Mohammad Pakravan

Central corneal thickness and correlation to optic disc size: a potential link for susceptibility to glaucoma

Aims: To evaluate a possible relationship between central corneal thickness (CCT) and optic disc area in patients with primary open-angle glaucoma (POAG). Methods: Patients with POAG underwent eye examination, optic disc imaging with the Heidelberg Retina Tomograph II (HRT II) and ultrasound corneal pachymetry. Exclusion criteria were prior ocular surgery and low-quality HRT II images (HRT standard deviation (SD) >50). Pearson’s correlation coefficients were calculated to assess the associations between CCT and optic disc area. Results: 212 eyes of 137 patients with POAG were examined. In all, 66 (48%) subjects were women, 104 (76%) were Caucasian, 26 (19%) African-American and 7 (5%) other races. 72 eyes remained after excluding those with prior intraocular surgery and low-quality HRT II images. In a univariate analysis of this group, CCT was inversely correlated with optic disc surface area (Pearson’s correlation coefficient ru200a=u200a−0.284, pu200a=u200a0.036, nu200a=u200a72). Mean (SD) disc area was 2 (0.53) mm2 (nu200a=u200a160). Caucasians had significantly smaller discs (p<0.001) than other races (Caucasian 1.9 (0.47) mm2 (nu200a=u200a119), African-Americans 2.4 (0.54) mm2 (nu200a=u200a31), other races 2.3 (0.45) mm2 (nu200a=u200a10)). Conclusion: CCT is inversely correlated to optic disc area. Although thicker corneas have been recognised to cause slight overestimation of true intraocular pressure (IOP), they may also indicate the presence of a substantially smaller, and thus more robust, optic nerve head. People with thinner corneas which slightly underestimate the true IOP may also have larger and more deformable optic discs.

Intravitreal bevacizumab for neovascular glaucoma: a randomized controlled trial.

PurposeTo determine the effect of intravitreal bevacizumab (IVB) on neovascular glaucoma (NVG) in terms of iris neovascularization (NVI), intraocular pressure (IOP), and visual acuity. MethodsThis randomized controlled trial included 26 eyes of 26 patients with NVG. All eyes received conventional treatment for NVG and were randomly allocated to three 2.5u2009mg IVB injections at 4-week intervals or a sham procedure (subconjunctival normal saline) at similar time intervals and in the same setting. ResultsOverall, 14 eyes of 14 patients received IVB and 12 eyes of 12 subjects were allocated to the sham procedure and followed for a mean period of 5.9±1.4 months. The IVB group demonstrated significant reduction in IOP from a baseline value of 33.4±14.5u2009mm Hg to 21.8±13.7u2009mm Hg (P=0.007), 25.1±20u2009mm Hg (P=0.058), and 23.9±18.7u2009mm Hg (P=0.047) at 1, 3, and 6 months after intervention, respectively. NVI was also significantly reduced from a mean baseline value of 347±48 degrees to 206±185 degrees (P=0.01), 180±187 degrees (P=0.004), and 180±180 degrees (P=0.004) at 1, 3, and 6 months after intervention. In contrast, IOP and NVI remained unchanged or increased insignificantly at all follow-up intervals in the control group. No significant change in visual acuity was observed within the study groups at any time interval. The study groups were comparable in terms of requirement for additional interventions such as panretinal photocoagulation and cyclodestructive procedures. ConclusionsIntravitreal injections of bevacizumab seem to reduce NVI and IOP in NVG and may be considered as an adjunct to more definitive surgical procedures for NVG.

Trabeculectomy with mitomycin C versus Ahmed glaucoma implant with mitomycin C for treatment of pediatric aphakic glaucoma.

PurposeTo compare trabeculectomy with mitomycin C (T+MMC) and Ahmed glaucoma implant with MMC (AGI+MMC) in treatment of aphakic glaucoma in children below 16 years of age. DesignRandomized clinical trial. ParticipantsSubjects less than 16 years of age who had previously undergone anterior lensectomy and vitrectomy for treatment of congenital cataract with unresponsive aphakic glaucoma (at least on 2 medications) were allocated in 2 groups: trabeculectomy with MMC (group A, 15 eyes) and AGI (group B, 15 eyes). MethodsFifteen eyes in each group underwent T+MMC or AGI+MMC. Complete and qualified success were defined as 5≤intraocular pressure≤21u2009mm Hg without and with medication, respectively. Main Outcome MeasuresIntraocular pressure, visual acuity, and complications. ResultsComplete and qualified success rates were 33.3% and 40% in T+MMC group versus 20% and 66.7% in AGI+MMC group, respectively (P=0.36). Mean follow-up was 14.8 and 13.1 months and complication rates were 40% and 26.7% (P=0.44), respectively. ConclusionsT+MMC and AGI+MMC are comparable in terms of success rate and complications in pediatric aphakic glaucoma. PrecisThis randomized clinical trial demonstrated comparable safety and efficacy for MMC trabeculectomy and AGI in the treatment of pediatric aphakic glaucoma.

Sensorineural Hearing Loss in Pseudoexfoliation Syndrome

PURPOSEnTo determine hearing thresholds at sound frequencies important for speech comprehension in subjects with ocular pseudoexfoliation and to compare them with that of age- and sex-matched controls without pseudoexfoliation.nnnDESIGNnCase-control study.nnnPARTICIPANTSnEighty-three subjects with ocular pseudoexfoliation and 83 age- and gender-matched controls without pseudoexfoliation.nnnMETHODSnPure tone audiometry (air and bone conduction) was performed at 1, 2, and 3 kilohertzes in all subjects. Hearing thresholds were compared with an age- and gender-stratified standard (ISO7029) and between study groups.nnnMAIN OUTCOME MEASURESnIndividual hearing thresholds at 1, 2, and 3 kilohertz and hearing loss, defined as the sum of tested thresholds lower than the ISO7029 standard median.nnnRESULTSnA total of 166 eligible subjects were evaluated. Equal numbers of male and female subjects were allocated into each of the study groups (60 male and 23 female subjects in either group). Mean ages of male and female participants did not significantly differ in cases versus controls (P = 0.88 and P = 0.83). Below average hearing thresholds were present in 88.4% of examined ears in the case group, versus 53.6% in the control group (P<0.001; odds ratio [OR], 6.69; 95% confidence interval [CI], 3.49-11.79). Overall, 78 subjects (94.0%) in the case group, versus 58 subjects (69.9%) in the control group, had below average hearing in one or both ears (P<0.001; OR, 6.72; 95% CI, 2.42-18.62). Hearing thresholds at each of the examined frequencies and the total threshold were also significantly higher in individuals with pseudoexfoliation. Although glaucoma was significantly more common in subjects with pseudoexfoliation, it was not associated with below average hearing in any of the study groups.nnnCONCLUSIONSnHearing thresholds at frequencies that are important for speech comprehension are significantly worse in individuals with ocular pseudoexfoliation than in matched controls. This finding may support the multiorgan nature of pseudoexfoliation syndrome.

Superior versus Inferior Ahmed Glaucoma Valve Implantation

PURPOSEnTo compare the efficacy and safety of Ahmed glaucoma valve (AGV) (New World Medical Inc., Rancho Cucamonga, CA) implantation in the superior versus inferior quadrants.nnnDESIGNnProspective parallel cohort study.nnnPARTICIPANTSnA total of 106 eyes of 106 patients with refractory glaucoma.nnnMETHODSnConsecutive patients with refractory glaucoma underwent AGV implantation in the superior or inferior quadrants.nnnMAIN OUTCOME MEASURESnMain outcome measures included intraocular pressure (IOP) and rate of complications. Other outcome measures included best corrected visual acuity (BCVA), number of glaucoma medications, and success rate (defined as at least 30% IOP reduction and 5<IOP <22 mmHg with or without medications). Criteria for failure included implant removal, additional glaucoma surgery, phthisis bulbi, or loss of light perception.nnnRESULTSnOf a total of 106 eyes, 58 and 48 eyes underwent AGV implantation in the superior and inferior quadrants, respectively. Baseline characteristics were comparable in the study groups, except for preoperative IOP, which was higher in the superior group (P = 0.01). Patients were followed for a mean period of 10.6+/-8.49 months and 10.58+/-6.75 months in the superior and inferior groups, respectively (P = 0.477). BCVA was comparable between the groups at all postoperative visits (P>0.122). After 1 year, statistically significant but comparable IOP reduction from baseline (P<0.001) was achieved in both groups (47.0%+/-27.2% and 43.0%+/-24.5% reduction for superior and inferior groups, respectively, P = 0.725). The mean number of glaucoma medications was comparable after 1 year (1.3+/-1.2 vs. 1.9+/-0.8 for superior and inferior implants, respectively, P = 0.256). Success rates were also similar at 1 year: 27 eyes (81.8%) versus 20 eyes (95.2%) for superior and inferior implants, respectively (P = 0.227). However, the overall rate of complications, such as implant exposure necessitating removal, cosmetically unappealing appearance, and endophthalmitis, was higher in the inferior group: 12 eyes (25%) versus 3 eyes (5.2%) for superior and inferior groups, respectively, (P = 0.004).nnnCONCLUSIONSnSuperior and inferior AGV implants have similar intermediate efficacy in terms of IOP reduction, decrease in number of glaucoma medications, and preservation of vision. However, the inferior quadrants entail significantly more complications. It may be prudent to avoid AGV implantation in the inferior quadrants if the superior quadrants have no contraindications to surgery.nnnFINANCIAL DISCLOSURE(S)nProprietary or commercial disclosure may be found after the references.

Variable expressivity and high penetrance of CYP1B1 mutations associated with primary congenital glaucoma.

OBJECTIVEnTo investigate penetrance and expressivity of CYP1B1 genotypes associated with primary congenital glaucoma (PCG).nnnDESIGNnObservational case series, systematic review, and comparative analysis of the literature.nnnPARTICIPANTSnForty probands affected with PCG, 16 siblings affected with PCG, and 103 siblings and 75 parents of the probands reported not to be affected by history. The participants were members of 40 unrelated families.nnnMETHODSnMutations were screened by restriction fragment length polymorphism, allele-specific polymerase chain reaction amplification, and direct sequencing. Ophthalmologic examination included slit-lamp biomicroscopy, intraocular pressure (IOP) measurement, gonioscopy, and high magnification stereoscopic fundus examination, followed by standard achromatic perimetry.nnnMAIN OUTCOME MEASURESnIdentification of subjects carrying CYP1B1 mutations. Glaucoma diagnosis based on slit-lamp examination, IOP measurement, gonioscopic findings, optic nerve appearance, and perimetry.nnnRESULTSnFifteen different homozygous or compound heterozygous mutant CYP1B1 genotypes were identified. Most probands and previously diagnosed subjects harbored G61E, R368H, R390H, and R469W mutations. Among the 178 apparently unaffected family members, 20 subjects from 12 families were observed to harbor 2 CYP1B1 mutations, suggesting an average penetrance of 73% for all the mutations. These 20 subjects ranged in age from 14 to 54 years. R390H appeared to have a notably high penetrance. Penetrance was 50% in the subset of families with incomplete penetrance. Ophthalmologic examination on 14 of the 20 apparently nonpenetrant individuals showed that 8 subjects were affected with juvenile open-angle glaucoma (JOAG) or primary open-angle glaucoma (POAG), and that 3 subjects were glaucoma suspect. One of the individuals with a JOAG diagnosis was the identical twin sibling of a proband affected with PCG.nnnCONCLUSIONSnAt least 57% of the PCG nonpenetrant individuals examined clinically were affected with JOAG or POAG to varying degrees, and overall penetrance of affected CYP1B1 genotypes with respect to glaucoma may be more than 90%. These findings suggest that affected CYP1B1 genotypes exhibit variable expressivity rather than nonpenetrance. The clinical implication of this observation is that seemingly unaffected relatives of patients with PCG, particularly those known to harbor CYP1B1 mutations, should undergo regular ophthalmologic examination to allow early diagnosis.

Pregabalin and gabapentin for post-photorefractive keratectomy pain: a randomized controlled trial.

Purpose To evaluate the efficacy of pregabalin and gabapentin for reducing post–photorefractive keratectomy (PRK) pain. Methods In this randomized clinical trial, 150 subjects undergoing PRK were allocated into 3 groups. In addition to the routine regimen, pregabalin 75 mg, gabapentin 300 mg, and placebo were administered 3 times daily for 3 days, in groups 1, 2, and 3, respectively. Subjects could take acetaminophen-codeine 300/10 mg tablets every 4 hours as needed. Patients completed a pain assessment survey (visual analogue scale ranging from 0 = no pain to 10 = most severe pain) 7 times in the first 3 days following PRK and also recorded the number of consumed acetaminophen-codeine tablets. Results Age, sex, refractive error, ablation depth, and mitomycin-C (MMC) application were similar in the 3 study groups (all p values>0.05). Overall pain scores in the placebo group were 0.9 and 1 unit higher than the pregabalin (p=0.029) and gabapentin (p=0.023) groups, respectively. Severe pain (score >7) was more frequent in the placebo group on the morning of the first postoperative day (p=0.043). The difference in the number of consumed acetaminophen-codeine tablets was statistically borderline (p=0.061) and less in the pregabalin (7.9±5.2) and gabapentin (9.0±4.1) groups in comparison to the placebo group (10.3±5.6). Conclusions Pregabalin and gabapentin seem to be helpful in alleviating post-PRK pain when combined with other measures. Depending on availability, either compound can be used as an adjuvant for pain control in this setting.

Effect of Early Treatment with Aqueous Suppressants on Ahmed Glaucoma Valve Implantation Outcomes

OBJECTIVEnTo evaluate the effect of early aqueous suppressant treatment on Ahmed glaucoma valve (AGV) surgery outcomes.nnnDESIGNnRandomized clinical trial.nnnPARTICIPANTSnNinety-four eyes of 94 patients with refractory glaucoma.nnnMETHODSnAfter AGV implantation, 47 cases (group 1) received topical timolol-dorzolamide fixed-combination drops twice daily when intraocular pressure (IOP) exceeded 10 mmHg, whereas 47 controls (group 2) received conventional stepwise treatment when IOP exceeded target pressure.nnnMAIN OUTCOME MEASURESnMain outcome measures included IOP and success rate (6 mmHg < IOP < 15 mmHg and IOP reduction of at least 30% from baseline). Other outcome measures included best-corrected visual acuity, complications, and hypertensive phase frequency.nnnRESULTSnGroups 1 and 2 were both followed up for a mean of 45±11.6 and 47.2±7.4 weeks, respectively (P = 0.74). Mixed model analysis revealed a significantly greater IOP reduction in group 1 at all intervals (P<0.001). At 1 year, the cases exhibited a significantly higher success rate (63.2% vs. 33.3%; P = 0.008) and reduced hypertensive phase frequency (23.4% vs. 66.0%; P<0.001).nnnCONCLUSIONSnEarly aqueous suppressant treatment may improve AGV implantation outcomes in terms of IOP reduction, success rate, and hypertensive phase frequency.

A Population-based Survey of the Prevalence and Types of Glaucoma in Central Iran : The Yazd Eye Study

PURPOSEnTo describe the prevalence and types of glaucoma in Yazd, central Iran.nnnDESIGNnPopulation-based, cross-sectional study.nnnPARTICIPANTSnIranian adults aged 40 to 80 years, residing in Yazd, Iran, in 2010 and 2011.nnnMETHODSnEligible samples were selected using cluster random sampling. Each participant underwent an interview and ophthalmologic examinations, including refraction, determination of uncorrected and best-corrected visual acuity, slit-lamp biomicroscopy, Goldmann applanation tonometry, gonioscopy, dilated fundus examination, central corneal thickness measurement, visual field testing, and stereoscopic fundus photography.nnnMAIN OUTCOME MEASURESnPrevalence of different types of glaucoma.nnnRESULTSnOf 2320 eligible individuals, 2098 (response rate, 90.4%) participated in the study and 1990 completed all evaluations for glaucoma diagnosis. Overall, 47 persons (2.4%) were categorized with ocular hypertension, 32 persons (1.6%) were categorized with primary angle-closure suspect (PACS), and 16 persons (0.8%) were categorized with primary angle closure (PAC). The total number of subjects with glaucoma was 87 (4.4%; 95% confidence interval, 3.3-5.4), consisting of primary open-angle glaucoma (POAG, 3.2%, including high-tension glaucoma [1.7%] and normal-tension glaucoma [NTG], 1.5%]), primary angle-closure glaucoma (PACG, 0.4%), pseudoexfoliation glaucoma (0.4%), and other secondary glaucomas (0.4%). The mean age of subjects with glaucoma was 63.3 ± 11 years, and 57.5% of them were female. Seventy-eight individuals (89.7%) were unaware of their disease. Positive family history of glaucoma was present in 6.9% of glaucoma subjects.nnnCONCLUSIONSnThe prevalence of glaucoma in Yazd (4.4%) is comparable to that in other population-based studies in Asia, with POAG accounting for the majority of cases. Most affected subjects were unaware of their disease.nnnFINANCIAL DISCLOSURE(S)nThe author(s) have no proprietary or commercial interest in any materials discussed in this article.

Erythropoietin treatment for methanol optic neuropathy.

Background: To present the effect of erythropoietin for the treatment of methanol optic neuropathy. Methods: Two patients with methanol optic neuropathy were treated with 10,000 IU of intravenous erythropoietin twice a day for 3 days, 500 mg of methylprednisolone twice a day for 5 days (followed by 2 weeks of oral prednisolone [1 mg/kg per day]), and daily doses of vitamin B12, vitamin B6, and folic acid for 1 month. Results: At presentation, the patients had no perception of light in both eyes, associated with mildly swollen optic discs. Both responded dramatically to the treatment regimen. In the first patient, visual acuity improved to 20/20 in both eyes within 3 days, whereas in the second patient, visual acuity returned to counting fingers at 6 feet, right eye, and 20/30, left eye, within 3 weeks. Conclusion: Intravenous erythropoietin may be an effective adjuvant when combined with current treatment for patients with methanol optic neuropathy.