Reduced best spectacle-corrected visual acuity from inserting a thicker Intacs above and thinner Intacs below in keratoconus.

PURPOSE: To report a case of decreased best spectacle-corrected visual acuity (BSCVA) 2 months after Intacs implantation. METHODS: A 33-year-old woman with keratoconus and contact lens intolerance underwent Intacs surgery in the left eye at another institution. Two segments were used--a thinner one (0.25 mm) below the cone and a thicker one (0.35 mm) above the cone. RESULTS: Two months postoperatively, the patient presented to our practice with BSCVA reduced from 20/20 to 20/30. The superior Intacs segment was explanted, the inferior segment was exchanged for a thicker one (0.35 mm), and collagen cross-linking with riboflavin treatment was performed. This resulted in visual, topographic, and refractive improvement with BSCVA returning to 20/20. CONCLUSIONS: Single inferior segment Intacs may be more appropriate for paracentral and peripheral cones. Collagen cross-linking may help cause further flattening. Using asymmetrical segments, with the thicker segment above the cone, may increase distortions and result in loss of BSCVA.

Higher order aberrations and relative risk of symptoms after LASIK.

PURPOSE: To understand what level of higher order aberrations increases the relative risk of visual symptoms in patients after myopic LASIK. METHODS: This study was a retrospective comparative analysis of 103 eyes of 62 patients divided in two groups, matched for age, gender, pupil size, and spherical equivalent refraction. The symptomatic group comprised 36 eyes of 24 patients after conventional LASIK with different laser systems evaluated in our referral clinic and the asymptomatic control group consisted of 67 eyes of 38 patients following LADARVision CustomCornea wavefront LASIK. Comparative analysis was performed for uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), contrast sensitivity, refractive cylinder, and higher order aberrations. Wavefront analysis was performed with the LADARWave aberrometer at 6.5-mm analysis for all eyes. RESULTS: Blurring of vision was the most common symptom (41.6%) followed by double image (19.4%), halo (16.7%), and fluctuation in vision (13.9%) in symptomatic patients. A statistically significant difference was noted in UCVA (P = .001), BSCVA (P = .001), contrast sensitivity (P < .001), and manifest cylinder (P = .001) in the two groups. The percentage difference between the symptomatic and control group mean root-mean-square (RMS) values ranged from 157% to 206% or 1.57 to 2.06 times greater. CONCLUSIONS: Patients with visual symptoms after LASIK have significantly lower visual acuity and contrast sensitivity and higher mean RMS values for higher order aberrations than patients without symptoms. Root-mean-square values of greater than two times the normal after-LASIK population for any given laser platform may increase the relative risk of symptoms.

Effect of inferior-segment Intacs with and without C3-R on keratoconus.

PURPOSE: To determine whether corneal collagen cross-linking with riboflavin (C3-R) augments the effect of inferior-segment Intacs (Addition Technology) in the treatment of keratoconus. SETTING: Private practice, Beverly Hills, California, USA. METHODS: A retrospective nonrandomized comparative case series comprised 12 eyes of 9 patients who had inferior-segment Intacs placement without C3-R (Intacs-only group) and 13 eyes of 12 patients who had inferior-segment Intacs placement combined with C3-R (Intacs with C3-R group). The 2 groups were matched preoperatively. All patients had inferior-segment Intacs placed with the incision in the steep axis of manifest refraction. Corneal collagen cross-linking with riboflavin was performed after the Intacs segments were inserted. Outcome measures were topographic keratometry values and the lower-upper (L-U) ratio, which is a topographic measure of the degree of keratoconus. Preoperative data were compared to results 1 day postoperatively and measurements at the last postoperative visit. RESULTS: The Intacs with C3-R group had a significantly greater reduction in cylinder than the Intacs-only group (P<.05). Steep and average keratometry were reduced significantly more in the Intacs with C3-R group (P<.05). There was a greater reduction in L-U ratio in the Intacs with C3-R group (P<.05). CONCLUSION: The addition of C3-R to the Intacs procedure resulted in greater keratoconus improvements than Intacs insertion alone.

Complex wavefront-guided retreatments with the Alcon CustomCornea platform after prior LASIK.

PURPOSE: To report the results of complex wavefront-guided LASIK retreatments. METHODS: Twenty eyes (15 patients) with histories of conventional LASIK surgery and significant visual complaints of glare and halos due to higher order aberrations were treated. Wavefront-guided retreatments were performed with the LADARVision CustomCornea system (Alcon, Ft Worth, Tex). Pre- and postoperative topographies, wavefront measurements, and subjective reports were analyzed. RESULTS: Postoperatively, patients had an expanded optical zone, many with improved centration. Lower and higher order aberrations decreased following wavefront-guided ablation. Mean higher order root-mean-square decreased from 1.01 +/- 0.25 microm preoperatively to 0.84 +/- 0.23 microm postoperatively. Mean coma decreased from 0.59 +/- 0.26 microm to 0.43 +/- 0.21 microm. Mean spherical aberration decreased from 0.66 +/- 0.25 microm to 0.54 +/- 0.27 microm. Subjective reports of glare and halo symptoms improved in all patients. CONCLUSIONS: CustomCornea wavefront-guided treatments are effective in reducing lower and higher order aberrations, expanding optical zones, and improving subjective reports of adverse aberration sequelae such as glare and halos.

Reversal of laser in situ keratomileusis-induced ectasia with intraocular pressure reduction.

A 40 year-old woman had laser in situ keratomileusis for --7.75 --0.75 x 20 in the right eye. Preoperative examinations, including topography, pachymetry, and intraocular pressures (IOPs), were normal, and best spectacle-corrected visual acuity (BSCVA) was 20/20 in each eye. By 4 months postoperatively, the uncorrected visual acuity and BSCVA in the right eye had decreased to 20/40. Corneal topography of that eye was consistent with ectasia. One drop per day of timolol 0.5% (Timoptic XE) was prescribed. Five months postoperatively, the IOP had decreased and BSCVA and topography had improved. At 11 months, BSCVA returned to 20/20 and corneal topography normalized. Topographic difference maps were used to monitor corneal shape changes. In this case, early reduction in IOP completely reversed the ectasia.

Understanding pre-market approval and labeling differences of two leading customized ablation platforms: a call for reform at the FDA.

PURPOSE: To analyze the Food and Drug Administration (FDA) pre-market approval reported data for two currently available wavefront-guided excimer laser systems. METHODS: VISX and Alcon myopic wavefront laser in situ keratomileusis (LASIK) trials were analyzed based on public information available in the pre-market approval documents. RESULTS: Clinical tests and outcomes reporting varied between pre-market approvals. One pre-market approval reported contrast sensitivity whereas the other did not, although data was collected in both studies. Based on the FDA definition of "accountability," one pre-market approval reported 12-month accountability of 97.7% although only 24.5% of patients were analyzed at that interval. One pre-market approval reported 6-month results whereas the other reported 6- and 12-month results. One pre-market approval reported grouped pre- and postoperative subjective survey results; the other reported individual changes in pre- to postoperative subjective symptoms. CONCLUSION: We recommend an FDA revision to the definition of "accountability" and also recommend future FDA refractive surgery trials be guided by standardized criteria.

Evaluation of tear film following Intacs for myopia.

PURPOSE: To evaluate the effect of intrastromal corneal ring segments (Intacs, Keravision) placement on the tear film quality as a measure of dry eye status. METHODS: Seventeen eyes of ten patients underwent Intacs placement for the correction of myopia with spherical equivalent refractions ranging from -1.75 to -3.25 D (mean, -2.43 +/- 0.56 D). Dry eye grade values were measured preoperatively and at 1 day, 1 week, and 1 month postoperatively using the Kowa-DR-1 interferometer. RESULTS: Preoperatively, the 17 eyes had a mean dry eye grade of 2.18 +/- 0.39 (range, 2 to 3). One day postoperatively, the 14 eyes measured had a mean dry eye grade of 2.64 +/- 0.63 (range, 2 to 4; P = .03). At 1 week the 17 eyes had a mean dry eye grade of 2.41 +/- 0.71 (range, 2 to 4; P = .25) and at 1 month, 2.18 +/- 0.39 (range, 2 to 3; P = .75). CONCLUSIONS: There was transient dry eye following Intacs placement, but the tear film quality was restored within 1 week of surgery.

Reduction of pupil size and halos with minus lenses after laser in situ keratomileusis.

PURPOSE: To evaluate the amount of miosis induced by over-minused lenses and to assess subjective reduction of halos following laser in situ keratomileusis (LASIK) with such lenses. METHODS: Part I: Infrared pupil diameter was assessed in 14 patients who had not had ocular surgery. The accommodative/miotic reflex was stimulated with concave trial lenses in -1.00-D increments up to -4.00 D while viewing the 20/40 acuity line. Part II. Subjective halos around a distant light were assessed in 14 patients following LASIK for myopia, with and without a -1.00-D lens over manifest refraction. RESULTS: Part I: 100%, 79%, and 64% of patients clearly saw the 20/40 line with a -1.00-D lens, -2.00-D lens, and -3.00/-4.00-D lens, respectively. Mean pupil diameter decreased by 0.2 mm with the -1.00-D lens (P = .02), 0.5 mm with the -2.00-D lens (P = .003), 0.9 mm with the -3.00-D lens (P = .008,), and 1.1 mm with the -4.00-D lens (P = .008). Part II: 11 of 14 patients (79%) noticed a decrease in the size of the halo (30% average reduction) when over-minused by -1.00 D. CONCLUSIONS: Pupil diameters and halos decreased with a -1.00-D overcorrection in patients following LASIK. Patients with pupil-dependent night halos after LASIK may benefit from mildly over-minused lenses.

Reasons patients recommend laser in situ keratomileusis.

PURPOSE: To evaluate the reasons patients who have had laser in situ keratomileusis (LASIK) recommend it to others and examine the disparity between high levels of satisfaction and patient reports of night-vision symptoms and/or dry eye after LASIK. SETTING: Northeastern Eye Institute, Scranton, and the University of Pittsburgh, Pittsburgh, Pennsylvania, and the University of California at Los Angeles, Los Angeles, California, USA. METHODS: Questionnaires assessing symptoms and satisfaction after LASIK were mailed to 2,100 patients. The questionnaires included items about night-vision symptoms and satisfaction and an open-ended question for patients to give their reasons for recommending LASIK to others. The open-ended responses were categorized and tabulated. RESULTS: Four hundred thirty-four patients provided reasons for recommending LASIK to others. Sixteen categories of reasons were identified. "No more spectacles/contact lenses" was listed by 180 patients (42%), followed by "better vision" (21%) and "convenience" (15%). Women were significantly more likely to cite "better comfort" (27 women versus 3 men; chi square = 8.99, P =.003) and "better quality of life" (41 women versus 9 men; chi square = 7.36, P =.007) as a reason for recommending LASIK. Of the 35 patients who reported dissatisfaction with post-LASIK vision, 20 (57%) would recommend LASIK to a friend because "LASIK helps others." CONCLUSIONS: Categories of reasons for recommending LASIK to others were similar to reasons given by patients for seeking LASIK. Some patients who reported dissatisfaction with their vision said they would recommend LASIK, suggesting that recommendation of LASIK to others is not necessarily a measurement of the quality of a patient's vision after LASIK.

Role of instrument cleaning and maintenance in the development of diffuse lamellar keratitis.

OBJECTIVE: To determine if instrument cleaning techniques affect the rate of diffuse lamellar keratitis (DLK) after laser in situ keratomileusis (LASIK). DESIGN: Retrospective case series. PARTICIPANTS: Two hundred ten eyes of 109 patients. METHODS: A record review was performed of all patients who underwent LASIK at the Jules Stein Eye Institute from April 1 through June 24, 1999. During the first 6 weeks, the instruments used in LASIK surgery were cleaned according to our conventional protocol. At the end of this 6-week period, the cleaning protocol was modified and used for a subsequent 6-week period. For each eye during the two periods, the status of DLK on the first postoperative day was recorded. MAIN OUTCOME MEASURES: Presence of DLK. RESULTS: During the first 6-week period, 118 eyes of 60 patients underwent LASIK surgery. In the subsequent 6 weeks, 92 eyes of 49 patients underwent LASIK surgery. The two groups included patients with similar demographic background: gender, age, and target correction. Diffuse lamellar keratitis was present in 13 of 118 eyes (11%) using our conventional protocol. In only 2 of 92 eyes (2%) did DLK develop after the protocol was modified. Using the chi-square test, the difference between the two groups was statistically significant (P = 0.01). CONCLUSIONS: Diffuse lamellar keratitis is a fairly uncommon phenomenon after LASIK surgery. Although the cause remains to be elucidated, these results demonstrated a reduced incidence of DLK associated with alteration of cleaning procedures and a decrease in stagnant instrument cleaning fluids. The authors recommend that refractive centers avoid the use of stagnant fluids in their instrument cleaning and sterilizing protocols to minimize the occurrence of DLK outbreaks.