Ocular surface staining: Current concepts and techniques.

The health of the ocular surface is vital for clear vision and comfort. Various factors can adversely influence the ocular surface and tear film homeostasis, and these include procedures like cataract and corneal refractive surgery. It is, therefore, important to assess the integrity of the ocular surface in a rapid, predictable, and consistent manner in the clinic. Various tests and devices have been described, and while these are useful, this article highlights the importance of using fluorescein staining of the ocular surface in detecting changes. This is a simple, inexpensive, rapidly performed test that is available in most eye clinics. However, a proper technique of dye instillation and assessment is important to recognize the changes that can occur. Once detected, these changes can be quantified, and the location and patterns can be used to diagnose the diseases that are present; these changes can also be used to monitor treatment outcomes and disease progression. The article discusses the technique, assessment, and interpretation of fluorescein staining of the ocular surface, along with the role of the two other vital dyes - rose bengal and lissamine green.

Severe and recurrent interface hemorrhage after endothelial keratoplasty.

PURPOSE: To report the occurrence and management of recurrent hemorrhage after Descemet stripping endothelial keratoplasty (DSEK) in a patient with pseudophakic bullous keratopathy. METHODS: An 84-year-old Chinese woman on two oral antiplatelet drugs underwent DSEK in her left eye. Preoperative best-corrected visual acuity was 20/30 OD and 14/200 OS. Intraoperative bleeding was noted from the iris root. Surgery was completed uneventfully, and interface was thoroughly irrigated in the end. Slit lamp examination on the first postoperative day showed a dense interface hemorrhage and an intraocular pressure of 24 mm Hg. Repeat interface irrigation was carried out on postoperative day 4, but the hemorrhage appeared again on the following day. Donor lenticule was well apposed to the corneal stroma, and visual acuity was hand motions in the operated eye. No further surgical interventions were performed. Corticosteroid eye drops were continued four times a day in the operated eye, and the patient was advised weekly follow-up. RESULTS: Over the next 4 weeks, the interface blood gradually started to clear from the central cornea. At the end of 4 months postoperatively, the interface hemorrhage disappeared completely. A final best-corrected visual acuity of 20/80 was achieved. Specular microscopy revealed an endothelial cell density of 1375 cells/mm2. CONCLUSIONS: Interface hemorrhage is a known complication after DSEK surgery. Recurrent hemorrhage may be expected in patients on oral antiplatelet treatment. In cases without associated graft dislocation, conservative management can still result in good visual outcome.

A new era in corneal transplantation: paradigm shift and evolution of techniques.

Penetrating keratoplasty is the replacement of a diseased cornea with a full-thickness donor graft. In the last century, this 'gold standard' procedure was long established as the treatment of choice for various corneal diseases. The classical indications for a penetrating keratoplasty entailed optical, tectonic, therapeutic, and cosmetic issues. Over the past decade however, surgical advances have now enabled operations involving the cornea to be performed with a major shift in emphasis, such that penetrating keratoplasty has given way to lamellar (layered) keratoplasty. This review provides the latest updates on developments in the field of corneal transplantation and the nomenclature of different types of component surgery, particularly from the perspective of Hong Kong.

Inflammation and dry eye disease-where are we?

The presence of inflammation in dry eye disease (DED) results in increased patient symptomatology, ocular surface damage and worsening tear dysfunction. It also affects the health of meibomian glands and their secretions which further aggravates ocular surface disease. This article reviews current knowledge regarding ocular surface inflammation in DED and explores the relationships between the vicious cycles of DED, inflammation and meibomian gland dysfunction (MGD). The clinical evaluation of eyes with such changes, markers that identify the presence of inflammation on the ocular surface and current treatment options are discussed.

Evaluation of ocular surface and tear function - A review of current approaches for dry eye.

An increasing prevalence of dry eye disease in the past decade has resulted in a greater focus on diagnostic methods for this condition. There has been a proliferation of technologies that attempt to quantify various aspects of tear function and ocular surface health. However, a cost-effective, simple, and efficient method remains elusive. In the Indian context, the majority of these patients present to the general ophthalmologist, and a clinical approach that is quick and easy to perform would allow widespread usage for accurate diagnosis. This article reviews currently available methods and their relevance to the general ophthalmologist.

Adjunctive effect of acupuncture to refractive correction on anisometropic amblyopia: one-year results of a randomized crossover trial.

OBJECTIVES: To evaluate the safety and adjunctive effect of acupuncture added to refractive correction for anisometropic amblyopia in younger children. DESIGN: Prospective, randomized, controlled, crossover trial. PARTICIPANTS: We included 83 children aged 3 to <7 years with untreated anisometropic amblyopia and baseline best-corrected visual acuity (BCVA) of 20/40 to 20/200 in the amblyopic eye. METHODS: Participants were randomized to receive spectacles alone (group 1; n = 42) or spectacles + acupuncture (group 2; n = 41) for 15 weeks, and were then crossed over to receive the other regimen for another 15 weeks. The BCVA in both eyes was measured at baseline and every 5 (±1) weeks for the initial 45 weeks and at 60 (±1) weeks. MAIN OUTCOME MEASURES: BCVA in the amblyopic eye at 15, 30, and 60 weeks. RESULTS: The mean baseline BCVA in the amblyopic eye was 0.50 and 0.49 logarithm of the minimum angle of resolution (logMAR) in groups 1 and 2, respectively. After 15 weeks of treatment, the BCVA had improved by a mean of 2.2 lines in group 1 and 2.9 lines in group 2. The mean difference in BCVA between groups was 0.77 lines (95% confidence interval (CI), 0.29-1.3; P = 0.0020) with baseline adjustment. BCVA of ≤0.1 logMAR was achieved in 14.6% of the patients in group 1 and 57.5% in group 2 (P<0.00010). After the regimens were crossed over at 30 weeks, group 1 had a mean of 1.2 (95% CI, 0.98-1.48; P = 2.0 × 10⁻¹²) lines additional improvement from the 15-week BCVA, whereas in group 2 the mean improvement was 0.4 (95% CI, 0.19-0.63; P = 0.0010) lines. The proportions of responders, resolution, and participants achieving a BCVA of ≤0.1 logMAR at 30 weeks were similar between groups. After completion of acupuncture, only 1 participant had >1 line of VA decrease to 60 weeks. Acupuncture was well-tolerated by all children, and no severe adverse effect was encountered. CONCLUSIONS: Acupuncture is a potentially useful complementary treatment modality that may provide sustainable adjunctive effect to refractive correction for anisometropic amblyopia in young children. Further large-scale studies seem warranted. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

A 3D Polymer Scaffold Platform for Enhanced in vitro Culture of Human & Rabbit Buccal Epithelial Cells for Cell Therapies.

BACKGROUND: Buccal mucosal epithelial cells show promising application for various regenerative medicine approaches. In this study, we examined the feasibility of culturing rabbit and human buccal mucosal epithelial cells in a novel thermoreversible gelation polymer (TGP) scaffold, without feeder layers or other foreign proteins. METHODS & RESULTS: The results of this 28-day in vitro culture, u sing the conventional technique (2D) and TGP (3D) showed that the epithelial cell morphology could be maintained only in the TGP group while cells in the 2D group de-differentiated to fibroblast morphology in both human and rabbit samples. CK3 expression, a marker for epithelial differentiation was higher in 3D-TGP cultured cells than 2D. CONCLUSION: TGP based in vitro cell culture is a prospective methodology to culture buccal mucosal epithelial cells efficiently without using foreign biological components for tissue engineering applications.

The effect of parental history of myopia on children's eye size and growth: results of a longitudinal study.

PURPOSE: To evaluate the effect of parental myopia on eye size and growth in Chinese children. METHODS: A school-based, cross-sectional survey was performed in Chinese children 5 to 16 years of age. A longitudinal cohort study was conducted 1 year later. The effects of parental myopia, parental education level, and near work performed by the child on the refractive error and ocular biometry of the child were assessed. RESULTS: There were 7560 children enrolled in the initial study (response rate: 76.3%). One year later, 4468 children (response rate: 75.9%) in the original cohort (with the exception of those who had completed primary schooling) were evaluated, to determine eye growth. Although children with a stronger parental history of myopia tended to be less hyperopic before the onset of myopia (spherical equivalent refraction [SER] = 0.43 D, 0.67 D, and 0.68 D in children with two, one, and no myopic parents respectively; P = 0.007), the axial lengths did not follow the same pattern (axial length [AL] = 23.11, 23.07, and 23.15 mm; P = 0.429). Eye growth and myopic shift in refraction occurred more rapidly among children with a stronger parental history of myopia (annual AL growth/myopia progression = 0.37 mm/-0.22 D, 0.26 mm/-0.07 D, and 0.20 mm/-0.02 D in children with two, one, and no myopic parents, respectively; P < 0.001). CONCLUSIONS: Ocular biometric data in Chinese children suggest that parental history of myopia influences the growth rate of the eye, rather than its size before the onset of myopia, as previously reported in Caucasian children. Further longitudinal studies involving children of different ethnicities are warranted.

Descemet stripping endothelial keratoplasty: effect of the surgical procedure on corneal optics.

PURPOSE: To determine the changes in corneal optical performance after posterior lamellar corneal transplantation. DESIGN: Retrospective case series. METHODS: The anterior segment in four eyes of four patients who underwent Descemet stripping endothelial keratoplasty (DSEK) with cataract extraction and intraocular lens (IOL) implantation were imaged with the Visante anterior segment optical coherence tomography [OCT] (Carl Zeiss Meditec, Dublin, California, USA). The curvature of the posterior surface of the donor graft was compared with that of the host cornea, and corneal thickness was measured. RESULTS: All eyes had a hyperopic refractive error after surgery. The posterior corneal curvature after surgery was more than that before surgery. Average preoperative keratometry was 43.4 diopters (D), and after surgery, it was 42.8 D using keratometry. However, when the postsurgical corneal power was calculated using the Gaussian optics method, the average value was 40.8 D. CONCLUSIONS: The addition of a donor corneal graft to the posterior surface of decompensated corneas may lessen the effective optical power of the cornea and may have implications for IOL power calculations in these eyes.

Central corneal thickness measurements by ultrasound, Orbscan II, and Visante OCT after LASIK for myopia.

PURPOSE: To compare central corneal thickness measurements obtained with Orbscan II scanning slit topography, Visante optical coherence tomography (OCT), and ultrasound pachymetry in myopic eyes after LASIK. METHODS: This retrospective study included 34 consecutive patients (68 eyes) who underwent LASIK for the correction of myopia. Six months after surgery, central corneal thickness measurements were obtained using ultrasound pachymetry, Orbscan scanning slit topography, and Visante OCT. Data were analyzed using paired sample t test, Bland and Altman plot, and linear regression. RESULTS: Average postoperative central corneal thickness was 436.65+/-43.82 microm for ultrasound pachymetry, 422.84+/-51.04 microm for Orbscan (0.89 acoustic equivalent correction factor), and 422.26+/-42.46 microm for Visante. Compared to the ultrasound measurement, Orbscan and Visante measurements significantly underestimated the corneal thickness by 13.81+/-17.34 microm (P<.01) and 14.38+/-10.13 microm (P<.01), respectively. CONCLUSIONS: Both Orbscan and Visante OCT underestimated central corneal thickness compared to ultrasound pachymetry 6 months after LASIK, although measurements obtained with Visante OCT had better agreement and correlation with ultrasound pachymetry than with Orbscan.

Posterior corneal curvature measurements with peripheral fitting zones before and after myopic LASIK using Orbscan II.

PURPOSE: To compare pre- and postoperative posterior corneal curvature measurements in peripheral fitting zones using the Orbscan II topographer in patients undergoing myopic LASIK. METHODS: Retrospective analysis of preoperative and 3-month postoperative Orbscan II data of 194 eyes that underwent myopic LASIK at a university eye center. Posterior corneal power was estimated using the peripheral 7- to 10-mm fitting zones. The pre- and postoperative values were analyzed and compared. RESULTS: The mean difference in estimated pre- and postoperative power of the posterior cornea was -0.04 +/- 0.16 diopters (P < .01). CONCLUSIONS: The difference in posterior corneal curvature measurement following myopic LASIK using the peripheral fitting zone with the Orbscan II, as compared to the preoperative values, is clinically insignificant.

Spontaneous closure of anterior capsule tear.

We report a case of anterior capsule tear that was closed spontaneously by fibrotic tissue during the postoperative period. The tear was inadvertently created during intraocular lens (IOL) implantation in the capsular bag. The IOL remained stable in the postoperative period, with excellent centration and no compromise in vision.

Anterior segment ischemia after two-muscle surgery in a patient with radiation-treated nasopharyngeal carcinoma.

Anterior segment ischemia after strabismus surgery is a rare occurrence. Risk factors include single-stage surgery of three or more muscles in one eye, dysthyroid eye disease, and advanced age. The authors report a case of anterior segment ischemia after single-stage surgery of two horizontal muscles without previous reported risk factors. However, the patient had received radiotherapy for nasopharyngeal carcinoma more than 20 years ago. The case was successfully treated with systemic steroids but with reduced best-corrected visual acuity. Previous radiotherapy in the related orbital field may be a new risk factor for this condition.

Calculating graft size and position in rotational corneal autografting: a simplified approach.

In eyes with eccentric corneal opacities partially involving the pupillary area, using a rotational corneal autograft, can help restore vision without the immunological complications associated with allografts. In this report, we describe a simple intraoperative method for determining trephine size and placement for rotational corneal autografting. This surgical approach helps in the planning and execution of rotational corneal autografting, to obtain good outcomes.

Repeatability and reproducibility of pachymetric mapping with Visante anterior segment-optical coherence tomography.

PURPOSE: To determine the repeatability and reproducibility of central and peripheral corneal pachymetry mapping with anterior segment-optical coherence tomography (AS-OCT). METHODS: An observational cross-sectional study involving two groups: 27 healthy eyes and 20 eyes with keratoconus. Each subject underwent scanning sessions with AS-OCT to determine intraobserver repeatability, interobserver reproducibility, and additionally for healthy eyes, intersession reproducibility for different regions of the cornea up to a 10-mm diameter. Main outcome measures were reproducibility and repeatability coefficients, intraclass correlation coefficients, and coefficients of variation of the average central (0-2 mm), pericentral (2-5 mm), transitional (5-7 mm), and peripheral (7-10 mm) corneal thicknesses generated by the Visante AS-OCT (Carl Zeiss Meditec, Inc., Dublin, CA) pachymetric mapping protocol. RESULTS: The coefficients of repeatability were less than 2% in healthy subjects and less than 3% in patients with keratoconus. The reproducibility coefficients were less than 2% and 4% in healthy subjects and patients with keratoconus, respectively. There was no significant difference between scans obtained by different observers or during different visits. The intraclass correlation coefficients were greater than 0.99 and 0.97 in healthy subjects and patients with keratoconus, respectively. CONCLUSIONS: With the pachymetric mapping protocol of Visante AS-OCT, these results suggest that central and peripheral corneal thickness measurements in healthy subjects and in eyes with keratoconus are repeatable and reproducible.

Agreement among 3 methods to measure corneal thickness: ultrasound pachymetry, Orbscan II, and Visante anterior segment optical coherence tomography.

PURPOSE: To assess the agreement of central and paracentral corneal thickness measurements between ultrasound pachymetry (USP), Orbscan II, and Visante anterior segment optical coherence tomography (ASOCT). DESIGN: Observational cross-sectional study. PARTICIPANTS: Seventy eyes of 70 subjects. METHODS: Each subject underwent Orbscan II (using an acoustic equivalent correction factor of 0.89), ASOCT, and USP examination. Bland-Altman plots were used to evaluate agreement between instruments. MAIN OUTCOME MEASURES: Central and paracentral corneal thickness measurements by the 3 methods and agreement, as evaluated by 95% limits of agreement (LOA). RESULTS: The mean measurements of average central corneal thickness by USP, Orbscan II, and ASOCT were 553.5+/-30.26 microm, 553.22+/-25.47 microm, and 538.79+/-26.22 microm, respectively. There was high correlation between instruments: USP with ASOCT (r = 0.936, P<0.001), USP with Orbscan II (r = 0.900, P<0.001) for central corneal thickness measurements, and Orbscan II with ASOCT for average paracentral 2- to 5-mm measurements (r = 0.947, P<0.001). The mean differences (and upper/lower LOA) for central corneal thickness measurements were 0.31+/-13.34 microm (26.44/-25.83) between USP and Orbscan II, 14.74+/-10.84 microm (36.0/-6.51) between USP and ASOCT, and 14.44+/-9.14 microm (32.36/-3.48) between Orbscan II and ASOCT. The average mean difference (and upper/lower LOA) between Orbscan II and ASOCT for paracentral 2- to 5-mm corneal thickness measurements was 10.35+/-8.67 microm (27.35/-6.65). CONCLUSION: Anterior segment optical coherence tomography underestimated corneal thickness compared with that measured with USP. Anterior segment optical coherence tomography had better agreement with the gold standard USP, as compared with Orbscan II. However, important discrepancies among instruments exist. Clinicians should be aware that corneal thickness measurements are influenced by the method of measurement and that, although highly correlated, these instruments should not be used interchangeably for the assessment of corneal thickness.

Comparison of outcomes of primary scleral-fixated versus primary anterior chamber intraocular lens implantation in complicated cataract surgeries.

OBJECTIVE: To compare the visual outcomes and complication profiles of primary scleral-fixated intraocular lens (SFIOL) versus primary anterior chamber intraocular lens (ACIOL) implantation in cataract surgeries complicated by inadequate capsular support. DESIGN: Retrospective, interventional, comparative cases series. PARTICIPANTS: Thirty-six eyes of 36 patients undergoing SFIOL implantation (group 1) and 46 eyes of 46 patients undergoing ACIOL implantation (group 2). METHODS: Retrospective analysis of medical records of a consecutive series of complicated cataract surgeries with primary SFIOL or ACIOL implantation. MAIN OUTCOME MEASURES: Postoperative best-corrected visual acuity (BCVA), intraoperative and postoperative complications, if any, and postoperative corneal endothelial cell counts. A multiple linear regression model was constructed with postoperative BCVA as the dependent variable and with IOL group (SFIOL vs. ACIOL), preoperative BCVA, surgeon's operative experience, planned operation, and patient's age as independent variables. RESULTS: Fifty-eight percent (group 1) and 37% (group 2) of patients underwent phacoemulsification, whereas the rest underwent extracapsular cataract extraction. The mean postoperative follow-up was 33.4+/-17.9 months (range, 6-61 months). Postoperative Snellen BCVA of 20/40 or better was achieved in 47.2% (group 1) and 71.7% (group 2) of patients (P = 0.038). Regression analysis showed that primary ACIOL implantation was associated with a significantly better postoperative BCVA of -0.157 on the logarithm of minimum angle of resolution scale (95% confidence interval, -0.306 to -0.007; P = 0.040), compared with primary SFIOL implantation. Although both the number of eyes with complications and the total number of complications were higher in the SFIOL group, the differences in early (P = 0.073) and late (P = 0.377) complications were not statistically significant. CONCLUSIONS: The results indicate that satisfactory results are achieved with primary implantation of current open-loop ACIOLs during cataract surgery complicated by loss of posterior capsule integrity. Eyes with these IOLs fared better than a cohort of eyes undergoing SFIOL implantation in a similar situation, at intermediate-term follow-up. Further prospective clinical trials with longer follow-up may help to evaluate the long-term visual outcomes and complication profiles after primary implantation of these lenses.

Visual function and postoperative care after cataract surgery in rural China: study of cataract outcomes and up-take of services (SCOUTS) in the caring is hip project, report 2.

OBJECTIVE: To study the postoperative visual function and uptake of refraction and second-eye surgery among persons undergoing cataract surgery in rural China. METHODS: Self-reported visual function was measured 10 to 14 months after surgery. Subjects with improvement of 2 or more lines with refraction were offered glasses, and those with significant cataract were offered second-eye surgery. RESULTS: Among 313 eligible subjects, 242 (77%) could be contacted; 176 (73%) of those contacted were examined. Interviewed subjects had a mean +/- SD age of 69.9 +/- 10.2 years, and 63.6% were female. The mean +/- SD visual function score was 88.4 +/- 12.3, higher than previously reported for cataract programs in rural China and significantly (P = .03) correlated with presenting vision. Forty-two percent of subjects had spectacles, more than half being reading glasses. Though 87% of subjects' vision improved with refraction, only 35% accepted prescriptions, the most common reason for refusal being lack of perceived need. Second-eye surgery was accepted by a total of 48% (85 of 176) of patients, cost being the biggest reason for refusal. CONCLUSIONS: Visual function was high in this cohort. Potential benefit of refraction and second-eye surgery was substantial, but uptake of services was modest. Programs to improve service uptake should focus on reading glasses and cost-reduction strategies such as tiered pricing.

Visual outcomes and astigmatism after sutureless, manual cataract extraction in rural China: study of cataract outcomes and up-take of services (SCOUTS) in the caring is hip project, report 1.

OBJECTIVE: To study the visual acuity and astigmatism of persons undergoing cataract extraction by local surgeons in rural China. METHODS: Visual acuity, keratometry, and refraction were measured 10 to 14 months postoperatively for all cataract cases during 4 months in Sanrao, China. RESULTS: Among 313 eligible subjects, 242 (77%) could be contacted, of whom 176 (73%) were examined. Of those who were examined, mean +/- SD age was 69.3 +/- 10.5 years, 66.5% were female, 35 had been operated on bilaterally at Sanrao, and 85.2% had a preoperative presenting visual acuity of 6/60 or worse. Presenting and best-corrected postoperative acuity in the eye that was operated on were 6/18 or better in 83.4% and 95.7%, respectively. Among 27 fellow eyes operated on elsewhere, 40.7% had a presenting acuity of 6/18 or better and 40.7% were blind (P < .001). Mean +/- SD postoperative astigmatism did not differ between 211 eyes that were operated on (-1.13 +/- 0.84 diopters) and 109 eyes that were not (-1.13 +/- 1.17 diopters; P = .27). Presence of operative complications (8.5%) and older age were associated with worse vision; bilateral surgery was associated with better vision. CONCLUSIONS: These results confirm the effectiveness of skill transfer in this setting, with superior outcomes to most studies in rural Asia and to eyes in this cohort operated on at other facilities.