Median visual acuity improved after photodynamic therapy with verteporfin (Visudyne, Novartis AG) for at least one year in a small uncontrolled group of patients with subfoveal CNV caused by OHS, reports an open-label, three-center, noncomparative pro-spective case series reviewed by the Verteporfin in Ocular Histoplasmosis (VOH) Study Group. The research indicates that verteporfin therapy seemed to be safe and well-tolerated in these patients.

The study included OHS patients with subfoveal CNV lesions no larger than 5,400 µm in greatest linear dimension with classic or occult CNV extending under the geometric center of the foveal avascular zone and best-corrected visual acuity letter score of 73 to 34.

A case of presumed ocular histoplasmosis syndrome before PDT (left) and after. Researchers from the Verteporfin in Ocular Histoplasmosis Study Group found PDT safe in such cases.

Twenty-six patients received verteporfin (6 mg/m2) infused IV over 10 minutes. Fifteen minutes after the start of infusion, a laser light at 689 nm delivered 50 J/cm2 over 83 seconds using a spot size with a diameter 1,000 µm larger than the greatest linear dimension of the lesion. At the three-month follow-up examinations, retreatment with the same regimen was applied if angiography showed fluorescein leakage. By the month-12 examination (excluding any retreatment at that visit), patients had received an average of 2.9 treatments of a maximum of four possible treatments.

The month-12 median improvement from baseline in visual acuity of 25 patients (one had been excluded) was seven letters, and the median contrast sensitivity improved by two letters. At the month-12 examination, 14 (56 percent) patients gained seven or more letters of visual acuity from baseline, and four (16 percent) patients lost eight or more letters, of which two (8 percent) lost 15 or more letters. No serious systemic or ocular adverse events were reported.

Researchers note that the study’s small sample size, short follow-up time, and lack of un-treated control group prevents them from making a definite conclusion on the visual acuity benefit of verteporfin therapy in these patients. They believe two-year data from this study will provide important additional information on the safety and effect of verteporfin therapy for the treatment of subfoveal CNV secondary to OHS.
(Ophthalmology 2002;109:1499-1505)
Saperstein D, Rosenfeld P, Bressler N, Rosa R, Sickenberg M, Sternberg P, Aaberg T, Aaberg Jr. T, Reaves T

Digital Infrared Pupillometer to Assess Patient Suitability for Refractive Surgery
British researchers recommend the use of binocular video pupillometry at low mesopic and scotopic illumination levels in assessing patient suitability for refractive surgery. Because patients in this study showed an appreciable degree of pupillary motion during measurement at all levels of illumination, and the two pupils were rarely identical, researchers found that multiple-measurement binocular pupillometry produced a precise description of pupil behavior before refractive surgery.

In this prospective study, investigators evaluated the pupil sizes of 58 patients presenting for refractive surgery assessment using the P2000 SA pupillometer (Procyon Instruments Ltd.). Each patient was measured at three illumination levels: 0.02 lux (scotopic), 0.15 lux (low mesopic), and 10.6 lux (high mesopic). At each level, 10 images were acquired by the system at five images per second. Both eyes were imaged at the same time, with a spatial accuracy of 0.03 mm per pixel.

Researchers observed pupillary unrest (PU) at all levels of illumination. Some degree of PU amplitude was seen in both eyes of all patients. The median PU was 0.12 mm in the scotopic range, 0.34 mm in the low mesopic range, and 0.28 mm in the high mesopic range. The degree of anisocoria varied among individuals — the median value was 0.28 mm in the scotopic range, 0.32 mm in the low mesopic range, and 0.16 mm in the high mesopic range. Because of PU and anisocoria, single vs. multiple binocular measurements demonstrated the possibility of errors greater than 1.0 mm in some patients.

An additional value of reliable pupil data, researchers say, is that it could help resolve poorly understood relationships such as that between pupil size and wavefront-guided treatments.
(J Cataract Refract Surg 2002; 28:1433-1438)
Rosen E, Gore C, Taylor D, Chitkara D, Howes F, Kowalewski E

LASEK vs. PRK for the Correction of Myopia
Both LASEK and PRK are ef fective and safe procedures in the surgical correction of myopia, finds a prospective comparative study conducted in Tijuana, Mexico. While patients reported less discomfort and better visual acuity in their PRK eye in the early postop period, recovery speed was similar following both procedures.

Researchers in Mexico say LASEK may be more similar to PRK than some may think.

This study included 50 eyes of 25 patients with myopia who received LASEK in one eye and PRK in the contralateral eye. Patients were told that each eye would have different surface laser refractive surgery but did not know which eye had LASEK and which had PRK. Researchers set out to compare the early postop visual rehabilitation after each procedure.

Patients were seen at one day and three days, and at one week and one month postop. Investigators analyzed discomfort, subjective UCVA, objective UCVA, BCVA, haze, and time for corneal reepithelialization.

Seventy-two percent and 80 percent of the LASEK eyes had more discomfort at one day and three days, respectively. Eighty percent and 96 percent of the PRK eyes had better subjective UCVA at one day and three days, respectively. Corneas were fully reepithelialized at a mean of 3.3 days ±0.5 (SD) in the PRK group, and a mean of 3.6 days ±0.5 days in the LASEK group. At one month, the UCVA was similar in both groups; no eye had lost lines of BCVA or developed haze.

Researchers concluded that LASEK did not result in faster visual rehabilitation than PRK in eyes with low to moderate myopia. Patients should be informed that recovery from LASEK might not as speedy as that from LASIK, and may be more similar to PRK recovery time.
(J Cataract Refract Surg 2002; 28:1330-1333)
Litwak S, Zadok D, Garcia-de Quevedo V, Robledo N, Chayet A

Viscocanalostomy vs. Trabeculectomy in Open-angle Glaucoma
In eyes with open-angle glaucoma, viscocanalostomy is less ef-fective in reducing intraocular pressure than standard filtering surgery, says a prospective randomized German trial. However, postoperative complications are more frequent after filtering surgery.

In viscocanalostomy, the viscoelastic is injected several times on either side of the dissection.

A consecutive series of 60 patients (60 eyes) with uncontrolled open-angle glaucoma underwent pressure-reducing surgery, assigned randomly to viscocanalostomy or trabeculectomy. All operations were performed by two experienced surgeons. Viscocanalostomy was performed according to Robert Stegmann’s technique using high-molecular weight sodium hyaluronate to fill the ostia of Schlemm’s canal. For trabeculectomy, a modified Cairns-trabeculectomy was performed. Eyes were examined before surgery and daily for one week postop. Follow-up visits were scheduled one, six and 12 months after surgery.

Schlemm’s canal will swell to around 200 - 250 µm.

Investigators defined complete success as IOP<22 mmHG without any additional glaucoma surgery or medication. They defined qualified success at IOP<22 mmHG with additional glaucoma medications. Postoperative complications received particular attention.

The mean (SD) preoperative IOP was 27.1 (7.1) mmHG for all patients enrolled. One day after surgery, mean (SD) IOP was 15.9 (5.2) for the trabeculectomy group (P<0.001) and 15.7 (3.6) for the viscocanalostomy group (P<0.001), respectively. The success rate, as defined above, was 56.7 percent in the trabeculectomy group and 30 percent in the viscocanalostomy group at 12 months postop (P=0.041).

Incidence of complications was lower in the viscocanalostomy group. For example, occurrence of hypotony (IOP<6 mmHG) was seen in 36.7 percent of eyes in the trabeculectomy group and in 20 percent of eyes in the viscocanalostomy group (P=0.152). Hyphema was present postop in 26.7 percent of eyes in the trabeculectomy group and in 10 percent of eyes in the viscocanalostomy group.

Researchers found that the two procedures reduced IOP to similar degrees only for the first two days after operation. Long-term follow-up data collected over a 12-month period demonstrated that, after viscocanalostomy, the IOP control persists in only 30 percent of eyes.
(J Glaucoma 2002;11:294-299)
Lüke C, Dietlein T, Jacobi P, Konen W, Krieglstein G

Removal of Intacs for Myopia
Removal of Intacs microthin prescription inserts for myopia (Addition Technology, Inc. Fremont, CA) is not associated with a loss (>2 lines) of BSCVA or induction (>1 D) of astigmatism or myopia, according to a subgroup analysis from a nonrandomized comparative interventional trial. Intacs removal is associated with a reversal to preoperative values in most cases.

In most cases, removal of INTACS will result in vision at pre-insertion levels.

This study examined three months of postremoval follow-up data for 41 of the 46 eyes from which Intacs were removed. Clinical results of the preoperative evaluation were compared with those taken at the three-month postremoval visit.

The principal reasons for Intacs removal for this set of 46 eyes were undercorrection (11 percent), overcorrection (11 percent), astigmatism (20 percent), visual symptoms included glare, halos, etc. (46 percent), infection (2 percent) and other (11 percent).

This study indicated that the refractive effect of Intacs inserts can be ra-pidly reversed on removal. Using the spherical equivalent measurements by manifest refraction, after removal, 88 percent of patients (of the 41 eyes for which data was collected) returned to within ±0.5 D, and 100 percent returned to within ±1.0 D, of their preoperative measurement.

None of the patients had an in-crease of greater than 1.0 D in their level of myopia. Comparison of the spherical equivalent at the preoperative and three-month postremoval visit, using MR and cycloplegic refraction, revealed that only one and three eyes, respectively, demonstrated re-duction of myopia greater than 1.0 D. Intacs removal did not induce substantial astigmatism in any patient.

Most patients had a substantial improvement in visual symptoms after Intacs removal, with only a few continuing to experience halos and night vision difficulties. Researchers reaffirmed the importance of informing patients that there is a small, but not insignificant, risk of persistent visual symptoms despite removal of Intacs. They note that further research into the resolution of visual symptoms following Intacs removal and convalescence beyond three months is warranted. 
(Ophthalmology 2002;109:1441-1446)
Clinch T, Lemp M, Foulks G, Schanzlin D