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Biomedical subjects

D R Sanders

Publications and source records attributed to D R Sanders.

At least 37 records · Page 2Linked to original sources
PubMed1990

Incidence of retinal detachment following posterior chamber intraocular lens surgery.

We examined the three-year incidence of retinal detachment in a consecutive cohort of 4,329 eyes which had cataract surgery with implantation of a posterior chamber intraocular lens between 1979 and 1984. The overall three-year incidence was 1.4%. The three-year incidence for open capsule cases (1.9%) was over twice that for intact capsule cases (0.8%). Axial myopes (axial length greater than or equal to 25 mm) overall were at least three times as likely to develop retinal detachment within three years (3.6%) as eyes with axial lengths less than 25 mm (1.1%). The combination of open capsule and axial myopia increased the three-year retinal detachment risk tenfold over that of the intact capsule in normal length eyes.

Chicago↗
PubMed1990

Effect of thermokeratoplasty on corneal curvature.

A cadaver eye model was used to evaluate and quantify the use of thermokeratoplasty for steepening the central cornea to correct hyperopia. Four groups of eye-bank eyes were treated with four separate surgical plans. Each plan involved the placement of controlled thermal burns (in the depths of the corneal stroma, using a cautery probe) applied in a radial pattern up to a premarked optical zone. The plans differed in the sequence of surgical steps. All plans progressively added radials and applications (to decrease optical zone) in various sequences. Corneal curvature was measured at baseline and at each surgical step. As more surgery was done within each plan, the corneas became progressively steeper. Total mean changes in corneal curvature ranged from 16.26 diopters to 19.76 diopters, depending on the plan. At each optical zone, as the number of radials increased, the effect increased. With progressively smaller optical zone size, the effect also increased.

Cornea↗
PubMed1989

Comparison of corneal storage in K-Sol and chondroitin sulfate corneal storage medium in human corneal transplantation.

Fifty-one pairs of corneas, stored in either K-Sol or CSM (chondroitin sulfate corneal storage medium) from 8 to 97 hours (mean +/- standard deviation, 58 +/- 21 and 57 +/- 21 hours, respectively), were transplanted in a prospective, randomized manner into 99 patients (n = 102 eyes), paired by diagnostic group and procedure. Ninety-six percent of K-Sol grafts (n = 51) and 94% of the CSM grafts (n = 51) were clear at 6 months; 92% of both the K-Sol (n = 38) and CSM (n = 35) grafts were clear at 12 months. One primary donor failure occurred, a K-Sol cornea stored for 76 hours. The CSM group experienced a greater number of persistent epithelial defects beyond 2 weeks (7 versus 4 defects) and graft reaction episodes (7 versus 3 episodes) than the K-Sol group; however, an equal number of late graft failures (3) occurred in both groups. No significant differences by paired t test analyses were found in endothelial cell density, area, coefficient of variation, or figure coefficient at 3 (n = 37 pairs), 6 (n = 36 pairs), and 12 (n = 26 pairs) months between the two groups. Mean endothelial cell density significantly decreased by 11% +/- 22 by 3 months in the K-Sol group, whereas the 7% +/- 24 decrease in the CSM group was insignificant. By 12 months, both groups experienced a significant decrease: K-Sol, 27% +/- 22; CSM, 17% +/- 26. A significant decrease in the mean coefficient of variation (polymegathism) was noted after 3 months in the K-Sol group which returned to the preoperative mean by 1 year, whereas this parameter remained unchanged in the CSM group. Both chondroitin sulfate-based media result in successful corneal transplantation with storage up to 4 days; however, endothelial survival with both media are comparable with previous studies with McCarey-Kaufman (M-K) medium.

Adolescent↗
PubMed1989

Effect of a pupillary light occluder on cystoid macular edema.

A prospective, randomized study of 291 patients was performed to determine the effect of a pupillary light occluder on the incidence of angiographic cystoid macular edema (CME) in patients having extracapsular surgery with implantation of a posterior chamber lens. Patients were randomized preoperatively into two groups: those having surgery with and without a pupillary light occluder on the cornea. The occluder was placed on the cornea during suture placement, following the extracapsular lens extraction and intraocular lens implantation. Of the 291 patients, 198 had angiograms readable for the presence or absence of CME. The incidence of angiographic CME in patients with the occluder was 15.0%; in those without the occluder it was 12.5%. The difference was not statistically significant. The presence or absence of an occluder on the cornea during suture placement does not affect the incidence of angiographic CME or the visual results of these cases.

Adult↗
PubMed1989

Analysis of astigmatic keratotomy.

Eighty-two keratotomy procedures were performed for both idiopathic and postsurgical astigmatism or myopic astigmatism and analyzed for efficacy using vector and linear regression analysis. Delta keratometry values (delta K) were computed for each case as delta K in the desired axis of effect using vector analysis. Six different procedures were compared including both intersecting and nonintersecting trapezoidal keratotomy, relaxing incisions with compression sutures, T cuts with radial keratotomy, T cuts alone, and RK with elliptical optical zones. Our results showed that the greatest shifts occurred in the trapezoidal groups, whereas the most predictable effects occurred in the relaxing incision/compression suture group. Astigmatic keratotomy is capable of producing large shifts in corneal astigmatism; however, the accuracy of these procedures remains highly variable.

Adult↗
PubMed1989

Refractive evaluation of astigmatic keratotomy procedures.

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 eyes.

Adult↗
PubMed1989

Small incisions to control astigmatism during cataract surgery.

Astigmatic changes in three series of cataract surgical procedures were compared. Two series comprised eyes having phacoemulsification and implantation of a foldable silicone lens through a 3.0 mm to 4.0 mm incision or a 5.8 mm diameter polymethylmethacrylate (PMMA) lens through a 6.0 mm incision. The third series comprised eyes having a planned extracapsular cataract extraction (ECCE) procedure through a 10.0 mm incision and implantation of a PMMA 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.

Adult↗
PubMed1988

The quantitative effect of 0.5% ketorolac tromethamine solution and 0.1% dexamethasone sodium phosphate solution on postsurgical blood-aqueous barrier.

Anterior chamber fluorophotometry was performed after the oral administration of fluorescein sodium in patients undergoing extracapsular cataract extraction and posterior chamber intraocular lens insertion before and after surgery. The administration of 0.5% ketorolac tromethamine solution (ketorolac solution) eye drops before and after surgery decreased the breakdown of the blood-aqueous barrier as compared with 0.1% dexamethasone sodium phosphate solution (dexamethasone solution) eye drops at each period, as measured by fluorophotometry. A single injection below Tenon's capsule of a short-acting corticosteroid had been given to each patient at the end of each surgical procedure. Slit-lamp observations of postoperative ocular inflammation were not different between treatment groups. Both ketorolac and dexamethasone solutions were well tolerated by patients. Ketorolac solution was more effective than dexamethasone solution in facilitating reestablishment of the blood-aqueous barrier after surgery, as measured by fluorophotometry, and was equal to dexamethasone solution as observed by slit-lamp observations. This study suggests that ketorolac ophthalmic solution may be effective and safe as a nonsteroidal anti-inflammatory agent for topical use after cataract surgery and intraocular lens implantation in place of topically administered corticosteroids.

Adult↗
PubMed1988

The nationwide study of epikeratophakia for aphakia in older children.

A nationwide study of epikeratophakia for aphakia in older children was conducted from March 1984 to March 1986. Sixty-three patients, 8 to 18 years of age, underwent this procedure in 65 eyes. Twenty-eight patients had congenital cataracts and 35 had traumatic cataracts. Fifty-one of the 65 eyes were aphakic at the time of surgery (secondary procedures). All surgeries were successful; no tissue lenses were lost or removed. Postoperatively, 73% of the patients were within 3 diopters (D) of emmetropia. The patients with congenital cataracts gained an average of one Snellen line of best-corrected visual acuity; patients with traumatic cataracts lost an average of one Snellen line of best-corrected visual acuity. In older pediatric patients, epikeratophakia appears to be a safe and effective procedure for the correction of aphakia.

Aphakia↗
PubMed1988

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

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 ophthalmologist's examination room is discussed. Clearly, indoor Snellen visual acuity alone is insufficient to evaluate functional visual impairment in cataract patients.

Cataract↗
PubMed1988

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

Cataract patients were tested for glare disability using the Miller-Nadler 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.

Cataract↗
PubMed1988

Comparison of the SRK II formula and other second generation formulas.

A simple modification of the SRK formula was developed for use with extreme axial length cases (short and long eyes) to maximize prediction accuracy in these groups. For "average" eyes (over 75% of all cases), SRK needed no modifications to maintain maximum predictive accuracy. The new, modified SRK formula (SRK II) was compared with current second generation formulas and the Binkhorst formula. The SRK II formula, while maintaining the simplicity and ease of the SRK, was comparable to and in some cases superior to the other formulas. Overall, 80.0% of 2,068 posterior chamber intraocular lenses from seven different manufacturers demonstrated less than one diopter of prediction error and only 0.5% had three or more diopters of error. In short eyes (less than 22 mm), 74.0% were corrected to within one diopter and less than 2.0% had three or more diopters of error. In long eyes (greater than or equal to 24.5 mm), 78.0% of cases demonstrated less than one diopter of error and less than 1.0% had three or more diopters of error. Although the SRK II formula is incorporated in most new A-scan units, the modifications are so simple that surgeons can take the standard SRK predictions and mentally calculate the modifications for extreme cases.

Humans↗
PubMed1987

The nationwide study of epikeratophakia for aphakia in adults.

In the nationwide study of epikeratophakia, 154 ophthalmic surgeons who had attended a training course performed 519 procedures for the correction of aphakia in adults: 310 of the eyes had 30 or more days of follow-up after suture removal. Of 229 eyes, 172 (75%) were within 3 diopters of emmetropia after surgery. Of 259 eyes, 245 (95%) demonstrated improved uncorrected visual acuity; 138 (53%) improved by four or more Snellen lines. Of 265 eyes, 209 (78%) achieved within two lines or improved their best corrected visual acuity. Of the 119 patients who achieved or improved their preoperative best corrected visual acuity, 110 (92%) were within two Snellen lines or better by 30 to 60 days after suture removal. Of the 127 patients with more than three months of follow-up after suture removal, 124 (98%) of those between 18 and 70 years of age but only 13 of 23 (54%) of those between 81 and 87 years of age achieved within two lines or better of their best corrected visual acuity. Corneal astigmatism measured by keratometry changed from a preoperative mean (+/- S.D.) of 2.1 +/- 1.8 diopters to a postoperative mean of 2.7 +/- 2.6 diopters. Of the 519 tissue lenses, 22 (4%) were removed, and one third of these patients underwent a second, successful epikeratophakia procedure.

Adolescent↗
PubMed1987

The nationwide study of epikeratophakia for aphakia in children.

In the nationwide study of epikeratophakia, 97 surgeons performed a total of 335 procedures in 314 eyes for the correction of aphakia in children under the age of 8 years 1 month. Fifteen children underwent bilateral surgery. Thirty-six tissue lenses were removed and 21 of these eyes underwent a second epikeratophakia procedure. Overall, the success rate for procedures was 89%, and with repeated surgery it was 95% for eyes. Seventy-three percent of the patients were within 3 diopters of emmetropia after surgery. Visual acuity results in patients able to provide verbal responses to the illiterate E, Allen card, or Snellen line chart testing showed improvement in most cases. The safety of epikeratophakia makes it a desirable option for the correction of aphakia in children who are spectacle or contact-lens intolerant, and the permanence of the correction eliminates the problem of optical noncompliance.

Aphakia↗
PubMed1987

The nationwide study of epikeratophakia for myopia.

In the nationwide study of epikeratophakia, 116 ophthalmic surgeons performed 352 procedures for the correction of myopia; 256 of the eyes had 30 or more days of follow-up after suture removal. Of 204 eyes, 153 (75%) were within 30% of emmetropia after surgery. Of 208 eyes, 202 (97%) had postoperative best corrected visual acuity within two Snellen lines or better of their preoperative visual acuity. All but one patient improved uncorrected visual acuity. Of the 120 patients who equaled or improved their preoperative best corrected visual acuity, 116 (97%) were within two Snellen lines of their preoperative measurement between 30 and 60 days after suture removal. Corneal astigmatism changed from a preoperative mean (+/- S.D.) of 1.4 +/- 0.8 diopters to a postoperative mean of 2.6 +/- 2.1 diopters. Of 352 tissue lenses, 36 (10%) were removed, largely as a result of inaccurate power, decay, or failure to reepithelialize, and 17 of these eyes underwent a second successful epikeratophakia procedure.

Adolescent↗
PubMed1987

A consecutive series (1982-1985) of radial keratotomies performed with the diamond blade.

The refractive and visual results of a consecutive series of diamond knife radial keratotomy procedures were evaluated at one year after surgery as part of an ongoing prospective study of radial keratotomy. Of the 972 procedures performed, 656 eyes (67.5%) were examined one year or more after surgery. The average amount of preoperative myopia was 4.4 diopters with a range of 0.6 to 11.9 diopters; 638 (97%) of the eyes had a preoperative uncorrected visual acuity of 20/100 or worse. The mean change in spherical equivalent after one year was 4.5 diopters. One year after surgery, 496 (76%) of the eyes were within 1 diopter of emmetropia; 310 (47%) had uncorrected distance visual acuity of 20/20 or better, 579 (88%) were 20/40 or better, and all but one eye had uncorrected visual acuity improved by at least two Snellen lines. Evaluation of refractive and visual results at the final available examination of those eyes not examined one year after surgery showed that 256 (81%) of the eyes were within 1 diopter of emmetropia; 176 (56%) had uncorrected distance visual acuity of 20/20 or better, and 287 (91%) were 20/40 or better.

Adolescent↗
PubMed1987

Secondary intraocular lens implantation: rigid/semi-rigid versus flexible lenses.

Two series of secondary intraocular lens implantations with anterior chamber lenses are reported. Series 1 consisted of our first 199 consecutive procedures using rigid or semi-rigid lenses, performed between May 1, 1977, and September 30, 1982. Series 2 consisted of our first 101 consecutive procedures using flexible lenses, performed between October 1, 1982, and October 30, 1984. Best-corrected final postoperative visual acuity was either better than or within one Snellen line of best-corrected preoperative vision in 84% of cases with rigid or semi-rigid lenses and in 85% of cases with flexible lenses. Surgical complications were minimal in both series. No instances of uveitis-glaucoma-hyphema syndrome were encountered. Endothelial cell loss was low. Because of the short follow-up in Series 2 and the fact that these groups were operated upon at different times, the two series are not directly comparable. Nonetheless, the results do show that secondary intraocular lens implantation is a viable alternative for aphakic patients, particularly those who are intolerant of aphakic spectacles and contact lenses. Certain provisos involving patient education and motivation as well as lens selection are noted in this report.

Adult↗