyes showed improved BCVA, disappearance of macular detachment on ophthalmoscopy, reduced retinal pigment epithelium distress on AF, and restored macular profile with no neuroretinal alterations on OCT scans.

Although PSF after RRD surgery is often a self-limiting disease, our results suggest that SML photostimulation may be effective and safe in patients with clinically significant long-lasting PSF. Larger case–control studies are necessary to confirm these results.

The evidence on the linear relationship between cognitive load, saccade, fixation, and task performance was uncertain. We tested pathway models for degraded task performance resulting from changes in saccadic and post-saccadic fixation under cognitive load.

Participants’ (n = 38) eye movements were recorded using a post-saccadic discrimination task with and without arithmetic operations to impose cognitive load, validated through recording heart rate variability and subjective measurement.

Results showed that cognitive load led to longer latencies of saccade and fixation; more inaccurate responses and fewer secondary saccades (P < 0.001). Longer saccade latencies influenced task performance indirectly via increases in fixation latency, therefore, longer reaction times and higher response errors were observed due to limited fixation duration on desired target.

We suggest that latency and duration of fixation indicate efficiency of information processing and can predict the speed and accuracy of task performance under cognitive load.

The management of conjunctival melanoma is challenging due to the more frequent local recurrence and metastasis compared to other conjunctival neoplasms. Locally advanced conjunctival melanoma may require an orbital exenteration, and treatment options for metastatic conjunctival melanoma have been limited until recently. This review aims to provide comprehensive updates on immunotherapy for conjunctival melanoma, focusing on immune checkpoint inhibitors. We reviewed the available literature on the use of immunotherapy for the treatment of conjunctival melanoma. Systemic immunotherapy, particularly with checkpoint inhibitors, has recently been reported to have improved outcomes for patients with conjunctival melanoma. Immune checkpoint inhibitors that are currently approved by the US Food and Drug Administration for melanoma include anti-PD-1 (nivolumab and pembrolizumab), anti- PDL-1 (avelumab and atezolizumab), and anti-CTLA-4 inhibitors (ipilimumab). Most recent reports described using immune checkpoint inhibitors in patients with locally advanced conjunctival melanoma in an attempt to avoid orbital exenteration or in patients with metastatic conjunctival melanoma. Although the current data are limited to case reports and small case series, eye care providers should be aware of the potential role of immunotherapy for patients with locally advanced, recurrent, or metastatic conjunctival melanoma.

Color blindness (color vision deficiency) is a disorder that impairs the true perception of colors. Using the information in this study, appropriate policy can be made to identify high-risk groups, as well as educational policies for families to perform more effective genetic diagnosis methods. This study aims to examine the prevalence of color blindness in Iranian students through a meta-analysis. Articles related to color blindness published between January 1990 and December 2020 were searched in Scopus, Cochrane Library, Web of Science (WoS), Science Direct, Embase, SID, MagIran, IranDoc, Medline, and Google Scholar databases. The keywords used were based on medical subject topics (MeSH Terms) and, after careful review, articles were selected according to varied sections of Participants, Exposure, Comparison, and Outcomes (PECO). Participants: students; Exposure: students with color blindness were examined; Comparison: Students from multiple provinces and regions of Iran were surveyed for color blindness; Outcomes: the pooled prevalence of color blindness in Iranian students reported from different provinces. The prevalence of color blindness in Iranian students was 3.8% (95% CI: 2.7–5.4%). The pooled prevalence of color blindness in Iranian male and female students was 4.7% (95% CI: 3.5–6.4%) and 0.7% (95% CI: 0.3–1.3%), respectively. The pooled prevalence of red–green color blindness (Tritan) was 41.7% (95% CI: 18.9–68.8%). The pooled prevalence of red color blindness (Protan) was 13.9% (95% CI: 7.8–23.8%), and the pooled prevalence of green color blindness (Deutan) based on meta-analysis was 45.3% (95% CI: 29–62.7%). Due to the high prevalence of color blindness in students, especially male students, it is necessary to be screened for through genetic tests in couples before having children.

Secondary infections in hospitalized and ill patients with coronavirus disease 2019 (COVID-19) are common. One of these life-threatening infectious diseases is rhino-orbital mucormycosis, which made an outbreak recently. This outbreak was mainly caused by the administration of high-dose corticosteroids in patients with COVID-19, especially those with diabetes mellitus. The increased incidence of rhino-orbital mucormycosis in the COVID-19 era presents different challenges for healthcare providers including ophthalmologists who are directly involved in disease management. We summarized the main challenges and recommendations for ophthalmologists on the management of rhino-orbital mucormycosis.

To report the findings of fluorescein angiography (FA) and optical coherence tomography angiography (OCTA) in a patient with malignant hypertensive retinopathy.

A 41year-old male was referred to our clinic with sudden visual loss in both of his eyes after an acute rise of blood pressure (200/150 mmHg). Optic disc swelling, flame shape hemorrhages especially around the optic disc, arterial narrowing, vessel tortuosity, cotton wool spots, hard exudate deposition, and multiple deep orange spots (Elschnig spots) were visible in both eyes. In the OCTA, disruption in the normal tapering patterns of the superficial and deep capillary plexuses was observed. Elschnig spots were observed as hypointense spots in the choriocapillaris slab. Leakage of the optic nerve head was seen in the FA.

When compared with the FA, the OCTA can illustrate the ischemic areas and the Elschnig spots with greater detail.

To report a case of bilateral refractory macular edema in a diabetic macular edema in a diabetic with an underlying systemic illness.

 A 65-year-old male presented with the symptom of blurred vision in both eyes for three months. He was a known diabetic patient and was also hypertensive for the last 10 years. The corrected distance visual acuity was 20/120 in the right eye and 20/80 in the left eye. Fundus examination revealed multiple deep and superficial retinal hemorrhages, cystoid macular edema, and serous macular detachment in both eyes. With a diagnosis of diabetic macular edema in both eyes, the patient was treated with multiple intravitreal injections of anti-vascular endothelial growth factor and steroids. Since he did not show a favorable response, the patient was further investigated and diagnosed with multiple myeloma. After undergoing treatment for the same, the patient was seen a year later and noted to have significant resolution of the macular edema and subretinal fluid in both eyes.

In patients who suffer with atypical macular edema that is resistant to conventional treatment, it is imperative to look for underlying systemic illnesses such as immunoproliferative disorders and hematologic malignancies.