Bioengineered corneal tissue for minimally invasive vision restoration in advanced keratoconus in two clinical cohorts

Visual impairment from corneal stromal disease affects millions worldwide. We describe a cell-free engineered corneal tissue, bioengineered porcine construct, double crosslinked (BPCDX) and a minimally invasive surgical method for its implantation. In a pilot feasibility study in India and Iran (clinicaltrials.gov no. NCT04653922 ), we implanted BPCDX in 20 advanced keratoconus subjects to reshape the native corneal stroma without removing existing tissue or using sutures. During 24 months of follow-up, no adverse event was observed. We document improvements in corneal thickness (mean increase of 209 ± 18 µm in India, 285 ± 99 µm in Iran), maximum keratometry (mean decrease of 13.9 ± 7.9 D in India and 11.2 ± 8.9 D in Iran) and visual acuity (to a mean contact-lens-corrected acuity of 20/26 in India and spectacle-corrected acuity of 20/58 in Iran). Fourteen of 14 initially blind subjects had a final mean best-corrected vision (spectacle or contact lens) of 20/36 and restored tolerance to contact lens wear. This work demonstrates restoration of vision using an approach that is potentially equally effective, safer, simpler and more broadly available than donor cornea transplantation.

The Antitumor Effect of Topotecan Loaded Thiolated Chitosan-Dextran Nanoparticles for Intravitreal Chemotherapy: A Xenograft Retinoblastoma Model

Purpose

This research intended to fabricate the thiolated chitosan-dextran nanoparticles (NPs) containing topotecan (TPH-CMD-TCS-NPs) to assess the ability of NPs in improving the efficacy of intravitreal chemotherapy of retinoblastoma in a rabbit xenograft model.

Methods

The coacervation process was used to produce the NPs. The cellular uptake of Cyanine-3 (CY3)-labeled NPs were investigated in human retinoblastoma Y79 cells using confocal microscopy. Also, the prepared TPH-CMD-TCS-NPs were tested in vitro by the tetrazolium dyes II (XTT) and flow cytometry in order to assess their cytotoxicity. In addition, a rabbit xenograft model of retinoblastoma was developed to test the antitumor effectiveness of TPH-CMD-TCS-NPs through intravitreal administration.

Results

NPs had a mean diameter, polydispersity index, and zeta potential of 30 ± 4 nm, 0.24 ± 0.03 and +10 ± 3 mV, respectively. NPs (IC50s 40.40 compared to 126.20 nM, P = 0.022) were more effective than free topotecan as a dose-based feature. The tumor reaction to intravitreal chemotherapy with NPs was measured by evaluating the percentage of necrosis in the tumor tissue (91 ± 2%) and vitreous seeds (89 ± 9%) through hematoxylin and eosin (H&E) staining. In comparison with the control group, the TPH-CMD-TCs-NPs treated group showed a significant decrease in tumor volume seven days after the intravitreal injection (P = 0.039). No significant changes were found in the ERG parameters after the intravitreal injection of TPH-CMD-TCs-NPs or TPH (P > 0.05).

Conclusion

This investigation revealed definitive antitumor efficacy of TPH-CMD-TCS-NPs by intravitreal administration in the rabbit xenograft retinoblastoma model.

3D Printed Hydrogels for Ocular Wound Healing

Corneal disease is one of the most significant causes of blindness around the world. Presently, corneal transplantation is the only way to treat cornea blindness. It should be noted that the amount of cornea that people donate is so much less than that required (1:70). Therefore, scientists have tried to resolve this problem with tissue engineering and regenerative medicine. Fabricating cornea with traditional methods is difficult due to their unique properties, such as transparency and geometry. Bioprinting is a technology based on additive manufacturing that can use different biomaterials as bioink for tissue engineering, and the emergence of 3D bioprinting presents a clear possibility to overcome this problem. This new technology requires special materials for printing scaffolds with acceptable biocompatibility. Hydrogels have received significant attention in the past 50 years, and they have been distinguished from other materials because of their unique and outstanding properties. Therefore, hydrogels could be a good bioink for the bioprinting of different scaffolds for corneal tissue engineering. In this review, we discuss the use of different types of hydrogel for bioink for corneal tissue engineering and various methods that have been used for bioprinting. Furthermore, the properties of hydrogels and different types of hydrogels are described.

Vector analysis of moderate to high myopic astigmatism after small-incision lenticule extraction (SMILE): 12-month follow-up

PURPOSE

To evaluate the refractive outcomes of small-incision lenticule extraction (SMILE) surgery in moderate to high myopic astigmatism.

STUDY DESIGN

Prospective interventional case series.

METHODS

This study evaluated 111 eyes of 68 patients treated with femtosecond SMILE surgery for the correction of myopia and astigmatism. Inclusion criteria were myopia of - 0.5 D or more and astigmatism between - 1.0 D and -5.0 D. Refractive and visual measurements were obtained preoperatively, 1 and 12 month(s) postoperatively. Vector analysis was used to study the astigmatic outcomes at 12-month follow-up. Comparison of results in two groups of patients with astigmatism below and over 3.00 D was performed.

RESULTS

The preoperative mean spherical equivalent was -5.48 ± 2.17 D (range - 1.75 to - 10.00 D) and the mean cylinder was -2.02 ± 1.09 D (range - 1.00 to - 5.00 D). The mean postoperative cylinder value was -0.60 ± 0.52 D at 12-month visit. The 12-month safety and efficacy indices were 0.98 ± 0.07 and 0.97 ± 0.12, respectively. The high astigmatism group showed significantly lower safety and efficacy indices. The postoperative residual astigmatism was 0.5 D or less in 73% of the eyes. Higher amount of residual astigmatism was observed in the high astigmatism group. The angle of error was ± 5 degrees in 49% and ± 15 degrees in 87% of the eyes.

CONCLUSION

SMILE surgery is effective and safe method for correcting myopic astigmatism. Vector analysis indicated a tendency for the under correction of astigmatism in subjects with high astigmatism.

Assessing Accuracy of Okulix Ray-Tracing Software in Calculating Intraocular Lens Power in the Long Cataractous Eyes

Purpose

To investigate the accuracy of Okulix ray-tracing software in calculating intraocular lens (IOL) power in the long cataractous eyes and comparing the results with those obtained from Kane, Holladay 1 with optimized constant, SRK/T with optimized constant, Haigis with optimized constant, and Barret Universal 2 formulas.

Methods

The present study evaluates the refractive results of cataract surgery in 85 eyes with axial length > 25 mm and no history of ocular surgery and corneal pathology. IOL power calculation was performed using the Okulix software. The performances of Okulix software in comparison with the five other formulas were evaluated by predicted error, mean absolute error, and mean numerical error 6 months after surgery.

Results

The mean calculated IOL power by the Okulix software was +13.48 ± 4.19 diopter (D). The mean of the 6-month postoperative sphere and spherical equivalent were +0.18 ± 0.63 and -0.34 ± 0.78 D, respectively. Also, the 6-month spherical equivalent in 56.6% and 80% of eyes were within ±0.05 and ±1.00 D, respectively. The predicted error (P < 0.001) and the mean numerical error (P < 0.001) were different between the six studied methods; however, we were not able to find any significant differences in the mean absolute error among six studied methods (P: 0.211).

Conclusion

The present study showed acceptable performance of the Okulix software in IOL power calculation in long eyes in comparison with the other five methods based on the postoperative refractive error, calculated mean absolute error, and mean numerical error.

Biodistribution of Cy5-labeled Thiolated and Methylated Chitosan-Carboxymethyl Dextran Nanoparticles in an Animal Model of Retinoblastoma

Purpose

The use of more potent medicine for local chemotherapy of retinoblastoma in order to minimize local and systemic adverse effects is essential. The main goal of this investigation was to assess the biodistribution of thiolated and methylated chitosan-carboxymethyl dextran nanoparticles (CMD-TCs-NPs and CMD-TMC-NPs) following intravitreal (IVT) injection into rat eyes with retinoblastoma.

Methods

An ionic gelation method was used to fabricate Cy5-labelled CMD-TCs-NPs and CMD-TMC-NPs. The NPs were characterized. Cellular internalization of Cy5-labelled NPs was investigated using confocal microscopy and the absorption of labeled NPs was quantified by flow cytometry in human retinoblastoma (Y79) cells. In addition, the Cy5-labeled distribution of nanoparticles in the posterior segment of the eye was histologically imaged by confocal microscopy after IVT injection of NPs into the eyes of rats with retinoblastoma.

Results

CMD-TCs-NPs and CMD-TMC-NPs showed a mean diameter of 34 ± 3.78 nm and 42 ± 4.23 nm and zeta potential of +11 ± 2.27 mV and +29 ± 4.31mV, respectively. The in vivo study of intraocular biodistribution of Cy5-labeled CMD-TCs-NPs and CMD-TMC-NPs revealed that there is more affinity of CMD-TCs-NPs to the retina and retinoblastoma tumor after IVT administration while methylated chitosan nanoparticles are immobilized in the vitreous and are not able to reach the retina even after 24 hr.

Conclusion

The ionic gelation technique was efficient in synthesizing a biocompatible polymeric nanosystem for drug delivery into the posterior segment of the eye. The current study demonstrated increased ocular bioavailability of CMD-TCs-NPs relative to CMD-TMC-NPs in retinoblastoma induced rat eyes.

Customized Stromal Lenticule Implantation for Keratoconus

PURPOSE

To investigate the potential benefit of keratoconus surgery using customized corneal stromal donor lenticules obtained from myopic small incision lenticule extraction (SMILE) surgery by femtosecond laser.

METHODS

In this prospective, consecutive, non-comparative series of cases, 22 lenticules were obtained from 22 myopic patients who had SMILE with a lenticule central thickness of greater than 110 µm. The lenticules were implanted in 22 eyes with advanced keratoconus. The lenticules were customized for the purpose of the implantation with either a simple necklace or necklace-with-ring shape (compound form) depending on the corneal thickness and corneal topography configuration of the implanted keratoconic eyes. The lenticules were implanted into a 9.5-mm corneal lamellar pocket created by the femtosecond laser. Changes in densitometry, thickness, confocal microscopy, corrected distance visual acuity (CDVA), and endothelial cell density were investigated.

RESULTS

Intrastromal lenticule implantation was successfully performed in all cases without any complication. Corneal thickness showed a mean enhancement of 100.4 µm at the thinnest point. On biomicroscopy, all corneas were clear at 1 year postoperatively and there was a significant improvement in corneal densitometry during the entire follow-up period. Confocal biomicroscopy showed collagen reactivation without any inflammatory features caused by the implanted fresh lenticules. CDVA improved from 0.70 to 0.49 logMAR (P = .001) and keratometry decreased from 54.68 ± 2.77 to 51.95 ± 2.21 diopters (P = .006).

CONCLUSIONS

Customized SMILE lenticule implantation by femtosecond laser proved to be feasible, resulting in an improvement in vision, topography, and refraction in the implanted eyes. [J Refract Surg. 2020;36(12):786-794.].

Changes in the Optical Corneal Densitometry, Visual Acuity, and Refractive Error after the Annular Intracorneal Inlay Implantation

Purpose:

To investigate the changes in the optical corneal densitometry as an objective method in assessing the corneal light back-scattering before and 1 year after the annular intracorneal inlay (AICI) implantation into the keratoconic corneas.

Methods:

Changes in the optical corneal densitometry, visual acuity, refractive, and tomographical status were assessed before and 1 year after the AICI implantation into the corneas with different stages of keratoconus. Optical corneal densitometry was evaluated using the Pentacam-HR in 0–2, 2–6, 6–10, and 10–12 mm rings in the anterior 120 μ, central layers, posterior 60 μ and also the total value were measured for cornea in the Grey Scale Unit criterion.

Results:

Totally, 34 patients with keratoconus were studied; the uncorrected and best corrected visual acuity were increased after the surgery (0.98 ± 0.25 to 0.53 ± 0.30 logMAR, P < 0.001 and 0.26 ± 0.18 to 0.19 ± 0.14, P = 0.007 logMAR, respectively); the spherical equivalent was decreased from −4.45 ± 2.25 to − 2.06 ± 2.01 D (P = 0.004). AICI implantation led to an increase in the amount of optical corneal densitometry in 0–2 mm central, 2–6 mm central, 6–10 mm central, total central, 2–6 mm posterior, and 2–6 mm total rings (all, P < 0.05); however, a decrease was observed in 0–2 mm anterior ring (P = 0.049). Results of statistical analysis showed that the total optical corneal densitometry, anterior total, and posterior total back-scattering did not change after the AICI implantation (all, P > 0.05).

Conclusions:

Our results revealed a significant improvement in the visual function, including refractive error and visual acuity following the AICI implantation. Changes in the optical corneal densitometry were different in distinct regions and layers however, the total amount did not change after the AICI implantation.

Efficacy of topotecan nanoparticles for intravitreal chemotherapy of retinoblastoma

Retinoblastoma (Rb) is the most common intraocular malignancy in children that accounts for approximately 4% of all pediatric malignancies. Since chemotherapy is a widely practiced treatment for Rb, there is a growing interest in developing new and effective drugs to overcome systemic and local side effects of chemotherapy to improve the quality of life and increase the chances of survival. This study sought to fabricate thiolated chitosan nanoparticles containing topotecan (TPH-TCs-NPs) with a view of enhancing drug loading and release control. This research was also designed to assess the ability of TPH-TCs-NPs to improve cell association, increase treatment efficacy in retinoblastoma cells and xenograft-rat-model of retinoblastoma, and overcome current topotecan hydrochloride (TPH) intravitreal administration challenges, including stability loss and poor cellular uptake. Modified ionic gelation method was optimized to fabricate TPH-TCs-NPs and TPH-TMC-NPs (N-trimethyl chitosan nanoparticles containing TPH). We characterized the NPs and quantified topotecan loading and release against a free TPH standard. The efficacy of TPH-NPs was quantified in human retinoblastoma cells (Y79) by XTT and flow cytometry measurement. In addition, Y79 cells were injected intravitreally in both eyes of immunodeficient wistar albino rats to create a xenograft-rat-model to compare the antitumor effectiveness of TPH-NPs and TPH by intravitreal administration. TPH-NPs complexation was confirmed by EDX, FTIR, and DSC techniques. TPH-TCs-NPs and TPH-TMC-NPs had high encapsulation efficiency (85.23 ± 2 and 73.34 ± 2% respectively). TPH-TCs-NPs showed a mean diameter, polidispersity index, and zeta potential of 25±2 nm, 0.21 ± 0.03 and +12 ± 2 mV, respectively. As a function of dose, TCs and TMC NPs were more efficacious than free topotecan (IC50s 53.17 and 85.88 nM, relative to 138.30 nM respectively, P = 0.012). Kruskal-Wallis test showed a statistically significant difference between the groups. Additionally, a significant difference between the tumor control and TPH-TCs-NPs treated group in xenograft-rat-model ( Range of P-value: 0.026 to 0.035) was shown by Bonferroni post hoc test. The current investigation demonstrated enhanced efficacy and association of TPH-TCs-NPs relative to free TPH in retinoblastoma cells and tumor in vitro and in vivo.

Corneal biomechanical outcome of collagen cross-linking in keratoconic patients evaluated by Corvis ST

PURPOSE

A 6-month evaluation of the topographic and biomechanical changes induced by corneal collagen cross-linking (CXL) in keratoconic eyes using Pentacam and Corvis ST.

DESIGN

Longitudinal prospective case series.

METHODS

In this study, 67 eyes of 67 patients with progressive keratoconus (KCN) treated with "Epithelium-off" CXL were evaluated. Patients with stages 1 or 2 of KCN and a corneal thickness of at least 400 μm at the thinnest point were included. Standard ophthalmologic examinations were carried out for all patients. The topographic and biomechanical measurements of the cornea were obtained by Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany) and Corvis ST (Oculus Optikgeräte GmbH, Wetzlar, Germany) preoperatively and 6-month postoperatively.

RESULTS

The mean age of the participants was 21.68 ± 4.23 years. There was significant difference in mean spherical equivalent (SE) before and 6 months after CXL. Uncorrected and best corrected visual acuity improved postoperatively, although not statistically significant. The mean and maximum keratometry showed a significant decrease 6 months after CXL (0.93 ± 0.38 D and 1.43 ± 0.62 D, respectively p < 0.001). Among Corvis ST parameters, first applanation length and velocity (AL1 and AV1) showed statistically significant changes. The radius at highest concavity changed significantly (0.13 ± 0.37 mm mean increase after CXL; p < 0.001). A significant increase was observed in stiffness parameter A1 (SP-A1; p < 0.001) and significant decreases were noted in integrated radius (IR) and deformation amplitude ratio (DAR; p < 0.001).

CONCLUSION

Analyzing biomechanical changes after corneal cross-linking can provide basis for efficient KCN treatment. Corvis ST parameters demonstrated changes in corneal biomechanical characteristics indicative of stiffing after CXL.

Retraction notice to "Endophthalmitis Occurring after Cataract Surgery: Outcomes of More Than 480 000 Cataract Surgeries, Epidemiologic Features, and Risk Factors" (Ophthalmology. 2016;123:295-301)

This article has been retracted: please see Elsevier policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). The editors wish to note that concerns were raised regarding coding errors in the data set that formed the basis of this study. Patient record numbers were found to be duplicated, so that the number of endophthalmitis cases was unclear as was the associated treatment, and the number of unique patients estimated to be far less than the 480,000 reported. Upon review of the information provided, Ophthalmology has determined the dataset to be flawed with unverifiable elements from which reliable conclusions cannot be drawn, and therefore has made the decision to issue a retraction of the manuscript.

Comparison between Pentacam HR and Orbscan II after Hyperopic Photorefractive Keratectomy

Purpose:

The aim of this study was to determine the agreement between Pentacam HR (Scheimpflug imaging, Oculus) and Orbscan II (scanning slit topography, Bausch and Lomb) in measuring corneal parameters after photorefractive keratectomy (PRK) for hyperopia.

Methods:

In this prospective cross-sectional study, 38 hyperopic eyes undergoing PRK were examined before refractive surgery and 8 to 10 months postoperatively using Pentacam HR and Orbscan II. Ultrasound (US) pachymetry was also used to measure central corneal thickness (CCT). The radius of anterior (A-) and posterior (P-) best-fit sphere size (BFS), central elevation (CE), and anterior maximum tangential power in 3 mm (TG3) and 3-5 mm (TG5) zones, anterior chamber depth (ACD), and central corneal thickness (CCT) were collected and used in the analyses. To study the agreement between the measurements made by the two devices, the method described by Bland and Altman was used and the 95% limits of agreement were calculated.

Results:

The 95% limits of agreement show reasonable agreement between the measurements by Pentacam HR and Orbscan II for A-BFS, P-BFS, A-TG3, and CCT, but not for A-CE, P-CE, A-TG5, or ACD. CCT values obtained by both Pentacam HR and Orbscan II correlated well with the values determined by US pachymetry.

Conclusion:

Pentacam HR and Orbscan II after PRK for hyperopia show reasonable agreement for determining A-BFS, P-BFS, A-TG3, and CCT, but not for A-CE, P-CE, A-TG5, or ACD. CCT measurements with Pentacam HR have reasonable agreement with US pachymetry.

Implantation of ArtificialIris, a CustomFlex irisprosthesis, in a trauma patient with an Artisan lens: A case report and review

PURPOSE

To evaluate probable complications of ArtificialIris implantation with iris fixated intraocular lens.

METHOD

Development of photophobia, glare, and psychological strain during face-to-face communication in a 23-year-old man with a widespread traumatic iris defect terminate to make a decision for performing implantation of an ArtificialIris (Humanoptics, Erlangen, Germany) under the remnant iris without removing the patient's existing Artisan lens.

RESULTS

Without any intraoperative or postoperative complications, the patient's visual acuity increased by 1 line, the endothelial cell loss was comparable with the cell loss associated with standard cataract surgery, and the anterior-chamber depth and anterior-chamber anatomy did not change. At the final follow-up examination, the mean intraocular pressure did not differ from baseline, and we achieved high level of patient satisfaction and subjective vision improvement. We discuss the particular importance of considering the patient's expectations, the appropriate measurements, ways to perfect color evaluation, and the types of ArtificialIris products.

CONCLUSION

The implantation of the ArtificialIris in patients with aphakic iris-supported lenses (ie, pre-existing Artisan lenses) is a feasible approach and a useful option for patients with thin irises and iris hypoplasia who are at risk of subluxation or the dislocation of the posterior-chamber intraocular lens (PCIOL), and also those with sclerally fixed PCIOLs.

Investigation of the effects of Islamic fasting on ocular parameters

Purpose

To investigate the effects of religious fasting during the month of Ramadan on intraocular pressure (IOP), refractive error, corneal tomography and biomechanics, ocular biometry, and tear film layer properties.

Methods

This prospective study was carried out one week before and in the last week of Ramadan. Ninety-four eyes of 94 healthy adult volunteers (54 males and 40 females) with a mean ± SD age of 35.12 ± 9.07 were enrolled in this study. Patients with any systemic disorder, ocular disease, or a history of previous surgery were excluded. Corneal tomography and biomechanics, ocular biometry, IOP, refractive error, and tear break up time (TBUT) were evaluated in non-fasting and fasting periods by the Pentacam (Oculus), Corvis ST (Oculus), IOL Master (Carl Zeiss), computerized tonometer (Topcon CT-1/CT-1P), auto kerato-refractometer (Topcon KR-1), and Keratograph 5M (Oculus), respectively.

Results

There was no significant difference in the central corneal thickness (CCT) between the study groups (P = 0.123) using the Pentacam while the Corvis ST showed a significant difference in all participants (P < 0.0001). Moreover, the peak distance (distance of the two surrounding peaks of the cornea at the highest concavity) of male and female participants showed a significant difference between the fasting and non-fasting groups (P = 0.002). The anterior chamber depth (ACD) using the Pentacam decreased in the male group (P = 0.004) in the fasting period. During the fasting period, computerized tonometer showed a decrease in IOP only in males in comparison to the non-fasting group (P = 0.018) while the Corvis ST showed decreased IOP in all participants (P < 0.0001). The steep keratometry (K2) in the corneal posterior surface appeared to be different in males between the study groups (P = 0.034). We were unable to show any significant difference in other ocular parameters between fasting and non-fasting periods.

Conclusion

This study showed that ACD, IOP, CCT, and peak distance were different between fasting and non-fasting groups while no difference was observed in other ocular parameters. Interpretations of these significant differences should be considered in the clinical setting.

Corneal hysteresis and corneal resistance factor in pellucid marginal degeneration

Purpose

To evaluate and compare corneal hysteresis (CH) and corneal resistance factor (CRF) in pellucid marginal degeneration (PMD), keratoconus (KCN), and normal eyes using the Ocular Response Analyzer (ORA).

Methods

In this retrospective study, corneal biomechanical parameters were measured in patients with PMD (n = 102) and KCN (n = 202) and normal subjects (n = 208) using the ORA. Data, including full patient history as well as the results of refraction, slit-lamp biomicroscopy, Pentacam HR (Oculus), and ORA (Reichert; Buffalo, New York, USA), were collected from medical records. Also, the data of only one eye per individual were selected for the analysis. The inclusion criteria for PMD and KCN groups were a reliable diagnosis of these ectatic disorders based on the clinical and corneal tomographic findings. CH, CRF, CH–CRF, intraocular pressure (IOP) measurements were assessed for each subject. Data were analyzed with SPSS and MedCalc using the ANOVA, Pearson Correlation, and receiver operating characteristic (ROC) curve analysis.

Results

The mean CH was 8.91 mmHg ± 1.05 [standard deviation (SD)], 8.43 ± 0.78, and 10.89 ± 1.08 in the PMD, KCN, and normal group, respectively. Also, the mean CRF was 8.21 ± 1.35, 7.19 ± 1.11, and 10.69 ± 1.41 in the PMD, KCN, and normal group, respectively. ANOVA showed differences in the mean CH, CRF, and CH–CRF between three groups (P < 0.001). Also, ROC curve analysis showed the cut-off points ≤9.5, ≤9.5, and >1.3 mmHg for CH, CRF, and CH–CRF in the PMD group, respectively. For biomechanical parameters in PMD eyes, CRF had the highest sensitivity (75.49%) while the greatest area under the ROC curve (AUC) was seen for CH (0.903). Moreover, central corneal thickness (CCT) showed no correlation with CH (P = 0.30, r = −0.104) or CRF (P = 0.75, r = 0.033) in the PMD group.

Conclusions

This study presented the values of corneal biomechanics for PMD using the ORA. The results of the ORA were markedly different between PMD, KCN, and normal eyes.

Adverse drug events leading to emergency department visits at an eye hospital: A brief report

PURPOSE

To evaluate adverse drug events (ADEs) resulting in emergency department visits in an eye hospital.

METHOD

Emergency department visits at Farabi Eye Hospital were assessed for a 7-day period. The patients' eye disorders and drug history were evaluated to detect ADEs.

RESULTS

Of 1631 emergency visits, 5 (0.3%, 95% CI: 0.13-0.71%) were drug related. Tetracaine eye drops accounted for 4 (80%, 95% CI: 38-96%) cases with corneal involvement. The other case was an intense conjunctival injection due to naphazoline eye drops.

CONCLUSION

ADEs should be considered in differential diagnosis of ocular emergency problems and preventive measure should be considered.

Femtosecond laser arcuate keratotomy for the correction of postkeratoplasty high astigmatism in keratoconus

BACKGROUND

Astigmatism is the leading complication in visual recovery after penetrating keratoplasty (PKP) and deep anterior lamellar keratoplasty (DALK); in this study, we evaluated the outcome of femtosecond laser arcuate keratotomy (FLAK) after DALK and PKP in Iranian keratoconic patients.

MATERIALS AND METHODS

In this prospective interventional case series, refractive and keratometric predictability, efficacy, and complications of FLAK for postkeratoplasty astigmatism in keratoconus were evaluated; 23 eyes of 23 consecutive patients (mean age of 32.43 ± 9.11 years) with high astigmatism were enrolled. The femtosecond laser performed paired 90°-angled arcuate incisions.

RESULTS

Mean logarithm of the minimum angle of resolution of corrected and uncorrected visual acuity improved from preoperative values of 0.30 ± 0.18 and 0.85 ± 0.32 to 6-month values of 0.19 ± 0.17 and 0.65 ± 0.33, respectively (P < 0.05). Mean subjective astigmatism was 7.79 ± 2.64 diopter (D) preoperatively and 3.69 ± 2.25D at 6-month after surgery (P < 0.05). Surgically induced astigmatism was 9.27 ± 5.00D. Mean refractive spherical equivalent showed no significant (P = 0.69) hyperopic shift from - 4.21 ± 4.84D preoperatively to - 2.16 ± 6.09D postoperatively. Two (8.7%) microperforations were observed.

CONCLUSION

FLAK is a relatively safe and effective method for the treatment of postkeratoplasty astigmatism.

Efficacy of Wavefront-guided Photorefractive Keratectomy with Iris Registration for Management of Moderate to High Astigmatism by Advanced Personalized Treatment Nomogram

Purpose:

To evaluate the efficacy of photorefractive keratectomy (PRK) using the advanced personalized treatment (APT) nomogram for correction of moderate to high astigmatism.

Methods:

This prospective interventional case series included 60 consecutive eyes of 30 patients undergoing wavefront-guided PRK (Zyoptix 217 Z100 excimer laser, Bausch & Lomb, Munich, Germany) using the APT nomogram and iris registration for myopic astigmatism. Mitomycin-C was applied intraoperatively in all eyes. Ophthalmic examination was performed preoperatively and 1, 3 and 6 months postoperatively.

Results:

Preoperatively, mean sphere was -1.68 ± 2.08 diopters (D), mean refractive astigmatism was -3.04 ± 1.05 D and mean spherical equivalent (SE) was -3.12 ± 1.77 D. Six months postoperatively, mean sphere was + 0.60 ± 0.64 D (P < 0.005), mean cylinder was -0.43 ± 0.46 D (P < 0.005) and mean SE was + 0.28 ± 0.48 D (P < 0.005). Hyperopic overcorrection (≥ +1.0 D) occurred in 3 (5%) eyes. Postoperatively, root mean square (RMS) of higher order aberrations (HOAs) was significantly increased (P = 0.041). RMS of spherical aberration (Z [4, 0]) showed no significant change after surgery (P = 0.972).

Conclusion:

Considering the acceptable residual refractive error, low rate of hyperopic overcorrection, acceptable uncorrected visual acuity, and low risk of postoperative corneal haze, PRK using the APT nomogram with iris registration and mitomycin-C use is a safe and effective modality for treatment of moderate to high astigmatism.

Correlations Between Histopathologic Changes and Clinical Features in Pterygia

Purpose:

To investigate the correlations between clinical findings and histopathologic changes in eyes with pterygium.

Methods:

This prospective study included 70 eyes with primary pterygia undergoing surgical excision. Prior to surgery, clinical features of the pterygia including extension over the cornea, redness, fleshiness (based on obscuration of the underlying episcleral vessels), and obliteration of the plica semilunaris were determined. Postoperatively, pterygium specimens were examined by hematoxylin-eosin and trichrome staining to evaluate histopathologic characteristics including vascular density, leukocytic infiltration, stromal elastosis, stromal fibrosis and subepithelial fibrosis. Correlations between clinical findings and histopathologic changes were then investigated.

Results:

There was a marginally significant correlation between the redness and the fleshiness of pterygium (P = 0.06). Both redness and fleshiness of the pterygium had significant positive correlation with dimensions of the lesion over the cornea. Moreover, larger pterygia were associated with obliteration of the plica semilunaris. Pterygium redness showed a significant correlation with vascular density (P = 0.04), and pterygium fleshiness had a significant correlation with stromal fibrosis (P = 0.04). Pterygium dimensions over the cornea demonstrated a positive correlation with vascular density and a negative correlation with stromal elastosis.

Conclusion:

Redness and fleshiness of pterygium were only marginally correlated with each other, and each one showed a correlation with different histopathologic features. Larger pterygia were associated with more significant changes at the clinical and histopathologic levels.

Correlation of higher order aberrations and components of astigmatism in myopic refractive surgery candidates

Purpose

To evaluate the correlation between refractive, corneal, and residual astigmatism and higher order aberrations (HOA) in refractive surgery candidates.

Methods

Three hundred and seventy-five eyes of 188 patients aged 28.2 ± 6.24 years with a predominance of females (62.7%) were enrolled in this study. Refraction, topography (Orbscan IIz, Bausch & Lomb, Rochester, NY, USA), and aberrometry (Zywave, Bausch & Lomb, Rochester, NY, USA) were performed to determine refractive and corneal astigmatism and HOA for all participants. Ocular residual astigmatism was calculated using vector analysis.

Results

The mean spherical equivalent was −3.59 ± 1.95 D and the mean refractive astigmatism was −1.97 ± 1.3 D. The mean HOA was 0.38 ± 0.15 μm in all cases, which increased with spherical equivalent (p < 0.05). There was a positive significant correlation between both corneal and refractive astigmatism and HOA (p < 0.05), but there was no significant correlation between residual astigmatism and HOA (p = 0.122).

Conclusion

The results of the study showed significant correlations between corneal and refractive astigmatisms and HOA.

Post-cataract surgery endophthalmitis: Brief literature review

PURPOSE

To investigate recent evidence in prophylaxis and management of post-cataract surgery endophthalmitis.

METHODS

We conducted a literature search using Pubmed database for post cataract surgery endophthalmitis, and relevant articles were selected from original English papers published since 2015.

RESULTS

Forty-nine articles were published regarding post-cataract surgery endophthalmitis from January 2015 to February 2016. A low incidence of post-cataract surgery endophthalmitis has been reported. A growing number of articles are focusing on preventing endophthalmitis using intracameral antibiotics.

CONCLUSION

Based on the current evidence, intracameral antibiotics seems to be effective in preventing endophthalmitis after cataract surgery.

Customized Clinical Practice Guidelines for Management of Adult Cataract in Iran

Purpose:

To customize clinical practice guidelines (CPGs) for cataract management in the Iranian population.

Methods:

First, four CPGs (American Academy of Ophthalmology 2006 and 2011, Royal College of Ophthalmologists 2010, and Canadian Ophthalmological Society 2008) were selected from a number of available CPGs in the literature for cataract management. All recommendations of these guidelines, together with their references, were studied. Each recommendation was summarized in 4 tables. The first table showed the recommendation itself in clinical question components format along with its level of evidence. The second table contained structured abstracts of supporting articles related to the clinical question with their levels of evidence. The third table included the customized recommendation of the internal group respecting its clinical advantage, cost, and complications. In the fourth table, the internal group their recommendations from 1 to 9 based on the customizing capability of the recommendation (applicability, acceptability, external validity). Finally, customized recommendations were sent one month prior to a consensus session to faculty members of all universities across the country asking for their comments on recommendations.

Results:

The agreed recommendations were accepted as conclusive while those with no agreement were discussed at the consensus session. Finally, all customized recommendations were codified as 80 recommendations along with their sources and levels of evidence for the Iranian population.

Conclusion:

Customization of CPGs for management of adult cataract for the Iranian population seems to be useful for standardization of referral, diagnosis and treatment of patients.

Histopathology of Conjunctivochalasis Compared to Normal Conjunctiva

Purpose:

To evaluate the histopathologic changes in the conjunctiva of patients with conjunctivochalasis (CCh) compared to age-matched controls.

Methods:

This cross-sectional, controlled study included 27 eyes of 27 patients with CCh and 16 eyes of 16 age-matched controls. A biopsy of the bulbar conjunctiva was performed along the temporal lower lid margin before cataract surgery in both groups. Histopathologic evaluation of the specimens was done with light microscopy using staining with hematoxylin/eosin, periodic acid Schiff, and van Gieson elastic stain. Various histopathologic features of the conjunctival epithelium and stroma were compared between the two groups.

Results:

The mean age of patients was 62.4 ± 6.9 years in the CCh group and 65.1 ± 6.3 years in the control group (P = 0.54). No significant differences were noted between the two groups in terms of conjunctival epithelial changes including papillomatosis, epithelial clefts, epithelial goblet cells, or infiltration of inflammatory cells. Mean thickness of the conjunctival stroma was 0.21 ± 0.08 mm in the CCh group and 0.26 ± 0.21 mm in the control group (P = 0.10). For the conjunctival stroma, there were no significant differences between the two groups in terms of elastosis, fibrosis, lymphangiectasia, or infiltration of inflammatory cells.

Conclusion:

No noticeable differences were found in the histopathologic features by light microscopy between eyes with CCh and those of age-matched controls. Therefore, the primary pathology of CCh may not be within the conjunctiva itself. Instead, loose attachment of the conjunctiva to the underlying tissue may be the reason for the redundant folds in the bulbar conjunctiva.

Ocular response analyzer parameters in healthy, keratoconus suspect and manifest keratoconus eyes

Background:

To evaluate and compare corneal biomechanical indices and their specificity among keratoconus (KC), keratoconus suspect (KCS), and normal eyes (NL) before and after controlling potential confounders.

Materials and Methods:

A total of 160 eyes in three groups were included prospectively: NL, KC, and KCS groups based on clinical examination and topography. Corneal hysteresis (CH) and corneal resistance factor (CRF) were measured by the ocular response analyzer. CH and CRF were compared between the three groups by analysis of variances test.

Results:

The three groups consisted of 80 NL, 48 KC, and 32 KCS eyes. The mean CH measured was 10.4 ± 1.25, 7.83 ± 1.28 and 10.17 ± 1.80 mm Hg in NL, KC and KCS eyes, respectively. The mean CRF was 10.23 ± 1.75, 6.5 ± 1.63 and 9.98 ± 2.00 mm Hg in NL, KC and KCS eyes, respectively. Mean CH and CRF were significantly different between the NL and KC (P < 0.05); however after controlling for central corneal thickness and sex; there was no significant difference between NL and KCS (P > 0.05).

Conclusion:

CH and CRF can be helpful in differentiating KC from NL eyes; however, they are not valuable for detecting KCS that is the main concern for refractive surgery. Future studies focusing on more accurate tests for identifying KCS, using a consistent grading scale for defining KC and KCS are still warranted.

Technique of simultaneous femtosecond laser assisted Myoring implantation and accelerated intrastromal collagen cross-linking for management of progressive keratoconus: A novel technique

PURPOSE

To describe a novel surgical technique for the management of progressive keratoconus by simultaneous femtosecond laser-assisted Myoring implantation and accelerated corneal intrastromal collagen cross-linking with Dextran Free Riboflavin.

METHODS

After creating a corneal pocket with femtosecond laser, Dextran Free Riboflavin was injected into the intrastromal pocket. Then the Myoring was implanted in the corneal pocket and accelerated corneal intrastromal collagen cross-linking was performed with no epithelial debridement.

RESULTS

The cornea remained clear and the central keratometry was decreased significantly with marked improvement in uncorrected visual acuity up to two years following treatment. Anterior segment OCT revealed good centration and intended implant depth with desirable increase in the corneal stromal reflectivity confirming effective collagen cross-linking.

CONCLUSION

Simultaneous femtosecond laser-assisted Myoring implantation and accelerated corneal intrastromal collagen cross-linking with Dextran Free Riboflavin is a safe and effective technique for management of keratoconus and improving vision.

National and sub-national burden of visual impairment in Iran 1990-2013; study protocol

BACKGROUND

Although Visual impairment (VI) and its prevention is a public health issue, sub-optimal information about its magnitude in national level and its distribution is one of the impediments for visual health advocacy. In this article, we are detailing the approaches which will be taken to estimate the magnitude (prevalence, incidence, and burden), distribution, and trend (1990 to 2013) of low vision and blindness in Iran. Besides that, an attempt will be made to describe inequalities and their determinants.

METHODS

After finalizing the list of diseases, a systematic search will be started using confirmed search terms and all published and unpublished data will be extracted. Other data sources, including data from hospital records will be added to the data extraction sheet. Using distinct statistical models including spatio-temporal model and multilevel autoregressive model, we will estimate rate of burden measures of eye disease and their uncertainty interval by sex, age, year, and province as well as social determinants of visual impairment inequality. The results are to be reported in separated analyses of meta-analysis, trend, risk factors and diseases burden, inequality, Bayesian prediction modeling, and map for visualizing the results.

CONCLUSION

The results of the current study will address gaps in different regions and have implication for evidence-based policy making in Iran.

Hinged Capsulotomy--Does it Decrease Floaters After Yttrium Aluminum Garnet Laser Capsulotomy?

Objectives:

The objective was to compare conventional circular yttrium aluminum garnet (YAG) laser capsulotomy with hinged capsulotomy to manage posterior capsular opacification (PCO).

Materials and Methods:

This prospective, randomized clinical trial enrolled pseudophakic patients with visually significant posterior capsule opacification. Patients were randomized to undergo posterior YAG laser capsulotomy with either conventional circular technique or a new technique with an inferior hinge. At 1-month postoperatively, patients were asked if they had any annoying floaters and the responses were compared between groups. P < 0.05 was considered statistically significant.

Results:

A total of 83 patients were enrolled. Forty-three patients underwent hinged posterior YAG capsulotomy and 40 patients underwent routine circular capsulotomy. At 1-month postoperatively, there was a statistically significant decrease in annoying floaters in the group that underwent circular capsulotomy (P = 0.02). There was no statistically significant association in the total energy delivered (P = 0.4) or the number of spots (P = 0.2) and patient perception of annoying floaters.

Conclusion:

Hinged YAG capsulotomy was effective at decreasing the rate of floaters in patients with PCO.

Prophylactic effect of topical silica nanoparticles as a novel antineovascularization agent for inhibiting corneal neovascularization following chemical burn

Background:

Angiogenesis-related corneal blindness includes the spectrum of corneal diseases that are caused by pathological angiogenesis, leading to untoward visual impairment. The purpose of this study was to investigate the antineovascularization effect of topical silica nanoparticles (SiNPs) in inhibiting chemical-burn-induced corneal neovascularization.

Materials and Methods:

A total number of 20 corneas of 10 Wistar Albino rats were included in this study. Silver nitrate cauterization was pressed to the central cornea for 5 s to induce corneal neovascularization. They were randomly allocated to case and control groups (ten eyes in each group). SiNPs were synthesized by the reverse microemulsion method. SiNPs drop 1 mg/ml was started in ten eyes and artificial tear drop was started in the control group (ten eyes) immediately after chemical cauterization. Video-based photography was performed before and after treatment. Corneal image analysis was performed on each cornea using an image analysis software program. All rats were euthanized and the eyes were sent for histopathologic examinations14 days after chemical cauterization.

Results:

Scanning electron microscopy (SEM) images showed spherical-shaped particles. The mean size and polydispersity index of prepared SiNPs were 30.1 ± 5.6 nm and 0.254 ± 0.11, respectively. Fourteen days after chemical cauterization, the mean vascularized corneal area was 21% of total corneal area in the case group and 85% in the control group (P < 0.05). The control group revealed more extensive intrastromal vascularization compared with the case group in histopathologic examinations (P < 0.05).

Conclusions:

SiNPs is an effective modality for inhibiting corneal neovascularization following chemical burn in an experimental model. Further investigations are suggested for evaluation of its safety and efficacy in human eyes.

Evaluation of corneal changes after conventional versus accelerated corneal cross-linking: a randomized controlled trial

PURPOSE

To evaluate the outcome of accelerated and conventional corneal cross-linking (CXL) procedures regarding their effect on morphological and optical properties of the cornea.

METHODS

One hundred fifty-three eyes of 153 patients were evaluated before and during a 15-month follow-up period after CXL (76 eyes in the conventional group and 77 eyes in the accelerated group). Measured variables include corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), refraction, maximum keratometry, endothelial cell density, anterior and posterior stromal keratocyte density, and subbasal nerve density. All variables were compared between the two study groups.

RESULTS

Cylindrical and spherical components of refraction improved significantly during 15 months of follow-up. No difference was observed between the two study groups. UDVA and CDVA improved in the same manner, with no intergroup differences. Endothelial cell density did not change significantly during the follow-up period in either group. K-max increased slightly in the first month of the follow-up, but started to decrease at postoperative visits without any significant difference in the two groups. Anterior stromal keratocyte density and subbasal nerve density decreased significantly in both groups 1 month postoperatively. Both variables had a more significant decrease in the conventional group at all visits before the 1-year visit. At the final 15-month visit, there were no significant differences in any value between the two groups.

CONCLUSIONS

Accelerated and conventional CXL seem to have a comparable and acceptable effect on keratoconus in the short-term follow-up period.

Femtosecond laser-assisted sutureless anterior lamellar keratoplasty for superficial corneal opacities

PURPOSE

To evaluate the visual and refractive outcomes, endothelial cell count (ECC), ocular surface changes, corneal aberrations, and biomechanical profile changes after femtosecond laser-assisted anterior lamellar keratoplasty surgery for superficial corneal scars.

SETTING

Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.

DESIGN

Prospective case series.

METHODS

Patients with superficial corneal scars had femtosecond laser-assisted anterior lamellar keratoplasty. Visual and refractive results, ECC, ocular surface changes, corneal aberrations, and biomechanical profiles were assessed preoperatively and for 1 year postoperatively.

RESULTS

Nineteen eyes (19 patients) were evaluated. A significant decline occurred in refractive astigmatism and corneal astigmatism after 1 year. There was a nonsignificant reduction in corneal hysteresis and the corneal resistance factor from preoperatively to 1 year postoperatively. The corneal-compensated intraocular pressure (IOP) and Goldmann-correlated IOP increased during the follow-up; the increase was not significant. A statistically insignificant reduction in the root mean square for trefoil and spherical aberrations occurred between 1 month and 1 year postoperatively (P=.1 and P=.4, respectively). The decreases in primary coma and total higher-order aberrations approached significance (P=.08 and P=.07, respectively). There were no significant changes in the central corneal thickness, ECC, or ocular surface parameters. No intraoperative complications occurred.

CONCLUSION

Femtosecond laser-assisted anterior lamellar keratoplasty was an efficient and safe procedure for improving the quality of vision in patients with anterior corneal pathology, and the results remained stable during the 1-year follow-up.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Preoperative anterior segment optical coherence tomography as a predictor of postoperative phakic intraocular lens position

PURPOSE

To evaluate anterior segment optical coherence tomography (AS-OCT) in the preoperative simulation of postoperative iris-fixated phakic intraocular lens (pIOL) position in the anterior chamber.

SETTING

Farabi Eye Research Center, Department of Ophthalmology, Tehran University of Medical Sciences, Tehran, Iran.

DESIGN

Case series.

METHODS

Using AS-OCT, the pIOL position was simulated preoperatively in 2 ways and compared with the actual postoperative pIOL position. For preoperative evaluations, the simulator was placed on the posterior pigmented epithelium of the iris. Then, the simulation was performed with the simulator placed in the middle of the iris tissue. The following distances were measured: from the center of the pIOL to the endothelium, from the edge of the pIOL to the endothelium, and from the posterior surface of the pIOL to the crystalline lens.

RESULTS

The study examined 26 eyes (16 patients). Although all distances in both simulation methods (except the lens vault in the first method of simulation) were highly correlated (all P<.009), only the results with the simulator placed in the middle of the iris tissue were not statistically different from the corresponding postoperative measurements (P=.209 and P=.564 for distance from endothelium to the center and the pIOL edge, respectively).

CONCLUSIONS

Using the pIOL template of the AS-OCT system for preoperative simulation of iris-fixated pIOLs improved the criteria for patient selection for implantation of these pIOLs. The simulator should be placed in the middle of the iris tissue for preoperative simulation.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Incidence of and risk factors for vitreous loss in resident-performed phacoemulsification surgery

PURPOSE

To determine the incidence of and risk factors for posterior capsule rupture and vitreous loss during phacoemulsification performed by ophthalmology residents.

SETTING

Academic ophthalmology resident training center, Tehran, Iran.

DESIGN

Cross-sectional study.

METHODS

This study included patients who had phacoemulsification by ophthalmology residents from August 2010 to August 2011. The complications occurring during surgery and the rate of vitreous loss and posterior capsule rupture were studied.

RESULTS

Five hundred eyes of 500 patients, including 255 (51%) men and 245 (49%) women with a mean age of 67 years ± 10 (SD) (range 27 to 105 years), were studied. Fifty-one eyes (10.2%) developed vitreous loss, and 48 eyes (9.6%) developed posterior capsule rupture and vitreous loss. On univariate analysis, significant risk factors for vitreous loss included diabetes mellitus (P=.001), shallow anterior chamber (P=.01), absence of supervision by a faculty member (P=.007), larger capsulorhexis (P=.02), anterior capsule tear (P=.001), and longer effective phacoemulsification time (EPT) (P=.003). Multivariate data analysis using stepwise logistic regression analysis showed anterior capsule tear (odds ratio [OR], 2.63; 95% confidence interval [CI], 1.09-6.29), longer EPT (OR, 1.01; 95% CI, 1.003-1.02), and lack of supervision by attending physicians (OR, 4.28; 95% CI, 1.44-12.67) to be significant independent risk factors associated with vitreous loss.

CONCLUSION

Direct attending supervision and careful case selection for the level of cataract surgery residency are of utmost importance in avoiding sight-threatening complications.

Continuous corneal intrastromal ring implantation for treatment of keratoconus in an Iranian population

PURPOSE

To evaluate the effect of mechanical implantation of a continuous intrastromal ring in keratoconus.

DESIGN

Prospective, interventional, nonrandomized, case series.

METHODS

The MyoRing (Dioptex GmbH) was implanted after creation of an intrastromal pocket for 95 eyes of 95 patients with moderate and advanced keratoconus. All patients had at least 12 months of follow-up. Preoperative and postoperative visual acuity, keratometry, aberrometry, and refraction were the main outcome measures of the study.

RESULTS

A significant improvement in uncorrected and corrected distance visual acuity was observed 1 month after surgery, which was consistent with the significant reduction in sphere (5.74 diopters [D]) and cylinder (3.02 D). No significant changes were detected in these parameters afterward. Furthermore, a significant corneal flattening of a mean value of 9.78 D was found. Both spherical myopia and astigmatism underwent reduction, but the reduction in myopia was more remarkable than astigmatism. Higher-order aberrations and coma-like aberrations decreased significantly, but spherical aberrations increased after surgery. No significant change in central corneal thickness was observed at any point after operation. There were no significant differences between 2 keratometry groups (higher or lower than 53 D) in visual gain after the procedure. There were no major complications during or after surgery. MyoRing explantation was performed in 4 eyes (4%). The refraction, visual acuity, and corneal topography returned to the preoperative status 1 month later for all 4 eyes.

CONCLUSIONS

MyoRing implantation has an acceptable efficacy profile in moderate and advanced keratoconus.

Radiation cataract: clinicopathologic report

We report the case of a 52-year-old woman who developed bilateral anterior and posterior subcapsular cataracts with anterior capsule fibrosis 12 years after exposure to intensive radiation therapy. The woman had uneventful cataract surgery and gained 20/20 corrected distance visual acuity in both eyes. Hematoxylin-eosin staining of the anterior capsule revealed significant subcapsular scar formation in the context of fibroblast proliferation.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Sheep practice eye for ophthalmic surgery training in skills laboratory

Pig eyes are not available for surgical practice in the Middle East and Central Asia. We reviewed the literature to select an alternative animal practice eye based on biometry, availability, expense, and the ethical issue of animal sacrifice. Twenty enucleated sheep eyes were studied with an ultrasonography immersion technique, and a variety of techniques for globe harvesting were tested and compared. The sheep eye was judged to be the best practical choice for ophthalmic surgery practice and the "bone shattering" exenteration maneuver, the most efficient harvesting method. Several anterior segment procedures were performed in the sheep eyes. Introduction of this sheep model would be instrumental in the development of ophthalmology skills laboratories and surgical training in Middle Eastern and Central Asian regions.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Transition to phacoemulsification at the farabi eye hospital, iran

PURPOSE

To provide objective evidence on the transition of cataract surgical care at Farabi Eye Hospital, Iran.

MATERIALS AND METHODS

Two separate years, 2003 and 2006, were selected for evaluation. One thousand nine hundred fifty-seven surgical records of age-related cataract cases were randomly selected and reviewed. Three hundred fifty-three patients (405 eyes) in 2006 and 125 patients (153 eyes) in 2003 were selected randomly for a follow-up examination. The two phases were compared in terms of surgical routines, patient characteristics and outcomes for statistical differences. P <0.05 was considered statistically significant.

RESULTS

The phacoemulsification rate increased from 25% to greater than 90% between 2003 and 2006, rates of corneal incisions and use of foldable intraocular lenses tripled, administration of general anesthesia dropped from 80% to 12%, the outpatient admission rate rose from 5.2% to 71%, 4% vs. 66% of the operations were performed by a senior phacoemulsification surgeon and the number of advanced surgeons changed from 6% to 38% (all P-values < 0.001). In 2006, more patients at the two extremes of age, more patients with poor systemic conditions and myopes underwent surgery (all P-values < 0.05); the cataract surgery volume increased by 49% and post-operative visual acuity improved (P = 0.03) while patient satisfaction was unchanged.

CONCLUSION

We objectively documented the transition in cataract surgery technique to phacoemulsification at the Farabi Eye Hospital in the mid-2000s. This was accompanied by significant expansion of the spectrum of cataract surgery candidates and remarkable attainment of surgical skill.