Evaluation of the effect of artificial tears on corneal epithelial thickness changes after photorefractive keratectomy

PURPOSE

This study aimed to evaluate the corneal epithelial thickness changes after photorefractive keratectomy (PRK) and the impact of long-term artificial tear usage on epithelial thickness changes in these patients.

METHODS

This study was performed on 71 patients (142 eyes) without dry eye disease who received PRK for myopic refractive correction. The corneal epithelial thickness profile was obtained before, one, three, and six months after surgery using anterior segment optical coherence tomography. Patients were randomly divided into two groups: group A, who received preservative-free artificial tears post-surgery, and group B, who did not receive artificial tears.

RESULTS

The epithelial thickness decreased universally in the first month and then increased in the 3- and 6-month follow-ups. Group A had a significantly thicker epithelium in central, paracentral, and midperipheral zones compared with group B in the 3-month follow-up. In the 6-month follow-up, no significant differences were detected between groups. At the last follow-up, the central, paracentral, and midperipheral zone epithelial thicknesses in all patients were significantly higher than preoperative values, but peripheral zone thickness only increased to preoperative values.

CONCLUSIONS

Patients using artificial tears showed a faster thickening, especially in the central and paracentral zones, but there were no significant differences between the two groups in the final follow-up. Artificial tear usage may increase the rate of the epithelial remodeling process in post-PRK patients without significantly altering the final epithelial thickness profile. Further studies are warranted to evaluate the influence of different factors on epithelial remodeling.

From the diagnosis of infectious keratitis to discriminating fungal subtypes; a deep learning-based study

Infectious keratitis (IK) is a major cause of corneal opacity. IK can be caused by a variety of microorganisms. Typically, fungal ulcers carry the worst prognosis. Fungal cases can be subdivided into filamentous and yeasts, which shows fundamental differences. Delays in diagnosis or initiation of treatment increase the risk of ocular complications. Currently, the diagnosis of IK is mainly based on slit-lamp examination and corneal scrapings. Notably, these diagnostic methods have their drawbacks, including experience-dependency, tissue damage, and time consumption. Artificial intelligence (AI) is designed to mimic and enhance human decision-making. An increasing number of studies have utilized AI in the diagnosis of IK. In this paper, we propose to use AI to diagnose IK (model 1), differentiate between bacterial keratitis and fungal keratitis (model 2), and discriminate the filamentous type from the yeast type of fungal cases (model 3). Overall, 9329 slit-lamp photographs gathered from 977 patients were enrolled in the study. The models exhibited remarkable accuracy, with model 1 achieving 99.3%, model 2 at 84%, and model 3 reaching 77.5%. In conclusion, our study offers valuable support in the early identification of potential fungal and bacterial keratitis cases and helps enable timely management.

A joinpoint and age-period-cohort analysis of ocular cancer secular trends in Iran from 2004 to 2016

Investigating secular trends of ocular cancer registration in Iran. After acquiring Iranian national population-based cancer registry data, trends of age-standardised incidence rates (ASIR) of ocular cancers and annual percent changes (APC) between 2004 and 2016 were analysed in age groups, gender, topography and morphology types with joinpoint regression analysis. Age, period, and cohort effects on incidence rates were estimated by age-period-cohort model. Geographic distribution of ASIR was assessed using GIS. Overall ASIR of ocular cancers was 16.04/100,000 (95% CI 15.77-16.32). Joinpoint regression analysis showed a significant increase of ASIR between 2004 and 2009 for males (APC = 5.5, 95% CI  0.9-10.2), ages over 50 years (APC = 5.2, 1.2-9.4), skin/canthus/adnexal cancers (APC = 4.2, 0.8-7.7), and carcinomas/adenocarcinomas (APC = 4.3, 0.6-8.1); however, between 2009 and 2016 a declining trend was observed in all investigated variables. ASIR of retinoblastoma was significantly increased (averaged APC = 20.7, 9-33.7) between 2004 and 2016. age-period-cohort analyses showed that incidence rates of ocular cancers significantly increased with aging, time periods, and birth cohort effects (p < 0.001). ASIR varied from 6.7/100,000 to 21.7/100,000 in Iran. Excepting retinoblastoma, all ocular cancer incidence trends were downward over a 13-year period; however, it was increasing between 2004 and 2009 cancer. ASIR was significant aging in Iran.

Associated factors and distribution of posterior corneal astigmatism in a middle-aged population

CLINICAL RELEVANCE

Posterior corneal astigmatism has an important role in diagnosis and treatment of astigmatism, but it is usually overlooked.

BACKGROUND

This cross-sectional study aimed to investigate the distribution of posterior corneal astigmatism (PCA) and its associated factors in a middle-aged population that participated in the Shahroud Eye Cohort Study (ShECS) phase II.

METHODS

Anterior corneal astigmatism (ACA) and PCA values were measured using rotating Scheimpflug System (Pentacam HR, Oculus). With-the-rule (WTR) astigmatism was considered when the steepest corneal meridian was aligned within 90° ± 30°, and against-the-rule (ATR) astigmatism when the steepest meridian was 0 ± 30°. All the remaining values were considered as oblique astigmatism. Logistic regression models were used for evaluating the association of PCA magnitudes with other factors.

RESULTS

The current study consisted of 3871 eyes with available Pentacam data. Mean age of participants was 55.4 ± 6.1 years and 1557 (40.2%) subjects were male. Means of ACA and PCA were 0.77 ± 0.67 and -0.24 ± 0.15 D, respectively. The majority of PCA consisted of WTR astigmatism (82.43%), while ACA mostly showed ATR astigmatism (55.46%). PCA > 0.3 D was associated with male sex (OR = 1.16, P-value = 0.028) and spherical equivalent (OR = 0.93, P-value = 0.011) in the adjusted model, while PCA > 0.5 dioptre was strongly associated with myopia (OR = 4.6, P-value < 0.001).

CONCLUSION

The most common forms of ACA and PCA in middle-aged Iranian adults were ATR and WTR, respectively. While the shape of posterior corneal surface remained mostly unchanged across ages of 45 to 69 years, ACA was associated with a decrease in ATR proportion. Moreover, the most significant factors associated with higher magnitudes of PCA were male sex and myopia.

Applications of Haptic Technology, Virtual Reality, and Artificial Intelligence in Medical Training During the COVID-19 Pandemic

This paper examines how haptic technology, virtual reality, and artificial intelligence help to reduce the physical contact in medical training during the COVID-19 Pandemic. Notably, any mistake made by the trainees during the education process might lead to undesired complications for the patient. Therefore, training of the medical skills to the trainees have always been a challenging issue for the expert surgeons, and this is even more challenging in pandemics. The current method of surgery training needs the novice surgeons to attend some courses, watch some procedure, and conduct their initial operations under the direct supervision of an expert surgeon. Owing to the requirement of physical contact in this method of medical training, the involved people including the novice and expert surgeons confront a potential risk of infection to the virus. This survey paper reviews recent technological breakthroughs along with new areas in which assistive technologies might provide a viable solution to reduce the physical contact in the medical institutes during the COVID-19 pandemic and similar crises.

The role of Guidance and Planning on Safety of Ophthalmic Practice during the COVID-19 Pandemic

This is an Editorial and does not have an abstract.

National and sub national prevalence of Amblyopia and its trends from 1990 to 2018 in Iran

PURPOSE

To determine the national and subnational prevalence of amblyopia and the respective provincial distribution and trend during 1990-2018 in Iran.

METHODS

Amblyopia data retrieved from 26 original studies, systematic reviews, Data has been cleaned by STATA and a linear mixed effect spatio-temporal model was used to calculate Gaussian process regression mean functions. Using a Bayesian approach, by pooling empirical data based on the assumed prior, a posterior distribution obtained for age and sex specific prevalence prediction nationally during the study time and provincially.

RESULTS

The overall age-adjusted prevalence of Amblyopia was 0.03 (95% CI, 0.022-0.035). The prevalence was comparable in boys and girls (p = 0.85), highest prevalence was in >30 years old (p = 0.038). Our extrapolation revealed a stable trend of prevalence of Amblyopia in Iran during 1990-2018 (national screening program has been active from 1990 onwards). While Amblyopia prevalence suggested a declining trend in three provinces of Hormozgan, Qom and Tehran and it went up in 13 other provinces.

CONCLUSION

Amblyopia prevalence seems unchanged despite the concurrent screening program. It is noteworthy that the coverage of the program has been improved and has reached more than 85% in 2018. Our finding mandates a formal evaluation on the program.

Diabetic Retinopathy and Laser Therapy in Rats: A Protein-Protein Interaction Network Analysis

Introduction: Diabetic retinopathy (DR) is a serious microvascular complication of diabetes which can cause vision loss or blindness ultimately. Non enzymatic glycation of proteins leads to advanced glycation end products (AGEs) in DR. Since laser therapy is a well-established method, in this study, protein-protein interaction (PPI) network is applied for protein targets in DR disease in rats treated by laser. Methods: In this study, we focused on articles that investigated and compared the proteome profiles of DR rats with healthy control and also DR rats before and after laser therapy. The networks of related differentially expressed proteins were explored using Cytoscape version 3.3.0, the PPI analysis methods and ClueGO. Results: Analysis of PPI network of 37 related proteins to DR rats including 108 nodes, introduced 10 hub-bottleneck proteins and 5 concerned biochemical pathways. On the other hand, PPI analysis of related proteins to DR rats before and after laser therapy corresponded to 33 proteins and 2 biological pathways. Discussion: Centrality and cluster screening identified hub-bottelneck genes, including Aldoa, HSPD1, Pgam2, Mapk3, SLC2A4, Ctnnb1, Ywhab, HSPA8, GAPDH and Actb for DR rats versus healthy control and ENO1, Aldoa, GAPDH for DR samples after laser therapy.

CONCLUSION

Gene expression analysis of the DR samples treated via laser therapy provides a molecular evidence in support of the therapeutic effect of laser.

Outcome of Single-piece Intraocular Lens Sulcus Implantation following Posterior Capsular Rupture during Phacoemulsification

Purpose:

To assess the safety and outcome of single-piece posterior chamber intraocular lens (PC-IOL) implantation in the ciliary sulcus following posterior capsular rupture during cataract surgery.

Methods:

Patients with posterior capsular rupture during cataract surgery with a single-piece acrylic IOL implanted into the ciliary sulcus were studied. Complete ocular examinations were performed after 6 months postoperatively.

Results:

Twenty-four eyes were included. Mean follow-up duration was 8.33 ± 2.33 months. There was no significant difference between preoperative and postoperative keratometric cylinder or intraocular pressure. Visual acuity of 87.50% of patients was ≥20/40 after surgery. Complications included foveopathy (10 eyes), iris transillumination defect (4 eyes), iris chafing (2 eyes), pigmented keratic precipitate (KP) (4 eyes), clinical IOL tilt (6 eyes), endothelial pigment dusting (14 eyes), IOL pigment dusting (17 eyes), iris bowing (6 eyes), IOL decentration (4 eyes), and IOL tilt detected with ultrasonography biomicroscopy (UBM) (4 eyes). IOL pigment dusting was significantly higher in eyes with short axial lengths, high IOL power, small sulcus-to-sulcus (STS) diameter, large STS IOL diameter mismatch, and small anterior chamber depth and angle. Significant relationships were observed between pigmented KP with small STS diameter and large STS IOL diameter mismatch, UBM and clinical IOL tilt with large anterior chamber depth and between iris transillumination defect and STS IOL diameter mismatch.

Conclusion:

This implantation is associated with higher incidence of complications. Single-piece acrylic IOLs are not designed for sulcus implantation. However, they may be used in eyes with longer axial length if the 3-piece IOL is not available.

Vision Examination Protocol for Archery Athletes Along With an Introduction to Sports Vision

Introduction:

Visual skills are one of the main pillars of intangible faculties of athletes that can influence their performance. Great number of vision tests used to assess the visual skills and it will be irrational to perform all vision tests for every sport.

Objectives:

The purpose of this protocol article is to present a relatively comprehensive battery of tests and assessments on static and dynamic aspects of sight which seems relevant to sports vision and introduce the most useful ones for archery.

Materials and Methods:

Through extensive review of the literature, visual skills and respective tests were listed; such as ‘visual acuity, ‘contrast sensitivity’, ‘stereo-acuity’, ‘ocular alignment’, and ‘eye dominance’. Athletes were defined as “elite” and “non-elite” category based on their past performance. Dominance was considered for eye and hand; binocular or monocular aiming was planned to be recorded. Illumination condition was defined as to simulate the real archery condition to the extent possible. The full cycle of examinations and their order for each athlete was sketched (and estimated to take 40 minutes). Protocol was piloted in an eye hospital. Female and male archers aged 18 - 38 years who practiced compound and recurve archery with a history of more than 6 months were included.

Conclusions:

We managed to select and design a customized examination protocol for archery (a sight-intensive and aiming type of sports), serving skill assessment and research purposes. Our definition for elite and non-elite athletes can help to define sports talent and devise skill development methods as we compare the performance of these two groups. In our pilot, we identified 8 “archery figures” (by hand dominance, eye dominance and binocularity) and highlighted the concept “congruence” (dominant hand and eye in the same side) in archery performance.

Incidence and risk factors of retinopathy of prematurity in a tertiary eye hospital in Tehran

AIM

To determine the incidence and risk factors of retinopathy of prematurity (ROP) in premature infants referred to a tertiary eye hospital during 2003-7 to provide preliminary evidence about ROP in Iran.

METHODS

In a cross-sectional study, data for premature infants screened for ROP in Farabi Eye Hospital including possible risk factors and eye exams' results were recorded and analysed using chi(2), univariate and multiple regressions. Severe ROP was defined as ROP needing treatment or stage 4 or 5 of ROP.

RESULTS

Among 953 premature infants, there were 329 (34.5%) different stages of ROP. Severe ROP was seen in 22.6% (215/953) of infants (16.5%: treatable, 6.1%: advanced untreatable). The mean gestational age (GA) and birth weight (BW) of infants with severe ROP were 28.8 (SD 2.4) weeks and 1256 (389) g respectively. Univariate analysis showed a significant relation between GA, BW, oxygen therapy, blood transfusion and ROP (p<0.001), while multiple-regression methods showed GA, BW and oxygen therapy as independent predictors of ROP (p<0.001, 0.019 and 0.033, respectively).

CONCLUSION

The authors observed a relatively high incidence of ROP in this series, especially its severe form affecting relatively more mature infants, which merits further investigation. GA, BW and oxygen therapy were independent ROP determinants.

Surgical induction of chorioretinal venous anastomosis in ischaemic central retinal vein occlusion: a non-randomised controlled clinical trial

AIM

To evaluate the safety and efficacy of surgical induction of chorioretinal venous anastomosis in the management of ischaemic central retinal vein occlusion (CRVO).

METHODS

In a comparative clinical trial, 28 patients with ischaemic CRVO were included, of whom 18 who declined surgery were considered as controls. The 10 surgical cases underwent standard vitrectomy with incisions into the choroids adjacent to the partially cut major retinal veins. Mersilene suture insertion was done to induce chorioretinal venous shunt. Mild endolaser was applied. Patients were followed up for 6-18 (mean 10) months.

RESULTS

Clinical success in shunt development was 90%. Surgical cases had a significantly better visual acuity improvement compared with controls (mean difference: 1.5 logMAR, p = 0.001) with 80% of them showing improvement (compared with 28% of the controls, p = 0.016). Neovascularisation developed in 39% of the control group compared with 0% of the surgical cases (p = 0.03). In multivariate analysis, surgery remained the sole significant predictor of visual improvement. There were three re-operations for vitreous cavity haemorrhage, cataract, and retinal detachment.

CONCLUSIONS

Surgical induction of chorioretinal venous anastomosis may result in visual acuity improvement and prevent neovascularisation in ischaemic CRVO. Randomised studies are needed to compare the current study modality with the natural course of CRVO and emerging procedures, such as optic neurotomy, in the management of ischaemic CRVO.

Frequency and assortment of self-report occupational complaints among Iranian ophthalmologists: a preliminary survey

BACKGROUND

Ophthalmology is unique in that its practitioners are exposed to a host of ergonomic (eg, indirect ophthalmoscopy), ergo-ophthalmologic (laser), infectious (adenovirus), and allergic (topical anesthetics) hazards. The purpose of this study is to provide a preliminary occupational health profile of Iranian ophthalmologists.

METHODS

A comprehensive list of occupation-related entities was incorporated into a questionnaire, which was distributed among 350 ophthalmologist participants of the Annual Iranian Congress of Ophthalmology (November 2000, Tehran) and was mailed twice to the 1050 nation's registered ophthalmologists. Independent Samples t and chi-square tests were used to assess the relationships.

RESULTS

One hundred sixty-two questionnaires were returned. The mean career time was 15.7 (range, 1-40) years. Twenty (12.3%) of the participants were women. The reported prevalences were as follows: history of infectious conjunctivitis, 49.4%; contact dermatitis, 43.2%; back pain, 80%; chronic headache, 54.9%; and laser or operating microscope-related visual disturbances, 15%. Psychological indispositions were reported by two thirds. Age and career time were inversely related to contact dermatitis, chronic headache, and stress-related problems (P < .05). Visual complaints were more prevalent in vitreoretina surgeons (P < .004). Psychosocial disorders were significantly more reported by women (P = .026; odds ratio = 4.4). Only 3% of participants reported to have none of the listed problems.

CONCLUSION

Our preliminary survey disclosed a high prevalence of diverse complaints from back and neck pain, contact dermatitis, visual disturbances, and infectious conjunctivitis to stress-related and psychosocial disorders among the participants. Younger age, being a woman, and vitreoretina practice were the complaints correlates. Due to the low response rate, uncertainty over the representativeness and coverage of the sample, and lack of control groups, the findings have to be interpreted conservatively.