Ophthalmology Volume 103, Number 2, February 1996

I believe it is essential to keep in mind that, in all pa­tients, we need to minimize any form of media opacity to maintain the best possible visual outcome for the pa-tients.

External OCR

Dear Editor:

ROBERT T. McBRATNEY, DO Tulsa, Oklahoma

It is laudable that the traditional external dacryocysto­rhinostomy (DCR) has received attention in your Journal through the publication of the article by Tarbet and Custer entitled, "External Dacryocystorhinostomy: Surgical Success, Patient Satisfaction, and Economic Cost" (Oph­thalmology 1995;102:1O65-70). Recently, the focus has been on endonasal techniques, although they have con­sistently had a 10% to 20% lower success rate than the external OCR. 1

-3 Tarbet and Custer recommend external

OCR as the standard therapy for acquired nasolacrimal obstruction based on the superior success rate and lower cost in comparison with intranasal techniques.

In our own prospective randomized study comparing three DCR techniques (laser-assisted endonasal DCR, en­doscopic endonasal DCR, and external DCR) in 96 pa­tients, preliminary analysis shows success rates of 70% to 80% for both endonasal techniques and 92% for external DCR, which is similar to that reported by the authors and in previous literature.3 The generally recognized postop­erative complications of external OCR were scarce: none of the patients had problems with the scar, and nasal hemorrhage requiring tamponade was observed in 3% of patients. In the endonasal endoscopic group, nasal hem­orrhage requiring tamponade postoperatively was ob­served in 3% of patients. In the laser-assisted endonasal group, none of the patients had postoperative nasal hem­orrhage, nor had they any intraoperative bleeding due to the coagulative effect of the combined CO2-neodymium: Y AG laser used.

Tarbet and Custer report a duration of 64 minutes for the basic external DCR. In earlier articles, durations of 60 to 90 minutes for the laser-assisted surgeries have been reported.4 In contrast to earlier reports, we find an average duration ofthe laser-assisted endonasal OCR considerably shorter than that of the external DCR, the average du­rations being 23 minutes for the laser OCR group and 78 minutes for the external DCR group.

We agree with the authors that the equipment costs of the endonasallaser DCR are higher than those of the ex­ternal OCR, but this has to be weighed against the savings of a surgery time being three times shorter with the laser. Also, we want to point out that the combined CO2-neo­dymium:YAG laser has many other uses in otorhinolar­yngo\ogic surgery as well as bronchoesophagologic surgery; therefore, the cost of the equipment will be covered by its use in other procedures as well.

200

JOUKO HARTIKAINEN, MD HEIKKI SEPPA, MD, PHD REIDAR GRENMAN, MD, PHD Turku, Finland

References

I. Boush GA, Lemke BN, Dortzbach RK. Results of endonasal laser-assisted dacryocystorhinostomy. Ophthalmology 1994;101:955-9.

2. Metson R, Woog 11, Puliafito CA. Endoscopic laser dac­ryocystorhinostomy. Laryngoscope 1994; 1 04:269-74.

3. Rosen N, Sharir M, Moverman DC, Rosner M. Dacryo­cystorhinostomy with silicone tubes: evaluation of253 cases. Ophthalmic Surg 1989;20: 115-9.

4. Bartley GB. The pros and cons of laser dacryocystorhinos­tomy. Am J Ophthalmol 1994;117: 103-6.

Corneal Decompensation after Cataract Surgery

Dear Editor: I read with interest the article by Courtright et al (Oph­thalmology 1995;102:1461-5) concerning an outbreak of corneal edema after cataract surgery using instruments soaked in glutaraldehyde. Since 1982, when I met Dr. Robert Rock on a mission trip to Nicaragua, I have been soaking all of my instruments in acetone, which has not only avoided the problem of rinsing the interior of the lumens with sterile water, but the logistics of rinsing off other instruments and keeping them sterile.

The use of acetone eliminates contamination of in­struments as a cause of postoperative endophthalmitis. In addition, its use accelerates the turnover during surgery performed in developing countries.

As an active participant in more than 30 medical mis­sion projects, the value of acetone in solving the problems mentioned in this article cannot be overestimated.

DENNIS L. WILLIAMS, MD Tarpon Springs, Florida

Success with Macular Hole Surgery

Dear Editor: The authors of the article entitled, "Human Autologous Serum for the Treatment of Full-thickness Macular Holes" (Ophthalmology 1995;102:1O71-6), are to be con­gratulated for their innovative idea to enhance the success rate of macular hole surgery.

As the article was originally submitted for publication in November \993, the authors, as well as many of the readers, probably now have a larger and possibly different experience with this technique. We would like to share our experience of 110 consecutive cases ofvitrectomy for macular hole performed by six surgeons from 1993 to 1994. The first 65 procedures were done without autol­ogous serum; the subsequent 45 procedures were done with autologous serum. Surgical technique was identical to that described by Liggett et al. Perfluorocarbon gas was used in only 60% of eyes (40% received sulfur hexafluoride gas), and almost all eyes treated with serum received the perfluorocarbon gas. Factors found by statistical analysis not to influence surgical outcome included number of procedures performed by a surgeon, stage of hole, selection of sulfur hexafluoride gas versus perfluorocarbon gas, and