Management of Dry Eye Disease for Intraocular Lens Power Calculation in Cataract Surgery: A Systematic Review.

Cataracts are characterized by the crystalline lens of the eye becoming cloudy, and dry eye disease (DED) is a multifactorial disease in which the homeostasis of the tear film is lost. As the prevalence of both diseases increases with age, there is a high prevalence of DED among patients who are candidates for cataract surgery. In recent years, cataract surgery has evolved from vision restoration surgery to refractive surgery. To achieve good surgical outcomes, it is necessary to minimize postoperative refractive error in intraocular lens (IOL) power calculation, which requires accurate preoperative keratometry measurements. A stable tear film is important for the accuracy and reproducibility of keratometry measurements, and DED may have a deleterious effect. In this study, original articles that focused primarily on findings related to this topic were evaluated. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Although appropriate DED diagnoses were not presented in the articles evaluated in this review, it was confirmed that the clinical signs of DED, particularly the shortening of the tear film break-up time (TBUT), negatively impact IOL power calculations. Improvement in these clinical signs might mitigate the negative effects on these calculations.

Treatment of Dry Eye Disease (DED) in Asia: Strategies for Short Tear Film Breakup Time-Type DED.

Dry eye disease (DED) is a multifactorial disorder in which tear fluid homeostasis is lost, resulting in increased tear film osmolarity and ocular surface irritation. In Asia, the short tear film breakup time-type DED, which has become a global problem in recent years, is common. While the mainstay of DED treatment in the West is the suppression of inflammation, the first goal of treatment is the stabilization of the tear film in Asia. To date, artificial tears and steroid eye drops have been the main treatment for DED. However, artificial tears require frequent administration of eye drops and thus pose adherence problems, while steroids have problems with side-effects (cataracts, increased intraocular pressure). This review evaluates the new generation therapies in Asia based on what is known about them and demonstrates that they are more effective for DED than traditional therapies such as artificial tears and steroids. Based on considerations, it is proposed that the optimal treatment for the short tear film breakup time-type DED is the initial application of mucin-secretion-enhancing eye drops (long-acting diquafosol) and oral supplements; and if additional treatment is needed, cyclosporine eye drops and the adjunctive therapies presented in this review are added.

A very early steroid responder after cataract surgery: a case report.

BACKGROUND: Increased intraocular pressure (IOP), a side effect of corticosteroid eye drops, typically develops during the first few weeks of administration, and steroid response is not generally considered a cause of increased IOP immediately after cataract surgery. CASE PRESENTATION: Here, I report a rare case of increased IOP due to steroid eye drops immediately after surgery. A man in his 80s presented with vision loss. Bilateral cataracts and pseudoexfoliation syndrome were confirmed. Postoperative eye drops including steroid eye drops were started immediately after cataract surgery in the right eye. High IOP was observed at the next and subsequent morning visits, but IOP normalized when steroid eye drops were discontinued. After surgery on the left eye, steroids were not administered postoperatively, and no increase in IOP was observed. CONCLUSION: This case report highlights that a very early steroid response may be potential cause of elevated IOP immediately after cataract surgery.

Predicting Residual Astigmatism in Cataract Surgery.

The purpose of this review is to evaluate the prediction of postoperative residual astigmatism and to determine the best prediction method for astigmatism correction. In recent findings for residual astigmatism in non-toric monofocal intraocular lens (IOL) implanted eyes, vector analysis can be used to correctly evaluate residual astigmatism by decomposing it. In predicting residual astigmatism, the with-the-rule (WTR) and against-the-rule (ATR) astigmatism components can now be almost predicted. This may be due to advances in inspection equipment and surgical technique. However, there are still issues with the oblique astigmatism component. In addition, corneal astigmatism is the most important predictor of postoperative residual astigmatism, and other predictors, such as refractive astigmatism, age, and lens thickness, have also been mentioned. However, all but corneal astigmatism are questionable because of the possibility of confounding variables. Total corneal astigmatism is more accurate in predicting residual astigmatism than anterior corneal astigmatism. Several predictions of residual astigmatism have been reported, but complete prediction has not been possible. Further research is needed, especially in predicting oblique astigmatism. However, I emphasize that the accuracy of predicting WTR and ATR astigmatism has improved considerably and can be predicted using regression equations with total corneal astigmatism.

Prediction of postoperative refractive astigmatism before toric intraocular lens implantation.

BACKGROUND: To determine the preoperative factors influencing refractive astigmatism after cataract surgery for astigmatism correction by toric intraocular lens (IOL) implantation and to evaluate the prediction model using these factors. METHODS: Prospective, observational case series. The right eyes of forty consecutive patients with preoperative corneal astigmatism of the total cornea of 1.5 diopters (D) or more in magnitude and scheduled for implantation of a non-toric IOL during cataract surgery with a 2.4-mm temporal clear corneal incision were examined prospectively. The vertical/horizontal astigmatism component (J0) and oblique astigmatism component (J45) of refractive and corneal astigmatism were converted using power vector analysis. Multivariate regression analysis was performed with refractive astigmatism at three months postoperatively as the dependent variable, and preoperative parameters including age, sex, refractive astigmatism, corneal astigmatism, sphere, spherical equivalent, intraocular pressure, corneal thickness, anterior chamber depth, lens thickness, lens positions (tilt and decentration), axial length, and corneal higher order aberrations as independent variables. The root mean square (RMS) errors were calculated to express the regression model fit. RESULTS: The regression model for the J0 component was [Formula: see text] (R2 = 0.96, P < 0.001). The model for the J45 component was [Formula: see text] (R2 = 0.72, P < 0.001). The mean RMS errors for preoperative corneal astigmatism alone and the multivariate model were 0.58 D and 0.46 D, respectively. There was a statistically significant difference between them (P = 0.02). CONCLUSIONS: Refractive astigmatism after implantation of a toric IOL can be predicted by the regression model more accurately than by corneal astigmatism alone. However, the prediction of oblique astigmatism remains a challenge.

Multivariate Regression Analysis to Predict Postoperative Refractive Astigmatism in Cataract Surgery.

PURPOSE: To assess the correlation between postoperative refractive astigmatism and preoperative parameters in cataract surgery. METHODS: Left eyes of 100 consecutive patients scheduled for cataract surgery with a 2.4 mm clear corneal incision were examined prospectively. Refractive astigmatism was measured using an autokerato/refractometer. Corneal astigmatism of the total cornea was calculated using a Scheimpflug camera. The vertical/horizontal component (J0) and oblique component (J45) of refractive and total corneal astigmatism were determined using power vector analysis. Refractive astigmatism at 8 weeks postoperatively was estimated using multivariate linear regression analysis. Independent variables analyzed included age, sex, refractive astigmatism, total corneal astigmatism, sphere, intraocular pressure, corneal thickness, anterior chamber depth, lens thickness, axial length, and pupil diameter. RESULTS: Multivariate regression analysis identified total corneal J0 and age as significant contributors to postoperative refractive J0 (P < 0.001 and P=0.029, respectively). The standard partial regression coefficients in the multiple regression analysis were 0.59 and -0.16 for total corneal J0 and age, respectively. Significant contributors to postoperative refractive J45 were total corneal J45 and lens thickness (P < 0.001 and P=0.015, respectively). The standard partial regression coefficients were 0.79 and -0.15 for total corneal J45 and lens thickness, respectively. CONCLUSION: These results suggest that preoperative total corneal astigmatism is the most significant predictor of postoperative refractive astigmatism when performing astigmatism correction in cataract surgery.

Acoustic emissions of Sorex unguiculatus (Mammalia: Soricidae): Assessing the echo-based orientation hypothesis.

Shrew species have been proposed to utilize an echo-based orientation system to obtain additional acoustic information while surveying their environments. This system has been supported by changes in vocal emission rates when shrews encounter different habitats of varying complexity, although detailed acoustic features in this system have not been reported. In this study, behavioral experiments were conducted using the long-clawed shrew (Sorex unguiculatus) to assess this orientation system. Three experimental conditions were set, two of which contained obstacles. Short-click, noisy, and different types of tonal calls in the audible-to-ultrasonic frequency range were recorded under all experimental conditions. The results indicated that shrews emit calls more frequently when they are facing obstacles or exploring the experimental environment. Shrews emitted clicks and several different types of tonal calls while exploring, and modified the use of different types of calls for varying behavior. Furthermore, shrews modified the dominant frequency and duration of squeak calls for different types of obstacles, that is, plants and acrylic barriers. The vocalizations emitted at short inter-pulse intervals could not be observed when shrews approached these obstacles. These results are consistent with the echo-based orientation hypothesis according to which shrews use a simple echo-orientation system to obtain information from their surrounding environments, although further studies are needed to confirm this hypothesis.

Comparison of refractive and keratometric astigmatism after microincision cataract surgery.

PURPOSE: To measure the correlation between refractive and keratometric astigmatism after microincision cataract surgery (MICS). SETTING: Takayanagi Clinic, Kushiro, Hokkaido, Japan. DESIGN: Retrospective case series. METHODS: This study evaluated patients having phacoemulsification and intraocular lens implantation through a 2.0 mm temporal clear corneal incision. Refractive astigmatism and keratometric astigmatism were described by Jackson cross-cylinder with-the-rule (J0) and oblique (J45) components and compared using linear regression analysis. RESULTS: The study comprised 90 eyes of 54 patients. The mean postoperative refractive J0 was -0.29 diopter (D) ± 0.46 (SD), and the mean postoperative refractive J45 was -0.09 ± 0.24 D. The multivariate model for the J0 component was postoperative J0 = 0.75 × keratometric J0 + 0.21 × preoperative J0 - 0.23 (R2 = 0.85, P < .001). The coefficient of determination of the multivariate model was higher than that of the univariate model (R2 = 0.82). The regression equation for the J45 component was postoperative J45 = 0.85 × keratometric J45 - 0.03 (R2 = 0.70, P < .001). CONCLUSION: Refractive astigmatism and keratometric astigmatism after MICS were strongly correlated.

Effects of Diquafosol Ophthalmic Solution on Quality of Life in Dry Eye Assessed Using the Dry Eye-Related Quality-of-Life Score Questionnaire: Effectiveness in Patients While Reading and Using Visual Display Terminals.

PURPOSE: Diquafosol ophthalmic solution improves objective findings in the ocular surface and subjective symptoms in patients with dry eye. The Dry Eye-Related Quality-of-Life Score (DEQS) questionnaire was developed to assess dry eye symptoms and their effects on quality of life. However, because little research using the DEQS has been reported, we evaluated the effects of diquafosol ophthalmic solution on ocular surface findings and quality of life using the DEQS in patients with dry eye. METHODS: Sixty-three patients with dry eye were assigned to the control group (artificial tears) or diquafosol group. Both groups instilled 1 drop of the solution in both eyes 6 times daily and were evaluated after 2 weeks; the diquafosol group also was instructed to be examined at 1 and 3 months. We evaluated the subjective symptoms using the DEQS, fluorescein staining score, tear film breakup time (BUT), Schirmer testing, and lower tear meniscus height with anterior-segment optical coherence tomography. RESULTS: In the diquafosol group, the fluorescein staining score, BUT, tear meniscus height, and DEQS scores improved significantly compared with before treatment in contrast to the control group. Furthermore, in the diquafosol group, the staining score and BUT improved significantly compared with the control group. Analysis of each DEQS item indicated that diquafosol ophthalmic solution relieved foreign body sensation and problems when reading and using visual display terminals compared with the control group. CONCLUSIONS: Diquafosol ophthalmic solution was effective in patients with dry eye, especially those with foreign body sensation and problems when reading and using visual display terminals.

Vector analysis investigation of toric intraocular lens with no deviation from the intended axis.

AIM: The aim of this research was to evaluate vector analysis after implantation of toric intraocular lenses (IOLs) without deviation from the intended axis. METHODS: The study included 18 eyes of 16 patients who underwent cataract surgery with the insertion of a toric implant (AcrySof IQ Toric). The postoperative IOL meridian placement completely corresponded to that planned. Using vector analysis, surgically induced astigmatism (SIA) was derived from the refractive outcome versus the predicted postoperative keratometric astigmatism and was compared with targeted induced astigmatism (TIA). The difference vector (DV) was derived by calculating the vector expression of the remaining astigmatic change. RESULTS: The mean postoperative remaining refractive astigmatism of 0.73±0.55 diopters (D) was achieved versus the mean target of 0.44±0.28 D. There was a difference of 0.29 D between the target and achieved values. The mean SIA value was 1.90±0.99 D compared with the mean TIA value of 2.00±0.85 D. The mean DV value was 0.87±0.56 D. The astigmatism correction index (SIA/TIA) was 0.95, which was near the ideal value of 1. The index of success (DV/TIA) was 0.44, which was far from the ideal value of 0. CONCLUSION: The implantation of toric IOLs is an effective, predictable method for astigmatic correction. However, some remaining astigmatism is present even if toric IOLs are placed accurately.

Comparison of effect of nepafenac and diclofenac ophthalmic solutions on cornea, tear film, and ocular surface after cataract surgery: the results of a randomized trial.

BACKGROUND: The aim of this study was to compare the effects of nepafenac ophthalmic suspension 0.1% (Nevanac) and diclofenac sodium ophthalmic solution 0.1% (Diclod) on the cornea, tear film, and ocular surface after cataract surgery. METHODS: A total of 60 eyes (60 patients) were selected for this study, with no ocular diseases other than cataract (scheduled for cataract surgery by one surgeon). Patients were randomly enrolled to receive nepafenac or diclofenac in the perioperative period, and cataract surgery was performed using torsional microcoaxial phacoemulsification and aspiration with intraocular lens implantation via a transconjunctival single-plane sclerocorneal incision at the 12 o'clock position. We compared intra- and intergroup differences preoperatively and postoperatively in conjunctival and corneal fluorescein staining scores, tear film breakup times, Schirmer's tests, the Dry Eye Related Quality of Life Scores, and tear meniscus areas using anterior segment optical coherence tomography. RESULTS: The diclofenac group had significantly higher conjunctival and corneal fluorescein staining scores at 4 weeks postoperatively compared with the nepafenac group (P<0.001). Within the diclofenac group, significantly higher conjunctival and corneal fluorescein staining scores were noted at 4 weeks postoperatively than those seen preoperatively (P<0.001) and at 1 week postoperatively (P<0.001). No statistically significant differences were found in any other items. CONCLUSIONS: Nepafenac ophthalmic suspension 0.1% is considered safe for the corneal epithelium after cataract surgery.

Usefulness of 3-dimensional CT angiograms obtained by 64-section multidetector row CT scanner for dural arteriovenous fistula.

The authors reported a case of a dural arteriovenous fistula (DAVF) in the left transverse-sigmoid sinus, in which 3-dimensional computed tomography (CT) angiograms (3D-CTAs) by a 64-section multidetector row CT scanner were useful for its diagnosis and treatment. The DAVF in the left transverse-sigmoid sinus appeared on the digital subtraction angiogram. 3D-CTAs were obtained by a 64-section multidetector row CT scanner before an endovascular treatment. The feeders and draining veins of the DAVF were clearly demonstrated on the 3D-CTAs, which clarified the relationship between the normal dural sinuses and DAVF. The DAVF was successfully treated with endovascular surgery, a transvenous embolization through the mastoid emissary vein, which was easily detected by using the 3D-CTA, showing both the subcutaneous vein and calvalium. 3D-CTAs by a 64-section multidetector row CT scanner are useful for both diagnosis and treatment of DAVFs.

Role of nitric oxide in regulation of retinal blood flow in response to hyperoxia in cats.

PURPOSE: To investigate whether nitric oxide (NO) regulates retinal circulation during and after induction of hyperoxia in cats. METHODS: Hyperoxia was induced for 10 minutes with 100% oxygen. The vessel diameter and blood velocity were measured simultaneously in second-order retinal arterioles by laser Doppler velocimetry; the retinal blood flow (RBF) and wall shear rate (WSR) were calculated during and after hyperoxia. PBS, L-NAME, D-NAME, BQ-123, BQ-788, and 7-nitroindazole (7-NI) were administered before induction of hyperoxia. RESULTS: In the PBS group, vessel diameter, blood velocity, and RBF decreased during hyperoxia and returned to baseline within 10 minutes after hyperoxia ended. WSR decreased transiently and then returned to baseline by the delayed constriction of retinal arterioles during hyperoxia. In the l-NAME and BQ-788 groups, the decreases in RBF during hyperoxia did not differ from those in the PBS group. However, the recovery of RBF after hyperoxia ended was attenuated significantly until 20 minutes after hyperoxia ended in both groups compared with the PBS group (P < 0.05). In the BQ-123 group, the intravitreous injection of BQ-123 caused less reduction of blood velocity and RBF during hyperoxia compared with that in the PBS group, whereas the RBF immediately returned to baseline after hyperoxia. D-NAME and 7-NI did not affect RBF in response to hyperoxia. CONCLUSIONS: The current results indicate that NO contributes to RBF recovery after hyperoxia, probably through the action of endothelial NOS via the ETB receptor in the vascular endothelium of the retinal arterioles, suggesting that the RBF response to hyperoxia may be used to evaluate the endothelial function of the retinal arterioles.

Adenosine agonist regulation of outward active transport of fluorescein across retinal pigment epithelium in rabbits.

To investigate the effect of an adenosine agonist, 2-5'-N-ethylcarboxamidoadenosine (NECA), on the outward active transport of fluorescein across the retinal pigment epithelium (RPE) in rabbits. High (5x10(-4)-2x10(-3) M) and low (1x10(-5)-1x10(-4) M) concentrations of NECA or phosphate buffered saline (PBS) were intravitreously injected into Dutch-belted rabbits. Sodium fluorescein was injected intravenously 180 min after NECA. Differential vitreous fluorophotometry was performed 3 hr after the sodium fluorescein injection and the vitreal fluorescein/fluorescein monoglucuronide (F/FG) ratio then was calculated. The F/FG ratios are inversely proportional to the outward active transport of fluorescein across the RPE. Retinal detachments were induced by injection of PBS into the subretinal space after the intravitreous injection of low- or high-dose NECA or PBS, and the size of the blebs was monitored. In eyes that received a low-dose injection of NECA, the F/FG ratio was higher compared with controls (P<0.05); in eyes that received a high-dose intravitreal injection, the F/FG ratio was significantly lower compared with controls (P<0.05). The effect of low-dose NECA on the F/FG ratio was suppressed by the A2 receptor antagonist, ZM241385, and the effect of high-dose NECA was suppressed by the A1 receptor antagonist, 8-cyclopentyl-1, 3-dipropylxanthine. The A3 receptor antagonist MRS1191 did not influence the effect of low- or high-dose NECA. Intravitreal injection of high-dose NECA enhanced the reabsorption of subretinal fluid compared with PBS; however, low-dose NECA inhibited reabsorption of subretinal fluid (P<0.02 and 0.05, respectively). Intravitreous injection of high-dose NECA accelerates the active outward transport across the RPE via A1 receptors and low-dose NECA decelerates it via A2 receptors.

Effect of nucleotide P2Y2 receptor agonists on outward active transport of fluorescein across normal blood-retina barrier in rabbit.

BACKGROUND: To evaluate the effect of nucleotide P2Y(2) receptor agonists INS542 and uridine 5'-triphosphate (UTP) on the outward active transport of fluorescein across rabbit blood-retina barrier (BRB) in vivo. METHODS: Injection (0.1 ml) of INS542 (0.1 or 1mM), phosphate buffered solution, or UTP (1 or 10mM) was made in Dutch-belted rabbits. Differential vitreous fluorophotometry (DVF) was performed 3hr later and the fluorescein (F)/fluorescein monoglucuronide (FG) ratio was then calculated. F/FG ratios are inversely proportional to outward active transport of F across BRB at the level of the retinal pigment epithelium (RPE). In another set of experiments, the effect of 0.1 ml vitreous injection of INS542 (1mM) on F/FG ratios was evaluated at different time points ranging from 0.5 to 48hr before conducting DVF. RESULTS: F/FG ratios obtained 3hr after intravitreal injection were as follows (mean+/-standard error): 0.49+/-0.14 (0.1mM INS542), 0.19+/-0.04 (1mM INS542), 0.48+/-0.09 (PBS), 0.40+/-0.08 (1mM UTP) and 0.36+/-0.05 (10mM UTP). The F/FG ratio for 1mM INS542 was significantly lower than in the other groups (P<0.05). In the time course experiments, a significant decrease in the F/FG ratios was observed between 1 and 12hr following administration of INS542 when compared with F/FG ratios obtained in the contralateral (untreated) eye. CONCLUSION: Intravitreal administration of INS542 (but not UTP) enhances outward active transport of F across RPE in intact rabbit eye, indicating that activation of P2Y(2) receptors in vivo directly stimulates RPE active transport.