Journal of Ophthalmic and Vision Research
Volume:14 Issue: 3, Jul-Sep 2019

To report histopathological findings for different types of polymers proposed as support for a Pintucci-type keratoprosthesis.

Six polymers, including three types of polyesters (#1-3), one type of polytetrafluoroethylene (PTFE, #4), polyethylene (#5), and expanded polytetrafluoroethylene (ePTFE, #6) were evaluated. Four samples of each material were placed under the orbicularis oculi muscles of 12 rabbits. After five weeks, the samples were removed and evaluated histopathologically. Fibrovascular tissue ingrowths were investigated in terms of tissue penetration depth into the materials (graded as none, mild, moderate, and intense) and fibrovascular ingrowth area at the ultimate level of tissue penetrance. ImageJ software was used to calculate fibrovascular tissue area between the material fibers, and the mean area values were compared between the materials.

Polyester materials #1 and #3 demonstrated intense fibrovascular tissue penetration with a large fibrovascular ingrowth area; no overt tissue ingrowth was observed into material #6. The mean area of penetrated fibrovascular tissues was significantly different between materials (𝑃 < 0.001). Materials #2, #4, and #5 showed moderate fibrovascular tissue ingrowth and the area of presented fibrovascular tissue at the paracentral parts of material #4 was significantly smaller than that of materials #1 (𝑃 = 0.02) and #3 (𝑃 = 0.01).

Two polyester materials that had relatively large pore sizes demonstrated a deep and large area of fibrovascular ingrowth. Given that material #3 is thicker and more consistent than material #1, the former can be used as the appropriate material for supporting the Pintucci-type keratoprosthesis.

To study the potential changes in pupil area within low-energy femtosecond-laser assisted cataract surgery (FLACS).

A retrospective assessment of the pupil size was performed in the eyes undergoing FLACS using the Ziemer LDV Z8. We measured the pupil diameters as part of the images taken preoperatively and at the completion of laser pretreatment (after releasing the suction). We calculated the pupil area in 40 eyes of 40 patients (14 right and 26 left eyes). The mean ± standard deviation (SD) of age of the patients was 74 ± 7.4 years (range: 51-87). Paired t-test was used for statistical analyses. Subgroups were built with reference to age and preoperative pupil area (smaller than or equal to the median versus larger than the median).

The mean ± SD axial length, anterior chamber depth, white-to-white distance and lens thickness were 24.01 ± 1.47, 3.23 ± 0.4, 11.97 ± 0.49, and 4.59 ± 0.41 mm, respectively. The mean ± SD pupil area was 39.33 ± 7.1 mm2 preoperatively and 39.3 ± 6.75 mm2 after laser pretreatment. The mean ± SD change in pupil area was -0.03 ± 2.12 mm2 . There were no statistically significant changes between preoperative and post-laser pupil areas (P = 0.93, 95% CI: -0.71 to 0.65). Comparisons within subgroups also did not detect pupil area reduction.

This study did not detect statistically significant changes in pupil area after laser pretreatment using low-energy FLACS. This observation is in contrast to previous studies using other laser platforms.

To report the investigation of an outbreak of multidrug-resistant (MDR) Pseudomonas aeruginosa endophthalmitis in 13 patients after cataract surgery and to emphasize on the importance of clinical profile, risk factors, and treatment outcomes.

This was a hospital-based, retrospective case study with 13 consecutive patients who had man- ual small-incision cataract surgery with intraocular lens (IOL) implantation and developed acute postoperative Pseudomonas aeruginosa endophthalmitis. The anterior chamber taps, vitreous aspirates, and environ- mental surveillance specimens were inoculated for culturing. Antibiotic susceptibility testing was performed using the agar diffusion method. Pulsed-field gel electrophoresis (PFGE) was used to determine the relation- ship between bacterial isolates recovered from study patients and contaminated surveillance samples.

Pseudomonas aeruginosa was isolated from all 13 eyes with acute postoperative endophthalmitis and the trypan blue solutions used during surgery. Sensitivity tests revealed that all isolates had an identical resistance to multiple drugs and were only susceptible to imipenem. Genomic DNA typing of Pseudomonas aeruginosa isolates recovered from patients and trypan blue solutions showed an identical banding pattern on the PFGE. Despite the prompt use of intravitreal antibiotics and early vitrectomy with IOL explantation in some patients, the outcome was poor in about 50% of patients.

Positive microbiology and genomic DNA typing results proved that the contaminated trypan blue solutions were the source of infection in this outbreak. Postoperative endophthalmitis caused by Pseudomonas aeruginosa is often associated with a poor visual prognosis despite prompt treatment with intravitreal antibiotics.

To compare the water-drinking test (WDT) and pharmacologic mydriasis as provocative tests in patients with primary angle closure suspect (PACS).

This observational non-randomized comparative study evaluated changes in intraocular pressure (IOP) in 21 patients with PACS who underwent pharmacologic mydriasis and compared it with IOP changes in 26 patients given the WDT. Ocular biometric and anterior chamber parameters were also assessed. Tests were repeated on the same patient two weeks after performing laser peripheral iridotomy (LPI).

The mean age± standard deviation was 60± 7 and 57± 9 years in the mydriasis and WDT groups, respectively (P = 0.201). Before LPI, both provocative tests were associated with a significant increase in IOP (mydriasis: 15.1± 3.1 to 16.6± 3.5 mmHg, P = 0.025; WDT: 16.2± 2.8 to 18.5± 3.3 mmHg, P < 0.001). However, the IOP changes were not statistically different between groups (P = 0.102). After LPI, only the WDT group showed a continued significant IOP elevation after the test (mydriasis: 16.4± 3.3 to 16.7± 3.5 mmHg, P = 0.569; WDT: 14.9± 3.0 to 17.8± 4.1 mmHg, P < 0.001). The post-test IOP change was significantly greater in the WDT than in the mydriasis group (3.0 versus 0.3 mmHg, respectively; P = 0.002). Step-wise multiple regression analysis verified the type of provocative test as the only independent factor affecting the post-test IOP change after LPI (regression coefficient: 2.664; P = 0.002).

Pharmacologic mydriasis and the WDT had similar IOP elevation before LPI, but after LPI, IOP elevation was much greater in the WDT group.

There is a growing interest in targeting minimally invasive surgery devices to the aqueous outflow system to optimize treatment outcomes. However, methods to visualize functioning, large-caliber aqueous and episcleral veins in-vivo are lacking. This pilot study establishes an ex-vivo system to evaluate the use of a confocal laser microendoscope to noninvasively image episcleral vessels and quantify regional flow variation along the limbal circumference.

A fiber-optic confocal laser endomicroscopy (CLE) system with lateral and axial resolution of 3.5 𝜇m and 15 𝜇m, respectively, was used on three porcine and four human eyes. Diluted fluorescein (0.04%) was injected into eyes kept under constant infusion. The microprobe was applied to the sclera 1 mm behind the limbus to acquire real-time video. Image acquisition was performed at 15-degree intervals along the limbal circumference to quantify regional flow variation in human eyes.

Vascular structures were visualized in whole human eyes without processing. Schlemm’s canal was visualized only after a scleral flap was created. Fluorescent signal intensity and vessel diameter variation were observed along the limbal circumference, with the inferior quadrant having a statistically higher fluorescein signal compared to the other quadrants in human eyes (𝑃 < 0.05).

This study demonstrates for the first time that the fiber-optic CLE platform can visualize the episcleral vasculature with high resolution ex-vivo with minimal tissue manipulation. Intravascular signal intensities and vessel diameters were acquired in real-time; such information can help select target areas for minimally invasive glaucoma surgery (MIGS) to achieve greater intraocular pressure reduction.

The aim of this study was to assess the correlation of hemoglobin A1c (HbA1c) levels with choroidal thickness in patients with type 2 diabetes mellitus (DM) using spectral domain optical coherence tomography (SD-OCT).

In this prospective case series, 180 eyes from 90 patients with type 2 DM were classified into three study groups based on HbA1c values: group 1 included patients with good glycemic control (HbA1c ≤ 7%), group 2 included patients with moderate glycemic control (HbA1c between 7% and 8%), and group 3 included patients with poor glycemic control (HbA1c ≥ 8%). Additionally, 50 eyes from 25 non-diabetic subjects were enrolled to group 4 as a control group. Sub-foveal, nasal, and temporal choroidal thickness were measured and compared.

Mean central, nasal, and temporal choroidal thicknesses in diabetic patients (247.80, 238.63, and 239.30 𝜇m) were significantly less than non-diabetic healthy subjects (277.56, 262.92, and 266.32 𝜇m). Additionally, mean central, nasal, and temporal choroidal thickness values in group 4 (277.56, 262.92, and 266.32 𝜇m) were significantly greater than the corresponding values in group 2 (248.34, 237.55, and 236.45 𝜇m) and group 3 (239.81, 234.62, and 233.94 𝜇m), but was not significantly different from corresponding values in group 1 (259.46, 246.12, and 251.00 𝜇m).

HbA1c values have a significant correlation with choroidal thickness in diabetic patients, and better glycemic control with HbA1c ≤ 7% may prevent choroidal thinning

The present study aimed to evaluate the frequency and risk factors of retinopathy of prematurity (ROP) among Iranian infants.

A retrospective cohort study was conducted on infants who had undergone screening for ROP at Farabi Eye Hospital, between March 2016 and March 2017. Data were analyzed based on the presence of extreme prematurity (gestational age ≤ 28 weeks), extremely low-birth-weight (≤ 1000 g), and multiplegestation (MG) infants.

The prevalence of ROP was 27.28% (𝑛 = 543) among all screened infants, 74.4% for extremely preterm (EP) infants, 77.5% for extremely low birth weight (ELBW) babies, and 27.25% for infants from MG pregnancies. On multivariate analysis, gestational age, birth weight, and history of transfusion (𝑃 < 0.0001, 𝑃 < 0.0001, and 𝑃 = 0.04, respectively) were found to be significantly associated with ROP. More advanced stages of ROP (𝑃 < 0.0001) were observed in EP and ELBW infants. Birth weight (𝑃 = 0.088), history of transfusion (𝑃 = 0.066), and intubation (𝑃 = 0.053) were not associated with increased risk of ROP in EP infants, while gestational age (𝑃 = 0.037) and history of transfusion (𝑃 = 0.040) were significant risk factors for ROP in ELBW infants. Gestational age (P < 0.001) and birth weight (𝑃 = 0.001) were significantly associated with ROP in infants from MG pregnancies in multivariate analysis.

ROP remains a commonly encountered disease, especially in ELBW and EP infants. The history of transfusion may have a role in stratifying the risk for ROP and guiding future screening guidelines.

To compare the short-term visual function results and safety of erythropoietin as an add-on to the standard corticosteroid therapy in retrobulbar optic neuritis (RON).

In this prospective pilot study, adult patients with isolated RON with less than 10 days of onset were enrolled. Patients were consecutively assigned to standard intravenous methylprednisolone treatment either in combination with intravenous erythropoietin (20,000 units/day for three days) (group-1) or intravenous methylprednisolone alone (group-2). Primary outcome measure was best-corrected visual acuity (BCVA), which was assessed up to 120 days from the day the treatment was begun. Systemic evaluations were performed during and after treatment.

Sixty-two patients with RON (mean age = 26.6 ± 5.77 years; range = 18–40 years) were enrolled into the study (group-1, 𝑛 = 35; group-2, 𝑛 = 27). BCVA three months after the treatment was 0.19 ± 0.55 logMAR and 0.11 ± 0.32 logMAR in group-1 and group-2, respectively (95% CI: −0.61 − 0.16; 𝑃 = 0.62). Change in BCVA after three months was 2.84 ± 3.49 logMAR in group-1 and 2.46 ± 1.40 logMAR in group-2 (95% CI: −0.93−1.91; 𝑃 = 0.57). Pace of recovery was not significantly different between the groups. No complications were detected among patients.

Intravenous erythropoietin as an add-on did not significantly improve the visual outcome in terms of visual acuity, visual field, and contrast sensitivity compared to traditional intravenous corticosteroid. This pilot study supports the safety profile of intravenous human recombinant erythropoietin, and it may help formulate future investigations with a larger sample size.

To determine the distribution of the near point of convergence (NPC) and near point of accommodation (NPA) in a young student population in Iran.

The subjects were selected using a cluster sampling method. All students underwent optometry tests, including visual acuity measurement, refraction, and cover test, as well as ophthalmic examinations. The NPC and NPA were measured using an accommodative target (near Snellen chart).

Of 1,595 students, the data of 1,357 were analyzed. The mean NPC and NPA in the total sample were 7.25 cm (95% confidence interval [CI], 7.02 to 7.48) and 9.99 cm (95% CI, 9.69 to 10.29), respectively. Older age was associated with an increase in the NPC, which increased from 6.98 cm in 18–20 years olds to 9.51 cm in those over 30 years. The NPA was significantly associated with age and refractive errors in the multiple linear regression model, increasing from 9.92 cm in 18–20 years olds to 11.44 cm in those over 30 years (𝑃 = 0.003). Hyperopic eyes had lower NPA than myopic and emmetropic eyes (𝑃 = 0.001). In younger age groups, the mean accommodation amplitude was lower than the mean Hofstetter value. Moreover, with age, especially after 30 years, the mean values surpassed those determined using the Hofstetter formula.

The NPC values in this study were lower than those previously reported for identical age groups. The Hofstetter formula is not always an accurate predictor of the accommodation amplitude in the Iranian adult population.

To evaluate the effect of fasting on contrast sensitivity (CS) in healthy male individuals during the month of Ramadan.

This study included 45 healthy male individuals, aged between 20 and 40 years, working in the same environment. Functional acuity contrast testing (F.A.C.T) was performed using the Optec 6500 vision testing system. Measurements taken during a state of satiety one week before Ramadan were compared with those taken a minimum of 12 hours after the start of fasting in the first and fourth weeks of Ramadan.

Contrast sensitivity (CS) was increased at the spatial frequency of three cycles per degree (cpd) at the end of the first week of Ramadan in comparison to the CS measured before Ramadan (𝑃 = 0.03). The mean CS values were increased at the spatial frequencies of 3 and 12 cpd at the end of the last week of Ramadan in comparison to the mean values measured before Ramadan (𝑃 = 0.01 for both).

Although we found statistically significant increases in CS at certain frequencies, we can conclude that Ramadan fasting has no negative effects on CS.

To estimate the pooled prevalence and incidence of diabetic retinopathy (DR) in Iran and to investigate their correlations with the Human Development Index (HDI), healthcare access (i.e., density of specialists and sub-specialists), and methodological issues.

Electronic databases such as PubMed, Embase, Scopus, Web of Science, Google Scholar, and local databases were searched for cohort and cross-sectional studies published prior to January 2018. Prevalence and incidence rates of DR were extracted from January 2000 to December 2017 and random effects models were used to estimate pooled effect sizes. The Joanna Briggs Institute critical appraisal tool was applied for quality assessment of eligible studies.

A total of 55,445 participants across 33 studies were included. The pooled prevalence (95% CI) of DR in diabetic clinics (22 studies), eye clinics (4 studies), and general population (7 studies) was 31.8% (24.5 to 39.2), 57.8% (50.2 to 65.3), and 29.6% (22.6 to 36.5), respectively. It was 7.4% (3.9 to 10.8) for proliferative DR and 7.1% (4.9 to 9.4) for clinically significant macular edema. The heterogeneity of individual estimates of prevalence was highly significant. HDI (𝑃 < 0.001), density of specialists (𝑃 = 0.004), subspecialists (𝑃 < 0.001), and sampling site (𝑃 = 0.041) were associated with heterogeneity after the adjustment for type of DR, duration of diabetes, study year, and proportion of diabetics with controlled HbA1C.

Human development and healthcare access were correlated with the prevalence of DR. Data were scarce on the prevalence of DR in less developed provinces. Participant recruitment in eye clinics might overestimate the prevalence of DR.

To evaluate the outcomes of different intravitreal injections for the treatment of retinal vein occlusion including central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO).

PubMed, Cochrane, the metaRegister of ControlledTrials, and ClinicalTrials were searched for intravitreal anti-Vascular Endothelial Growth Factor (VEGF) and steroids with relevant keywords and date limitation of 2009-2018. Meta-analysis was performed on studies that met the defined inclusion criteria. Main outcomes were visual acuity (VA) and central macular thickness (CMT).

Out of 681 studies, 36 articles (including 21 reporting CRVO and 15 dealing with BRVO) were selected for systematic review. All five intravitreal drugs including triamcinolone, dexamethasone, ranibizumab, bevacizumab, and aflibercept showed improvement of CMT and VA as compared to placebo or laser treatment. Six randomized controlled trials were selected for meta-analysis in RVO patients. The pooled mean difference of visual improvement between sham and ranibizumab was 12.7 Early Treatment for Diabetic Retinopathy Study (ETDRS) letters (95%CI: 11.00 to 13.2), and the pooled mean difference in CMT reduction was 221𝜇m (95%CI: 153 to 284); both changes were significantly in favor of ranibizumab. The pooled mean difference of visual improvement between bevacizumab and triamcinolone was 5.3 ETDRS letters in favor of bevacizumab (95%CI: 16 𝜇m to 17.5 𝜇m). Triamcinolone led to 68.1 𝜇m greater CMT reduction than bevacizumab (95%CI: 58 𝜇m to 76 𝜇m). However, none of these differences were statistically significant.

Treatment with anti-VEGF agents in RVO is superior to observation. No significant difference was seen between the eyes treated with bevacizumab or triamcinolone based on these results.

To report corneal toxicity following intentional inoculation of the juice of crushed leaves of datura (Datura Inoxia).

Case Report:

 A 70-year-old male presented with diminished vision, redness, watering, and photophobia in his right eye one day before his presentation. The patient had instilled the juice of datura leaves in his right eye to treat his ocular problems. Slit lamp examination revealed mild conjunctival and circumcorneal congestion, corneal edema, and folds in Descemet’s membrane. The left eye was pseudophakic with an otherwise unremarkable examination. The patient was treated with dexamethasone, cycloplegics, and lubricants. The cornea did not sufficiently recover after one month of treatment leaving him with permanent corneal decompensation that required a referral for keratoplasty. The patient was followed up for six months. We hypothesize damage to the corneal endothelial Na+/K+-ATPase pump by tropane alkaloids as a cause for corneal decompensation.

Awareness about toxicity of this commonly grown plant in the tropics and subtropics is essential in order to avoid blindness due to accidental or deliberate use.

To report a case of advanced childhood glaucoma secondary to congenital ectropion uveae (CEU).

Case Report:

 The patient was a seven-year-old boy with unilateral glaucoma secondary to CEU and facial asymmetry, mild unilateral ptosis, and proptosis in the left eye. The intraocular pressure (IOP) was 28 mmHg and cup-to-disc ratio was 0.8 in the left eye. After starting glaucoma medication, IOP decreased to 21 mmHg. In view of the uncontrolled IOP with medication and high cup-to-disc ratio and increased axial length of the left eye, mitomycin-C (MMC)-augmented trabeculectomy was planned. Despite sub-tenon MMC injection and bleb needling, the bleb failed after six months, and we had to perform a shunt procedure to control the IOP.

Although CEU is rare, ophthalmologists should be familiar with this syndrome because of the high frequency of glaucoma and its challenging management during childhood.

To report an extremely rare case of tapioca melanoma of the iris in an Iranian patient.

Case Report:

 A 50-year-old male patient presented with ocular pain and redness in the right eye for two weeks. The visual acuity was 7/10 and the intraocular pressure (IOP) was 30 mmHg. A lobulated amelanotic vascularized and nodular (tapioca-like) iris mass with a 180o extent was seen in the right eye. Incisional biopsy of the mass revealed atypical mixed type (epithelioid and spindle cell) melanoma. Brachytherapy with the ruthenium-106 plaque resulted in complete regression of the tumor.

Tapioca melanoma of the iris should be considered in the differential diagnosis of patients presenting with nodular vascularized amelanotic iris mass and elevated IOP. Brachytherapy with ruthenium106 seems to be an effective treatment for tapioca melanoma of the iris.

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare, lifethreatening multi-system adverse drug reaction characterized by febrile skin rash, hematologic abnormalities, and involvement of internal organs. We report a case of DRESS syndrome in a child presenting with primary ophthalmic manifestations. Case Report: An 11-year-old boy presented with severe pain and diminished vision in both eyes six weeks after starting carbamazepine therapy for seizure disorder. Ocular examination revealed features of bilateral acute anterior uveitis, acute onset myopia, and angle closure glaucoma secondary to uveal effusion. Additionally, the patient was febrile with a generalized maculopapular rash, and blood investigations revealed eosinophilic leukocytosis. A diagnosis of carbamazepine-induced DRESS syndrome was made, and carbamazepine therapy was discontinued. Treatment with cycloplegics, topical, and systemic steroids resulted in prompt clinical recovery.

Ophthalmologists should be aware that hypersensitivity to anticonvulsants, such as carbamazepine, can present with bilateral uveitis and uveal effusion along with systemic symptoms. Prompt diagnosis and treatment can prevent vision loss and life-threatening complications. Patients should be counselled about potential adverse effects of anticonvulsants before therapy

Submacular perfluorocarbon liquid (PFCL) retention is a well-known complication of vitreoretinal surgeries; however, the optimal surgical technique for the removal of subfoveal PFCL is yet to be determined. We describe a novel surgical technique for the removal of retained submacular PFCL by performing a retinotomy adjacent to the inferotemporal arcade using a 41-gauge extendible subretinal injection needle and inducing a therapeutic retinal detachment. Through the same retinotomy, the bent 41-gauge needle was advanced into the subretinal space to reach the PFCL bubble. Subsequently, active aspiration of PFCL was performed. The surgical procedure was successfully performed in two patients. This technique appears to be an effective surgical approach for removing retained submacular PFCL bubble.