Clinical outcomes and functional visual performance: comparison of the ReSTOR apodised diffractive intraocular lens to a monofocal control

AIMS

To compare clinical outcomes of patients bilaterally implanted with SN60D3 intraocular lenses (IOLs) with outcomes of bilateral monofocal controls, and to determine the validity of implanting an apodised diffractive lens in a healthy patient population.

METHODS

Six unmasked US investigators prospectively enrolled 72 patients aged </=70 years with bilateral cataracts in otherwise healthy eyes. Patients underwent routine cataract extraction via phacoemulsification with SN60D3 implantation. Visual outcomes were assessed 1 week, 1 month and 6 months postoperatively. Patients completed two subjective surveys. As controls, 51 patients who were 6 months postoperative to bilateral implantation of AcrySof monofocal IOLs also were assessed.

RESULTS

Corrected and uncorrected distance visual acuity was similar across groups. For uncorrected near and intermediate visual acuity, statistically significant differences were found favouring the SN60D3 group (p<0.0001). Contrast sensitivity was significantly better in monofocal patients at 6 cpd and 18 cpd under various lighting conditions. The Functional Evaluation and the Questionnaire demonstrated that SN60D3 patients achieved significantly higher levels of functional vision and spectacle freedom (p<0.0001).

CONCLUSION

Despite mildly decreased contrast sensitivity when compared with a monofocal IOL, the SN60D3 provided high patient satisfaction, excellent functional vision, and high rates of spectacle freedom.

A prospective multicenter clinical trial to evaluate the safety and effectiveness of the implantable miniature telescope

PURPOSE

To evaluate the safety and preliminary efficacy of a novel visual prosthetic device, the Implantable Miniature Telescope, IMT (by Dr Isaac Lipshitz) (IMT), in a phase I trial in patients with significant bilateral central vision impairment from late-stage age-related macular degeneration (AMD). The IMT is designed to reduce the relative size of the scotoma by rendering enlarged (threefold) central visual field images over the central and peripheral retina.

DESIGN

Prospective, multicenter, open-label clinical trial.

METHODS

In this prospective, multicenter phase I trial, 14 patients aged 60 or older with bilateral geographic atrophy or disciform scar AMD, cataract, and best-corrected visual acuity (BCVA) between 20/80 and 20/400 had an IMT implanted in one eye. Distance and near BCVA, endothelial cell density, and quality of life, measured as activities of daily life (ADL), were evaluated preoperatively and postoperatively.

RESULTS

At 12 months, 10 (77%) of 13 patients gained 2 more lines of either distance or near BCVA, and eight (62%) of 13 patients gained 3 or more lines in either distance or near BCVA. Mean endothelial cell density decreased by 13%. All adverse events resolved without sequelae. ADL scores improved in the majority of patients.

CONCLUSION

The results of this phase I trial support further evaluation of the IMT in a larger study population with late-stage AMD. A phase II/III trial is in progress.

Traumatic flap displacement and subsequent diffuse lamellar keratitis after laser in situ keratomileusis

A 45-year-old man was struck in the left eye by the edge of a paper shopping bag 3 weeks after having laser in situ keratomileusis (LASIK). The injury resulted in partial displacement of the LASIK flap. The patient developed diffuse lamellar keratitis (DLK) the day after the flap was repositioned. By day 4, visual acuity diminished to 20/60. By day 9, the clinical evidence of the DLK had resolved, and by day 15, uncorrected visual acuity was 20/20. Eye trauma 3 weeks after LASIK can result in displacement of the LASIK flap, and DLK can develop following flap replacement. Long-term anatomic and visual results are usually good.

Long-term results of transsclerally sutured posterior chamber lenses in penetrating keratoplasty

PURPOSE

To evaluate the long-term safety and efficacy of transsclerally sutured posterior chamber lenses in penetrating keratoplasty.

METHODS

This was a retrospective review of 130 patients who underwent penetrating keratoplasty and placement of a transsclerally sutured posterior chamber lens with at least 1 year of follow-up. The mean follow-up period was 38.8 months. There were 61 patients who had been followed for at least 3 years (mean, 59 months).

RESULTS

At follow-up the visual acuity was 20/40 or better in 40 patients (31%) and 20/50 to 20/200 in 48 patients (36%). The primary reasons for decreased visual acuity were age-related macular degeneration (18%) and graft failure (13%). New-onset glaucoma was found in 19 of 82 patients (23%). In the 48 patients who had elevated intraocular pressures preoperatively, the pressure improved in 13 patients (27%) and worsened in 12 patients (25%). Exposure of the haptic suture through the conjunctiva occurred in 14 patients (11%) at an average of 12 months after surgery. Of these, seven (19%) occurred in patients with conjunctival flaps, and seven (16%) in patients who had scleral flaps covering the haptic suture. No erosions occurred in the cases in which the suture was rotated inside the eye.

CONCLUSION

Improvements in the surgical technique have made transsclerally sutured posterior chamber lenses safer in patients with inadequate capsular support. The long-term visual results in penetrating keratoplasty are acceptable and comparable to those of other techniques.

Effects of diet-age and streptomycin on virulence of Autographa californica M nucleopolyhedrovirus against the tobacco budworm

Addition of the antibiotic streptomycin to two artificial diets routinely used in bioassays of neonate lar vae of Heliothis virescens (tobacco budworm) infected with Autographa californica M nucleopolyhedrovirus (AcMNPV) increased lethal times of the virus. After storage of diets for 3 weeks at 4 degrees C, lethal times of infected larvae were significantly slower compared to those for larvae bioassayed using diets stored for 2 weeks or less. The effect of diet-age on rate of mortality was not the result of a change in total protein content or pH of the diet, but was apparently the result of some other alteration in the quality of the diet (e.g. microbial spoilage, palatibility, and/or nutritional value unrelated to total protein). Although we did not determine why lethal times were slower in response to streptomycin concentration or diet-age, we did find that slower lethal times were correlated with slower relative growth rates (RGR) of infected larvae. In addition, RGR of infected larvae decreased as a function of increasing streptomycin concentration, diet-age, and the interaction of the two factors. These results demonstrate that it is difficult to obtain consistent and comparable bioassay results if antibiotic composition and diet-age are not controlled. We suggest a standardized diet or highly standardized procedures for a given diet be developed that permits comparison of bioassays among and within laboratories.

Results one year after using the 193-nm excimer laser for photorefractive keratectomy in mild to moderate myopia

As part of a clinical trial, photorefractive keratectomy using the VISX 2015 193-nm excimer laser was performed on 91 healthy eyes of 91 patients. Preoperative refractive errors (spherical equivalent) ranged from -1.00 to -7.50 diopters (mean, -4.16 +/- 1.41 diopters). No patient had more than 1 diopter of refractive astigmatism. Six months postoperatively, the average residual refractive error was +0.09 +/- 0.63 diopters (range, -2.13 to +1.63 diopters). Correction within 1 diopter of that attempted was attained in 85 eyes (93%). Uncorrected visual acuity of 20/40 or better was attained in 86 eyes (95%) and was 20/25 or better in 67 eyes (74%). At one year, follow-up information was available on 85 eyes of 85 patients. The average residual refractive error was -0.15 +/- 0.65 diopters (range, -2.50 to +1.63 diopters). Correction within 1 diopter of that attempted was attained in 85 eyes (93%). Uncorrected visual acuity was 20/40 or better in 83 eyes (98%) and was 20/25 or better in 68 eyes (80%). One patient lost three lines of best-corrected visual acuity because of corneal haze, dropping from 20/15 to 20/30, whereas all other patients returned to best-corrected visual acuity within one line of their preoperative best-corrected visual acuity. Photorefractive keratectomy with the 193-nm excimer laser appears to be a useful treatment modality for the reduction of mild to moderate myopia.

193-nm excimer photorefractive keratectomy in high myopia

PURPOSE

To evaluate the refractive results of 193-nm excimer laser photorefractive keratectomy (PRK) performed on 48 highly myopic eyes in a multicenter study.

METHODS

A Visx 2015 or 2000 argon-fluoride excimer laser and a single-zone ablation technique were used. Postoperatively, eyes were treated with topical fluoromethalone for up to 5 months. Most eyes were treated with a 6.0- to 6.2-mm beam diameter after undercorrections and increased regression were noted with a 5.5-mm beam in earlier studies. Forty-eight eyes were treated for myopia, which was between -8.0 and -15.25 diopters (D) (spherical equivalent). The mean preoperative refraction was -11.2 D. Retreatment was performed after 6 to 16 months on 11 eyes for undercorrection. All eyes not retreated were followed for at least 12 months.

RESULTS

At 6 months, follow-up was available on 47 eyes. Of these eyes, 40% and 64% achieved corrections within 1 and 2 D of attempted correction, respectively. At 1 year, 60% of eyes attained 20/40 visual acuity or better uncorrected. Eleven patients (23%) were retreated between 6 to 16 months for undercorrection and/or regression. After retreatment, 47% and 81% of eyes achieved corrections within 1 and 2 D of attempted correction, respectively. At 1 year, 15% of eyes lost two lines of best-corrected visual acuity, and no eyes lost more than two lines. There was slightly more corneal haze seen in this group compared with the haze seen in patients undergoing PRK for low and moderate myopia.

CONCLUSIONS

These data show that excimer PRK can correct high amounts of myopia with reasonable stability after 6 months. Excimer PRK is an effective surgical treatment of severe myopia, but long-term follow-up is still needed to assess the stability of its effect.

Whole globe enucleation versus in situ corneal excision: a study of tissue trauma and contamination

Twenty-four pair of eyes donated to the Minnesota Lions Eye Bank were studied to determine the effect of corneal procurement methods on tissue quality. Eyes studied were ineligible for transplantation because of a preexisting medical condition other than sepsis or age of > 75 years. The procurement technique was randomized for each donor. One cornea was procured in situ (IS), whereas the fellow eye was enucleated and processed in the laboratory (EN). Procurement protocols were standard Eye Bank Association of America methods. Tissue characteristics were scored according to standard eye bank protocols. Cultures were performed at the time of tissue procurement and following storage for 7 days in Dexol media. With the exception of endothelial striae, no statistical difference was found between groups for any tissue characteristics. The average score for endothelial striae in the IS group was greater than twice that of the EN group. Initial cultures were positive in 10 of 24 in the IS group and four of 24 in the EN group. Each group had three positive end-storage cultures. These results demonstrate superior tissue decontamination after initial processing and less endothelial cell trauma with standard enucleation when compared to in situ corneal excisions.

Use of the 193 nm excimer laser for photorefractive keratectomy in low to moderate myopia

As part of a Phase III clinical trial, photorefractive keratectomy using the VISX 2015 193 nm excimer laser was performed on 91 sighted eyes of 91 patients. Preoperative refractive errors (spherical equivalent) ranged from -1.00 diopters (D) to -7.50 D (mean -4.11 D +/- 1.43 D). At six months, average residual refractive error was 0.02 D +/- 0.64 D (range -2.21 D to +1.38 D). Ninety-three percent of eyes were within 1.00 D of attempted correction, 93% had uncorrected visual acuity of 20/40 or better, and 72% achieved uncorrected visual acuity of 20/25 or better. All patients returned to their best corrected visual acuity within one line of their preoperative best corrected visual acuity. Photorefractive keratectomy with the 193 nm excimer laser appears to be useful in reducing low to moderate myopia.

Undesired light images associated with ovoid intraocular lenses

Ovoid intraocular lenses (IOLs) accounted for approximately 35% of the lenses implanted in 1991. Despite their popularity among surgeons, patient observations and complaints suggest that ovoid lenses are associated with undesired optical images postoperatively. A pilot clinical study was carried out to test that hypothesis. A multicentered investigation of 289 cases with well-centered IOLs determined that 45% of 168 patients with ovoid lenses observed unwanted optical phenomena at some time after surgery, whereas 17% of 121 patients with round IOLs had similar complaints. Based upon the preliminary clinical study a laboratory investigation was designed to assess optical performance differences between ovoid and round IOLs. One testing system used scatterometry and a second, ray tracing analysis. Both methods determined that the truncated, thickened edge of ovoid lenses was associated with significant light scattering, possibly accounting for the extraneous light images observed by some patients. The results of the clinical and laboratory investigations suggest that undesired optical images produced by ovoid IOLs are due to lens shape rather than to the reduced dimension of the optic.

Topical diclofenac in the treatment of ocular pain after excimer photorefractive keratectomy

BACKGROUND

Following excimer laser photorefractive keratectomy, patients experience significant ocular pain until corneal reepithelialization. Despite the use of cold compresses, bandage soft contact lenses, cycloplegics, narcotics, and topical corticosteroids, the pain has not been adequately controlled in many patients.

METHODS

A randomized, double-masked, parallel-group study of diclofenac sodium 0.1% ophthalmic solution and its placebo vehicle was evaluated. Patients undergoing excimer myopic photorefractive keratectomy on their second eye were admitted overnight. Postoperative procedures included two drops of diclofenac or placebo immediately after surgery and then qid until reepithelialization, topical tobramycin (qid), 0.1% fluorometholone (q2h), cycloplegics, and a disposable soft contact lens. Thirty-two patients (diclofenac = 16, placebo = 16) were evaluated from +30 minutes to +96 hours by several types of questionnaires.

RESULTS

Most patients who received placebo experienced pain, starting within 1 hour, peaking at 4 to 6 hours and lasting 36 to 48 hours. The diclofenac-treated patients rarely experienced the early peak in pain, had less pain overall until 72 hours postoperatively, and experienced significantly less photophobia and burning/stinging. Significantly fewer patients on diclofenac required oral narcotics. Three patients (diclofenac = 2, placebo = 1) developed corneal infiltrates, the etiology of which is not known. In a separate study we conducted, there was no difference in epithelial healing times between the diclofenac-treated eyes and those not receiving the drug.

CONCLUSIONS

Diclofenac appears to significantly reduce the ocular pain following excimer photorefractive keratectomy.

Clinical findings in Brown-McLean syndrome

The Brown-McLean syndrome is a clinical condition with corneal edema involving the peripheral 2 to 3 mm of the cornea. The edema typically starts inferiorly and progresses circumferentially, but spares the central portion of the cornea. Additionally, the edema is associated with a punctate orange-brown pigmentation on the endothelium underlying the edematous areas. Central cornea guttata is frequently seen. This condition occurs most frequently after intracapsular cataract extraction, but may also occur after extracapsular cataract extraction and phacoemulsification, or pars plana lensectomy and vitrectomy. Surgical complications and multiple intraocular procedures are frequently observed in these patients. Less frequently, the Brown-McLean syndrome can occur in eyes that have not had surgery. We studied the clinical characteristics of 43 affected eyes of 32 patients. New findings included Brown-McLean syndrome occurring in two eyes of a phakic patient with intermittent angle-closure glaucoma. Two eyes developed Brown-McLean syndrome after phacoemulsification and one eye developed peripheral edema after pars plana vitrectomy and lensectomy. Additionally, severe, infectious keratitis occurred after rupture of peripheral bullae in two eyes. Patients with this condition should be examined periodically and educated regarding the early clinical signs of corneal ulceration.

Penetrating keratoplasty and transscleral fixation of posterior chamber lens

We reviewed the outcome in 115 patients who underwent penetrating keratoplasty and transscleral fixation of a posterior chamber lens. One patient died soon after surgical procedures, and nine patients were lost to follow-up, leaving a cohort of 105 patients. Mean follow-up time was 26.8 months (range, six to 43 months). Visual acuity of 20/40 or better was found in 29 patients (27.6%) and 20/50 to 20/200 in 37 patients (35.2%). Reasons for poor visual outcome included cystoid macular edema in ten patients (9.5%), age-related macular degeneration in six patients (5.7%), and retinal detachment in four patients (3.8%). None of the patients developed lens decentration. There were no instances of hyphema and only one patient had a perioperative limited suprachoroidal hemorrhage. New-onset increase in intraocular pressure developed in 20 of 66 patients (30.3%). Analysis of the 39 patients with preoperative increase in intraocular pressure that required medical treatment demonstrated an improvement in 13 patients (33.3%), worsening in 12 patients (30.8%), and unchanged status in 14 patients (35.9%). The exposed haptic suture was covered by using one of the following three alternative methods: a conjunctival flap, a scleral flap, or a corneal tissue button. Exposure of the haptic suture through the conjunctiva was a complication in 21 patients (20%). Of these 16 (76.1%) occurred in the group with a conjunctival covering, five (23.8%) occurred in the group with a scleral flap, and none occurred in the corneal tissue button group. This study demonstrated that transscleral fixation of a posterior chamber lens is a viable option in the treatment of patients undergoing penetrating keratoplasty and intraocular lens implantation with absent capsular support.

The use of the 193-nm excimer laser for myopic photorefractive keratectomy in sighted eyes. A multicenter study

Photorefractive keratectomy was performed at three centers using the 193-nm excimer laser on 31 sighted myopic eyes. Preoperative refractive errors (spherical equivalent) ranged from -12.00 to -4.00 diopters (D) (mean, -6.49 +/- 1.75 D). Peribulbar anesthesia, a 5.2- to 6.0-mm beam diameter, and topical corticosteroids were used for up to 6 months after surgery. The epithelium healed within 3 to 4 days, and all patients returned to their best corrected visual acuity within 1 line of their preoperative acuity. There was minimal subepithelial reticular haze, peaking at 3 weeks and diminishing over the next 3 to 4 months, which was not felt to be visually significant. At 6 months, the average residual refractive error was -1.85 +/- 2.5 D. Sixty-eight percent of eyes were corrected within 2 D and 55% within 1 D of attempted correction. There was no significant change in astigmatism, contrast sensitivity, corneal sensation, or endothelial cell counts. This preliminary work shows that photorefractive keratectomy has promise in the reduction of moderate myopia.

Prospective comparison of the effects of Occucoat, Viscoat, and Healon on intraocular pressure and endothelial cell loss

We compared the effect of Occucoat (2% hydroxypropylmethyl-cellulose), Viscoat (sodium hyaluronate-chondroitin sulfate), and Healon (sodium hyaluronate) on postoperative intraocular pressure (IOP) and endothelial cell damage. One hundred fourteen patients having planned extracapsular cataract extraction with posterior chamber lens implantation using a viscomaterial were prospectively randomized into one of five groups. Group I received Occucoat which was removed from the anterior chamber at the conclusion of surgery. Group II received Occucoat which was not removed (retained). Group III received Viscoat which was removed, Group IV received Viscoat which was retained, and Group V received Healon which was removed. No prophylactic ocular hypotensive medications were given. Intraocular pressure was measured at four hours, 24 hours, one week, one month, three months, and one year postoperatively. Compared to preoperative IOP, all groups had a significant IOP increase at four hours. All but the Viscoat removed group (Group III) showed a statistically significant increase at 24 hours postoperatively (P less than .05). No group had a significant increase at one week or later. Specular microscopy showed no significant difference in cell loss between any of the groups at three months or within each group when compared to preoperative cell counts (P greater than .1).

Transscleral fixation of posterior chamber intraocular lenses in the absence of capsular support

We present results obtained by transscleral ciliary sulcus fixation of posterior chamber intraocular lenses in secondary implantation, lens exchange, and in primary implantation of transsclerally fixated lenses during complicated cataract extraction. Follow-up data on 38 patients, 17 of whom have been followed for more than 12 months, are included. We conclude that the procedure is safe, effective, and predictable.

The importance of intraocular lens inspection prior to implantation

Open-loop, posterior chamber intraocular lenses were obtained from existing inventories of regional hospitals and surveyed for functional (optical) and structural defects. The majority of lenses (90%) were acceptable by industry optical grade standards. Most of the lenses (90%) varied by at least 0.5 diopter from the power stated on the packaging. Two lenses did not meet optical resolution standards. Most of the lenses (80%) had some surface or loop surface abnormality as judged by scanning electron microscopy. Four of the lenses had surface protrusions or burrs, either at the tip of the loop or at the lens-optic junction. These more serious defects could be seen easily at magnifications of the operating microscope. The lenses with serious structural defects tended to be the same as those lenses with functional (optical) defects. This study demonstrates the usefulness of careful intraoperative examination using the operating microscope prior to intraocular lens implantation to detect manufacturing defects which continue to exist in currently manufactured lenses. Lens inspection should be directed to the ends of the loops, the loop-optic junction, and the internal surface of the positioning holes.

Implantation of a posterior chamber lens without capsular support during penetrating keratoplasty or as a secondary lens implant

We have devised a technique to fixate a posterior chamber lens in the ciliary sulcus when no posterior capsular support exists. Our short-term follow-up of 22 eyes with lenses thus fixated has shown these eyes to be quiet and to have good pupillary motility after at least 3 months. We believe this new technique is a significant advancement in corneal and anterior segment surgery.

Treatment of phacolytic glaucoma with extracapsular cataract extraction

The treatment of choice for phacolytic glaucoma has been intracapsular cataract extraction (ICCE). The current study was undertaken to determine the efficacy of extracapsular cataract extraction (ECCE) as a definitive treatment for phacolytic glaucoma. Five cases of phacolytic glaucoma that occurred between 1984 and 1986 were studied after a retrospective chart review; ECCE (with placement of a posterior chamber intraocular lens [PC IOL]) was performed without complication and was curative in all five eyes. All patients (100%) maintained intraocular pressures (IOPs) of less than 20 mmHg, without medical therapy. The best-corrected visual acuity for all cases was 20/50 or better (80%, greater than or equal to 20/40) with 5 months to 3 years follow-up. These results suggest that ECCE is an effective alternative for the treatment of phacolytic glaucoma and allows surgeons the freedom to choose the procedure with which they are most comfortable. Additionally, implantation of a PC IOL is a safe and efficacious procedure in restoring visual function in these patients.