Ocular vestibular evoked myogenic potentials in different types of amblyopia.

CLINICAL RELEVANCE: The visual system plays an important role in the development of the vestibular-ocular reflex (VOR). In clinical practice, the ocular vestibular evoked myogenic potential (oVEMP) test is used to assess contralateral VOR. BACKGROUND: This study sought to compare the oVEMP in patients with anisometropic, strabismic, and mixed amblyopia using unilateral and bilateral (simultaneous binaural) stimulation. METHODS: Forty-two amblyopic patients (20 males and 22 females) with a mean age of 10.48 ± 4.00 years (range: 5 - 20 years) were examined. The Titmus stereopsis test, alternate cover test, and best-corrected visual acuity were evaluated. Patients were divided into three groups: anisometropic, strabismic, and mixed amblyopia. The oVEMP responses including the amplitude of electrical activity (n1-p1 complex) and the latencies (n1 and p1) of the VOR responses were recorded under unilateral and bilateral stimulations. RESULTS: In the anisometropic and strabismic group, n1 latency was significantly faster in the non-amblyopic eyes compared to amblyopic eyes (Z = -2.04, p = 0.042, andZ = -2.54, p = 0.024 respectively). Mean p1 latency was significantly faster in the non-amblyopic eyes compared to the amblyopic eyes of the strabismic group (Z = -2.31, p = 0.011)In all groups, the p1 latency was faster in the non-amblyopic eye compared to bilateral stimulation (all, p < 0.05). In all groups, the n1-p1 amplitude was not significantly different between the two eyes, and between each eye and bilateral stimulation (all, p > 0.05). No significant correlation was found between the depth of amblyopia and n1 and p1 responses (all, p > 0.05). In all groups there was no significant difference in the latency of n1 and p1 between the amblyopic eye and bilateral stimulation (all, p > 0.05). CONCLUSION: Regardless of its type, amblyopia affects vestibular-ocular reflex responses. Further research is warranted to clarify the effect of the disease and its treatment on the ocular-vestibular system.

Comparison of 110- and 145-µm Small-Incision Lenticule Extraction Cap Thickness: A Randomized Contralateral Eye Study.

PURPOSE: To investigate the visual, refractive, and biomechanical outcomes of small incision lenticule extraction (SMILE) with two different cap thicknesses. METHODS: Thirty-four patients were included in this prospective, randomized, contralateral eye study. Subjects were randomized to receive SMILE surgery with a 110-m cap thickness in one eye and 145-µm cap thickness in the fellow eye. Uncorrected and corrected distance visual acuity, contrast sensitivity (CS), total higherorder aberrations (THOAs) and corneal biomechanical properties were compared 3 months after surgery. RESULTS: Postoperative refractive and visual outcomes, CS and THOAs were similar between the two groups ( P > 0.05 for all parameters). At 3 months postoperatively, there was a significant difference in Corvis ST Biomechanical Index (CBI); stiffness parameter at first applanation (SP A1), and Integrated Radius between the two groups (all P < 0.05). CONCLUSIONS: Eyes with thicker SMILE corneal caps showed no advantage regarding visual acuity, CS and THOAs over eyes with thinner caps. However, higher cap thickness may result in better corneal biomechanical properties postoperatively.

Computer-aided diagnosis of keratoconus through VAE-augmented images using deep learning.

Detecting clinical keratoconus (KCN) poses a challenging and time-consuming task. During the diagnostic process, ophthalmologists are required to review demographic and clinical ophthalmic examinations in order to make an accurate diagnosis. This study aims to develop and evaluate the accuracy of deep convolutional neural network (CNN) models for the detection of keratoconus (KCN) using corneal topographic maps. We retrospectively collected 1758 corneal images (978 normal and 780 keratoconus) from 1010 subjects of the KCN group with clinically evident keratoconus and the normal group with regular astigmatism. To expand the dataset, we developed a model using Variational Auto Encoder (VAE) to generate and augment images, resulting in a dataset of 4000 samples. Four deep learning models were used to extract and identify deep corneal features of original and synthesized images. We demonstrated that the utilization of synthesized images during training process increased classification performance. The overall average accuracy of the deep learning models ranged from 99% for VGG16 to 95% for EfficientNet-B0. All CNN models exhibited sensitivity and specificity above 0.94, with the VGG16 model achieving an AUC of 0.99. The customized CNN model achieved satisfactory results with an accuracy and AUC of 0.97 at a much faster processing speed compared to other models. In conclusion, the DL models showed high accuracy in screening for keratoconus based on corneal topography images. This is a development toward the potential clinical implementation of a more enhanced computer-aided diagnosis (CAD) system for KCN detection, which would aid ophthalmologists in validating the clinical decision and carrying out prompt and precise KCN treatment.

Agreement between a Spectral-Domain Ocular Coherence Tomography Biometer with a Swept-Source Ocular Coherence Tomography Biometer and an Optical Low-Coherence Reflectometry Biometer in Eyes with Cataract.

Purpose: To assess the agreement between biometric parameters measured by a spectral-domain optical coherence tomography optical biometer device (Optopol Revo NX) with a validated swept-source biometer (IOLMaster 700) and a validated optical low-coherence reflectometry biometer (Lenstar LS 900), in cataract surgery candidates. Methods: In this prospective comparative study, 100 patients (100 eyes) who were eligible for cataract surgery were involved. Bland-Altman plots were used to assess agreement between devices for biometric parameters including axial length (AL), anterior chamber depth (ACD), lens thickness (LT), and central corneal thickness (CCT). Results: AL measurements were successful in 82 eyes (82.0%) with Revo NX, in 91 eyes (91.0%) with Lenstar LS 900, and in 97 eyes (97.0%) with IOLMaster 700. When Revo NX was compared to IOL Master 700 and Lenstar LS 900, the mean differences were as follows: -0.02 ± 0.02 mm and -0.02 ± 0.03 mm (P = 0.313, P = 0.525) for AL, 0.01 ± 0.03 mm and 0.10 ± 0.03 mm (P = 0.691, P = 0.002) for ACD, -0.15 ± 0.03 mm and 0.001 ± 0.04 mm (P < 0.001, P = 0.95) for LT, and -2.29 ± 0.92 µm, and 0.73 ± 1.43 µm (P = 0.015, P = 0.612) for CCT. Three devices were highly correlated for AL, ACD, LT, and CCT (interclass correlation coefficient > 0.75). Bland-Altman plots showed a narrower 95% limit of agreement (-0.35 to 0.31) between Revo NX and IOLMaster 700 in measuring AL. Conclusions: Despite the higher measurement failure rate in eyes with cataract, the Revo NX showed very good agreement with the IOLMaster 700 and Lenstar LS 900 optical biometers in measuring AL, ACD, LT, and CCT. However, ACD and LT measurements cannot be considered interchangeable between these devices.

Changes in Corneal Biomechanical Properties After Small-Incision Lenticule Extraction and Photorefractive Keratectomy, Using a Noncontact Tonometer.

PURPOSE: The aim of this study was to evaluate and compare early corneal biomechanical changes after small-incision lenticule extraction (SMILE) and photorefractive keratectomy (PRK). METHODS: The study comprised 74 patients eligible for refractive surgery, equally allocated to PRK (37 patients) and SMILE (37 patients). Corneal biomechanical properties were recorded and compared between the 2 groups at preoperatively and 3 months after surgery using a dynamic ultra-high-speed Scheimpflug camera equipped with a noncontact tonometer. RESULTS: Both procedures significantly affected corneal biomechanical properties at 3 months after surgery. Patients in the PRK group showed significantly better results for deformation amplitude ratio (DA ratio) ( P = 0.03), maximum inverse radius (InvRadMax) ( P = 0.02), and A2 time ( P = 0.03). The mean changes in DA ratio, HC radius, InvRadMax, and Ambrosio relational thickness were significantly higher in the SMILE group in comparison with those of the PRK group (all, P < 0.05). In both groups, change in CCT was significantly correlated with changes in DA ratio and InvRadMax ( P < 0.05). CONCLUSIONSS: Both SMILE and PRK refractive surgeries significantly altered corneal biomechanical properties but the changes were more prominent after SMILE.

Efficacy of five-flash intense pulsed light therapy technique in patients with meibomian gland dysfunction.

CLINICAL RELEVANCE: Meibomian gland dysfunction is the main cause of evaporative dry eye disease and can lead to ocular discomfort and ocular surface damage. Early diagnosis and management of this condition can prevent its impact on patients 'visual health and quality of life. BACKGROUND: In the last decade, intense pulsed light therapy (IPL) has been introduced as a therapeutic option for patients with meibomian gland dysfunction (MGD). Various treatment modalities and protocols have been reported to increase the efficacy of this technique. This study aimed to assess the efficacy of a novel five-flash IPL technique in combination with home-based therapy and to compare it with conventional home care alone in patients with MGD. METHODS: In a randomised controlled trial, 100 symptomatic MGD patients were enrolled. The treatment group underwent three sessions of a five-flash IPL therapy. For all participants, eyelid warming, lid hygiene and lubricant therapy was prescribed. Ocular surface parameters were compared for control and treatment groups. RESULTS: Ocular Surface Disease Index (OSDI), non-invasive keratograph tear break up time (NIKBUT), fluorescein TBUT, MG expressibility, meibum quality and tear osmolarity were improved at follow up visits in both groups (p < 0.05). On day 75, NIKBUT was significantly higher in the IPL group (p = 0.045). The IPL treatment effect was not statistically significant (p > 0.05), except for bulbar and limbal hyperaemia (p = 0.02 and p = 0.02). In both groups, younger patients showed more improvement in NIKBUT (p = 0.02, r = -0.32; p < 0.001, r = -0.52). CONCLUSION: IPL therapy combined with conventional home-based therapy, and home care alone are both effective for patients with MGD. IPL may have an additional role in the improvement of ocular hyperaemia.

Corneal Ectasia after Laser-Assisted Small-Incision Lenticule Extraction: The Case for an Enhanced Ectasia Risk Assessment.

Purpose: To present a case of asymmetric progressive corneal ectasia following femtosecond laser-assisted small-incision lenticule extraction. Methods: After obtaining a patient's consent, preoperative and postoperative findings were represented in this case report. Results: A 29-year-old woman presented with normal preoperative Placido disk-based corneal topography and tomographic findings. The corrected refractive error was -4.00 and -4.50 -1.00 × 177 in the right and left eye, respectively, with a maximal lenticule thickness of 87 and 115 µm OD/OS. Twenty months postoperatively, the patient presented with decreased vision in the left eye and mild ectatic changes in corneal shape in both eyes. The retrospective evaluation of the integrated rotating Scheimpflug tomography (Pentacam; Oculus, Wetzlar, Germany) and corneal biomechanical (Corvis ST) assessment revealed moderate susceptibility for corneal ectasia in the right eye and a significant corneal ectasia in the left eye. Conclusion: This case corroborates the need for an enhanced multimodal approach to characterize the risk for postoperative corneal ectasia after laser vision correction.

The Effect of Meibomian Gland Dysfunction Treatment on Sleep Quality.

PURPOSE: To assess the therapeutic efficacy of a combinational therapy, including conventional treatment and intense pulsed light (IPL) technique on sleep quality of patients with meibomian gland dysfunction (MGD). METHODS: Fifty participants with a clinical diagnosis of MGD were enrolled in this study. Participants underwent three sessions of IPL therapy. There was a 2-week interval between IPL sessions 1 and 2 and 1 month between sessions 2 and 3. Treatment was supplemented with conventional home-based therapy (including lid hygiene, warm compress, eyelid massage, and lid margin scrub) for MGD. Dry eye symptomatology, tear film, and ocular surface parameters were evaluated at baseline (day 0) and days 15, 45, and 75. Sleep quality was assessed before and after the study using Pittsburgh Sleep Quality Index (PSQI). RESULTS: PSQI components improved significantly at day 75 in comparison with the baseline (all P < 0.05). Ocular Surface Disease Index (OSDI) score, noninvasive Keratograph tear break-up time (NIKBUT), fluorescein tear break-up time (FTBUT), meibomian gland expressibility, meibum quality score, and tear osmolarity improved at follow-up visits (P < 0.05). Younger patients showed more improvement in NIKBUT, sleep quality, and duration (P = 0.024, P = 0.047, and P = 0.008). Sleep latency decreased with increased NIKBUT and FTBUT and decreased OSDI score (P = 0.001, P = 0.005, and P = 0.041). CONCLUSIONS: The treatment of MGD is effective for improving sleep quality. Younger patients may preferentially benefit from the treatment.

Global Prevalence of Meibomian Gland Dysfunction: A Systematic Review and Meta-Analysis.

Purpose: The purpose of this study is to assess the pooled prevalence of meibomian gland dysfunction (MGD) and evaluate its risk factors by gender, age, and ethnicity.Methods: Articles were searched reporting the prevalence of MGD from PubMed, Scopus, Web of Science, and Embase databases.Results: The estimated pooled prevalence of MGD was 0.358 (95% CI 0.26-0.46; I2: 99.57%). The prevalence of MGD was 0.358 (95% CI 0.24-0.50) in clinical and 0.359 (95% CI 0.22-0.52) in population-based studies. Men were more prone to MGD than women (OR: 1.24, 95% CI 1.01-1.52, p = 0.034). The rate of MGD was between 21.2% and 29.5% in Africans and Caucasians, to 71.0% in Arabs, and 67.5% in Hispanics.Conclusion: MGD is a quite prevalent disorder with an estimated pooled prevalence of 35.8%. Men are more prone to MGD than women. There is a large variation between studies in terms of quality, sample size, age ranges, diagnostic criteria, and ethnicity.

Serum 25-Hydroxyvitamin D, Selenium, Zinc and Copper in Patients with Keratoconus.

PURPOSE: To assess the possible association between keratoconus (KC) and serum levels of 25-hydroxyvitamin D (25OHD), Selenium (Se), Zinc (Zn), and Copper (Cu) and to compare it with age-matched healthy subjects. METHODS: One hundred patients with KC and 100 normal subjects were included. The two groups were compared for serum 25OHD and serum levels of three trace elements: Se, Zn, and Cu. These factors were also compared between groups with different KC stages. RESULTS: Serum levels of vitamin D, Zn, Cu, and Se were significantly different between the KC and normal groups (P = 0.006, P = 0.015, P = 0.004, and P = 0.038, respectively). Although a lower level of 25OHD was found in severe stages of KC, it was not significantly different among different KC groups (P = 0.441). KC stage groups were not significantly different for mean serum Zn, Cu, and Se (P = 0.130, P = 0.98, P = 0.113, respectively). Although the Cu/Zn ratio was higher in cases than in controls, there was no significant difference between the two groups and between KC stages (P = 0.168, P = 0.143, respectively). CONCLUSION: Lower serum 25OHD, Cu, Zn, and Se were found in the KC group compared to the control group. The results of this study suggest that a lower antioxidative activity may be involved in the possible etiology of KC.

Refractive outcome of intravitreal bevacizumab injection in comparison to spontaneous regression of retinopathy of prematurity (ROP).

Purpose: To assess refractive errors in preterm infants following intravitreal bevacizumab (IVB) injection for retinopathy of prematurity (ROP) and to compare it with premature babies with spontaneous regressed ROP.Materials and Methods: Eighty seven premature infants were included in this study, comprising group1: 38 infants who underwent IVB monotherapy, and group2: 49 infants with spontaneously regressed ROP. Cycloplegic refraction was performed for all infants at 1-year adjusted age and the refractive outcome was compared between the groups.Results: At 1- year adjusted age, the mean SEQ value was not significantly different between group 1 and 2 (p = .646). Four eyes (10.5%) in group1 and 4 eyes (8.2%) in group 2 were myopic. Also, refractive anisometropia was found in 9 infants (23.7%) from group1 and 5 infants (10.2%) in groups 2, which was not significantly different between groups (χ2 (1, n = 87) = 2.87, p = .081). At the time of follow up, none of our cases were strabismic. After making an adjustment for gestational age and birth weight in a logistic regression model, mean SEQ was not significantly different between two groups (p = .61)Conclusion: At adjusted 1 year of age, refractive outcomes were not significantly different between premature infants who underwent IVB injection and the infants with spontaneous regression of ROP. Further studies with longer duration are warranted to elucidate the effects of IVB on the emmetropization process. Biometry assessments would be helpful in this regard.

The effect of eye dominancy on patients' cooperation and perceived pain during photorefractive keratectomy.

PURPOSE: To find a possible association between patients' cooperation, perceived pain, and ocular dominance in patients who undergo photorefractive keratectomy (PRK). METHODS: One hundred-one eligible candidates for PRK refractive surgery were recruited. Preoperative exams were performed for all patients, and the dominant eye was specified. The surgeon was unaware about which eye was dominant. After surgery, the surgeon completed a cooperation score form for each patient. Ocular cyclotorsion, cooperation, and perceived pain scores were compared between the first-second eye surgeries and between dominant-non-dominant eyes surgeries. RESULTS: The dominant eye was the right eye in 68 patients and the left eye in 33 patients. First, eye surgery was performed on the dominant eye in 56 patients and on the non-dominant eye in 45 patients. Cooperation score and perceived pain were not significantly different between the first and second eye surgeries (P = 0.902 and P = 0.223, respectively), but cyclotorsion was more in the second eye (P = 0.031). Cooperation score, pain score, and cyclotorsion were not significantly different between dominant and non-dominant eye surgeries (P = 0.538, P = 0.581, and P = 0.193, respectively). Also, there was no correlation between cooperation score and duration of the surgery for the first or second eye (P = 0.12 and P = 0.78). CONCLUSION: During PRK surgery, the patients' cooperation and perceived pain did not seem to be associated with eye laterality or dominancy.

Effect of night work on image quality of optical coherence tomography angiography.

PURPOSE: To assess the effect of night shift work on image quality and artifacts when performing optical coherence tomography angiography (OCT-A). METHODS: In a prospective case series study, twenty nurses underwent OCT-A in two separate sessions: early in the morning before duty shift and at the end of a night shift. Quantitative measurements of horizontal and vertical saccadic, blink, and stretch artifacts and also signal strength of the images were recorded. Moreover, using visual analogue scale of pain (VAS), the perceived pain and discomfort by blue focus light and red scanning laser were recorded. RESULTS: Vertical and horizontal saccades, blink, and stretch artifacts were significantly higher after the night shift (P = 0.004, P = 0.015, P < 0.001, and P < 0.001, respectively). Signal strength was not significantly different between the two measurements (P = 0.71). Also, the level of discomfort which was experienced by blue focus light and red scanning laser light was significantly higher after the night shift (P = 0.009 and P = 0.004, respectively). CONCLUSION: Our study suggests that night shift may affect image quality of OCT-A by imposing more artifacts.

Preferred Learning Styles among Ophthalmology Residents: An Iranian Sample.

PURPOSE: This study was performed to assess the learning styles of a sample of Iranian residents through Kolb's and VARK questionnaires. METHODS: In this descriptive-analytical study, 45 ophthalmology residents of Mashhad University of Medical Sciences were enrolled. Kolb's and VARK questionnaires were provided, and residents were oriented and guided on how to complete them. RESULTS: Forty-three out of the forty-five ophthalmology residents completed the questionnaire (95.5% response rate). The preferred learning style among ophthalmology residents was assimilative (51.2%), followed by convergent (37.2%), accommodative (7.7%), and divergent (4.7%), based on Kolb's questionnaire. According to the results of the VARK questionnaire, most ophthalmology residents were auditory learners (34.9%), followed by multimodal learners (30.2%). In addition, there was no significant relation between genders, stage of residency, and Kolb's and VARK learning styles (P > 0.05 for all). CONCLUSION: The most preferred learning styles of ophthalmology residents were assimilative and auditory. Considering the dominant learning styles of learners and incorporating various teaching methods are recommended to enhance the learning among residents.

Short-Term Results of Sutureless Scleral Tunnel Trabeculectomy Using Adjunctive Topical Bevacizumab.

This study was performed to assess the short-term effect of sutureless scleral tunnel trabeculectomy procedure with and without topical bevacizumab. Thirty patients with Primary Open-Angle Glaucoma (POAG) were enrolled and randomly divided to two groups. Patients in the first group (15 patients) underwent sutureless trabeculectomy without topical bevacizumab and patients in the second group (15 patients) underwent sutureless trabeculectomy with 1.25 mg of topical bevacizumab. Intraocular Pressure (IOP) of both groups was measured by an expert ophthalmologist, without awareness of the patient's study group before the operation and six months post-operatively. Out of 30 patients in this study, six females (40%) and nine males (60%) underwent the sutureless trabeculectomy procedure (group A) as well as seven females (46.7%) and eight males (53.3%) underwent sutureless trabeculectomy with topical bevacizumab (group B). The mean age of the patients was not significantly different between the two groups (P = 0.91). A statistically significant difference in time variation of IOP was found between the two groups (P < 0.001). Mean IOP was 18.4 ± 4.35 mmHg in the sutureless group without bevacizumab and 11.73 ± 2.12 mmHg in the sutureless group with bevacizumab, six months post-surgically. No statistical significant differences were found in the baseline IOP between the two groups (P = 0.28). However, IOP changed significantly in group A and B from baseline to six months post-operatively (P = 0.004 and P < 0.001 respectively). According to the current findings, the sutureless trabeculectomy procedure is an effective surgical method for reduction of IOP. Addition of a single dose of 1.25 mg topical bevacizumab was more effective in reduction of IOP compared to sutureless trabeculectomy alone.

A comparative study on visual and optical performance of Akreos AO and Kontur AB IOLs after phacoemulsification cataract surgery.

PURPOSE: Akreos AO and Kontur AB are two commonly used intraocular lenses (IOLs) in Iran. This study was designed to evaluate the visual performance of these lenses. METHODS: In a comparative interventional study, 35 patients (70 eyes) were recruited, and each IOL was implanted in one eye of the patients, randomly. Best corrected visual acuity (BCVA), contrast sensitivity, aberrometric analysis, and depth of focus were evaluated 1 month and 3 months postoperatively. A visual quality questionnaire was also filled for each eye, and the results were compared. RESULTS: Mean age of the patients was 60.97 ± 7.00 years. BCVA was not significantly different between the two eyes, before, 1 month, and 3 months postoperatively (p > 0.05 for all). Photopic and mesopic contrast sensitivity was not different between the two lenses instead of photopic 18 cycles per degree, 3 months postoperatively and in mesopic 6 cycles per degree 1 month postoperatively (p = 0.034 and p = 0.002, respectively). Aberrometric factors including HoRMS, Total RMS, and Higher order without Z(4,0) were not significantly different between the two lenses (p > 0.05 for all), but they were slightly lower for Akreos AO. Post-operative distance-corrected visual acuity for intermediate and near vision were not different between the two groups (p > 0.05, respectively). CONCLUSION: Visual performance of Akreos AO and Kontur AB is similar. However, contrast sensitivity and aberrometric parameters are slightly better for Akreos AO IOL.

Effects of Biebersteinia multifida hydro-ethanol extract on proliferation and apoptosis of human prostate cancer and human embryonic kidney cells.

OBJECTIVE: Biebersteinia (Geraniaceae) has a history of use in traditional medicine in some countries including Iran. In the present study, cytotoxic and apoptogenic properties of hydro-ethanol extract of B. multifidi was investigated on human prostate cancer cell lines (PC3 and DU 145) and human embryonic kidney 293 (HEK293) cells. MATERIALS AND METHODS: Cells were cultured in RPMI-1640 medium supplemented with 10% FBS at 37ºC in a humidified atmosphere of 95% air and 5% CO2. The root of the plant was macerated with EtOH 70%. Cytotoxic activity of ethanol extract of B. multifida was assessed using alamarBlue® assay after 48 hr of treatment. Apoptotic cells were stained with propidium iodide (PI) and detected by flow cytometry (sub-G1 peak). RESULTS: B.multifidi had cytotoxic effect on malignant cells and normal HEK293 cells in a dose-dependent manner and significantly decreased the cell viability (IC50 values were between 199.2 and 302.9 µg/ml). B. multifida increased the sub-G1 peak in flow cytometry histogram of treated PC3 cells compared to control showing the induction of apoptosis and DNA fragmentation. CONCLUSION: Due to cytotoxic and apoptotic activity of B. multifida, the plant is suggested for further phytochemical analysis and mechanistic evaluation.

The corneal volume and biomechanical corneal factors: Is there any orrelation?

BACKGROUND: The aim of this study was to determine the correlation between corneal hysteresis (CH) and the corneal resistance factor (CRF), which are both novel methods of analyzing ocular rigidity/elasticity, and various corneal characteristics, mainly corneal volume in normal subjects. METHODS: This cross-sectional study included 500 normal eyes of volunteers. An ocular response analyzer (ORA) was used to measure CH and CRF. Patient age and the Pentacam-measured corneal volume (CV), posterior elevation, anterior elevation, corneal curvature, central corneal thickness (CCT), corneal thickness of apex (CTA), and corneal thinnest thickness (CTT) were compared with CH and CRF. Statistical significance was defined at p < 0.05. RESULTS: The mean CH and CRF for all eyes were 9.9 ± 1.4 mmHg and 10.1 ± 1.6 mmHg, respectively. The mean CVs of the 3, 5, 7, and 10 mm zones for all eyes were 3.8 ± 0.2 mm(3), 11.2 ± 0.6 mm(3), 24.3 ± 1.4 mm(3), and 60.1 ± 3.5 mm(3), respectively. The correlations between CV and the hysteresis or CRF were significant in all zones. The CV of the 7-mm zone had the strongest correlation with CH (r = 0.438) and the CV of the 5-mm zone had the strongest correlation with CRF (r = 0.574). CONCLUSIONS: CH and CRF correlate with CV. Moreover, the correlation between CV and CRF is stronger than that between CV and CH. The CV may be valuable for determining patient's qualification for and predicting the outcome of refractive surgery. It would also be helpful in other cases in which corneal biomechanics are important.

A comparative study of the usefulness of color vision, photostress recovery time, and visual evoked potential tests in early detection of ocular toxicity from hydroxychloroquine.

Ocular toxicity from hydroxychloroquine (HCQ) is rare, but its potential permanence and severity makes it imperative to employ measures and screening protocols to minimize its occurrence. This study was performed to assess the usefulness of color vision, photo stress recovery time (PSRT), and visual evoked potentials (VEP) in early detection of ocular toxicity of HCQ, in patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). 86 patients were included in the study and divided into three groups: (1) with history of HCQ use: interventional 1 (Int.1) without fundoscopic changes and Int.2 with fundoscopic changes; and (2) without history of HCQ use, as control. Visual field, color vision, PSRT and VEP results were recorded for all patients and the effect of age, disease duration, treatment duration and cumulative dose of HCQ on each test was assessed in each group. There was a significant relationship among PSRT and age, treatment duration, cumulative dose of HCQ and disease duration (P<0.001 for all). Color vision was normal in all the cases. P100 amplitude was not different between the three groups (P=0.846), but P100 latency was significantly different (P=0.025) and for Int.2 it was greater than the others. The percentage of abnormal visual fields for Int.2 was more than Int.1 and control groups (P=0.002 and P=0.005 respectively), but Int.1 and control groups were not significantly different (P>0.50). In the early stages of maculopathy, P100 latencies of VEP and PSRT are useful predictors of HCQ ocular toxicity. In patients without ocular symptoms and fundoscopic changes, the P100 latency of VEP predicts more precisely than the others.