Sandy T. Feldman

Vision-threatening Complications of Surgery for Full-thickness Macular Holes

OBJECTIVE To study complications of vitrectomy surgery for full-thickness macular holes. DESIGN A multicentered, randomized, controlled clinical trial. PARTICIPANTS Community and university-based ophthalmology clinics. INTERVENTION Standardized macular hole surgery versus observation. MAIN OUTCOME MEASURES Assessment of anatomic and visual outcomes and determination of postoperative complications at 12 months after randomization. RESULTS Posterior segment complications were noted in 39 eyes (41%). The incidence of retinal pigment epithelium (RPE) alteration and retinal detachment (RD) were 33% and 11%, respectively. One RD due to a giant retinal tear resulted in a visual acuity of light perception. Other complications included a reopening of the macular hole in 2 eyes (2%), cystoid macular edema in 1 eye (1%), a choroidal neovascular membrane in 1 eye (1%) and endophthalmitis in 1 eye (1%). Eyes with complications had significantly worse visual acuity outcomes as determined by the Early Treatment Diabetic Retinopathy Study, Word Reading, and Potential Acuity Meter charts (P < 0.01 for all comparisons). Eyes with macular holes greater than 475 microns were more than twice as likely to have complications than eyes with holes less than 475 microns (odds ratio [OR] = 2.2, P = 0.07). Before surgery, the stage of the hole was related to postoperative RPE changes (P < 0.0001) and the occurrence of postoperative RD (P = 0.0002). Intraoperative trauma was related to the occurrence of these complications (P < 0.0001 for RPE changes, P = 0.02 for RDs). Epiretinal membrane removal was related to RPE changes (P = 0.02) but not RDs. CONCLUSIONS The RPE alterations and RDs are common after macular hole surgery and result in significantly reduced postoperative visual acuity. The RPE changes may be related to surgical trauma or light toxicity. Further efforts to reduce complications associated with macular hole surgery are indicated.

Intraocular Pressure Elevation Associated with Inhalation and Nasal Corticosteroids

BACKGROUND The ocular hypertensive response to corticosteroids is well established. Elevated intraocular pressure (IOP) secondary to corticosteroids by nasal spray or inhalation has rarely been reported. RESULTS Three patients showed a possible ocular hypertensive response to beclomethasone dipropionate by nasal spray or inhalation. In two patients, the IOP returned to pretreatment levels after discontinuing nasal corticosteroid spray. One patient required medication to control IOP with continued inhaled corticosteroid. One patient later demonstrated an ocular hypertensive response to oral steroids. CONCLUSION Corticosteroids by nasal spray or inhalation may cause ocular hypertension in susceptible patients. The authors recommend surveillance of IOP in patients using these medications.

Calculation of Intraocular Lens Power After Radial Keratotomy With Computerized Videokeratography

PURPOSE Because standard methods to determine intraocular lens power are not adequate in eyes that have had radial keratotomy, we undertook this study to evaluate the corneal power derived from computerized videokeratography for use in intraocular lens power calculations. METHODS We examined four eyes of three patients who had radial keratotomy and who underwent phacoemulsification cataract surgery with implantation of a posterior chamber intraocular lens. We used a computerized videokeratography-derived corneal curvature value in the Holladay formula for intraocular lens calculations. We determined the ideal intraocular lens power and the keratometric value that would have led to the ideal intraocular lens power from the postoperative refraction at 6.1 +/- 1.1 months after cataract extraction. The ideal keratometric value was compared with the keratometric values derived from computerized videokeratography, standard keratometry, contact lens overrefraction, and refractions before and after radial keratotomy. RESULTS The postoperative refraction at approximately six months averaged -0.32 +/- 0.63 diopter (range, -0.88 to +0.75 diopter) different than the aim. The mean power in ring 3, which was the closest keratometric value to the ideal, disclosed only 0.09 +/- 0.73 diopter and -0.10 +/- 0.72 diopter of deviation from the ideal keratometric and intraocular lens powers, respectively. One to two weeks after phacoemulsification cataract surgery with implantation of a posterior chamber intraocular lens, the videokeratographic differential map disclosed steepening at the wound site with variable regression by six months in all patients. CONCLUSION Results suggest that, after radial keratotomy, using the keratometric value derived from computerized videokeratography in intraocular lens calculations is more accurate than using keratometric values measured by routine methods.

Videokeratography of Keratoconus in Monozygotic Twins

PURPOSE To determine the corneal topographic appearance in a pair of monozygotic twins and family members of the twins because one of the twins had keratoconus and the other appeared normal by clinical examination. METHODS Clinical examination and videokeratography (Topographic Modeling System, Tomey) of the patient, his monozygotic twin brother, an older brother, and his parents were performed. The I-S values (difference in the average dioptric powers of symmetrical points between the inferior and superior cornea) were calculated. RESULTS The patient, a 28-year-old man, had clinical keratoconus confirmed with videokeratography. Clinical examination of family members including a twin brother, an older brother and both parents revealed no corneal abnormalities. Videokeratography of the clinically normal twin brother showed inferior steepening with progression over time. The I-S value of the clinically normal brother was 1.36 (right eye) (greater than 2.00 SD of normal controls), which progressed to 1.69 (right eye), 1.32 (left eye) 5 months later and to 1.87 (right eye), 1.43 diopters (D) (left eye) 14 months later. Minimal asymmetric inferior steepening was noted in an older brother who had an I-S value of 0.81 (right eye), 1.27 (left eye). The mother appeared topographically normal. CONCLUSIONS This study lends support to the existence of subclinical keratoconus detectable by videokeratography only.

Regression of Effect Following Radial Thermokeratoplasty in Humans

Radial thermokeratoplasty is a new refractive surgical technique designed to reduce hyperopia and/or astigmatism. Four patients underwent this surgery between February and March 1988 and were monitored postoperatively for the refractive effect and evidence of endothelial cell damage. Immediately following surgery, all eyes were overcorrected, but with time regression of the effect occurred. By 10 to 12 months postoperatively, only 18% of the desired effect remained. No decrease in the central endothelial cell density occurred during this time. Further investigation into the predictability and stability of results is needed to evaluate the long-term effectiveness of this technique.

Baseline characteristics natural history, and risk factors to progression in eyes with stage 2 macular holes: Results from a prospective randomized clinical trial

PURPOSE The purpose of this study is (1) to determine baseline characteristics and natural history of immature full-thickness macular holes, (2) to describe progression and resolution, and (3) to present new aspects of pathogenesis of idiopathic macular hole. METHODS The authors analyzed 41 eyes with stage 2 macular holes (37 patients) in a multicentered prospective randomized trial; 19 eyes were randomized to observation (versus surgery) and had more than 12 months of follow-up, allowing determination of the natural course. Baseline and subsequent examinations included best-refracted visual acuity (Early Treatment of Diabetic Retinopathy Study, potential acuity meter, Pelli-Robson contrast sensitivity, and Bailey-Lovie reading vision), of clinical examinations, photography, and fluorescein angiography. RESULT Mean Snellen visual acuity was 20/66 at baseline. Centric holes usually had a small break (201 microns average mean diameter) with a dark yellow ring and without significant retinal elevation. Eccentric holes had a high maximum/minimum diameter ratio (mean, 1.88 +/- 0.7) and an incomplete cuff of subretinal fluid or yellow ring. Posterior vitreous detachment prevalence was 32% (8/25) in the centric hole group and 0% (0/ 16) in the eccentric hole group (P < 0.05). For the 19 eyes with 12 months of followup, progression rate to stage 3 (or 4) was 74% (n = 14). The diameter of the stage 2 holes increased significantly between baseline and 12 months (P < 0.001). Progression rate to stage 3 was 100% (8/8) in the eyes with pericentral hyperfluorescence (PCH) and 55% (6/11) in eyes without PCH (P < 0.05). Enlargement occurred in 100% of eccentric holes and 60% of centric holes (P = 0.09). Different progression patterns in eccentric and centric holes suggest different mechanisms of pathogenesis. CONCLUSION Eccentric and centric stage 2 macular holes may have a different pathogenesis. Most stage 2 macular holes, especially with PCH (P < 0.05) or eccentric holes, progressed to stage 3 or 4. In addition to purely tangential traction, some component of obliquely oriented anteroposterior vitreous traction component may be important for pathogenesis of senile macular holes, particularly eccentric stage 2 macular holes.

The Effect of Artificial Tears on Computer-assisted Corneal Topography in Normal Eyes and After Penetrating Keratoplasty

PURPOSE To examine the effect of adding artificial tears for one minute to normal eyes and eyes that have undergone keratoplasty by using computer-assisted videokeratography. METHODS We prospectively analyzed 24 normal corneas (24 patients) chosen by random number table (reproducibility section [10 eyes], tear section [14 eyes]) as well as 14 postkeratoplasty corneas. The parametric descriptors analyzed statistically included the simulated keratometry value, surface asymmetry index, surface regularity index, power at the vertex normal, and the pupil offsets from the visual axis. Vectoral analysis was used to calculate the difference in power and axis between the simulated keratometry values before and after tear instillation. RESULTS In normal eyes, tear instillation increased the surface asymmetry index (0.28 +/- 0.34, P = .01), changed the simulated keratometry value (0.23 diopter by 27.8 degrees), and power (0.79 +/- 0.82 diopters, P = .004) and location (0.91 +/- 0.76 mm) of the steepest point of the cornea changed. In postkeratoplasty eyes, the surface regularity index decreased (0.49 +/- 0.80, P = .04), surface asymmetry index decreased (0.37 +/- 1.03, P = .21), mean simulated keratometry value changed (1.04 diopters by 1.01 degrees), and power (0.70 +/- 2.34 diopters, P = .28) and location (1.04 +/- 1.17 mm) of the steepest point of the cornea changed. Changes were greater than the variability of the surface regularity index (0.07 +/- 0.05), surface asymmetry index (0.04 +/- 0.03), simulated keratometry value power (0.08 +/- 0.06 diopter), and axis (4.6 +/- 5 degrees). CONCLUSIONS The addition of artificial tears to normal or regular and symmetric eyes that have undergone keratoplasty worsened symmetry and changed the power and location of the steepest point. However, the addition of artificial tears to irregular eyes that have undergone penetrating keratoplasty created a more regular and symmetric surface and significantly altered the simulated keratometry values. We recommend that corneal topography be performed before the application of artificial tears.

Calculating intraocular lens power in eyes with keratoconus using videokeratography

Abstract A patient with keratoconus had cataract extraction and intraocular lens (IOL) implantation in both eyes. The IOL power was determined using keratometric values (K‐values) measured by standard keratometry in the right eye and videokeratography in the left eye. The ideal IOL power and the K‐value that would have led to the ideal IOL power were determined from the postoperative refraction at 6 weeks. The ideal K‐value was compared with the K‐values derived from videokeratography and standard keratometry. Refraction at 6 weeks postoperatively was 5.60 and 1.00 diopter more myopic than the aim in the right and left eye, respectively. The mean power in ring 3 in videokeratography of the left eye was the same as the ideal K‐value calculated using the Holladay formula. Determining IOL powers with videokeratography‐derived K‐values might be more accurate than standard keratometry in patients with keratoconus.

Running Nylon Suture Dissolution After Penetrating Keratoplasty

We attempted to evaluate whether the low degrees of astigmatism achieved early in the postkeratoplasty period with the combined interrupted/running suturing technique were maintained for long periods of time. For 13 to 70 months (mean, 30.2 months), we monitored a group of patients (25 eyes) who had previously undergone the combined interrupted/running suturing technique (12 interrupted 10-0 nylon sutures and one running 11-0 nylon suture). Nine running sutures broke spontaneously, causing a significant increase of the keratometric astigmatism of the entire population from 1.7 +/- 1.6 to 3.4 +/- 2.6 diopters (mean +/- standard deviation). The mean vector-corrected change in astigmatism after suture breakage was 4.9 +/- 2.6 diopters. Surgical procedures to reduce astigmatism were required in many of the eyes in which the 11-0 running nylon suture broke. Our results suggested that 11-0 nylon is not an ideal material for the running suture because its high rate of spontaneous disruption leads to undesired, statistically significant increases in postkeratoplasty astigmatism. Further, our results indicated that the selective suture technique can maintain low degrees of astigmatism only if the sutures remain intact. Studies of the effect of keratoplasty suturing techniques on astigmatism should probably include a follow-up that is sufficiently long to indicate its long-term value to the patient.

Retinal Detachment Following Radial and Astigmatic Keratotomy

Serious complications of radial keratotomy are infrequent, but include: iridocyclitis, microbial keratitis, endophthalmitis, corneal perforation, and traumatic wound rupture. We report a case of retinal detachment following microperforation during radial keratotomy.