A technique to treat Descemet's membrane detachment following cataract surgery.

We describe a technique to reattach the detached Descemet's membrane, following cataract surgery. From the main clear corneal cataract incision, aqueous humor is ejected completely by apposition of the cornea to the iris for approximately 3 s. This ensures the fluid in the space between the stroma and Descemet's membrane is ejected and the detached Descemet's membrane returns to its original position. Sterile air is injected through a paracentesis 180 degrees away from the Descemet's membrane detachment, to maintain a complete air-filled chamber. Full air tamponade is maintained for 20 min, following which one-third of the air is ejected from the chamber to prevent an increase of postoperative intraocular pressure.

Total keratometry for toric intraocular lens calculation: comparison from two swept-source optical coherence tomography biometers.

Purpose: To compare the astigmatism prediction accuracy of total keratometry (TK) from the IOLMaster 700 and total corneal power (TCP) from Anterion based on swept-source optical coherence tomography (SS-OCT) technology in toric intraocular lens (toric IOL) calculation. Design: A retrospective observational study. Methods: Total corneal astigmatism (TCA) were obtained using IOLMaster 700 and Anterion. Z CALC 2.0 was used to calculate the expected postoperative refractive astigmatism in conjunction with TCA. Prediction errors (PE) in refractive outcomes was analyzed 1 month postoperatively using the vector analysis by the Holladay method, including the mean vector PE magnitude, percentage of cases with vector PE in certain intervals, and the centroid PE. Results: A total of 56 eyes from 56 patients were enrolled in the study with an insertion of an AT TORBI 709 toric IOL. The difference in mean vector PE of postoperative refractive astigmatism between TK and TCP was not statistically significant (0.48D versus 0.46D, P = 0.281). TK and TCP yielded 27.3 and 40.0% of eyes with vector PE ≤ 0.25D, and 58.2 and 63.6% with vector PE ≤ 0.5D (both P > 0.05), respectively. TK and TCP resulted in similar ATR centroid PE of 0.10D@35° ± 0.60D and 0.15D@22° ± 0.57D, respectively, and there were no significant differences between x-PE component and y-PE component. Conclusion: IOLMaster 700 and Anterion provided comparable astigmatic predictability in toric IOL implantation using total keratometry and Z CALC 2.0.

Comparison of intraocular lens power calculation formulas in Chinese eyes with axial myopia.

PURPOSE: To assess the accuracy of intraocular lens (IOL) power calculation formulas in Chinese eyes with axial lengths (ALs) longer than 26.0 mm. SETTING: Department of Cataract Surgery, Shanxi Eye Hospital, China. DESIGN: Prospective case series. METHODS: This study evaluated (1) two new formulas (Barrett Universal II and Hill-RBF 2.0), (2) three vergence formulas (Haigis, Holladay 1, and SRK/T), and (3) the original and modified Wang-Koch AL adjustment formulas with Holladay 1 and SRK/T. The User Group for Laser Interference Biometry lens constants were used for IOL power calculation. The refractive prediction error was calculated by subtracting the predicted refraction from the actual refraction postoperatively. The mean numerical error (MNE), percentage of eyes with hyperopic outcomes, and mean absolute error (MAE) were determined. RESULTS: The study comprised 136 eyes. The Barrett and Hill-RBF formulas had MNEs close to zero (-0.09 D to 0.03 D), the Haigis, Holladay 1, and SRK/T produced hyperopic MNEs (0.25 to 0.70 D), and the original and modified Wang-Koch AL adjustment formulas induced myopic MNEs (-0.48 to -0.22 D). The original Wang-Koch formulas produced significantly lower percentages of eyes with hyperopic outcomes (15% to 18%) than all other formulas (28% to 91%). There were no significant differences in MAEs between the Barrett, Hill-RBF, Haigis, and original and modified Wang-Koch adjustment with the Holladay 1 (0.32 to 0.41 D). CONCLUSION: The performances of the Barrett and Hill-RBF were comparable in long eyes. The incidence of hyperopic outcome with the Wang-Koch AL adjustment formula was significantly lower than other formulas.

Effects of N-acetylcysteine and glutathione ethyl ester drops on streptozotocin-induced diabetic cataract in rats.

PURPOSE: To evaluate the effect of N-acetylcysteine (NAC) and glutathione ethyl ester (GSH-EE) eye drops on the progression of diabetic cataract formation induced by streptozotocin (STZ). METHODS: One hundred and thirty Sprague-Dawley (SD) rats were selected, and diabetes was induced by streptozotocin (65 mg/kg bodyweight) in a single intraperitoneal injection. The control group (group I) received only vehicle. Then, 78 rats with random blood glucose above 14 mmol/l were divided into four groups (group II-V). The drug-treated rats received NAC and GSH-EE eye drops five days before STZ injection. Group I and V animals received sodium phosphate buffer drops (pH 7.4), and those in groups II, III, and IV received 0.01% NAC, 0.05% NAC, and 0.1% GSH-EE drops, respectively. Lens transparency was monitored with a slit lamp biomicroscope and classified into six stages. At the end of four weeks, eight weeks, and 13 weeks, animals were killed and components involved in the pathogenesis of diabetic cataract including thiols (from glutathione and protein), glutathione reductase (GR), catalase (CAT), and glycated proteins were investigated in the lens extracts. Blood glucose, urine glucose, and bodyweight were also determined. RESULTS: The progression in lens opacity induced by diabetes showed a biphasic pattern in which an initial slow increase in the first seven weeks after STZ injection was followed by a rapid increase in the next six weeks. The progression of lens opacity in the treated groups (group II-IV) was slower than that of the untreated group (group V) in the earlier period and especially in the fourth week. There were statistically significant differences between the treated groups and the untreated group (p<0.05). However, these differences became insignificant after the sixth week, and the progression of lens opacification in all diabetic groups became aggravated. The content of thiol (from glutathione and protein), glutathione reductase (GR), and catalase (CAT) were lower in the lens extracts of the diabetic rats four weeks, eight weeks, and 13 weeks after the STZ injection while the levels of thiol and CAT activity were both higher in the treated groups (group II-IV) than in the untreated group (group V) at every stage. However, there was no statistically significant difference (p>0.05). Moreover, the diabetes resulted in an increased level of glycated proteins in both the treated groups and the untreated group, but there was no statistically significant difference between all the diabetic groups (p>0.05). CONCLUSIONS: NAC and GSH-EE can slightly inhibit the progression of the diabetic cataract at the earlier stage. They may maintain lens transparency and function by serving as a precursor for glutathione biosynthesis and by protecting sulfhydryl groups from oxidation.

[Thioltransferase and thioredoxin system in cataract].

The lens depends on a balanced redox state and SH/-S-S- ratio for maintaining its transparency. The endogenous high level of glutathione (GSH) and its intrinsic repair enzymes are very important lines of defense for the health of the lens. However, ageing lenses or cataract lenses show an extensively diminished size of GSH pool. The research in thioltransferase (TTase) and thioredoxin (Trx) system show TTase can specifically dithiolate protein-S-S-glutathione and restore protein free SH groups for proper enzymatic or protein functions; Trx system can dithiolate protein disulfides and thus is an extremely important regulator for redox homeostasis in the cells. The two enzymes may work synergistically to repair thiols in lens proteins and enzymes and maintain the function of the lens effectively.