George R. McCarty

Small incisions to control astigmatism during cataract surgery

ABSTRACT Astigmatic changes in three series of cataract surgical procedures were compared. Two series comprised eyes having phacoennilsification and implantation of a foldable silicone lens through a 3.0 mm to 4.0 mm incision or a 5.8 mm diameter polyinethylmethacrylate (PMMA) lens through a 6.0 min incision. The third series comprised eyes having a planned extracapsular cataract extraction (ECCE) procedure through a 10.0 min incision and implantation of a PIMA posterior chamber lens. Surgically induced cylinder changes were compared by examining preoperative and postoperative dioptric cylinder power changes without regard to axis changes and by using vector analysis to compute induced cylinder for cases with axis changes. Both phacoemulsification series had similar mean induced cylinder levels, which were significantly less than mean induced cylinder in the ECCE group at both three and six months after surgery. Over 70% of the eyes in the two small incision phacoemulsification groups achieved an uncorrected visual acuity of 20/40 or better at three months, whereas only 28% of the ECCE group achieved that acuity. We concluded that the phacoemulsification procedure induced significantly less astigmatism and provided faster visual rehabilitation than the ECCE procedure. Furthermore, the use of small diameter PMMA IOLs inserted through small incisions minimized surgically induced cylinder in a way comparable to the use of foldable silicone implants, while maintaining good visual results with fewer postoperative complications.

Glare disability devices for cataractous eyes: a consumer's guide

ABSTRACT We evaluated five commercially available glare testers to determine how accurately each device predicted outdoor Snellen acuity in cataract patients. Predicted outdoor Snellen acuity was compared to actual Snellen outdoor acuity for the Miller‐Nadler glare tester, the brightness acuity tester (BAT), the InnoMed true vision analyzer (TVA), the VisTech VCT 8000, and the EyeCon 5. All five devices were evaluated in a single series of eyes. We ranked the five glare testers as follows based upon their ability to predict outdoor Snellen acuity within one Snellen line: (1) BAT (73%), (2) TVA (69%), (3) VisTech VCT 8000 (56%), (4) Miller‐Nadler (47%), and (5) EyeCon 5 (15%). All five devices were also evaluated for their capacity to provide false negative or false positive results and for testing time per eye, test difficulty level for the patient, versatility, upgrading capacity, examining room adaptability, and price. We concluded that glare testing of cataract patients is necessary to measure visual disability and that glare testing devices vary in their ability to predict outdoor vision.

Complications associated with STAAR silicone implants

ABSTRACT We compared the incidence of various complications in consecutive series of cases in which 76 eyes received STAAR silicone intraocular implants and 76 eyes received small incision IOLAB G708G polymethylmethacrylate (PMMA) intraocular implants. All surgeries were performed by the same surgeon employing the same phacoemulsification technique. A higher incidence of lens subluxation, lens repositioning, corneal edema, and elevated intraocular pressure was observed in the eyes receiving STAAR silicone implants than in the eyes receiving IOLAB PMMA implants, In addition, a YAG laser posterior capsulotomy could not be performed through several STAAR silicone RMX 1 model implants. An invasive pars plana posterior capsulotomy was necessary in these eyes. We also found that the STAAR silicone RMX 3 model implants were often pitted by the YAG laser during successful posterior capsulotomies. Despite these problems, the STAAR silicone intraocular lens group achieved corrected vision similar to the PMMA lens group.

Prophylactic use of apraclonidine for intraocular pressure increase after Nd:YAG Capsulotomies.

We evaluated the prophylactic effect of 1% apraclonidine HCl in controlling the increase in intraocular pressure after Nd:YAG posterior capsulotomy in a large, multicenter double-masked clinical trial. One hundred sixty-four patients were enrolled into the apraclonidine-treated group, and 165 into the vehicle-treated group. The incidence of increase in intraocular pressure (greater than 5 mm Hg) in the apraclonidine-treated group (7%, 11 of 163 patients) was significantly less than that in the vehicle-treated group (39%, 64 of 164 patients). Similarly, the mean maximal change in intraocular pressure in the apraclonidine-treated group (1.3-mm Hg decrease) was significantly different from the increase in the vehicle-treated group (5.3-mm Hg increase). Few adverse reactions were observed. The risk for significant loss of visual function after Nd:YAG laser posterior capsulotomy, combined with the efficacy and relative safety of prophylactic apraclonidine, suggest its addition to the treatment armamentarium.

Clinical comparison of Provisc and Healon in cataract surgery

Abstract This prospective, randomized, multicenter clinical trial compared the safety and efficacy of the Proviscs® and Healon® viscoelastics. Sixty‐one eyes of 61 patients had an extracapsular cataract extraction with implantation of a posterior chamber intraocular lens with the aid of Provisc (n = 32) or Healon (n = 29). Mean changes in preoperative versus postoperative corneal thickness and intraocular pressure and the incidence and magnitude of postoperative corneal edema and iritis were not significantly different between the two groups. Observed complications were considered consequences of the surgery and unrelated to viscoelastic use. No adverse medical events occurred. These results indicate Provisc and Healon are clinically equivalent in terms of safety and efficacy when used as surgical aids.

Hexagonal keratotomy for correction of low hyperopia: Preliminary results of a prospective study

ABSTRACT Fifteen sighted eyes of 11 patients had hexagonal keratotomy for the correction of low hyperopia. Mean preoperative hyperopia of +3.21 diopters (range +1.75 to +5.50) was reduced a mean of 2.16 diopters (range 0 to −3.25) and keratometry was increased a mean of +2.22 diopters (range +0.75 to +3.71). Follow‐up averaged 9.5 months (range 2.0 to 17.5). Ten of the 15 eyes (67%) had at least six months follow‐up. No eye had better than 20/80 uncorrected visual acuity preoperatively. Fourteen eyes (93%) had 20/80 or better uncorrected acuity at the most recent postoperative visit. Nine of the 15 eyes (60%) had uncorrected acuity of 20/40 or better. Refractive spherical equivalent appeared to stabilize by three months for most patients. Astigmatism was increased a mean of only +0.02 diopter and no serious complications occurred. Further follow‐up is required to assess the safety and efficacy of hexagonal keratotomy for reducing low levels of hyperopia.

Refractive evaluation of astigmatic keratotomy procedures

ABSTRACT We evaluated the efficacy of three transverse incision astigmatic keratotomy procedures using a vector analysis that enabled us to determine the magnitude of the effect and the axis in which it occurred. These procedures were used for low levels of astigmatism (0.5 diopter [D] to 3.75 D): (1) staggered, radial‐touching transverse (T) incisions, (2) non‐radial‐touching T incisions, and (3) T incisions with interrupted radial. Most procedures were performed in conjunction with radial keratotomy for spherical correction of myopia. The non‐radial‐touching T procedure was the least effective method of reducing astigmatism. The staggered, radial‐touching T and T with interrupted radial procedures were equally effective in reducing over 93% (on the average) of the preoperative astigmatism. Of these two procedures, the T with interrupted radial procedure was the most accurate, with the effect of the surgery deviating less than ten degrees from the desired axis in over 70% of the eves.

The relationship between indoor and outdoor Snellen visual acuity in cataract patients

ABSTRACT One hundred six cataractous eyes of 78 patients were evaluated to examine the relationship between indoor and outdoor Snellen visual acuity. While 81 of all cataractous eyes (76.4%) had Snellen visual acuities of 20/40 or better when tested indoors, only 33 eyes (31.2%) had 20/40 or better Snellen visual acuities when tested outdoors facing the sun. When tested indoors, only three eyes (2.8%) had Snellen visual acuities worse than 20/80, while 31 eyes (29.2%) had outdoor Snellen visual acuities worse than 20/80. Ten eyes (9.4%) had outdoor Snellen visual acuities worse than 20/200. Seventy‐four eyes (69.8%) had outdoor visual acuities that were at least two Snellen lines worse than those measured indoors and 23 eyes (21.7%) had outdoor visual acuities that were at least five Snellen lines worse. The median difference between indoor and outdoor visual acuity was three Snellen lines. The need for increased precision in the ability to assess outdoor “real world” vision while in the ophthalmologists examination room is discussed. Clearly, indoor Snellen visual acuity alone is insufficient to evaluate functional visual impairment in cataract patients.

The relationship between cataract type and glare disability as measured by the Miller-Nadler glare tester

ABSTRACT Cataract patients were tested for glare disability using the MillerNadler glare tester. Predicted outdoor visual acuity was then compared with the actual outdoor visual acuity. The Miller‐Nadler glare test scores predicted actual outdoor visual impairment to within one Snellen line in 46.7% of the eyes, underestimated actual outdoor visual impairment by more than one Snellen line in 31.5% of the eyes, and overestimated outdoor visual impairment by more than one Snellen line in 21.7% of the eyes. Overall, 64.1% of the eyes had outdoor vision which was more closely predicted by their glare scores than by their indoor Snellen acuity. When the cataractous eyes were divided into three categories, eyes with pure nuclear sclerosis, eyes with nuclear sclerosis and posterior subcapsular opacities, and eyes with all other cataractous combinations, predictability differences were observed. Although we found that actual outdoor visual acuities were not precisely predicted by disability glare scores in a substantial proportion of our subjects, the glare scores were considerably more predictive than indoor Snellen acuity. Further development and field testing of glare testing devices as predictors of outdoor visual impairment is necessary.

Phacoemulsification devices: A consumer's report

ABSTRACT This report deals with our evaluation of six phacoemulsification devices tested at the Neumann Eye Institute (two additional devices have been evaluated since this paper was presented at the ASCRS meeting). The devices were compared for operating cost of the first 1,000 cases, dependability, ease of usage, and level of safety for the patient.