May 2003
Volume 44, Issue 5
Free
Cornea  |   May 2003
Antioxidant Protection against Corneal Damage by Free Radicals during Phacoemulsification
Author Affiliations
  • Alexander Rubowitz
    From the Department of Ophthalmology, Meir Hospital, Sapir Medical Center, Kfar-Saba, Israel; the
  • Ehud I. Assia
    From the Department of Ophthalmology, Meir Hospital, Sapir Medical Center, Kfar-Saba, Israel; the
  • Mordechai Rosner
    Department of Ophthalmology and
    Goldschleger Eye Research Institute, Sheba Medical Center, Tel-Hashomer, Israel; the
  • Morris Topaz
    Department of Chemistry, Bar-Ilan University, Givat-Shmuel, Israel; and the
    Plastic Surgery Unit, Hillel-Yaffe Hospital, Hadera, Israel.
Investigative Ophthalmology & Visual Science May 2003, Vol.44, 1866-1870. doi:10.1167/iovs.02-0892
  • Views
  • PDF
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Alexander Rubowitz, Ehud I. Assia, Mordechai Rosner, Morris Topaz; Antioxidant Protection against Corneal Damage by Free Radicals during Phacoemulsification. Invest. Ophthalmol. Vis. Sci. 2003;44(5):1866-1870. doi: 10.1167/iovs.02-0892.

      Download citation file:


      © 2016 Association for Research in Vision and Ophthalmology.

      ×
  • Supplements
Abstract

purpose. To examine the role of ascorbic acid in reducing corneal endothelial cell loss secondary to high-energy ultrasound energy during phacoemulsification surgery.

methods. Seventeen rabbit eyes were subjected to prolonged phacoemulsification within the anterior chamber, without manipulation or damage to other ocular structures. In nine eyes, a balanced salt ophthalmic solution was used as the phacoemulsification irrigation solution, and in eight eyes the solution plus 0.001 M ascorbic acid was used, all other parameters being identical between the two groups. Specular microscopy was performed in all eyes before and 1 week after surgery. The animals were then killed, and the corneas were examined histologically.

results. There was no significant difference in preoperative endothelial cell counts between the two groups. Postoperative cell counts were reduced by 453.9 ± 233.3 (SEM) cells/mm2 in the solution-alone group versus 123.2 ± 196.4 (SEM) cells/mm2 in the solution-plus-ascorbic acid group, (P = 0.011). Corneal histology revealed a marked difference in endothelial cell morphology between the two groups.

conclusions. The addition of ascorbic acid to the irrigation solution significantly reduced the amount of endothelial cell loss during phacoemulsification by approximately 70%. This is thought to be due to the free-radical–scavenging properties of ascorbic acid. Further studies are warranted to find the optimal concentrations and combinations of free radical scavengers to be used in phacoemulsification irrigation solutions.

Since the introduction of high-energy ultrasonic medical devices, increasing interest and concern have been directed toward the biological and cellular effects of the production of large amounts of free radicals and ultraviolet radiation within tissues. 1 2 3 4 5 6 7 8 9 10  
Studies of the harmful effects of phacoemulsification on corneal endothelial cells suggest that much of this damage is mediated by free radicals. 10 11 12 13 Subsequent articles have emphasized the potential protective effects of various free radical scavengers, 10 14 15 16 17 18 and suggest that these substances may help prevent phacoemulsification-induced endothelial cell loss, a common and well-documented side effect of cataract surgery. 19 20 21 22 23 24 25  
Holst et al. 7 showed the formation of large amounts of free radicals and ultraviolet radiation in phacoemulsification in both in vivo and in vitro environments. This, it was shown, could be reduced by the addition of superoxide dismutase to the irrigating solution; however, they did not examine whether this reduction could effectively reduce endothelial cell loss. 
Other studies 14 17 have shown a nonspecific beneficial effect of irrigating solutions containing glutathione (a free radical scavenger) in reducing cell loss from prolonged endothelial exposure to irrigating solutions, but we did not specifically investigate the effects of phacoemulsification or free radical damage. In a study in which a similar irrigation model in dogs was used, 26 the investigators found no beneficial effect of glutathione. A study of the protective effects of different viscoelastic materials against endothelial damage by intraocular hydrogen-peroxide solutions 15 suggested that their protective effect may be due in part to free-radical–scavenging properties. 
Several researchers have compared the results of cataract surgery using a balanced saline ophthalmic irrigating solution to those obtained using solutions containing glutathione. Some have reported a protective effect of glutathione on the corneal endothelium, 27 28 whereas others have found no effect. 29 These studies, while important in determining the clinical use of glutathione, do not exclude other causes of endothelial damage, such as intraocular lens implantation, release of inflammatory substances in the eye, or release of lens particles. Also, these studies examined only one concentration of one free radical scavenger (glutathione), because it is the only commercially marketed solution in this category. We elected to examine the role of ascorbic acid, a well-known scavenger of free radicals, 30 31 32 because this chemical is found in naturally high concentrations in normal aqueous, 33 34 would therefore be less likely to cause chemical damage to intraocular structures, and has not previously been tested in the present setting to our knowledge. 
To elucidate the role of free radicals in endothelial cell loss secondary to phacoemulsification, we devised an experiment that would attempt to isolate the endothelial damage due to formation of free radicals during phacoemulsification from mechanical and thermal damaging effects. 
Methods
Seventeen eyes of 17 New Zealand White female rabbits, weighing 3 to 4 kg each, were exposed to high-energy ultrasound by the activation of a phacoemulsification probe in the anterior chamber. Treatment and handling of the rabbits was performed in accordance with the ARVO Statement for the Use of Animals in Ophthalmic and Vision Research. Before surgery, the rabbits were anesthetized by intramuscular injection of 35 mg/kg ketamine hydrochloride and 7 mg/kg xylazine, and the right eye was then examined by specular microscopy (EM-1000 specular microscope; Tomey, Waltham, MA), obtaining three corneal endothelial photographs for analysis, all from within the central 3 mm of cornea. The right eye was cleansed with topical povidone iodine and draped, and a lid speculum was inserted. Next, a clear corneal incision was made in the superotemporal corneal quadrant with a disposable 3.2-mm keratome blade. Using 70% power, and 25 mL/min of irrigation, a 20-g phacoemulsification probe (Series Ten Thousand Phacoemulsification System; Alcon Surgical, Fort Worth, TX) was introduced through the corneal incision into the anterior chamber, taking care to avoid touching all ocular structures including the lens and cornea, and activated in the center of the anterior chamber. Each eye was continuously irrigated, with the power turned alternately on and off every 10 seconds to avoid overheating, until the required 5 minutes of net time (10 minutes in all) was completed. 
The rabbits were randomized to receive either balanced salt solution, or BSS with 0.001 M of sterile ascorbic acid introduced into the BSS bottle immediately before phacoemulsification. The two groups were similar in all other respects of surgical and postoperative treatment. Each animal was number encoded before treatment, and surgery, postoperative, and histologic examinations and analysis were all performed with blinding as to the treatment grouping. 
On completion of phacoemulsification, the incision was sealed by injection of BSS solution (for both groups) into the incision margins, followed by a subconjunctival injection of betamethasone acetate and betamethasone phosphate (Celestone Chronodase; Schering-Plough, Kenilworth, NJ) and gentamicin. No additional postoperative medications were given. 
One week later, the rabbits were again anesthetized as described above, the surgical eye was again examined by specular microscopy, and the rabbits were killed by an overdose of phenobarbital. The right eye of each rabbit was enucleated and preserved in formaldehyde, and corneal sections were stained with hematoxylin and eosin and examined by an experienced ocular pathologist who was blinded to the treatment received by each rabbit, as mentioned previously. 
The specular microscopy results were analyzed with the software application for endothelial cell analysis that accompanied the specular microscope (EM-1100 software; Tomey). The results of the three preoperative and three postoperative endothelial cell counts were averaged separately, and the reduction in cell count 1 week after surgery was calculated by subtraction. The nonparametric Mann-Whitney test was used to examine possible differences in preoperative cell counts between the two groups, as well as differences in postoperative cell count reduction. Cell counts are presented as the mean ± SEM. 
Results
Preoperative and postoperative endothelial cell counts are shown in Table 1 , in random and nonchronological order within each group. It should be noted that we previously found the normal interexamination variation between endothelial cell counts to be approximately ±5%, and postoperative results showing minor increases in endothelial cell counts are probably due to this variation. 
The reduction in endothelial cell count (cells per square millimeter) 1 week after surgery was 453.9 ± 233.3 (SEM) in the group that received the irrigation solution alone and 123.2 ± 196.4 (SEM) in the group treated with the solution plus ascorbic acid (Fig. 1)
The postoperative reduction in cell count differed significantly between the two groups (Mann-Whitney test P = 0.011). Thus, the cell count was significantly higher in the group treated with solution plus ascorbic acid than in the group treated with solution alone. The mean reduction in cell count in the solution-alone group was more than 3.5 times greater than in the group treated with solution plus ascorbic acid. 
Histologic slides prepared from all corneas of rabbits in the two treatment groups showed marked differences in endothelial cell morphology. Endothelial cells from the central corneas in the solution-alone group contained more and much larger vacuoles than those from the group treated with solution plus ascorbic acid (Fig. 2) . For each group, similar findings were obtained in all 10 central corneal sections examined. 
Discussion
In previous studies, our group has examined the production of free radicals by ophthalmic (and other medical) phacoemulsification probes in vitro, as well as the effects of free radical scavengers, such as ascorbic acid and glutathione, on the formation of these radicals. 8 10 35 As a continuation of those studies, we designed the present in vivo experiments with the purpose of determining whether our chemically quantified results could be translated into clinically significant protective effects on the corneal endothelium. 
This study was preceded by a pilot study in which we used smaller groups of rabbits to establish optimal parameters, especially with regard to various amounts of phacoemulsification time. We found that phacoemulsification times of less than 5 minutes produced minor endothelial cell loss, indistinguishable from the normal inter-examination variation in specular microscopy endothelial cell count analysis (±5%). Also, as can be seen in Table 1 , the variation in endothelial cell loss within each treatment group was substantial and only the large protective effect of the ascorbic acid enabled us to show a statistically significant difference between the two groups, despite this variability. In contrast, phacoemulsification times significantly longer than 5 minutes caused severe endothelial cell loss, with resultant corneal edema that prevented postoperative specular microscopy. We therefore decided that 5 minutes of exposure to anterior chamber phacoemulsification would cause sufficient and measurable endothelial damage. As this is longer than most clinical phacoemulsification times, we believe the protective effect of scavengers in phacoemulsification surgery may be more pronounced in difficult and prolonged surgeries. Also, as rabbit endothelium is capable of some regeneration, it was decided that a period of 1 week between surgery and analysis would enable us to measure the extent of endothelial cell damage while minimizing the effects of regeneration on cell counts. 37 38 39 40  
The eyes we studied were not subjected to cataract surgery, because this would have introduced several confounding and nonquantifiable causes of endothelial damage, such as the intraocular release of lens particles, various amounts of remaining intracapsular cells and debris, and different degrees of ocular inflammation and release of inflammatory products. Also, by restricting surgery to a minimum we were able to minimize variations in surgical technique between eyes. In terms of free radical production, phacoemulsification performed in the anterior chamber is sufficient to release the radicals under study, while avoiding the mentioned confounding effects of cataract surgery. 
Several previous studies regarding endothelial cell regeneration and repair have shown that 1 week of postoperative healing in rabbits is comparable to approximately 3 months in humans and that, after this time, cellular regeneration (not found in humans) takes place, 38 40 which may be a confounding factor, altering postoperative cell counts. Indeed, several studies have provided evidence that ascorbic acid may be an important factor in endothelial cell healing, migration, and regeneration. 41 42 We therefore decided to kill the animals 1 week after phacoemulsification. 
We have shown that ascorbic acid can reduce the amount of endothelial cell loss after phacoemulsification surgery, and this effect may be due to its free-radical–scavenging properties. Because the two groups were identical in all parameters except for the presence of ascorbic acid in the irrigating solution, the difference in outcome between them strongly suggests that a large part of the endothelial cell loss after phacoemulsification is due to the formation of free radicals (and not solely to thermal and mechanical factors, as previously held). We have also demonstrated that that ascorbic acid sharply reduces the amount of intracellular vacuoles in endothelial cells after phacoemulsification. Because free radicals are known to cause cellular damage by damaging plasma membranes, 5 8 9 12 14 we believe that the presence of these vacuoles indicates the rupture of intracellular organelle membranes. 
Further study is needed to establish the concentration of ascorbic acid required. There may be a concentration that provides more endothelial cell protection than we obtained in the current study. The natural concentration of ascorbic acid in human vitreous is approximately 0.001 M, 33 34 37 and we therefore used this concentration for this experiment, although further experiments may reveal a more optimal concentration. It is also possible that combinations of several scavenger chemicals (such as glutathione for example) with ascorbic acid would yield an even greater effect. We believe that continuing studies are warranted to find the optimal protective solution to be used in phacoemulsification cataract surgery. 
 
Table 1.
 
Specular Microscopy Results
Table 1.
 
Specular Microscopy Results
Eye Irrigating Solution Preoperative Cell Count/mm3 Postoperative Cell Count/mm3 Cell Loss/mm3 % Change in Endothelial Cell Density
1 Solution* 3011 2381 630 −20.9
2 Solution 3294 3027 267 −8.1
3 Solution 3000 2390 610 −20.3
4 Solution 3631 3112 519 −14.3
5 Solution 3058 2205 853 −27.9
6 Solution 3199 2908 291 −9.1
7 Solution 3123 2914 209 −6.7
8 Solution 3135 2883 252 −8.0
9 Solution+AA, † 3058 3195 −137 +4.7
10 Solution+AA 2756 2835 −79 +2.8
11 Solution+AA 3021 3170 −149 +4.9
12 Solution+AA 2885 2655 230 −7.9
13 Solution+AA 3493 3363 130 −3.7
14 Solution+AA 3525 3154 371 −10.5
15 Solution+AA 2968 2765 203 −6.8
16 Solution+AA 3082 2854 228 −7.4
17 Solution+AA 3137 2825 312 −9.9
Figure 1.
 
Preoperative and postoperative endothelial cell counts in groups treated with a saline ophthalmic irrigation solution (Solution Alone) and with the same solution plus ascorbic acid (Solution+AA).
Figure 1.
 
Preoperative and postoperative endothelial cell counts in groups treated with a saline ophthalmic irrigation solution (Solution Alone) and with the same solution plus ascorbic acid (Solution+AA).
Figure 2.
 
Postoperative central corneal sections from the two study groups. Top: postoperative corneas from the group treated with solution plus ascorbic acid; bottom: corneas from the group treated with BSS. The two latter slides show a marked decrease in endothelial cell density, as well as marked endothelial cell vacuolization. Magnification, ×400.
Figure 2.
 
Postoperative central corneal sections from the two study groups. Top: postoperative corneas from the group treated with solution plus ascorbic acid; bottom: corneas from the group treated with BSS. The two latter slides show a marked decrease in endothelial cell density, as well as marked endothelial cell vacuolization. Magnification, ×400.
Taleyarkhan, RP, West, CD, Cho, JS, Lahey, RT, Jr, Nigmatulin, RI, Block, RC. (2002) Evidence for nuclear emissions during acoustic cavitation Science 295,1868-1873 [CrossRef] [PubMed]
McNamara, WB, III, Didenko, YT, Suslick, KS. (1999) Sonoluminescence temperatures during multi-bubble cavitation Nature 401,772-775 [CrossRef]
Putterman, S, Evans, PG, Vazquez, G, Weninger, K. (2001) Cavitation science: is there a simple theory of sonoluminescence? Nature 409,782-783 [CrossRef] [PubMed]
Suslick, KS. (1989) The chemical effects of ultrasound Sci Am 260,62-69 [CrossRef] [PubMed]
Riesz, P, Kondo, T. (1992) Free radical formation induced by ultrasound and its biological implications Free Rad Biol Med 13,247-270 [CrossRef] [PubMed]
Shimmura, S, Tsubota, K, OguchiY,, Fukumura, D. (1992) Oxiradical-dependent photoemission induced by a phacoemulsification probe Invest Ophthalmol Vis Sci 33,2904-2907 [PubMed]
Holst, A, Rolfsen, W, Svensson, B, Ollinger, K, Lundgren, B. (1993) Formation of free radicals during phacoemulsification Curr Eye Res 12,359-365 [CrossRef] [PubMed]
Topaz, M. (1998) Possible long term complications in ultrasound-assisted lipoplasty induced by sonoluminescence, sonochemistry, and thermal effect. Long-term possible hazardous effects of ultrasonically assisted lipoplasty Plast Reconstr Surg 102,280-281 [PubMed]
Armour, EP, Corry, PM. (1982) Cytotoxic effects of ultrasound in vitro dependence on gas content, frequency, radical scavengers and attachment Radiat Res 89,369-380 [CrossRef] [PubMed]
Topaz, M, Motei, M, Assia, E, Meyerstein, D, Meyerstein, N, Gedanken, A. (2002) Acoustic cavitation in phacoemulsification: chemical effects, modes of action and cavitation index Ultrasound Med Biol 28,775-784 [CrossRef] [PubMed]
Hull, DS. (1990) Oxygen free radicals and corneal endothelium Trans Am Ophthalmol Soc 88,463-511 [PubMed]
Hull, DS, Green, K, Thomas, L, Alderman, N. (1984) Hydrogen peroxide-mediated corneal endothelial damage: induction by oxygen free radical Invest Ophthalmol Vis Sci 2,1246-1253
Takahashi, H, Sakamoto, A, Takahashi, R, Ohmura, T, Simmura, S, Ohara, K. (2002) Free radicals in phacoemulsification and aspiration procedures Arch Ophthalmol 120,1348-1352 [CrossRef] [PubMed]
Nakamura, M, Nakano, T, Hikida, M. (1994) Effects of oxidized glutathione and reduced glutathione on the barrier function of the corneal endothelium Cornea 13,493-495 [PubMed]
Artola, A, Alio, JL, Bellot, JL, Ruiz, JM. (1993) Protective properties of viscoelastic substances (sodium hyaluronate and 2% hydroxymethylcellulose) against experimental free radical damage to the corneal endothelium Cornea 12,109-114 [CrossRef] [PubMed]
Kasetsuwan, N, Wu, FM, Hsieh, F, Sanchez, D, McDonnell, PJ. (1999) Effect of topical ascorbic acid on free radical tissue damage and inflammatory cell influx in the cornea after excimer laser corneal surgery Arch Ophthalmol 117,649-652 [CrossRef] [PubMed]
Edelhauser, HF, Gonnering, R, Van Horn, DL. (1978) Intraocular irrigating solutions: a comparative study of BSS Plus and lactated Ringer’s solution Arch Ophthalmol 96,516-520 [CrossRef] [PubMed]
Beesly, RD, Olson, RJ, Brady, SE. (1986) The effects of prolonged phacoemulsification time on the corneal endothelium Ann Ophthalmol 18,216-219222 [PubMed]
Werblin, TP. (1993) Long-term endothelial cell loss following phacoemulsification: model for evaluating endothelial damage after intraocular surgery Refract Corneal Surg 9,29-35 [PubMed]
Diaz-Valle, D, Benitez del Castillo Sanchez, JM, Castillo, A, Sayagues, O, Moriche, M. (1998) Endothelial damage with cataract surgery techniques J Cataract Refract Surg 24,951-955 [CrossRef] [PubMed]
Ravalico, G, Tognetto, D, Palomba, MA, Lovisato, A, Baccara, F. (1997) Corneal endothelial function after extracapsular cataract extraction and phacoemulsification J Cataract Refract Surg 23,1000-1005 [CrossRef] [PubMed]
Ventura, AC, Walti, R, Bohnke, M. (2001) Corneal thickness and endothelial density before and after cataract surgery Br J Ophthalmol 85,18-20 [CrossRef] [PubMed]
Faulkner, GD. (1987) Endothelial cell loss after phacoemulsification and insertion of silicone lens implants J Cataract Refract Surg 13,649-652 [CrossRef] [PubMed]
Dick, HB, Kohnen, T, Jacobi, FK, Jacobi, KW. (1996) Long term endothelial cell loss following phacoemulsification through a temporal clear corneal incision J Cataract Refract Surg 22,63-71 [CrossRef] [PubMed]
Hayashi, K, Hayashi, H, Nakao, F, Hayashi, F. (1996) Risk factors for corneal endothelial injury during phacoemulsification J Cataract Refract Surg 22,1079-1084 [CrossRef] [PubMed]
Nasisse, MP, Cook, CS, Harling, DE. (1986) Response of the canine corneal endothelium to intraocular irrigation with saline solution, balanced salt solution, and balanced salt solution with glutathione Am J Vet Res 47,2261-2265 [PubMed]
Joussen, AM, Barth, U, Cubuk, H, Koch, H. (2000) Effect of irrigating solution and irrigation temperature on the cornea and pupil during phacoemulsification J Cataract Refract Surg 26,392-397 [CrossRef] [PubMed]
Matsuda, M, Kinoshita, S, Ohashi, Y, et al (1991) Comparison of the effects of intraocular irrigating solutions on the corneal endothelium in intraocular lens implantation Br J Ophthalmol 75,476-479 [CrossRef] [PubMed]
Puckett, TR, Peele, KA, Howard, RS, Kramer, KK. (1995) Intraocular irrigating solutions: a randomized clinical trial of balanced salt solution plus and dextrose bicarbonate lactated Ringer’s solution Ophthalmology 102,291-296 [CrossRef] [PubMed]
Niki, E. (1991) Action of ascorbic acid as a scavenger of active and stable oxygen radicals Am J Clin Nutr 54(suppl 6),1119S-1124S [PubMed]
Regoli, F, Winston, GW. (1999) Quantification of total oxidant scavenging capacity of antioxidants for peroxynitrite, peroxyl radicals, and hydroxyl radicals Toxicol Appl Pharmacol 156,96-105 [CrossRef] [PubMed]
Sies, H, Stahl, W. (1995) Vitamins E and C, Beta-carotene, and other carotenoids as antioxidants Am J Clin Nutr 62(suppl 6),1315S-1321S [PubMed]
Davson, H. (1990) The aqueous humor and the intraocular pressure Physiology of the Eye 5th ed. ,3-95 Pergamon Press New York.
Millar, C, Kaufman, PL. (1997) Aqueous humor: secretion and dynamics Duane’s Foundations of Clinical Ophthalmology 2,15 Lippincott-Raven Philadelphia.
Topaz, M, Motiei, M, Gedanken, A, Meyerstein, D, Meyerstein, N. (2001) EPR analysis of radicals generated in ultrasound-assisted lipoplasty simulated environment Ultrasound Med Biol 27,851-859 [CrossRef] [PubMed]
Topaz, M. () Acoustic Cavitation in Phacoemulsification-Clinical Significance and Modes of Prevention. XIX Congress of the European Society of Cataract and Refractive Surgery, Amsterdam, September, 2001
Taylor, A, Jacques, PF, Nowell, T, et al (1997) Vitamin C in human and guinea pig aqueous, lens and plasma in relation to intake Curr Eye Res 16,857-864 [CrossRef] [PubMed]
Nakahori, Y, Katakami, C, Yamamoto, M. (1996) Corneal endothelial cell proliferation and migration after penetrating keratoplasty in rabbits Jpn J Ophthalmol 40,271-278 [PubMed]
Miyazaki, M, Tanaka, T, Nishida, T. (2000) Morphological changes in rabbit corneal endothelium after surgical injury Jpn J Ophthalmol 44,342-347 [CrossRef] [PubMed]
IchijimaH,, et al (1993) In vivo confocal microscopic studies of corneal endothelial wound healing in rabbit cornea Cornea 12,369-378 [CrossRef] [PubMed]
Yue, BY, Niedra, R, Baum, JL. (1980) Effects of ascorbic acid on cultured rabbit corneal endothelial cells Invest Ophthalmol Vis Sci 19,1471-1476 [PubMed]
Reddy, TS, Varnell, ED, Beuerman, RW, Bazan, NG, Kaufman, HE. (1989) Endothelial cell damage in human and rabbit corneas stored in K-Sol without antioxidants Br J Ophthalmol 73,893-898
Figure 1.
 
Preoperative and postoperative endothelial cell counts in groups treated with a saline ophthalmic irrigation solution (Solution Alone) and with the same solution plus ascorbic acid (Solution+AA).
Figure 1.
 
Preoperative and postoperative endothelial cell counts in groups treated with a saline ophthalmic irrigation solution (Solution Alone) and with the same solution plus ascorbic acid (Solution+AA).
Figure 2.
 
Postoperative central corneal sections from the two study groups. Top: postoperative corneas from the group treated with solution plus ascorbic acid; bottom: corneas from the group treated with BSS. The two latter slides show a marked decrease in endothelial cell density, as well as marked endothelial cell vacuolization. Magnification, ×400.
Figure 2.
 
Postoperative central corneal sections from the two study groups. Top: postoperative corneas from the group treated with solution plus ascorbic acid; bottom: corneas from the group treated with BSS. The two latter slides show a marked decrease in endothelial cell density, as well as marked endothelial cell vacuolization. Magnification, ×400.
Table 1.
 
Specular Microscopy Results
Table 1.
 
Specular Microscopy Results
Eye Irrigating Solution Preoperative Cell Count/mm3 Postoperative Cell Count/mm3 Cell Loss/mm3 % Change in Endothelial Cell Density
1 Solution* 3011 2381 630 −20.9
2 Solution 3294 3027 267 −8.1
3 Solution 3000 2390 610 −20.3
4 Solution 3631 3112 519 −14.3
5 Solution 3058 2205 853 −27.9
6 Solution 3199 2908 291 −9.1
7 Solution 3123 2914 209 −6.7
8 Solution 3135 2883 252 −8.0
9 Solution+AA, † 3058 3195 −137 +4.7
10 Solution+AA 2756 2835 −79 +2.8
11 Solution+AA 3021 3170 −149 +4.9
12 Solution+AA 2885 2655 230 −7.9
13 Solution+AA 3493 3363 130 −3.7
14 Solution+AA 3525 3154 371 −10.5
15 Solution+AA 2968 2765 203 −6.8
16 Solution+AA 3082 2854 228 −7.4
17 Solution+AA 3137 2825 312 −9.9
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×